Overview of the Immune System: Innate vs. Adaptive Defenses
Innate-Nonspecific Defenses
First Line of defense: Physical barriers
Second Line of defense:
- Major cellular components
Phagocytes
Basophils
Eosinophils
NK cells
- Chemical signals
Interferons
Complement Proteins
Inflammation
Fever (pyrogens)
Overview of the Immune System: Innate vs. Adaptive Defenses
Innate-Nonspecific Defenses
First Line of defense: Physical barriers
Second Line of defense:
- Major cellular components
Phagocytes
Basophils
Eosinophils
NK cells
- Chemical signals
Interferons
Complement Proteins
Inflammation
Fever (pyrogens)
Immunity :
It is defined as the resistance exhibited by the host against any
foreign antigen including microorganisms.
Plays a major role in prevention of infectious diseases.
antimicrobial peptides are class of biological defense molecules which act as a part of our innate immune system.in oral cavity any microbial insult will be resisted by physical,biological and chemical barrier there by maintaining oral homeostasis.these molecules are of low molecular weight with less than 100 amino acids. main antimicrobial peptides include defensin,histatin,cathelicidin and statherin etcc.they develop resistence very slowly,prvrnt biofilm formation and in future they can be used as therapeutic agents
This presentation explains about the concept of food intoxication. The toxins produced by the microbes in food (fungal) and toxins present in the food stuff were provided. The information about the diseases caused by such toxins were disclosed.
Immunity :
It is defined as the resistance exhibited by the host against any
foreign antigen including microorganisms.
Plays a major role in prevention of infectious diseases.
antimicrobial peptides are class of biological defense molecules which act as a part of our innate immune system.in oral cavity any microbial insult will be resisted by physical,biological and chemical barrier there by maintaining oral homeostasis.these molecules are of low molecular weight with less than 100 amino acids. main antimicrobial peptides include defensin,histatin,cathelicidin and statherin etcc.they develop resistence very slowly,prvrnt biofilm formation and in future they can be used as therapeutic agents
This presentation explains about the concept of food intoxication. The toxins produced by the microbes in food (fungal) and toxins present in the food stuff were provided. The information about the diseases caused by such toxins were disclosed.
This presentation describes the morphology and cultural characteristics of veterinary important Clostridia; their main virulence factors, pathogenesis and the common diseases in animals.
This slide covers briefly how intracellular and extracellular bacteria elicits an immune response, how bacteria evade from the immune system, what complement system is, opsonization, neutralisation, septic shock, sepsis, superantigens, phagocytosis, interleukins, Toll-like receptors, a list of diseases caused by bacterias and their names etc.
This lecture prepared and presented by Ph.D. students : Mohammed Mohsen and Aliaa Hashim
for communication :-
pilotmohammed82@gmail.com
aliaahashim1996@gmail.com
These Slides are my presentation in M.s degree in Immunology lesson for my Classmates at my university. You can found important information about Virulence factors of Listeria monocytogenes that can Scape from immune responds and defeat them.
Engineering of Phage-Derived Lytic Enzymes: Improving Their Potential as Antimicrobials
Carlos São-José
ID
Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa,
Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; csaojose@ff.ul.pt; Tel.: +351-217-946-420
The Biology of HIV-AIDS Acquired immune deficiency syndrome (AIDS) is.pdfaadyacouture
The Biology of HIV/AIDS Acquired immune deficiency syndrome (AIDS) is a disease
characterized by the progressive deterioration of an individual's immune system. The
immunological impairment allows infectious agents such as viruses, bacteria, fungi and parasites
to invade the body and propagate unchecked. In addition, the incidence of certain cancers
dramatically increases in these patients because of faulty immunosurveillance. AIDS is a serious
threat to human health and is a global problem. Intensive research is being done to advance
methods of detection, clinical treatment and prevention. The HIV Virus The AIDS etiologic
agent is the human immunodeficiency virus type 1 (HIV-1), a retrovirus. HIV-1 contains an
RNA genome and the RNA-dependent-DNA-polymerase termed reverse transcriptase. Members
of the retrovirus family are involved in the pathogenesis of certain types of leukemias and other
sarcomas in humans and animals. The structure and replication mechanism of HIV is very
similar to other retroviruses. However, HIV is unique in some of its properties - it specifically
targets the immune system, is very immunoevasive, forms significant amounts of progeny virus
in vivo during initial stages of infection and can be transmitted during sexual activity. The HIV
viral particle is surrounded by a lipid Human Immunodeficiency Virus bilayer derived from the
host cell membrane during budding. The viral proteins are identified by the prefix gp
(glycoprotein) or p (protein) followed by a number indicating the approximate molecular weight
in kilodaltons. The lipid bilayer contains gp120 and gp41. These two proteins are proteolytic
products of the precursor gp160. The gp41 anchors gp120 in the bilayer. The protein gp120 is
routinely used as a diagnostic marker for HIV in Western Blot Analysis. More recently other
viral gp proteins are also included in the test. Beneath the bilayer is a capsid consisting of p17
and p18. Within this shell is the viral core. The walls of the core consist of p 24 and p25. Within
the core are two identical RNA molecules, 9800 nucleotides in length. Hydrogen bonded to each
viral RNA is a cellular tRNA molecule. The viral RNA is coated by tightly bound molecules of p
7 and p 9 . The core also contains approximately 50 molecules of reverse transcriptase. There are
several other viral proteins whose precise functions are not fully understood. The virus can be
grown in tissue culture for diagnostic and research purposes. Several of the viral proteins have
been cloned and generated in relatively large quantities. An individual can receive an inoculum
of HIV through an abrasion in a mucosal surface (e.g., genital and rectal walls), a blood
transfusion, or by intravenous injection with a contaminated needle. Virus or virally infected
cells are found in body fluids such as semen and blood. The most important target for the virus is
hematopoietic cells such as bone marrow derived monocytes, myelocytes and lymphocytes.
Infection of im.
رواية أياً يكن للدكتور محمد القزاز, و يتحدث فيها عن قصة حياته خلال دراسته الجامعية في كلية الطب و معلناً عن لعنه لهذه الكلية شاهراً نقده للجامعة و المجتمع و عمادة الكلية.
يتعرض الكتب لعدد من المتاعب خلال رحلته لاثبات حقه في قضية القصة, و يحاول الكاتب أن يعرض الاحداث في اطار من الكوميديا الساخرة ..
قصة حقيقة للكاتب :)
to down load this presentation from this link
https://mohmmed-ink.blogspot.com/2020/11/deep-vein-thrombosis-dvt.html
deep vein thrombosis, diagnosis and managment.
prdiatrics notes, croup, upper respiratoty track infection
to download this presentation from this link
https://mohmmed-ink.blogspot.com/2020/11/pediatrics-notes-croup.html
to download this presentation from this link
https://mohmmed-ink.blogspot.com/2020/11/evaluation-of-peripheral-blood-smear.html
Evaluation of the Peripheral Blood Smear
to download this presentation form this link
https://mohmmed-ink.blogspot.com/2020/11/herbal-medicine.html
herbal medicine in Gaza .. use and side effect
this work first was done by a medic student in the islamic University .... because its a good work i shared it . and i never asked for the permission .... sorry
but this link will lead to the original one...
http://www.slideshare.net/FaToOoMaa/final-herbal-medicine
to download this presentation from this link
https://mohmmed-ink.blogspot.com/2020/11/conjunctival-diseases-overview.html
over view for the conjunctival diseases. clinical presentation treatment .
to download this presentation from this link
https://mohmmed-ink.blogspot.com/2020/11/diabetic-ketoacidosis.html
Diabetic Ketoacidosis, diabetus type 1 complection. diagnosisi and managment
to download this presentation from this link
https://mohmmed-ink.blogspot.com/2020/11/energy-drinks.html
energy drink and effect on human health , hazards
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
Instructions for Submissions thorugh G- Classroom.pptx
Antigens and toxins
1.
2. Staphylococcus aureus :
Protein A :
Protein A is a 40-60 kDa MSCRAMM surface protein originally found in the cell
wall of the bacteria Staphylococcus aureus. It is encoded by the spa gene and its
regulation is controlled by DNA topology, cellular osmolarity, and a two-
component system called ArlS-ArlR. It has found use in biochemical research
because of its ability to bind immunoglobulin. It binds proteins from many of
mammalian species, most notably IgGs. It binds with the Fc region of
immunoglobulins through interaction with the heavy chain. The result of this type
of interaction is that, in serum, the bacteria will bind IgG molecules in the wrong
orientation (in relation to normal antibody function) on their surface which
disrupts opsonization and phagocytosis.
3. Techoic acid:
skin-colonizing gram-positive bacteria produce Wall teichoic acids (WTAs) or related
glycopolymers for unclear reasons. Using a WTA-
deficient Staphylococcus aureus mutant, we demonstrated that WTA confers
resistance toantimicrobial fatty acids from human sebaceous glands by preventing
fatty acid binding. Thus, WTA is probably important for bacterial skin colonization.
Polysaccharide capsule :
It gives 11 serotype based on its antigenicity .
Enterotoxin :
which cause a form of food poisoning characterized by vomiting and diarrhea one to six
hours after ingestion of the toxin .
4. Toxic shock syndrome toxin :
This is characterized by fever, erythematous rash, hypotension, shock, multiple organ failure,
and skin desquamation .
Exfoliatin :
EF toxins are implicated in the disease staphylococcal scalded-skin syndrome (SSSS), which
occurs most commonly in infants and young children. It also may occur as epidemics in hospital
nurseries. The protease activity of the exfoliative toxins causes peeling of the skin observed with
SSSS.
P-V leukoidin :
The bicomponent toxin Panton-Valentine leukoidin (PVL) is associated with severe necrotizing
pneumonia in children. The genes encoding the components of PVL are encodedon
a bacteriophage found in community-associated methicillin-resistant S. aureus (MRSA) strains.
5. Streptococcus :
C carbohydrate :
Determine the group of β hemolytic streptococcus and its located in the cell wall
M Protein :
M protein is a virulence factor that can be produced by certain species of Streptococcus. M
protein is strongly anti-phagocytic and is a major virulence factor. It binds to serum factor H,
destroying C3 convertase and preventing opsonization by C3b. However plasma B cells can
generate antibodies against M protein which will help in opsonization and further off destruction
of the microorganism by the macrophages and neutrophilis. Cross-reactivity of anti-M protein
antibodies with heart muscle is the basis for rheumatic fever.
It was originally identified by Rebecca Lancefield, who also formulated the Lancefield
classification system for Streptococcal bacteria. Bacteria like S. pyogenes which possess M
protein are classified in group A of the Lancefield system.
6. Erythrogenic toxin :
An Erythrogenic toxin is a toxin produced by strains of Streptococcus pyogenes, the primary
cause of Scarlet fever. Past studies have shown that multiple variants of erythrogenic toxins
may be produced, depending on the strain of S. pyogenes present in the host. A small
percentage of strains may not produce a detectable toxin at all.
Streptolysin :
Streptolysin is a streptococcal hemolytic exotoxin.
Types include Streptolysin O (SLO), which is oxygen-labile, and Streptolysin S (SLS), which is
oxygen-stable.
An antibody, anti-Streptolysin O, can be detected in an antistreptolysin O titer.
Streptolysin O is hemolytically active only in a reversibly reduced state unlike Streptolysin S
which is stable in the presence of oxygen. Another difference is that that SLO is antigenic while
SLS is non-antigenic due to its small size.
7. Neisseria meningitides :
Lipopolysaccharides (LPS),
also known as lipoglycans, are large molecules consisting of a lipid and
a polysaccharide joined by a covalent bond; they are found in the outer membrane of Gram-
negative bacteria, act as endotoxins and elicit strong immune responses in animals. LPS is
the major component of the outer membrane of Gram-negative bacteria, contributing greatly
to the structural integrity of the bacteria, and protecting the membrane from certain kinds of
chemical attack. LPS also increases the negative charge of the cell membrane and helps
stabilize the overall membrane structure. It is of crucial importance to gram-negative
bacteria, whose death results if it is mutated or removed. LPS is an endotoxin, and induces
a strong response from normal animal immune systems. It has also been implicated in non-
pathogenic aspects of bacterial ecology, including surface
adhesion, bacteriophage sensitivity, and interactions with predators such as amoebae.
8. Lipooligosaccharides
are naturally occurring variants of the more common glycolipid, lipopolysaccharide.
While lipopolysaccharides are common in the enteric bacteria, LOS is present in
bacteria that colonize those mucosal surfaces that are not bathed in bile. LOS is a
highly phase variable molecule.
LOS is clinically relevant in Neisseria meningitidis infections, where it has been
shown to correlate with the severity of disease, as well as cause the complications
listed above which are hallmarks of meningococcal meningitis.
IgA protease :
Many bacteria which colonize the mucous membranes produce an IgA protease
which degrades secretory IgA.
9. Neisseria gonorrhoeae :
IgA protease .
Lipooligosaccharides.
Pili .
Bacillus anthracis :
D-glutamate capsule:
It is the only bacterium known to synthesize a protein capsule (D-glutamate) capsular
polypeptide of Bacillus anthracis is composed of a unique polyglutamic acid polymer in which D-
glutamate monomers are joined by gamma-peptidyl bonds. The capsule is poorly immunogenic, and
efforts at exploiting the polymer for vaccine development have focused on increasing its inherent
immunogenicity through chemical coupling to immune-stimulating protein carriers .
10. Anthrax toxin :
each individual anthrax toxin protein is, in fact, nontoxic. Toxic symptoms are
not observed when these proteins are injected individually into laboratory
animals. However, the co-injection of PA and EF causes edema, and the co-
injection of PA and LF is lethal. The former combination is called edema
toxin, and the latter combination is called lethal toxin. Thus the manifestation
of physiological symptoms requires, in either case, the presence of the PA
component.
11. The PA requirement observed in animal-model experiments demonstrates a
common paradigm for bacterial toxins, called the A / B paradigm.
The A component(s) are enzymatically active, and the B component is the cell
binding component. Anthrax toxin, in fact, is of the form A2B, where the
two enzymes, EF and LF, are the A components and PA is the B component. Thus
PA acts as a Trojan Horse, which carries EF and LF through the plasma
membrane into the cytosol, where they may then catalyze reactions that disrupt
normal cellular physiology.
12. Clostridium tetani :
Tetanus toxin :
Tetanus toxin is an extremely potent neurotoxin , causing tetanus. It has no
known function for clostridia in the soil environment where they are normally
encountered. It is also called spasmogenic toxin, tetanospasmin or
abbreviated to TeTx or TeNT. C. tetani also produces
the exotoxin tetanolysin, the effects of which are as yet unclear.
13. Clostridium botulinum :
Botulinum toxin :
Botulinum toxin is extremely neurotoxic. When introduced intravenously in
monkeys, type A (Botox Cosmetic) of the toxin exhibits an LD50 of 40-56 ng, type
C1 around 32 ng, type D 3200 ng, and type E 88 ng, rendering the above types
some of the most powerful neurotoxins known. Popularly known by one of its
trade names, Botox or Dysport, it is used for various cosmetic and medical
procedures.
14. Clostridium Perfringns :
Alpha toxin lecithinase :
Lecithinase is a type of phospholipase that acts upon lecithin. C. perfringens
alpha toxin (lecithinase) causes my necrosis and hemolysis.
Enterotoxin .
Clostridium Difficile :
Exotoxin A & B .
15. Cyanobacteria diphtheria :
Diphtheria toxin :
causes diphtheria. Unusually, the toxin gene is encoded by
bacteriophage (a virus that infects bacteria). The toxin causes the disease
diphtheria in humans by gaining entry into the cell cytoplasm and inhibiting protein
synthesis. Diphtheria toxin is a single polypeptide chain of 535 amino acids
consisting of two subunits linked by disulfide bridges. Binding to the cell surface of
the less stable of these two subunits allows the more stable part of the protein to
penetrate the host cell.
16. Listeria monocytogenes :
internalin :
Listeria monocytogenes can use two different surface proteins, internalin (InlA) and
InlB, to invade mammalian cells. The exact role of these invasiveness factors in vivo
remains to be determined. In cultured cells, InlA is necessary to promote Listeria
entry into human epithelial cells, such as Caco-2 cells, whereas InlB is necessary to
promote Listeria internalization in several other cell types, including
hepatocytes, fibroblasts, and epithelioid cells, such as Vero, HeLa, CHO, or Hep-
2 cells. We have recently reported that the InlA receptor on Caco-2 cells is the cell
adhesion molecule E-cadherin and demonstrated that nonpermissive fibroblasts
become permissive for internalin-mediated entry when transfected with the gene
coding for LCAM, the chicken homolog of the human E-cadherin gene. In this study,
we demonstrate for the first time that the internalin protein alone is sufficient to
promote internalization into cells expressing its receptor
17. . Indeed, internalin confers invasiveness toboth Enterococcus faecalis and
internalin-coated latex beads. As shown bytransmission electron
microscopy, these beads were phagocytosed via a"zipper" mechanism similar to
that observed during the internalin-E-cadherin- mediated entry of Listeria.
Moreover, a functional analysis of internalin demonstrates that its amino-terminal
region, encompassing the leucine-rich repeat (LRR) region and the inter-repeat
(IR) region, is necessary and sufficient to promote bacterial entry into
cells expressing its receptor. Several lines of evidence suggest that the
LRR region would interact directly with E-cadherin, whereas the IR region
would be required for a proper folding of the LRR region.
18. Listeriolysin :
Seeligeriolysin O (LSO), one of the cholesterol-dependent
cytolysins produced by Listeria seeligeri, shows 80% homology to
listeriolysin O (LLO) produced byListeria monocytogenes at the
amino acid sequence level. In addition to cytolytic activity, LLO has
been shown to exhibit cytokine-inducing activity. In order to
determine whether LSO is also capable of exhibiting these two
different activities, we constructed a recombinant full-length LSO
(rLSO530)and a noncytolytic truncated derivative with a C-terminal
deletion (rLSO483) and compared these molecules with
recombinant LLO. The cytolytic rLSO530 molecule could induce
gamma interferon (IFN- ) production in spleen cells when the
19. cytolytic activity was blocked by treatment with cholesterol.
The noncytolytic truncated rLSO483 molecule also induced
IFN- production. Anti-LLO polyclonal antibody inhibited not
only LLO-induced IFN- production but also LSO-induced IFN-
production. Both NK cells and CD11b+ cells were required for
LSO-induced IFN- production. Among the various cytokines
expressed in CD11b+ cells, interleukin-12 (IL-12) and IL-18
appeared to be essential. We concluded that LSO exhibits the
same biological activity as LLO.
20. Gram negative rods :
Cell wall antigen O
Flagellar protein H
Capsular K
E coli :
Shiga toxin and LT toxin which is adeylate cyclase and heat labile and the other
toxin is ST which is the heat staple low molecular weight toxin and its guanylate
cyclase .
21. Salmonella :
It has the O and H and Vi antigens and the type of typhoid salmonella has a
typhoid toxin .
Shegilla :
Shiga toxin and O antigen give 4 types of shegilla A B C D .
Proteus :
It has an O antigen and some of them are famous because they cross react
with the rickettsia antigen and they are OX-1 OX-2 OX-K
22. Pseudomonas aeruginosa :
Pyocyanin :
is an antibiotic pigment produced by the Gram negative
bacterium Pseudomonas aeruginosa. It is a redox-active virulence factor which
allows P. aeruginosa to kill cells, disrupts cilia actions,
inhibit lymphocyte proliferation, and alter phagocytic function. Due to its redox-
active properties, pyocyanin generates reactive oxygen species that
induce oxidative stress in bacterial and mammalian cells.
23. Pyoverdin :
is a fluorescent siderophore secreted by e.g. Pseudomonas aeruginosa. It's used
to help the microbe leech iron out of its surroundings and is produced mostly in iron
deficient environments.
Bortetella :
Pertussis toxin :
is a protein-based AB5-type exotoxin which causes whooping cough. PT is involved
in the colonization of the respiratory tract and the establishment of
infection. Research suggests PT may have a therapeutic role in treating a number
of common human ailments including hypertension, viral inhibition, and
autoimmune inhibition.
24. Filamentous haemagglutinin :
is a large, filamentous protein that serves as a dominant attachment factor for
adherence to host colliery epithelia cells of the respiratory tract. It is associated
with biofilm formation and possesses at least four binding domains which can
bind to different cell receptors on the epithelial cell surface.
25. Yersinia :
Polysaccharide protein complex
capsule
Envelope capsular antigen F1
Y. pestis has typical cell wall and whole-cell lipid compositions and an enterobacterial
antigen. Its lipopolysaccharide is characterized as rough, possessing core
components but lacking extended O-group side chains; while there is no true
capsule, a carbohydrate-protein envelope, termed capsular antigen or fraction 1
(F1), forms during growth above 33 C (14, 32, 215). This facultative anaerobe
possesses a constitutive glyoxylate bypass and unregulated L-serine deaminase
expression but lacks detectable adenine deaminase, aspartase, glucose 6-
phosphate dehydrogenase, ornithine decarboxylase, and urease activities, as well as
a possible lesion in -ketoglutarate dehydrogenase
26. Exotoxin W and V antigens .
Yop " Yersinia outer protein " :
Yersinia outer protein E (YopE) are delivered directly into the cytosol of target cells
in a TTSS-dependent fashion. This unique translocation mechanism can be used
by attenuated Salmonella carrier vaccines for the delivery of heterologous antigens
fused to YopE into the MHC class I-restricted antigen processing pathway. In orally
immunized mice, this novel vaccination strategy results in the induction of
pronounced peptide-specific cytotoxic CD8 T cell responses.
28. Papilloma virus :
Genes E6 and E7:
Cervical cancer is the second most common cancer in women worldwide and is
caused by human papillomavirus (HPV). Silencing of HPV E6 and E7 gene
expression was achieved using siRNAs to target the respective viral mRNAs. E6
silencing induced accumulation of cellular p53 protein, trans activation of the cell
cycle control p21gene, and reduced cell growth. By contrast, E7 silencing induced
apoptotic cell death. HPV-negative cells appeared to be unaffected by the antiviral
siRNAs. Thus siRNA can induce selective silencing of exogenous viral genes in
mammalian cells, and the process does not interfere with the recovery of cellular
regulatory systems previously inhibited by viral gene expression.
29. Influenza virus :
Hemoglutinin :
Influenza hemagglutinin (HA) or haemagglutinin (British English) is a type
of hemoglutinin found on the surface of the influenza viruses. It is
an antigenic glycoprotein. It is responsible for binding the virus to
the cell that is being infected.
The name "hemoglutinin" comes from the protein's ability to cause red
blood cells (erythrocytes) to clump together ("agglutinate") in vitro
30. Neuraminidase :
viral neuraminidase is a type of neuraminidase found on the surface of influenza viruses that
enables the virus to be released from the host cell. Neuraminidases are enzymes that
cleave sialic acid groups from glycoproteins and are required for influenza virus replication.
When influenza virus replicates, it attaches to the cell surface using hemoglutinin, a molecule
found on the surface of the virus that binds to sialic acid groups. Sialic acids are found on
various glycoproteins at the host cell surface, and the virus exploits these groups to bind the
host cell. In order for the virus to be released from the cell, neuraminidase must enzymatically
cleave the sialic acid groups from host glycoproteins. As an integral part of influenza replication,
blocking the function of neuraminidase with neuraminidase inhibitors is an effective way to treat
influenza.
In some viruses including Mumps virus and Human Para influenza virus, a hemagglutinin-
neuraminidase protein combines the neuraminidase and hemoglutinin functions in a single
protein.
NS1 Protein :
Inhibit the interferon
32. Human t cell lymphotropic :
Tax protein:
The viral Tax protein is considered to play a central role in the process leading to ATL.
Tax modulates the expression of many viral and cellular genes through the
CREB/ATF-, SRF- and NF-κB-associated pathways. In addition, Tax employs the
CBP/p300 and p/CAF co-activators for implementing the full transcriptional activation
competence of each of these pathways. Tax also affects the function of various other
regulatory proteins by direct protein-protein interaction. Through these activities Tax
sets the infected T-cells into continuous uncontrolled replication and destabilizes their
genome by interfering with the function of telomerase and topoisomerase-I and by
inhibiting DNA repair. Furthermore, Tax prevents cell cycle arrest and apoptosis that
would otherwise be induced by the unrepaired DNA damage and
enables, thereby, accumulation of mutations that can contribute to the leukemogenic
process
33. Hepatitis B:
Surface antigen HBsAg:
Surface antigen HBsAg The first marker to appear after HBV infection, preceding
clinical disease by weeks, peaking with the onset of symptoms and disappearing six
months post-infection; as long as HBsAg is positive, the Pt is considered infectious
and must follow prescribed sanitary procedures to avoid infecting others; if the
hepatitis does not resolve, HBsAg persists and can be detected for many years or
life.
Antibody to surface antigen HBsAb, anti-HBs, antibody to surface antigen HBsAb
begins to rise as the HBsAg falls; it is detectable 8-10 weeks post infection, is
regarded as being protective against re-infection, and persists for life; HBsAb is
formed after using the HBV vaccine, and is not present in the chronic phase of the
disease.
34. Core antigen HBcAg:
Core antigen The HBc particle that contains double-stranded DNA and DNA
polymerase, and is associated with the HBe antigen; HBc is not directly detected by
currently-used assays; its presence indicates persistently replicating hepatitis B
virus
Core antibody A long-term serologic marker for HBV, with 2 antibodies
• IgM HBcAb A marker of acute infection, which rises early–within 2-4 weeks of
HBV infection and slowly disappears; ↓ levels of IgM HBcAb indicate resolving
infection; IgM HBcAb is the best serologic marker for acute HBV infection
• IgG HBcAb A 'convalescent' antibody that indicates prior HBV infection; it rises 4-
6 months after infection and persists for life, especially in those with active liver
disease; partially protective anti-HBc antibody levels can be induced by
recombinant vaccination, but are short-lived
35. e antigen HBeAG
e antigen An antigen that rises and falls parallel to HBsAg, and derives from the
proteolytic cleavage of the nucleocapsid; its presence implies a carrier state
e antibody Anti-HBe An antibody that rises as HBe falls, appearing in convalescent
Pts, persisting for up to several years after resolution of hepatitis