Gingival epithelium acts as an important part of the innate immune response. It expresses toll-like receptors that recognize pathogens and produce chemokines. The epithelium also produces antimicrobial peptides like defensins and has antigen presenting cells that link the innate and adaptive immune responses. This represents a paradigm shift from the gingiva being considered a passive physical barrier to an active player in the host defense against bacterial challenges.
The gingiva provides three lines of defense against pathogens:
1. The epithelial surface acts as a mechanical and chemical barrier. Tight junctions between keratinocytes and antimicrobial peptides in epithelial layers prevent pathogen entry.
2. Components in saliva and gingival crevicular fluid (GCF) maintain tissue health and help remove debris from the sulcus. GCF is an inflammatory exudate containing enzymes, electrolytes, and host/bacterial compounds.
3. The gingival tissue mounts an innate and adaptive immune response. Langerhans cells and neutrophils present in the junctional epithelium phagocytose pathogens, while T cells and antibodies provide acquired immunity. Together,
Epidermal Growth Factor use in Diabetic Foot UlcersG H PRABHU
The document discusses epidermal growth factor (EGF) and EGF receptor (EGFR). It describes how Stanley Cohen discovered EGF in the 1950s while working with Rita Levi-Montalcini. It provides details on the structure and function of EGF, which is a 6045 Da protein, and EGFR. EGFR is a receptor tyrosine kinase that is activated upon binding of EGF or other ligands, leading to dimerization and autophosphorylation of tyrosine residues which propagate intracellular signaling cascades that influence cell proliferation, survival and other processes.
The document summarizes the immune mechanisms in the gingiva. The gingival defense system includes innate immunity components like toll-like receptors, complement system, and natural killer cells. It also contains adaptive immunity components like humoral and cell-mediated immunity. Toll-like receptors are expressed by various cells and recognize pathogen patterns to initiate signaling pathways that result in inflammatory responses. The gingival crevicular fluid contains enzymes, proteins, antibodies, cytokines, and cellular components that help fight infection and promote healing in the gingiva.
Cytoskeleton of a cell is made up of microfilaments, microtubules and intermediate filaments. Keratins are diverse proteins. These intermediate filaments maintain the structural integrity of the keratinocytes. The word keratin covers these intermediate filament-forming proteins within the keratinocytes. They are expressed in a specific pattern and according to the stage of cellular differentiation. They always occur in pairs. Mutations in the genes which regulate the expression of keratin proteins are associated with a number of disorders which show defects in both skin and mucosa. In addition, there are a number of disorders which are seen because of abnormal keratinization. These keratins and keratin-associated proteins have become important markers in diagnostic pathology. This review article discusses the classification, structure, functions, the stains used for the demonstration of keratin and associated pathology. The review describes the physiology of keratinization, pathology behind abnormal keratin formation and various keratin disorders.
This document provides an overview of intracellular receptors, enzymes, signals, transcription factors, structural proteins, and nucleic acids. It discusses in detail the structures and functions of DNA, RNA, nuclear receptors, IP3 receptors, intracellular enzymes, transcription factors, and structural proteins like collagen, keratin, myosin, and actin. The presentation was given by S. Dinakar from the Department of Pharmacology at PSG College of Pharmacy in Coimbatore, India.
1) The study examined the role of Rho kinase in T cell activation and immune responses.
2) Inhibition of Rho kinase attenuated T cell proliferation, cytokine gene expression, actin polymerization, and aggregation of T cell receptors.
3) Treatment with a Rho kinase inhibitor prolonged survival of allogeneic heart transplants in mice and diminished cytokine mRNA expression in the transplants.
4) Rho kinase promotes structural rearrangements in T cells that are critical for T cell signaling and activation during cellular immune responses.
Enzybiotics New era of antimicrobials.pptMedhavi27
In the current era of emergence of resistance against traditionally used antibiotics researchers are trying to devise treatment strategies to combat resistant infections. Phage derived lysins are such effective and alternative antimicrobials which kill bacteria with very low chances of developing resistance.
The gingiva provides three lines of defense against pathogens:
1. The epithelial surface acts as a mechanical and chemical barrier. Tight junctions between keratinocytes and antimicrobial peptides in epithelial layers prevent pathogen entry.
2. Components in saliva and gingival crevicular fluid (GCF) maintain tissue health and help remove debris from the sulcus. GCF is an inflammatory exudate containing enzymes, electrolytes, and host/bacterial compounds.
3. The gingival tissue mounts an innate and adaptive immune response. Langerhans cells and neutrophils present in the junctional epithelium phagocytose pathogens, while T cells and antibodies provide acquired immunity. Together,
Epidermal Growth Factor use in Diabetic Foot UlcersG H PRABHU
The document discusses epidermal growth factor (EGF) and EGF receptor (EGFR). It describes how Stanley Cohen discovered EGF in the 1950s while working with Rita Levi-Montalcini. It provides details on the structure and function of EGF, which is a 6045 Da protein, and EGFR. EGFR is a receptor tyrosine kinase that is activated upon binding of EGF or other ligands, leading to dimerization and autophosphorylation of tyrosine residues which propagate intracellular signaling cascades that influence cell proliferation, survival and other processes.
The document summarizes the immune mechanisms in the gingiva. The gingival defense system includes innate immunity components like toll-like receptors, complement system, and natural killer cells. It also contains adaptive immunity components like humoral and cell-mediated immunity. Toll-like receptors are expressed by various cells and recognize pathogen patterns to initiate signaling pathways that result in inflammatory responses. The gingival crevicular fluid contains enzymes, proteins, antibodies, cytokines, and cellular components that help fight infection and promote healing in the gingiva.
Cytoskeleton of a cell is made up of microfilaments, microtubules and intermediate filaments. Keratins are diverse proteins. These intermediate filaments maintain the structural integrity of the keratinocytes. The word keratin covers these intermediate filament-forming proteins within the keratinocytes. They are expressed in a specific pattern and according to the stage of cellular differentiation. They always occur in pairs. Mutations in the genes which regulate the expression of keratin proteins are associated with a number of disorders which show defects in both skin and mucosa. In addition, there are a number of disorders which are seen because of abnormal keratinization. These keratins and keratin-associated proteins have become important markers in diagnostic pathology. This review article discusses the classification, structure, functions, the stains used for the demonstration of keratin and associated pathology. The review describes the physiology of keratinization, pathology behind abnormal keratin formation and various keratin disorders.
This document provides an overview of intracellular receptors, enzymes, signals, transcription factors, structural proteins, and nucleic acids. It discusses in detail the structures and functions of DNA, RNA, nuclear receptors, IP3 receptors, intracellular enzymes, transcription factors, and structural proteins like collagen, keratin, myosin, and actin. The presentation was given by S. Dinakar from the Department of Pharmacology at PSG College of Pharmacy in Coimbatore, India.
1) The study examined the role of Rho kinase in T cell activation and immune responses.
2) Inhibition of Rho kinase attenuated T cell proliferation, cytokine gene expression, actin polymerization, and aggregation of T cell receptors.
3) Treatment with a Rho kinase inhibitor prolonged survival of allogeneic heart transplants in mice and diminished cytokine mRNA expression in the transplants.
4) Rho kinase promotes structural rearrangements in T cells that are critical for T cell signaling and activation during cellular immune responses.
Enzybiotics New era of antimicrobials.pptMedhavi27
In the current era of emergence of resistance against traditionally used antibiotics researchers are trying to devise treatment strategies to combat resistant infections. Phage derived lysins are such effective and alternative antimicrobials which kill bacteria with very low chances of developing resistance.
Immuno microbial pathogenesis of periodontal diseaseGanesh Nair
The document provides an overview of the inflammatory response in periodontal disease. It discusses how bacterial virulence factors like lipopolysaccharide activate the host immune system through toll-like receptors and pro-inflammatory cytokines like IL-1β and TNF-α are released, leading to tissue damage. It also describes other microbial products like fimbriae, DNA, and enzymes that stimulate inflammation and host mediators that perpetuate the inflammatory response and cause bone resorption and tissue destruction.
This document discusses genetic polymorphism and its relationship to periodontal disease. It begins by defining key genetic terms and describes how periodontal disease can be caused by single gene mutations (monogenic disorders) or variations in multiple genes (polygenic disorders). Several specific gene polymorphisms are examined, including genes related to cytokines, receptors, metabolism, and innate immunity. The roles of the IL-1, TNF-α, IL-10 genes and others are summarized. The document also explores several genetic syndromes associated with early-onset periodontitis, such as Papillon-Lefevre syndrome. In conclusion, genetic testing is available to assess patient susceptibility to severe periodontal disease.
The red blood cell membrane consists of three layers - an outer glycocalyx, lipid bilayer in the middle, and inner phospholipid and cholesterol layer. The lipid bilayer contains phospholipids like phosphatidylcholine and sphingomyelin in the outer monolayer, and phosphatidylethanolamine, phosphatidylserine, and phosphoinositol in the inner monolayer. Transport proteins maintain this asymmetric distribution, which is important for cell integrity and survival. The membrane also contains proteins that contribute to cell structure, transport, adhesion, and signaling.
Antimicrobial peptides are polypeptide substances between 12-50 amino acids in length that have antimicrobial properties. They are classified based on their secondary structure as either beta-sheets, alpha-helices, extended coils or loop structures. They are found in many organisms and body locations where they participate in the innate immune system and have multifunctional roles beyond direct antimicrobial activity, including immunomodulation and cell migration. Their mechanisms of action generally involve interactions with and disruption of microbial membranes through electrostatic and hydrophobic interactions.
This study investigated whether oligomerization regulates ectodomain shedding and intramembrane cleavage of mammalian Notch proteins by γ-secretase. The researchers found that while Notch epidermal growth factor repeats can promote dimer formation, most surface Notch molecules in mammalian cells and constitutively active or inactive Notch1 proteins are monomeric. Using a bacterial assay, they also found that the isolated transmembrane domain of Notch and amyloid precursor protein self-associate, and mutations affecting Notch cleavage by γ-secretase do not alter transmembrane domain dimerization. Therefore, the study concludes that ligand-induced reversal of controlled transmembrane domain dimerization by the Notch extracellular domain is unlikely to underlie the
ROLE OF NEUTROPHILS IN HEALTH & DISEASE.pptxjasmine918783
Neutrophils are the most abundant white blood cells and form the first line of defense against pathogens. They are formed in the bone marrow through a process called granulopoiesis regulated by G-CSF and migrate to sites of infection. Neutrophils phagocytose and kill microbes via oxidative and non-oxidative mechanisms. Disorders can cause quantitative or qualitative neutrophil defects, resulting in increased susceptibility to infection. Periodontal disease is more severe and widespread in patients with neutrophil disorders due to impaired host response and bacterial modulation of neutrophil functions.
JBEI Research Highlights - September 2018 Irina Silva
- Three members of the Arabidopsis thaliana glycosyltransferase family 92 (GALS1, GALS2, GALS3) were found to be β-1,4-galactan synthases that add galactose residues to the rhamnogalacturonan-I backbone.
- Overexpression of GALS proteins led to accumulation of unbranched β-1,4-galactan in Arabidopsis, while triple knockout mutants lacked detectable β-1,4-galactan but showed no developmental phenotypes.
- The study provides insight into the properties and roles of these galactan synthase enzymes in pectin biosynthesis in Arabidopsis.
1. Odontoblasts differentiate from dental papilla cells under the influence of inner dental epithelium and form dentin.
2. Initial odontoblast differentiation requires a fibronectin-rich substratum, aperiodic fibrils, TGF-β1, calcium, and enamel matrix proteins.
3. Mature odontoblasts are polarized cells that synthesize and secrete dentin matrix proteins such as collagen type I, dentin sialophosphoprotein, dentin phosphoprotein, and proteoglycans via the rough endoplasmic reticulum, Golgi complex, and secretory granules.
1. The document describes a study that used site-directed mutagenesis to alter a single amino acid (phenylalanine to serine at position 67) in the furin protein sequence to examine its structure, function, and trafficking.
2. The methods included designing mutagenic primers, performing site-directed mutagenesis on the furin cDNA cloned in a plasmid, transforming E. coli with the plasmid, isolating and sequencing the plasmid DNA, and future plans to transfect mutant and wild-type furin into cells for analysis.
3. Furin is involved in development, homeostasis, and disease pathways by processing precursor proteins, and its structure and trafficking are important for understanding its functions.
This document discusses genomics and the usage and effects of mutations in genomics. It begins by defining genomics and the different types including structural, functional, comparative, and mutation genomics. It then describes different types of mutations that can occur at the DNA level like transitions, transversions, deletions, and insertions. It also discusses how mutations can affect proteins by being neutral, silent, missense, nonsense, or causing frameshifts. The document outlines several ways mutation genomics is used, including determining gene function, demonstrating metabolic pathways, and understanding metabolic regulation. It concludes by covering applications of genomics in crop improvement like predicting gene-phenotype relationships and improving drought, salt, and disease tolerance.
This document provides an overview of host modulation therapy for periodontal diseases. It discusses the pathogenesis of periodontal diseases and the balance between pro-and anti-inflammatory mediators in health and disease. It defines key terms and outlines the historical background of host modulation therapy. The document then classifies and describes various approaches to host modulation therapy, including modulation of the immune response targeting cytokines, modulation of matrix metalloproteinases, and use of chemically modified tetracyclines and bisphosphonates to modulate bone remodeling and inflammatory pathways.
This presentation gives the basic idea, about the information on the role of tyrosine kinases in cancer. I have also included a phylogenetic tree for finding the relatedness between different organisms.
This document provides an overview of pulmonary surfactant including its definition, discovery, composition, synthesis, functions, recycling, regulation, and disorders of surfactant homeostasis. Surfactant is a mixture of phospholipids and proteins that is secreted by type 2 pneumocytes in the lungs. It reduces surface tension at the air-liquid interface to prevent alveolar collapse and maintain gas exchange. Disorders associated with surfactant deficiency include infant respiratory distress syndrome and acute respiratory distress syndrome. Surfactant replacement therapy using animal-derived surfactants is an effective treatment for surfactant deficiency disorders.
Evaluation of the lacZ gene in Escherichia coli mutagenesis using pBluescript...Emilio Solomon
This was a research paper I wrote for my Integrated Laboratory Techniques in Biological Sciences II course.
Evaluation of the lacZ gene in Escherichia coli mutagenesis using pBluescript and pTn5: Km vectors
Pathogenic mechanishm of group a streptococcusHamna Sadaf
Group A Streptococcus (GAS) causes infections ranging from mild to severe through multiple virulence mechanisms. GAS adheres to host surfaces using proteins like M protein and pili. It resists innate immunity through factors inhibiting complement deposition and neutrophil killing, like the hyaluronic acid capsule. GAS also degrades antibodies and antimicrobial peptides using enzymes like SpeB. Together, these redundant mechanisms allow GAS to colonize diverse tissues and spread through the host.
The current study investigated the immunomodulatory
potential of ethyl acetate soluble supernatant of
Lactobacillus casei (LC-EAS) in vitro. The effect of
LC-EAS on nitric oxide release was analyzed in RAW
264.7 cells, wherein, an inhibition in nitric oxide production
through suppression of inducible nitric oxide synthase
mRNA expression was observed. Evaluation of LC-EAS
on LPS-induced peripheral blood mononuclear cells
showed a down-regulation in TNF-a and IL-6 genes and an
upregulation of IL-10. An inhibition in the protein
expression of NF-kB, ERK1/2 and STAT3 phosphorylation
confirms the immunomodulatory potential of LC-EAS. The
effect of LC-EAS on in vitro intestinal epithelial cells was
investigated using HT-29 human colon adenocarcinoma
cancer cells. LC-EAS exhibited an inhibition of NF-jB and
ERK1/2 phosphorylation, whereas STAT3 phosphorylation
was unregulated. To evaluate the downstream target of
STAT3 upregulation, expression of the intestinal trefoil
factor TFF3 which is a NF-jB regulator and STAT3
downstream target was studied. LC-EAS was observed to
elevate TFF3 mRNA expression. Overall the study shows
that the anti-inflammatory potential of LC-EAS is through
inhibition of NF-kB in different cell types.
Senior Thesis-Analyzing the interactions between MYOGEF and a component of er...Dougan McGrath
This document summarizes a study analyzing the interaction between MYOGEF, a guanine nucleotide exchange factor that activates RhoA, and SPTA1, a major component of the erythrocyte cytoskeleton. Previous research identified SPTA1 as an interacting partner of MYOGEF. The current study aims to characterize this interaction through constructing cDNA fragments of different regions of MYOGEF and SPTA1 and examining their interaction using yeast two-hybrid and in vitro pull-down assays. The results showed that the C-terminal region of MYOGEF interacted with the EF-hand motifs located in the C-terminal region of SPTA1. This interaction may lead to MYOGEF-mediated
Porphyromonas gingivalis is a gram-negative, anaerobic bacteria that is a major pathogen in periodontal disease. It has several virulence factors that contribute to its role in periodontitis, including a capsule that aids evasion of the immune system, fimbriae that mediate adhesion, and gingipains which are proteolytic enzymes that degrade host proteins and modulate the immune response. P. gingivalis inhabits the gingival crevice and has been strongly associated with progressive bone and tissue destruction in periodontitis. Treatment of periodontal disease can reduce but may not eliminate P. gingivalis from the oral cavity.
This study investigated the histopathological changes and expressions of ADAMTS-5 and TNF-α in the gingival tissue of streptozotocin-induced diabetic rats compared to controls. Rats were divided into control and diabetic groups, with the latter receiving a single dose of streptozotocin to induce diabetes. Gingival tissues were examined using hematoxylin-eosin staining and immunohistochemical staining for ADAMTS-5 and TNF-α. Results showed thinning of the epithelial layer, degeneration of epithelial cells, and inflammatory cell infiltration in diabetic rats compared to controls. Diabetic rats also showed positive expression of ADAMTS-5 in epithelial cells and TNF-α in basal lamina
This document provides information on epithelial tissue and cell junctions. It discusses the general features of epithelial tissue, including that epithelial cells are closely packed with many cell junctions. It also describes the different types of epithelial tissue (simple vs stratified), the cell shapes (squamous, cuboidal, columnar), and locations in the body. The document further explains the structure and functions of the basement membrane and cell junctions, including occluding junctions, anchoring junctions, and communicating junctions. Key cellular adhesion molecules and proteins involved in different junction types are also outlined.
This document provides information about lymph nodes and the lymphatic system. It discusses the anatomy, embryology, histology, and physiology of lymph nodes and lymphatic drainage. Key points include:
- Lymph nodes act as filters for the lymphatic system and help fight infection. They are located along lymphatic vessels.
- The primary lymphoid organs are the bone marrow and thymus, where lymphocytes develop. Secondary lymphoid organs include the spleen, lymph nodes, tonsils, and skin.
- Lymph nodes have an outer cortex and inner medulla. Lymph enters through afferent vessels and exits through efferent vessels. High endothelial venules are found
Immuno microbial pathogenesis of periodontal diseaseGanesh Nair
The document provides an overview of the inflammatory response in periodontal disease. It discusses how bacterial virulence factors like lipopolysaccharide activate the host immune system through toll-like receptors and pro-inflammatory cytokines like IL-1β and TNF-α are released, leading to tissue damage. It also describes other microbial products like fimbriae, DNA, and enzymes that stimulate inflammation and host mediators that perpetuate the inflammatory response and cause bone resorption and tissue destruction.
This document discusses genetic polymorphism and its relationship to periodontal disease. It begins by defining key genetic terms and describes how periodontal disease can be caused by single gene mutations (monogenic disorders) or variations in multiple genes (polygenic disorders). Several specific gene polymorphisms are examined, including genes related to cytokines, receptors, metabolism, and innate immunity. The roles of the IL-1, TNF-α, IL-10 genes and others are summarized. The document also explores several genetic syndromes associated with early-onset periodontitis, such as Papillon-Lefevre syndrome. In conclusion, genetic testing is available to assess patient susceptibility to severe periodontal disease.
The red blood cell membrane consists of three layers - an outer glycocalyx, lipid bilayer in the middle, and inner phospholipid and cholesterol layer. The lipid bilayer contains phospholipids like phosphatidylcholine and sphingomyelin in the outer monolayer, and phosphatidylethanolamine, phosphatidylserine, and phosphoinositol in the inner monolayer. Transport proteins maintain this asymmetric distribution, which is important for cell integrity and survival. The membrane also contains proteins that contribute to cell structure, transport, adhesion, and signaling.
Antimicrobial peptides are polypeptide substances between 12-50 amino acids in length that have antimicrobial properties. They are classified based on their secondary structure as either beta-sheets, alpha-helices, extended coils or loop structures. They are found in many organisms and body locations where they participate in the innate immune system and have multifunctional roles beyond direct antimicrobial activity, including immunomodulation and cell migration. Their mechanisms of action generally involve interactions with and disruption of microbial membranes through electrostatic and hydrophobic interactions.
This study investigated whether oligomerization regulates ectodomain shedding and intramembrane cleavage of mammalian Notch proteins by γ-secretase. The researchers found that while Notch epidermal growth factor repeats can promote dimer formation, most surface Notch molecules in mammalian cells and constitutively active or inactive Notch1 proteins are monomeric. Using a bacterial assay, they also found that the isolated transmembrane domain of Notch and amyloid precursor protein self-associate, and mutations affecting Notch cleavage by γ-secretase do not alter transmembrane domain dimerization. Therefore, the study concludes that ligand-induced reversal of controlled transmembrane domain dimerization by the Notch extracellular domain is unlikely to underlie the
ROLE OF NEUTROPHILS IN HEALTH & DISEASE.pptxjasmine918783
Neutrophils are the most abundant white blood cells and form the first line of defense against pathogens. They are formed in the bone marrow through a process called granulopoiesis regulated by G-CSF and migrate to sites of infection. Neutrophils phagocytose and kill microbes via oxidative and non-oxidative mechanisms. Disorders can cause quantitative or qualitative neutrophil defects, resulting in increased susceptibility to infection. Periodontal disease is more severe and widespread in patients with neutrophil disorders due to impaired host response and bacterial modulation of neutrophil functions.
JBEI Research Highlights - September 2018 Irina Silva
- Three members of the Arabidopsis thaliana glycosyltransferase family 92 (GALS1, GALS2, GALS3) were found to be β-1,4-galactan synthases that add galactose residues to the rhamnogalacturonan-I backbone.
- Overexpression of GALS proteins led to accumulation of unbranched β-1,4-galactan in Arabidopsis, while triple knockout mutants lacked detectable β-1,4-galactan but showed no developmental phenotypes.
- The study provides insight into the properties and roles of these galactan synthase enzymes in pectin biosynthesis in Arabidopsis.
1. Odontoblasts differentiate from dental papilla cells under the influence of inner dental epithelium and form dentin.
2. Initial odontoblast differentiation requires a fibronectin-rich substratum, aperiodic fibrils, TGF-β1, calcium, and enamel matrix proteins.
3. Mature odontoblasts are polarized cells that synthesize and secrete dentin matrix proteins such as collagen type I, dentin sialophosphoprotein, dentin phosphoprotein, and proteoglycans via the rough endoplasmic reticulum, Golgi complex, and secretory granules.
1. The document describes a study that used site-directed mutagenesis to alter a single amino acid (phenylalanine to serine at position 67) in the furin protein sequence to examine its structure, function, and trafficking.
2. The methods included designing mutagenic primers, performing site-directed mutagenesis on the furin cDNA cloned in a plasmid, transforming E. coli with the plasmid, isolating and sequencing the plasmid DNA, and future plans to transfect mutant and wild-type furin into cells for analysis.
3. Furin is involved in development, homeostasis, and disease pathways by processing precursor proteins, and its structure and trafficking are important for understanding its functions.
This document discusses genomics and the usage and effects of mutations in genomics. It begins by defining genomics and the different types including structural, functional, comparative, and mutation genomics. It then describes different types of mutations that can occur at the DNA level like transitions, transversions, deletions, and insertions. It also discusses how mutations can affect proteins by being neutral, silent, missense, nonsense, or causing frameshifts. The document outlines several ways mutation genomics is used, including determining gene function, demonstrating metabolic pathways, and understanding metabolic regulation. It concludes by covering applications of genomics in crop improvement like predicting gene-phenotype relationships and improving drought, salt, and disease tolerance.
This document provides an overview of host modulation therapy for periodontal diseases. It discusses the pathogenesis of periodontal diseases and the balance between pro-and anti-inflammatory mediators in health and disease. It defines key terms and outlines the historical background of host modulation therapy. The document then classifies and describes various approaches to host modulation therapy, including modulation of the immune response targeting cytokines, modulation of matrix metalloproteinases, and use of chemically modified tetracyclines and bisphosphonates to modulate bone remodeling and inflammatory pathways.
This presentation gives the basic idea, about the information on the role of tyrosine kinases in cancer. I have also included a phylogenetic tree for finding the relatedness between different organisms.
This document provides an overview of pulmonary surfactant including its definition, discovery, composition, synthesis, functions, recycling, regulation, and disorders of surfactant homeostasis. Surfactant is a mixture of phospholipids and proteins that is secreted by type 2 pneumocytes in the lungs. It reduces surface tension at the air-liquid interface to prevent alveolar collapse and maintain gas exchange. Disorders associated with surfactant deficiency include infant respiratory distress syndrome and acute respiratory distress syndrome. Surfactant replacement therapy using animal-derived surfactants is an effective treatment for surfactant deficiency disorders.
Evaluation of the lacZ gene in Escherichia coli mutagenesis using pBluescript...Emilio Solomon
This was a research paper I wrote for my Integrated Laboratory Techniques in Biological Sciences II course.
Evaluation of the lacZ gene in Escherichia coli mutagenesis using pBluescript and pTn5: Km vectors
Pathogenic mechanishm of group a streptococcusHamna Sadaf
Group A Streptococcus (GAS) causes infections ranging from mild to severe through multiple virulence mechanisms. GAS adheres to host surfaces using proteins like M protein and pili. It resists innate immunity through factors inhibiting complement deposition and neutrophil killing, like the hyaluronic acid capsule. GAS also degrades antibodies and antimicrobial peptides using enzymes like SpeB. Together, these redundant mechanisms allow GAS to colonize diverse tissues and spread through the host.
The current study investigated the immunomodulatory
potential of ethyl acetate soluble supernatant of
Lactobacillus casei (LC-EAS) in vitro. The effect of
LC-EAS on nitric oxide release was analyzed in RAW
264.7 cells, wherein, an inhibition in nitric oxide production
through suppression of inducible nitric oxide synthase
mRNA expression was observed. Evaluation of LC-EAS
on LPS-induced peripheral blood mononuclear cells
showed a down-regulation in TNF-a and IL-6 genes and an
upregulation of IL-10. An inhibition in the protein
expression of NF-kB, ERK1/2 and STAT3 phosphorylation
confirms the immunomodulatory potential of LC-EAS. The
effect of LC-EAS on in vitro intestinal epithelial cells was
investigated using HT-29 human colon adenocarcinoma
cancer cells. LC-EAS exhibited an inhibition of NF-jB and
ERK1/2 phosphorylation, whereas STAT3 phosphorylation
was unregulated. To evaluate the downstream target of
STAT3 upregulation, expression of the intestinal trefoil
factor TFF3 which is a NF-jB regulator and STAT3
downstream target was studied. LC-EAS was observed to
elevate TFF3 mRNA expression. Overall the study shows
that the anti-inflammatory potential of LC-EAS is through
inhibition of NF-kB in different cell types.
Senior Thesis-Analyzing the interactions between MYOGEF and a component of er...Dougan McGrath
This document summarizes a study analyzing the interaction between MYOGEF, a guanine nucleotide exchange factor that activates RhoA, and SPTA1, a major component of the erythrocyte cytoskeleton. Previous research identified SPTA1 as an interacting partner of MYOGEF. The current study aims to characterize this interaction through constructing cDNA fragments of different regions of MYOGEF and SPTA1 and examining their interaction using yeast two-hybrid and in vitro pull-down assays. The results showed that the C-terminal region of MYOGEF interacted with the EF-hand motifs located in the C-terminal region of SPTA1. This interaction may lead to MYOGEF-mediated
Porphyromonas gingivalis is a gram-negative, anaerobic bacteria that is a major pathogen in periodontal disease. It has several virulence factors that contribute to its role in periodontitis, including a capsule that aids evasion of the immune system, fimbriae that mediate adhesion, and gingipains which are proteolytic enzymes that degrade host proteins and modulate the immune response. P. gingivalis inhabits the gingival crevice and has been strongly associated with progressive bone and tissue destruction in periodontitis. Treatment of periodontal disease can reduce but may not eliminate P. gingivalis from the oral cavity.
This study investigated the histopathological changes and expressions of ADAMTS-5 and TNF-α in the gingival tissue of streptozotocin-induced diabetic rats compared to controls. Rats were divided into control and diabetic groups, with the latter receiving a single dose of streptozotocin to induce diabetes. Gingival tissues were examined using hematoxylin-eosin staining and immunohistochemical staining for ADAMTS-5 and TNF-α. Results showed thinning of the epithelial layer, degeneration of epithelial cells, and inflammatory cell infiltration in diabetic rats compared to controls. Diabetic rats also showed positive expression of ADAMTS-5 in epithelial cells and TNF-α in basal lamina
This document provides information on epithelial tissue and cell junctions. It discusses the general features of epithelial tissue, including that epithelial cells are closely packed with many cell junctions. It also describes the different types of epithelial tissue (simple vs stratified), the cell shapes (squamous, cuboidal, columnar), and locations in the body. The document further explains the structure and functions of the basement membrane and cell junctions, including occluding junctions, anchoring junctions, and communicating junctions. Key cellular adhesion molecules and proteins involved in different junction types are also outlined.
This document provides information about lymph nodes and the lymphatic system. It discusses the anatomy, embryology, histology, and physiology of lymph nodes and lymphatic drainage. Key points include:
- Lymph nodes act as filters for the lymphatic system and help fight infection. They are located along lymphatic vessels.
- The primary lymphoid organs are the bone marrow and thymus, where lymphocytes develop. Secondary lymphoid organs include the spleen, lymph nodes, tonsils, and skin.
- Lymph nodes have an outer cortex and inner medulla. Lymph enters through afferent vessels and exits through efferent vessels. High endothelial venules are found
Dr. Sonam Rani presented on the topic of cementum to several professors and colleagues. Cementum is a calcified tissue that covers tooth roots and provides attachment for periodontal ligaments. It comes in several types classified based on cellularity, presence of fibers, and origin. Cementum is formed by cementoblasts and cementocytes and plays an important role in tooth adaptation and repair. Systemic conditions like Paget's disease and cleidocranial dysplasia can affect cementum formation and structure.
This document provides an overview of pain, including its definition, classification, theories, transmission and modulation pathways, assessment, and management approaches. It begins with definitions of pain from Dorland's Medical Dictionary and Monheim. It then classifies pain according to intensity, temporal relationship, qualities, onset, and localization. Theories of pain discussed include specificity, pattern, and gate control theories. It describes the dual nature of pain and the transduction, transmission, modulation, and perception of pain. It discusses referred pain and neuropathic pain. The document concludes by covering pain assessment tools and pharmacological and non-pharmacological management strategies.
COMMON SEMINAR STERILISATION, INFECTION CONTROL AND HOSPITAL MANAGEMENT.pptxmalti19
This document discusses sterilization, infection control, and hospital management in dentistry. It defines key terms like sterilization, disinfection, and asepsis. It then describes various methods of sterilization including physical methods like heat and radiation, and chemical methods like alcohols, phenols, aldehydes, halogens, and gases. The document provides details on specific sterilization techniques and protocols for sterilizing dental instruments used in different specialties. It emphasizes the importance of proper sterilization to prevent disease transmission between patients.
This document summarizes key concepts in immunology as they relate to periodontal disease. It discusses the epithelial barrier and pattern recognition receptors that detect pathogens. Inflammatory mediators recruit immune cells through chemotaxis. T lymphocytes develop and differentiate into subsets like Th1, Th2, Th17 that activate different immune responses. B cells produce antibodies through somatic hypermutation. Regulatory T cells control self-tolerance. The adaptive response becomes antigen-specific and develops memory. Dendritic cells present antigens to activate T cells. An imbalance in T cell subsets can lead to tissue destruction in periodontal disease.
Thrombosis, embolism, and infarction are related pathological processes involving blood clots. Thrombosis is the formation of a blood clot within a blood vessel, while embolism occurs when a piece of a clot breaks off and travels to another location. Infarction results from obstruction of blood flow by a clot, causing tissue death. The document discusses the mechanisms, types, features, and progression of thrombosis, embolism, and infarction. It also covers related topics like Virchow's triad, hypercoagulable states, fat embolism, and amniotic fluid embolism.
Thrombosis, embolism, and infarction are related pathological processes involving blood clots. Thrombosis is the formation of a blood clot within a blood vessel, while embolism occurs when a piece of a clot breaks off and travels to another location. Infarction results from obstruction of blood flow by a clot, causing tissue death. The document discusses the mechanisms, classifications, and morphological features of thrombosis, embolism, and infarction. It also covers related topics like Virchow's triad, hypercoagulable states, and the development and types of infarcts over time.
Immune responses in periodontal disease final.pptxmalti19
This document discusses the immune responses involved in periodontal disease. It begins by defining periodontitis as an infectious disease caused by anaerobic bacteria. Both bacteria and a susceptible host are required to cause disease. It then describes the pathogenesis which involves environmental and genetic risk factors interacting with the microbial challenge to activate the host immune response, resulting in inflammation and bone/tissue destruction. The document discusses the types of immunity, including innate and adaptive immunity. It covers topics such as dendritic cells, T-cell and B-cell roles, the roles of cytokines and RANKL in linking the immune response to bone loss, and hypotheses about the roles of the Th1 and Th2 responses in periodontitis.
This document provides an overview of antibiotics used in periodontics. It begins with an introduction to antibiotics and their historical background. It then covers classification of antimicrobial agents based on chemical structure, mechanism of action, organisms targeted, and spectrum of activity. Guidelines for antibiotic use in periodontal diseases are presented, along with the diseases where antibiotics can be used. Commonly used antibiotics like tetracycline, doxycycline, metronidazole, penicillin, and amoxicillin-clavulanate are described in detail. The document concludes with a reference to research on systemic antibiotic use in periodontics.
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1. Epithelium- Role in defense
Dr. Vamsi Lavu
Dept of Periodontics
Sri Ramachandra Dental College
2. • In the past- gingiva was considered as a
“physical barrier”.
• Current findings in periodontal research-
Paradigm shift to
“deterministic role in host immune
response to bacterial challenge”
4. Review of some studies
Authors Study Result
Takata et al 1988 Colloidal gold labelled
Concavalin A- JE of rats
JE cells- phagoctic activity.
Possible first line defense
Krisanaprakornkit S et al
1998
HBD-1 expression in
gingival epithelial cells
culture and tissue- PCR
Constitutive expression in
epithelial cells but not
fibroblasts
Tonetti et al 1998 IL-8 mRNA and ICAM-1
expression in JE of healthy
gingiva
Gradient in expression of
ICAM -1 and IL-8
Seguier S et al 1999 Immunohistologic and
morphometric analysis for
cytotoxic lymphocytes in
gingivitis
Detected Intra-epithelial
lymphocytes which are CD
3+ve and CD 8 +ve.
5. Review of studies- Contd
Authors Study Result
Miyauchi M et al 2001 Expression of TNF alpha, Il-
1 by JE cells-
(Immunohistochemistry)
Demonstrated expression
of the Pro-inflammatory
cytokines
Ren L et al 2004 Expression profile of LBP in
gingival epithelium
(peptide and m-RNA)
LBP expression decreases
from coronal to apical
aspect (ie) from sulcular to
junctional epithelium.
Found in cytoplasm of
granular and cornified
layers.
Re-think of the concept of the epithelium as a
physical barrier.
6. • The role of epithelium in active defense is
outlined below:
– Expression of toll-like receptors.
– Production of antimicrobial peptides.
– Antigen presenting cells.
– Expression of cell adhesion molecules.
– Pro-inflammatory cytokine and chemokine
production.
8. • Toll gene – discovered in 1985- implicated in
development- Drosophila.
• Drosophila- Toll protein- mediated immune
response to fungal infection.
• Toll like receptors- recognize specific
conserved microbial components- “Pathogen
associated molecular patterns”.
• Constitute an important part of innate
immune response.
12. TLR’s in gingival epithelium
• Kisumoto Y et al 2004, constitutive expression
of TLR-2- TLR-6 and TLR-9.
• Ckhara et al 2002, low levels of TLR-4
expression .
• TLR-2 distribution in the epithelium (Kisumoto
et al 2004), TLR-2 expression is denser in the
spinous layers than basal epithelial layers
13. • Asai et al 2001, demonstrated that Il-8 and
MCP-1 production by gingival epithelial cells in
response to P.gingivalis fimbriae and Staph
aureus peptidoglycan was mediated through
TLR-2.
• TLR-3 and TLR 9 have also been demonstrated
and these are specific for viruses.
14. SUMMARY:
TLR’S ARE EXPRESSED ON GINGIVAL EPITHELIAL
CELLS.
GINGIVAL EPITHELIUM ACTS AS ALERT SENTINELS-
PRODUCE CHEMOKINES REQUIRED FOR INNATE
IMMUNE CELL MIGRATION WHEN THE TLR’S ON
EPITHELIAL CELLS RECOGNIZE PAMP’S.
15. Why is there no continuous inflammation
of the gingiva??
• Oral gingival epithelium- exposed to several
hundred bacterial species.
• How is it that gingiva mediates the response
to microbes through TLR signalling and avoids
severe chronic inflammation – “Question of
Debate”.
16. • Hajishengallis G et al, Genco RJ et al 2004,
Mutukuru et al 2005 have suggested that there is
a development of tolerance in the gingival
epithelium that is mediated through down-
regulation of TLR expression and inhibition of
intracellular signalling in the oral gingival
epithelium.
• This hypothesis is based on the findings in the gut
epithelium which have a similar environment
(Abreu MT 2003).
18. • Four different families of anti-microbial
peptides:
– Alpha defensins.
– Beta defensins.
– Cathellicidins.
– Saponins.
Others include calprotectin, histatin 5, hepcidin,
lactoferrin, cathepsin G, adrenomedullin.
19. Defensins
• Best characterized antimicrobial proteins in
humans.
• Localized to 8p23 chromosome.
• Beta defensins are phylogenetically older.
20. Structure of defensins:
• They have an amphipathic organization- allows
clustering of the hydrophobic , hydrophilic and the
cationic sections of the molecule into separate areas.
• Some antimicrobial peptides are linear in structure but
assume this organization after entering the microbial
membrane, whereas others maintain this structure
with anti-parallel beta sheet arrangement that is
constrained by the number of disulfide bonds.
21. • Basket like structure – due to combination of
disulfide crosslinks with amphiphilic nature of
the peptides.
• The top of the basket consists of N and C
terminal residues giving a polar positively
charged region.
• The hydrophobic regions are grouped at the
bottom of the basket.
23. • Alpha and beta defensins differ in their
location of di-sulfide bonds between cysteine
residues:
– Beta defensins- (C1-5,C2-4,C3-6).
– Alpha defensins- (C1-6, C2-4, C3-5).
The alpha defensins are found as full protein in the
neutrophils and are termed as HNP1-4.
The HNP-5,6 are found in the Paneth cells of the gut
as the proform
25. Mechanism of the antimicrobial peptide action
• SHAI MATSUZAKI- HUANG MODEL
• Bacterial cell wall – negative charge due to
phospholipid layer with negatively charged
phosphate towards the outer surface.
• The defensins have a positive charged end (top of
the basket) which is attracted towards the
negatively charged phospholipid layer.
• The initial electrostatic attraction is then followed
by displacement of the membrane lipids in a
wedge like manner.
27. • The mechanisms after this stage probably differ
depending on the molecule and the bacterial cell
wall, resulting in a leakage of the cytoplasmic
contents due to a new osmotic equilibrium.
• In some cases the defensins have specific
intracellular targets such as inhibition of ATPase
actions and preventing chaperone assisted
protein folding (KragolG et al 2001).
28. Beta defensins
• Beta defensins are expressed in gingiva,
tongue, salivary glands, mucosa.
• Gingiva and oral mucosa express Beta
defensin 1,2,3 (Krisanaprakornkit et al 1998,
2000).
• hBD-1- constitutive.
• hBD-2- inducible.
29. Beta defensin expression:
• Associated with differentiation of the
epithelium.
Normal gingiva:
• mRNA expression is strong in the spinous layer
of the tissue while the peptides are detected
in the upper granular and cornified layer.
31. • The strongest expression is at the gingival margin,
adjacent to the region of plaque formation on the
tooth surface and in the inflammed sulcular
epithelium (Dale et al 2001).
• HBD-1 and hBD-2 are not detectable in the JE.
• Lui et al 2002, proposed that differentiation is a
pre-requisite for beta defensin expression in
epidermis. This appears to hold good in the oral
epithelium also as evidenced by the lack of
expression in the JE.
33. • HBD-2 is expressed in the normal and
inflamed human gingiva, unlike in other
epithelia such as skin, gut epithelium (Dale et
al 2001).
• Krisanaprakornkit et al 2000 have suggested
that this hBD-2 expression is in response to
oral commensals and it indicates a heightened
state of readiness.
34. Epithelial receptors for hBD-2 induction
Two families have been implicated:
• TLR family.
• PAR family- Proteinase activated receptors.
• TLR-2,4 have been shown to be involved in
bacterial sensing and intracellular signalling.
There is however no evidence for available for
TLR induced hBD expression.
35. PAR family:
• PAR’s are seven trans-membrane domain G
protein coupled receptors.
• PAR activation involves proteolytic cleavage of
the extracellular domain resulting in a new
amino terminus that acts as a tethered ligand
that binds to one of the extracellular loops of
the receptor (Coughlin and Camires 2003).
36. • PAR-2 is activated by various trypsin like enzymes
including mast cell tryptase, neutrophil
proteinase 3 as well as P.gingivalis proteinases.
(Lourbakes et al 1998).
• Chung WO, Dale A et al 2004, demonstrated the
involvement of PAR-1 receptor in upregulation of
hBD-2 mRNA expression in gingival epithelial cells
stimulated by P.gingivalis proteinases.
38. • They include
– bactericidal/ permeability increasing protein like
protein.
– Calprotectin.
– Adrenomedullin.
– The neutrophils migrating through the epithelium
also contribute Alpha defensins and LL-37
although they are strictly of not epithelial origin.
39. Bactericidal/permeability increasing protein like
protein
• BPIP like protein is an antibacterial protein with
selectivity for gram negative bacteria.
• BPIP like protein are either about 250 amino
acids in length or more than 450 amino acids.
Structure:
• It consists of BPIP domains BPI1 and BPI2.
• They have a disulfide bridge between cysteine
residues.
40. The different types of BPIP like protein found
include:
• Parotid secretory protein. (Madsen HO, Hjorth
JP, 1985).
• Palate, lung, nasal epithelium carcinoma
associated protein. (Wetson WM et al 1999).
• Bovine salivary protein. (Rajan GH et al 1996)
• von Ebner’s minor salivary gland protein.
41. Expression of BPIP like proteins by gingival
epithelium:
• Are expressed in human gingival keratinocytes
where their expression is regulated by the oral
bacterium P. gingivalis and the pro-
inflammatory cytokine tumor necrosis factor
alpha. (Shiba H et al 2005, Gorr et al
manuscript in prepn).
42. Functions of BPIP like protein:
• Parotid secretory protein structure: block the binding
of LPS to lipopolysaccharide binding protein and blocks
the LPS stimulated secretion of TNF alpha from
macrophages.
• PSP is also antibacterial to Pseudomonas aeruginosa.
• The other epithelial secreted BPIP like proteins also
have antimicrobial proteins.
43. Calprotectin:
• Also called calgranulin.
• Is a calcium and zinc binding protein also
referred to as S100 A8 and S100 A9. It is
constitutively expressed in cells of stratified
oral epithelia and in cultured gingival
epithelial cells (Ross & Herzberg, 2001).
44. MOA of calprotectin:
• Competition for zinc, a growth requirement for
many microbial species (Brandtzaeg et al 1995).
• Calprotectin expression confers protection from
bacterial binding and invasion and may
contribute to resistance of gingival cells to
invasion by P.gingivalis, a gram negative
periodontal pathogen (Nisapakultorn et al 2001).
45. Adrenomedullin:
• It is a multifunctional peptide that was initially
characterized for vasodilatory action.
• Allaker & Kapas 2003, have demonstrated that it
has anti-bacterial function against g+ve and g-ve
bacteria but not anti-fungal activity.
• It is constitutively expressed and secreted by oral
epithelial cells and expression is increased in
response to live oral bacteria, IL-1, TNF alpha
(Kapas et al 2001a, Kapas et al 2001b).
46. • Adrenomedullin has structural homology with
calcitonin gene related peptide and functional
homology with beta defensins.
LL-37:
• Is a cathellicidin with conserved pro-region
which keeps it inactive till proteases cleave
the protein after the protein is secreted
(Zanetti et al 2008).
47. Functions of LL-37:
• It is a chemoattractant for neutrophil, monocytes and T
cells (Chertov et al 1996).
• It also stimulates mast cells and alters macrophage gene
expression to upregulate chemokines and their receptors
resulting in greater responsiveness to the environment
(Scott et al 2000).
• LL-37 has the greatest activity against A.a and
Capnocytophaga species.
48. Alpha defensins :
• are relatively ineffective against most oral microbes
tested except C.ochracea and C.albicans.
• HNP 1-3 also inhibit HIV virus.
• Alpha defensins also are involved in modulation of
adaptive immune response by selectively attracting
naïve CD4 T cells and immature dendritic cells via a G
protein coupled receptor (Yang et al 2000).
49. Defensins- Link between innate and adaptive immunity
Alpha defensins
• Activate the classical complement pathway (Panyutich AV
et al 1994).
• Upregulate IL-8 production by epithelial cells which in turn
increase neutrophil recruitment. (Van Wetering S et al
1997).
• Are chemotactic for CD 8 and CD4/CD45 RA T cells and
immature dendritic cells (Chertov O et al 2000).
• In vitro they enhance the release of TNF alpha and IL-1
from activated monocytes (Chertov O et al 2000).
• Decrease VCAM-1 expression from TNF alpha activated
endothelium without affecting ICAM-1 expression (Chaly
YV et al 2000).
50. Defensins- Link between innate and adaptive immunity
Beta defensins
• Chemoattractant for immature dendritic
cells, CD 4/CD 45 RO (memory) T cells and CD
8 cells via binding to chemokine receptor
CCR6 (Yang D et al 1999).
52. Antigen presenting cells
Introduction
• They represent a unique family of cells that
are involved in antigen capture, processing
and presentation to the T cells.
• They represent a bridge between innate and
adaptive immunity.
54. Studies done in localization of dendritic cells in the
gingiva and the PDL with markers used
Study Dendritic cell &
markers
Tissues Disease
studied
Major finding
Cutler &
Jotwani 2004
Langerhans
cells
Immature
dendritic cell
Lysosomal
dendritic cell,
Mature
dendritic cell
Langerin, Cd1a
DC-LAMP, CD
83
Periodontitis Lysosomal
bearing
dendritic cells,
C 83 +ve,
mature
dendritic cells
engaged with T
cells
Cirrincione et
al 2002
Langerhans
cells
Co-stimulatory
markers
CD 1a, CD 80,
CD 86
MHC II, CD 54
Periodontitis DC are
abundant in
lamina propria
of pocket
epithelium,
expression of
MHC II
55. Jotwani et al Langerhans
cells , mature
and immature
dendritic cells
LAG,Cd1a,CD
83
Periodontitis,
gingivitis
Increased LC in
the epithelium
of
periodontitis
Seguier et al
2000
Langerhans
cells
CD1a Periodontitis,
gingivitis
Morph of LC
changed in
upper vs lower
epithelia of
gingivitis and
pditis.
Seguier et al
2000
Langerhans
cells
CD1a Periodontitis,
gingivitis,
healthy
LC decreased in
epithelia of
gingivitis and
pditis,
intraepithelial
lymphocytes
are increased
56. Jotwani et al
2001
Langerhans
cell, mature
and immature
Dendritic cell
LAG, CD 1a, CD
83
Periodontitis,
gingivitis
Increased Lc in
epithelium of
periodontitis
and CD 83+ve
dendritic cells
in lamina
propria
forming Oral
lymphoid
follicle
Lundqvist and
Hammarstrom
1993
Langerhans
cells
Cd1a,b,c Inflamed
gingiva
Mostly CD1a
cells found in
epithelium.
CD1b cells not
found, CD 1c
cells found in
basal
epithelium
57. Conclusion from the studies listed:
• CD1a langerhans cells are the primary leukocytes
involved in the response of oral epithelium to
infectious , dysplastic, atopic diseases.
• Langerhans cells have been shown to increase in
number in epithelium with gingivitis,
experimental gingivitis and periodontitis.
• The identity of the precursors of the langerhans
cells that infiltrate the oral/gingival epithelium is
unclear at present.
58. Concept of oral lymphoid follicle
• The mature dendritic cells play a role of in the
formation of the “Oral lymphoid follicle” or
lymphoid foci that develop inter-proximally
around the teeth in periodontitis.
• In gingivitis stage- migration of langerhans
cells or their progenitors homing to the
epithelium in response to the “pathogen
molecular patterns” from the oral biofilm.
61. Role in antigen recognition and capture
• The dendritic cells are localized to the gingival
epithelium where they play a role in recognizing
and capturing conserved sequences of the
microbes called as “pathogen associated
molecular patterns”.
• This is achieved by a an array of receptors that
the dendritic cells possess
– Toll like receptors.
– C-lectin receptors.
In addition the dendritic cells also possess phagocytosis
receptors for antibody and complement.
62. • Signal transduction is mediated by IL-1
receptor and MyD88 and ultimately results in
release of NF-kB which translocates to the
nucleus.
• This translocation is followed by activation of
genes involved in dendritic cell maturation
and upregulation of the expression co-
stimulatory molecules.
65. Conclusion : Role of epithelium in defense.
• Epithelium plays a deterministic role through:
– Production of defensins.
– Expression of TLR’s
– Through chemokine and cytokine production.
production.
– Tolerance when required.
– Dendritic cell influx and emigration.
66. References
1. Toll like receptors and their role in periodontal
disease. Mahanonda R and Pichyangkul.
Periodontology 2000, 2007.
2. Antimicrobial peptides in the oral environment:
Expression and function in health and disease.
Dale BA, Federicks LP. Curr issues Mol Biol 2005
July;7(2): 119-133.
3. Periodontal epithelium- A newly recognized role
in health and disease. Dale BA. Periodontology
2000,2002.
67. References (contd)
4. Human variability in innate immunity. Kinane DF
et al. Periodontology 2000,2007.
5. Oral mucosal dendritic cells and periodontitis.
Cutler and Teng. Periodontology 2000,2007.
6. Modulation of the innate immune response in
the periodontium. Douglas et al. Periodontology
2000,2004.
7. The junctional from health to disease. Bosshardt
and Lang. Critical reviews in Oral Biology and
Medicine. J Dent Res 2005;84(1):9-20.
68. ACKNOWLEDGMENT
• Professor R.Suresh, Dean, Head of
Department, Department of Periodontics, Sri
Ramachandra Dental College.
• All my senior staff and colleagues of my
department.
• My postgraduate students and undergraduate
students.
• The Management – for the excellent online
library facility.
69. Thank you
“The past is known, the
present is happening and
the future is unknown”