Antimicrobial peptides in periodontics

DEPARTMENT OF PERIODONTOLOGY
ANTIMICROBIAL PEPTIDES IN PERIODONTICS
DR.ANN THERESA TOMY
2nd YEAR P.G
SEMINAR-6

 AMP’S OF PERIODONTAL SIGNIFICANCE
 DEFENSINS
 HISTATINS
 STATHERIN
 ADRENOMEDULLIN
 CATHELICIDIN
 C-C MOTIF CHEMOKINES
 NEUROPEPTIDES
 DISORDERS ASSOCIATED WITH AMPS
 MORBUS KOSTMAN SYNDROME
 PAPILLON LEVFRON SYNDROME
 HAIN MUNK SYNDROME
CONTENTS
 INTRODUCTION
 ORAL HOMEOSTASIS
 HISTORICAL TRACK ON ANTIMICROBIAL PEPTIDES
 DEFENITION
 IMMUNITY AND ANTIMICROBIAL PEPTIDES
 GENERAL STRUCTURE
 BIOLOGICAL ROLE
 GENERAL CLASSIFICATION
 MECHANISM OF ACTION
 AMP’S OF ORAL CAVITY

 AMPS AS THERAPEUTIC AGENTS
 ACHIEVEMENTS IN THE TOPOGRAPHIC DESIGN OF COMMERCIAL TITANIUM DENTAL
IMPLANTS: TOWARDS ANTI-PERI-IMPLANTITIS SURFACES
 AN ANTIMICROBIAL DENTAL LIGHT CURABLE BIOADHESIVE HYDROGEL FOR TREATMENT
OF PERI-IMPLANT DISEASES
 CLINICAL STUDY -THE EFFECTS OF ANTIMICROBIAL PEPTIDE NAL-P-113 ON INHIBITING
PERIODONTAL PATHOGENS AND IMPROVING PERIODONTAL STATUS-BY WANG
 ANTIMICROBIAL PEPTIDES AND PROTEINS AS BIOMARKERS FOR PERIODONTAL DISEASE
 CONCLUSION

INTRODUCTION
 Periodontal disease is an inflammatory disease initiated by the formation of mixed biofilms on the teeth .
 Biofilm bacteria and their toxins perturb gingival epithelial cells leading to a sequence of inflammatory and
immune processes that may result in the destruction of gingival tissues, attachment loss and periodontal pockets
 The host-response consists of a cascade of events by the innate and acquired immune systems
 These antimicrobial peptides are part of the innate immune system, a complex set of responses that keeps
microbial invaders in check and maintains the microbial ecology of the healthy periodontium(Weinberg A,
Krisanaprakornkit S, Dale BA. Epithelial antimicrobial peptides: review and signiﬁcance for oral applications. Crit Rev Oral Biol Medical 1998: 9: 399–414)

ORAL HOMEOSTASIS
MECHANICAL BARRIERPHYSICAL BARRIER
CHEMICAL BARRIER
“Hancock, and Sahl, 2006”

HISTORICAL TRACK ON ANTIMICROBIAL PEPTIDES
 1922-ALEXANDER FLEMMING -isolated first human antimicrobial peptide from nasal mucous
 1939- Dubos extracted an antimicrobial agent from a soil Bacillus strain.
 HOTCHKISS AND DUBOS fractionated this extract and identified an AMP which was named gramicidin.
 The first reported animal-originated AMP is defensin, which was isolated from rabbit leukocytes in 1956.
 1966 ZEYAAND SPITZNAGEL first decribed Peptides with anti microbial activity
 SCHONWETTER- mammalian AMP’S participate in oral host defense mechanism
 To date around 106 Human host defense peptides have been identified (Wang, 2014).

 THE AMPS ARE BIOLOGICAL DEFENSE MOLECULES ENCODED BY SPECIFIC GENES EXRESSED BY
THE HOST CELLS AS AN ACTIVE PARTICIPANT IN THE INNATE IMMUNE SYSTEM ( Antimicrobial
peptides: The miraculous biological molecules, J Indian Soc Periodontol. 2017 Nov-Dec; 21(6): 434–438.)
 KEEPS NATURAL MICROFLORA IN A STEADY STATE.
GENERAL FEATURES OF AMP’S:
 POSITIVE CHARGE
 PEPTIDE CHAIN OF LESS THAN 60-100 AMINO ACID UNITS
 BROAD SPECTRUM OF ANTIMICROBIAL ACTION
 ABILITY TO ADOPT AN AMPHIPATHIC SHAPE

 AMPs are miraculous in that they:-
- do not or develop resistance very slowly
- control the development and progression of biofilm formation and
- might potentially contribute toward the development of therapeutic mimetics, probiotics, and antibiotics in
the near future.
- Antimicrobial peptide = “ Natural antibiotics”
AMPs have also been referred to as :
cationic host defense peptides ,
anionic antimicrobial peptides/proteins ,
cationic amphipathic peptides ,

IMMUNITY AND ANTIMICROBIAL PEPTIDES
 The fundamental guarding complex for almost all human organisms comprises of innate immunity
 AMPs are components of innate immunity, forming the first-line of defense used by many organisms against the
invading pathogens (Jenssen et al., 2006).
 AMPs interact with immunereceptors,such as pattern recognition (PRRs) or chemokine receptors (CCRs), as
well as inflammasomes and their complement systems creating a link between innate and adaptive immunity.

GENERAL STRUCTURE OF ANTIMICROBIAL PEPTIDES
• Antimicrobial peptides and proteins contain a short chain of about 12–
100 amino acids ,
• Molecular mass between 3.5 to 6.5 kDa
• And are classified according to their conformational structure (α, β, αβ,
and non-αβ), amino acid motifs, and expression patten.
• Among these structural groups, α-helix and β-sheet structures are more
common ;
α-helical peptides are the most studied AMPs to date.

ANTIMICROBIAL PEPTIDES – GENERAL CLASSIFICATION ON DIFFERENT BASIS.
CLASSES
Anionic peptides They are small, rich in glutamic acids and
aspartic acids, present in human sheep ,
cattle
Linear cationic a-helical peptide They are short of cysteine and short peptides.
e.g. LL37 from human
Cationic peptides enriched for specific amino acids They are proline rich peptides e.g. abaecin
from honeybees
Anionic and cationic peptides (contain cysteine
and disulfide bonds
They contain cysteines with one or more
disulfide bonds e.g. protegrin from pigs,
tachyplesins from horse crabs and a–
bdefensins from humans, cattle, mice and
pigs
Anionic and cationic peptides fragments of larger
protein
They are similar to other AMPs but their role in
innate immunity is not yet clear. e.g.
lactoferricin from Lactoferrin and casocidin-I
from human casein

BIOLOGICAL ROLES OF ANTIBACTERIAL
PEPTIDES AND PROTEINS

MECHANISMS OF ACTION
 Interactions of AMPs with microbial cell membranes have led to dynamic interchange in
their structure and topologies
 primary mechanism for antimicrobial activity of AMPs is the electrostatic interaction of
peptides with negatively charged molecules on the membrane

1.Extracellular targets of AMPs: membrane damage by pore
formation, inhibition of peptidoglycan cell wall synthesis,
disruption of membrane integrity, and neutralization of
extracellular virulence factors.
2. Intracellular targets of AMPs: disruption of protein synthesis
and its function, inhibition of DNA function [Shah et al., 2016].

The mechanism of action of the AMPs involves a series of steps described as follows
1. Attraction – the electrostatic interaction between the cationic peptides and the anionic moieties on bacterial
membrane (Gram-negative bacteria: lipopolysaccharide [LPS] phosphate group and anionic lipids; Gram-positive bacteria:
teichoic acids) is presumed to cause attraction

 2. Attachment – after getting bound to the bacterial membrane surface the AMPs get transformed into a secondary
structure which causes them to orient either parallel or perpendicular to the membrane. The initial low and later high
peptide/lipid ratios allow the bacterial membrane to stretch causing it to thin down. This is followed by subsequent pore
formation with the peptides getting oriented in a perpendicular fashion to insert into the bilayer
 3. Models of insertion – the penetration of the AMPs across the bacterial membrane takes place by either the
carpet model, the barrel-stave model, or the toroidal pore model causing the ultimate bacterial cell death

 BARREL-STAVE MODEL:
 peptides position themselves for binding on the cell membranes,
this leads to peptide aggregation and conversion to a bilayer
membrane.
 So in this way the hydrophobic peptides align with the lipid core
and hydrophilic peptides form an access pore in the interior part of
membrane
 Leading to Leakage of cytoplasmic content ↓ Cell lysis

 THE CARPET MODEL :
 is described as a disruption of the
membrane by the binding of
peptides to the outer surface
(phospholipids) of cell membrane
and forming a prolonged layer or
carpet .
 When these peptides reach a
threshold concentration ↓
Membrane disintegration ↓ Cell
lysis

Energy dependent uptake mechanism- MACROPINOCYTOSIS

ANTIMICROBIAL PEPTIDES OF ORAL
CAVITY
 antimicrobial proteins and peptides (AMPs) are expressed by salivary glands, oral epithelial cells and neutrophils.
 A complex mixture of over 45 antimicrobial proteins and peptides are found in oral fluids (Denny et al., 2008);
13 are upregulated in periodontal disease, while 11 are down-regulated.
 Defensins, cathelicidin and ADM are important contributors for maintaining the balance between the healthy and diseased
conditions of the oral cavity

 The known AMPs belong to six functional families:
 CATIONIC PEPTIDES,
 BACTERIAL AGGLUTINATION AND ADHESION,
 METAL ION CHELATORS,
 PEROXIDASES,
 PROTEASE INHIBITORS, AND
 AMPS WITH ACTIVITY AGAINST BACTERIAL CELL WALLS
It is thought that this functional and structural diversity is necessary to protect the
oral epithelia from the large number of possible invading microbes and maintain the
oral homeostasis of commensal and pathogenic bacteria.

LIST OF HUMAN ORAL ANTIMICROBIAL PEPTIDES FROM ANTIMICROBIAL PEPTIDE DATABASE
(APD)
Antimicrobial peptides Year Site of expression
a-Defensins (HNP-1) 1985 Neutrophils (azurophilic granules), gingival crevicular fluid and bone
marrow
marrow
marrow
a-Defensins (HNP-4) 1989 Neutrophils /
b-Defensins (hBD-1) 1995 Suprabasal layer of stratified epithelium and saliva
b-Defensins (hBD-2) 1997 Gingival epithelium and saliva
b-Defensins (hBD-3) 2001 Skin and salivary gland
Histatin-1 1988 Saliva (parotid and submandibular)
Adrenomedullin 1993 Epithelium
Cathelicidins (LL-37) 1995 Neutrophils, inflamed epithelia, submandibular glands and saliva

AMP’S OF PERIODONTAL SIGNIFICANCE
• Periodontal infection and inﬂammation is thought to aﬀect the expression of each antimicrobial peptide (Gursoy and
Könönen, 2012
• The AMPs react to the periodontopathogen bacteria in a synergistic manner, and secrete chemical innate immunity signal
molecules like interleukin, chemokines and cytokines attracting neutrophils at the site and caution the host response .

TYPES OF ANTIMICROBIAL PEPTIDES
 DEFENSINS-(Ganz et al., 1985)
 low molecular weight 4-5kDa peptides
 beta-sheet fold structure containing three disulfide bonds among six cysteines.
 expressed in different forms in healthy and inﬂamed tissues.
 oral epithelial cells and neutrophils .
 Human defensins are two types-
alpha defensin and beta-defensins (hBD)

Role of defensins in innate and adaptive immune response
 pattern-recognition receptors (PRRs)
 pathogen-associated molecular patterns such as lipopolysaccharide (LPS),
peptidoglycan, zymosan and possibly isoleucine
 triggers rapid effector responses including complement activation, phagocytosis and
expression of proinflammatory mediators
 antimicrobial response and try to contain the infection, which involves the
up-regulation of specific antimicrobial peptides
 defensins

Alpha-defensins/human neutrophil
peptide
 synthesized by neutrophils migrating into the
gingival sulcus as primary host response, or
by Paneth cells as preprodefensins
 They are further secreted into the lumen of
the small intestine ,are proteolytically
cleaved into active antimicrobial peptides.
 They are stored in secretory granules

 antibacterial effect of defensin is by permeabilization
of target organism and inhibiting DNA and RNA
synthesis
 Inhibit LPS-stimulated inflammatory responses in host
cells,
 hNP-1, hNP-2, hNP-3, hNP-4 ,hNP-5 and hNP-6 .
 hNP-1 or hNP-2 - Staphylococcus aureus, Pseudomonas
aeruginosa and Escherichia coli
 hNP-3 and hNP-4 -Candida albicans, E. coli and
Streptococcus faecalis.
 hNP-5 and hNP-6 -present in the enteric system

 Antiviral activity of human neutrophil peptide-1 has been shown toward HIV-1, serotype 5
 It diminishes HIV replication by blocking steps subsequent to
 reverse transcription and integration
 by hindering a cellular protein kinase C-dependent mechanism that participates in viral infection

• The most abundant peptide present in saliva is hNP-1-3 (99%)
• Levels of HNP1-3 in gingival crevicular fluid are up-regulated 60-fold in chronic periodontitis and 15-fold in aggressive
periodontitis .
• Also other oral diseases such as Bechet's syndrome, oral leucoplakia ,recurrent aphthous stomatitis –increased HNP
• Human neutrophil peptides chemotactic activity to T-cells, dendritic cells, inhibition of glucocorticoid synthesis, mast cell
degranulation and complement activation
• enhance the production of interleukin-8 and leukotriene B4 in macrophages and epithelial cells

Beta-defensins
 Small, cationic peptides expressed in epithelial cells of various tissues and organs such as gingiva, skin,
gastrointestinal tract, respiratory tract and kidney
 four hBDs -- hBD 1-3 are expressed and secreted in the human oral cavity
 The number of hBDs has been suggested to be over 28 based on genomic targeting (Lehrer, 2011).
 Out of 28 hBD genes, only 4 (hBD 1-4) have been detected in the gingival epithelium.
 human beta-defensins are expressed in the upper spinous, granular and corniﬁed layers, whereas no
expression was detected in the junctional epithelium.

• broad spectrum of antimicrobial activity - depolarizing and permeabilizing microbial cell membranes
• Pore formation on the membrane stimulates the leakage of small molecules
• human beta-defensin-1 is weakly active against gram-negative bacteria, human beta-defensin-2 is highly effective
against gram-negative bacteria
• human beta-defensin-3 is an effective antimicrobial agent against both gram-positive and gram-negative bacterial
species, as well as Candida albicans

Bacterial resistance against β-defensins:
β-defensins, bacteria exert resistance:
 Porphyromonas gingivalis, degrades hBD-3 with its gingipains that leads to the inactivation of the peptide.
 other periodontal bacteria -by inhibiting the defensin expression pathways.
 Treponema denticola inhibits the secretion of hBD2 and hBD- 3 by suppressing- the expression of tumour necrosis factor
(TNF)-α and toll-like receptor 2 (TLR 2).
 by forming a capsule,
 modifying their cell
envelope molecules,
 forming biofilms or
cleaving defensins

Histatins
 salivary proteins with low molecular weight cationic peptides synthesized by parotid and submandibular salivary
duct cells
 Around 50-425 micrograms/mi produced in healthy adults
 They are 7-38 amino acid residue in length with at least 12 histidine residue
 Hence called histidine rich protein
The first ever histatin was isolated from human parotid salivary gland secretions in 1988

• These are predominantly antifungal and the three main members are His-1, His-3 and His-5.
• by means of proteolytic cleavage of these members, the other members are generated.
Functions of histatins
I. Anti-fungal, inhibition of growth of Candida species, also antibacterial and viral
II. bonding of metal ions in saliva,
III. regulation of oral hemostasis,wound healing
IV. and formation of acquired enamel pellicle due to high affinity for enamel surfaces
 Histatin-5 inhibited the activity of proteases and clostripain (clostridiopeptidase B,
Clostridium histolytium proteinase B)
 It binds to the protease active sites making non-covalent complexes,
therefore playing a key role in preventing the periodontitis

ANTIFUNGALACTIONOF
HISTATIN(Pollocketal
• Histatins at physiological concentration (15–30 lM), especially Hst-5,
inhibit Candida species.
• In patients with human immunodeficiency virus (HIV), histatin 5 12-mer
P113 (Demegen) appears to be a promising AMP and works as a mouth
rinse for oral candidiasis

Statherin
 It is a 5.4 kDa basic histadine-rich peptide present in saliva and GCF with antimicrobial properties
 Secreted by submandibular and parotid glands
 In C-terminal peptide, growth of statherin inhibits anaerobic bacteria
 prevents plaque formation as crystallization of calcium phosphate is restrained by them
 It is used as a biomarker in the proteomic analysis of saliva

 Statherin is an enamel pellicle protein
 high affinity for calcium phosphate minerals, maintains the appropriate mineral solution dynamics of enamel,
promotes selective initial bacterial colonization of enamel, and functions as a boundary lubricant on the enamel
surface.
 Statherin inhibits both nucleation and growth of hydroxyapatite crystal
 It is the only salivary protein that inhibits spontaneous precipitation of calcium phosphate salts from the
supersaturated saliva.
 statherin promotes bacterial adhesion to enamel surfaces, although weakly compared with other salivary
macromolecule

ADRENOMEDULLIN
 Adrenomedullin is produced from cells of adrenal medulla, kidney, lung as well as epithelial lining of
skin, gut and oral cavity when microbes come in contact with epithelial cells .
 Cationic amphipathic peptide with one disulfide bond
 Present in GCFand Saliva and largely present in whole saliva
 concentration in whole saliva is around 55 to 65µg/µL.
 Whole saliva contains higher concentrations of adrenomedullin than glandular saliva, suggesting that oral
epithelial cells contribute to the salivary expression.

 Fibroblasts actively synthesise and secrete ADM-And displays autocrine or paracrine anti-
inflammatory activity in mesenchymal tissue.
 Potential importance in periodontitis is the fact that ADM suppresses the propagation of
inflammation through the inhibition of tumour necrosis factor-a production in fibroblasts.
 Influence the function of inflammatory cells such as mast cells by inducing histamine release in
a dose-dependent manner

 It creates a feedback mechanism to activate the inflammatory response to pathogens.
 Adrenomedullin has vasodilator effects and might increase the numbers of inflammatory cells and mediators in inflamed
gingival tissue
 ADM is also mitogenic to osteoblastic cells in vitro and has been shown to promote bone growth in vivo.
 osteoblasts co-express both ADM and its receptors suggests that ADM may be an important paracrine/autocrine regulator of
bone metabolism

• In gingival crevicular ﬂuid, the amount of ADM is about twice as high in periodontal disease sites than in healthy sites.
• Levels of adrenomedullin in GCF has been described to be higher in periodontitis than in healthy patients and positively
correlated with the severity of periodontal destruction.
• This increase in GCF ADM level in patients with periodontitis could be because
 the presence of more severe inﬂammation and periodontal destruction
 an increase of bacteria-stimulated ADM production by epithelial cells to protect the host from bacterial
invasion, all of which exhibit increased LPS-induced ADM production
• The rise in ADM GCF levels in type 2 diabetic patients can be due to hyperglycemia induced increase expression of ADM.

Cathelicidin (LL-37)
 Cathelicidin is a family of AMPs that comprise a cathelin domain at their N-terminus and a mature peptide at
their C-terminus.
 Is a multifunctional 37 amino acid peptide derived from human cathelicidin by proteolytic processing of a
precursor peptide, human cationic antimicrobial protein-18 (hCAP-18),
 Cathelicidins are small(18kDA), cationic amphipathic peptides, expressed in epithelial cells, and defense cells
such as neutrophils, lymphocytes, natural killer cells monocytes, and macrophages.
 secondary granules (peroxidase-negative) of neutrophils and macrophages and are concerned with non-oxidative
killing of pathogens

• In healthy subjects, LL-37 is found at a salivary concentration of 0.5 μg/ml and GCF concentration of 10 μg/ml in periodontitis
patients

1) AMPs have broad antimicrobial activity;
2) their action is synergistic with other antimicrobials in saliva; co-expression of
cathelicidins and defensins with peptides, such as histatins, and proline-rich
proteins may enhance antimicrobial function;
3) they stimulate the acquired immune system and could function to enhance IgA
production as well as IgG production;
4) these AMPs may function to keep overall bacteria in check and to help prevent
biofilm formation.

CATHELICIDIN AND PERIODONTAL DISEASE
 It has been shown that LL-37 expression increases with increase in severity of periodontal disease.
 a positive correlation has been established between the LL-37 levels and gingival sulcus depth.
 when inflammation sets in the periodontium, the oxygen content is significantly reduced rendering the oxygen
mediated killing of PMNs ineffective.
 Such a situation calls for nonoxidative killing facilitated by AMPs such as LL-37.
 LL-37 is present at sites of inflammation at a concentration(inflamed epithelium) as high as 30 μg/ml.
 is active against Gram negative and Gram positive bacteria, including A. actinomycetemcomitans and P.
gingivalis and capnocytophages

 LL-37 can be looked upon as an anti-endotoxin and LPS neutralizing factor
 The LL-37 peptides possess a direct bactericidal action against LPS of Gram-negative and teichoic acid of
Gram-positive bacteria.
 Using either the barrel stave, tripodal or the carpet model the LL-37 cathelicidin is inserted into the bacterial
cell membrane causing cell rupture and leakage of cytoplasm causing bacterial cell death.
 the erythrocyte membrane contains sialic acid making them vulnerable to an unwanted attack by the LL-37.
 The only nonhemolytic variety of cathelicidin derived from LL7 is L-27
LL-37 and Bacterial LPS

ANTIBIOFILM PROPERTIES
 LL-37 has also emerged as having novel antibiofilm properties at low concentration
 Also fight the biofilm bacteria such as Pseudomonas aeruginosa, Burkholderia pseudomallei, Streptococcus mutans, and
Staphylococcus epidermidis.
 It prevents the adherence of bacteria to the tooth surface by controlling the genes responsible for quorum sensing, which
are necessary for the formation of biofilm.
 It also increases the surface motility of bacteria (twitching) on top the biofilm thus interfering with its thickness
 By preventing the bioﬁlm formation, the bacteria are exposed to and rendered susceptible to the body’s immune responses.

VITAMIN D AND CATHELICIDIN
 Vitamin D results in up regulation of cathelicidin, since the cathelicidin gene contains vitamin D response element
sequence in its promoter region.
 But, during the periods of inﬂammation, vitamin D acts to down regulate the expression of cathelicidin.
 Furthermore, a c-AMP signaling pathway is concerned with the constitutive expression of LL-37 in epithelial
cells

C–C motif chemokine 28
 It is present mostly in saliva and exhibits both broad-spectral antimicrobial activity and
chemotactic activity.
 This is a 128-amino acid peptide secreted by epithelial cells and salivary glands.
 C–C motif chemokine 28 is a salt-sensitive peptide and causes an increase in permeability of cell
membrane.
 Two cysteine residues in position 52 and 68 are essential for antimicrobial activity

Neuropeptides
 The neuropeptides, calcitonin gene-related peptide and substance P are expressed in GCF, salivary fluids contains-
-neuropeptide Y and vasoactive intestinal peptide.
 Since the minimum inhibitory concentrations (MIC) required to be effective against C. Albicans and bacteria are
higher than their concentrations which varies from 2 to 45 pg/ml; therefore, their antimicrobial role is extremely
limited

DISORERS ASSOCIATED WITH AMP
 Genetic variance is a major determinant of the differential risk for most human diseases,
including periodontitis
 Nearly twenty genetic disorders connected to periodontal disease have been identified
and are associated with the expression of AMPs to date (Hartand Atkinson,2007)
 It has been shown that conditions of sever congenital neutropenia (Morbus Kostmann disease) are associated with severe
irreversible periodontitis (Putsep et al., 2002).
 Periodontal disease is also common in children with Down’s Syndrome (Trisomy 21) (Orner,1976). Mucin-7 and lactoferrin are
other AMPs that are associated with periodontal disease.
 Haim–Munk syndrome and the Papillon–Lefe‘vre syndrome are induced by allelic mutations of the cathepsin C gene,CTSC 1
and identified by severe periodontitis and palmoplantar keratoderma(Hart, Hart et al., 2000).

 Morbus Kostmann Syndrome (MK)
 Autosomal recessive ,inherited disorder
 Congenital neutropenia
 lower levels of neutrophils- susceptible to periodontal disease
 MK is associated with :
 complete absence of LL-37
 lower concentrations of HNP1-3 in saliva,
 chronic periodontitis and overgrowth with A. actinomycetemcomitans .
 when these patients receive a bone marrow transplant, normal concentration
of LL-37 is found in their saliva
 Rolf Kostmann (1909-1982)

 Papillon-Lefèvre Syndrome
 Rare autosomal recessive disorder, characterized by
 diffuse palmoplantar keratoderma
 precocious aggressive periodontitis,
 leading to premature loss of deciduous and permanent dentition at a very
young age
 Deficiency of LL-37 due to deficient serine proteinases that process hCAP-18
to the mature, active LL-37 peptide.
 Eruption of the primary dentition is typically accompanied by severe
gingivitis and generalized aggressive periodontitis.
 The primary teeth frequently become loose and exfoliate by the age of 5. With
loss of the dentition, gingival inflammation resides.
 With the eruption of the permanent teeth, the same cycle of events unfold
and, without intervention, the permanent teeth may be lost within a few year

 Haim–Munk syndrome
 Haim-Munk syndrome is an extremely rare autosomal
recessive disorder characterized clinically by palmoplantar hyperkeratosis,
aggressive periodontitis with severe alveolar bone destruction, arachnodactyly,
and acro-osteolysis
 The periodontium in HMS may be less severely affected than in PLS, but
gingival inflammation and alveolar-bone destruction are present and severe.
 clinical findings such as nail deformities and arachnodactyly suggest that HMS
is a distinct disorder.
 Parenteral consanguinity is characteristic of both disorders, which are
genetically related caused by allelic mutations in the lysosomal protease
cathepsin C (CTSC) gene..

Antimicrobial peptides as therapeutic agents
 Around 1000 natural APs may serve as lead compounds for future development.
 However, currently only few APs are approved for clinical use.
 Polymyxin B, a cyclic cationic lipopeptide from Bacillus polymyxa, was discovered in 1947.
 Since the 1960s polymyxins have been used in topical applications . Further approved drugs are the linear polypeptide
gramicidin, derived from Bacillus brevis, as a combination product and daptomycin.
 Daptomycin is active against Gram-positive bacteria only (skin and soft tissue infections)and is currently the most
bactericidal drug on the market used as a reserve antibiotic against opportunistic pathogens (like methicillin-resistant
Staphylococcus aureus, MRSA

Antimicrobial peptides as therapeutic agents in the oral cavity
• Antimicrobial peptides are under investigation for control of oral infections.
• One such drug is ISEGANAN, an analog of protegrin-1, a porcine cathelicidin, which has broad spectrum bactericidal activity.
• Iseganan has recently completed Phase III clinical trials for prevention of ulcerative oral mucositis.
• Reduces clinical problems such as mouth pain, throat pain and difficulty swallowing (Giles et al., 2003).
• A second investigational peptide is the antifungal, HISTATIN-5.
• The yeast Candida is a commensal organism on skin and mucosal surfaces but is a growing problem in causing opportunistic
infections.

• Histatin-5 and several variants are under active investigation for this purpose since their mechanism of action differs from
the main antifungal drugs in current use and they are effective against azole-resistant Candida strains
• As an alternative to human antimicrobial peptides, peptides from plants exhibiting antimicrobial activity may be
applicable to prevent/treat infectious diseases .
• For instance, hydroxychavicol is an extract of the Piper betle leaf that shows inhibitory activity against oral
microorganisms, and its potential use as an oral health-care agent has been suggested

Achievements in the Topographic Design of Commercial
Titanium Dental Implants: Towards Anti-Peri-Implantitis
Surfaces Gerardo Asensio , Blanca Vázquez-Lasa ,and Luis Rojo
• Titanium and its alloys constitute the gold standard materials for oral
implantology in which their performance is mainly conditioned by their
osseointegration capacity in the host’s bone.
• its biological response can be improved by numerous surface treatments that
provide bioactivity and osseointegration
• The most widespread manufacturing techniques used to obtain bioactive
commercially implants are sandblasting, acid-etching, anodization, plasma
spraying, and laser radiation.
• These treatments modify implants’ topography, varying the values of some
properties, such as free surface energy, chemical composition, and roughness,
which have been demonstrated to allow fast healing and better osseointegration

 SILANIZATION is a methodology employed to covalently bind bactericidal peptides and antibiotics to titanium
surfaces.
 the covalent fixation of the anti-inflammatory and bactericidal GL13K peptide on Titanium implants has been
reported .
 The authors studied the osseointegration capacity of GL13K peptides through micro-CT scanning and
histomorphometry in a rodent model, identifying acceptable levels of regenerated bone tissue with good clinical
outcomes of the modified implants and the prevention of microbial infection.

 other authors have described the anchoring of RGD, KRWWKWWRR (HHC36) and human lactoferrin-derived
(hLf1-11) peptides with a silane coupling agent, resulting in excellent inhibition of bacteria adhesion and good
biocompatibility
 The physical adsorption of bactericidal peptides, such us streptococcal collagen-like protein and b-defensin 3
(HBD-3) peptides on titanium substrates, constitute other interesting ways to prevent the development of
infections, showing rapid early bone regeneration, despite some limitations regarding peptide stability and
lifespan

An antimicrobial dental light curable bioadhesive hydrogel
for treatment of peri-implant diseases
NONSURGICAL PROCEDURES, -
 local and systemic administration of antibiotics may result in
hypersensitivity reactions in allergic patients, as well as the
development of antibiotic-resistant strains of pathogenic bacteria
mechanical debridement, alone or in
combination with local delivery of
antibiotics such as Arestin (minocycline
HCl), Elyzol (metronidazole 25%), and
Atridox (doxycycline hyclate 10%),
“Matter 1, 926–944, October 2, 2019 ª 2019 Elsevier Inc”

 hydrogel is Antimicrobial bioadhesive, GelAMP, based on a visible-light-activated naturally derived polymer
(gelatin) and an antimicrobial peptide (AMP).
 cationic antimicrobial peptide
(AMP) (Tet213)
 photocrosslinkable gelatin
methacryloyl hydrogels
 gelatin methacryloyl-
antimicrobial peptide
(GelAMP) bioadhesives
 higher adhesion to physiological tissues and titanium surfaces.
 high cytocompatibility and could efficiently promote cell
proliferation and migration in vitro
 remarkable antimicrobial activity against Porphyromonas
gingivalis
 tunable mechanical stiffness and elasticity, and comparatively
higher adhesive strength to implant and oral surfaces than
commercial adhesives
 highly cytocompatible and provide a suitable microenvironment for
migratory stromal cells deployed from encapsulated bone sutures.
 bioadhesives could promote bone regeneration

Clinical Study -The Effects of Antimicrobial Peptide Nal-P-113 on Inhibiting
Periodontal Pathogens and Improving Periodontal Status-By WANG
 Replaces the histidine residues of P-113 with the bulky amino acid -naphthyl alanine, Nal-P-113 has a stronger
bactericidal ability and greater stability in blood, saliva, and salt solution than P113 does indicating its potential
applicability in the clinic.
 At concentration of 20 �g/mL restrained the growth of S. gordonii, F. nucleatum, and P. gingivalis and biofilm
formation.
 perforate the cytoplasmic membrane and cause the cytoskeleton to completely collapse, and the bactericidal
function of Nal-P-113 is stronger and faster than that of metronidazole or penicillin in vitro

• injection of the antimicrobial peptide gel or
placebo into the pocket.
• Nal-P-113 entered the subgingival dental plaque
and alleviated gingival infammation in the human
oral environment.
• efectively controlled subgingival plaque and
improved periodontal status in vivo
 It improved periodontal clinical
status by inhibiting periodontal
pathogens growth and controlling
dental bioflms formation.
 Nal-P-113 may be an auxiliary
means to prevent or cure
periodontitis in the future

SPECIFICALLY-TARGETED ANTI MICROBIAL PEPTIDES (STAMPS)
 To control oral microbial pathogenesis via a new class of antimicrobials, called specifically-targeted AMPs (STAMPs)
 The STAMP requires two functionally independent peptide domains,
 a killing moiety comprised of a non-specific AMP that can rapidly kill bacterial cells, and
 a targeting moiety consisting of a species-specific, high-affinity binding peptide
 two moieties are then integrated through a small linker, generating a fusion AMP without detrimental changes in the
independent functions of the two domains.
 The major strength of such an AMP is that the targeting moiety can guide the conjoined peptide to selectively recognize the
target organism, allowing peptide-guided killing

 ADVANTAGES
AND
DISADVANTAGE
OF SYNTHETIC
ANTIMICROBIAL
PEPTIDES
Broad-spectrum activity
(anti-inflammatory,
antibacterial, antiviral and
antifungal)
Rapid onset of killing with
potentially low levels of
induced resistance.
Systemic and local toxicity with
susceptibility to proteolysis
Reduced activity based on salt,
serum and pH sensitivity
Sensitization and allergy after
repeated application with natural
resistance
Confounding biological functions
(e.g., angiogenesis)
High manufacturing costs.

ANTIMICROBIAL PEPTIDES AND PROTEINS AS BIOMARKERS FOR PERIODONTAL
DISEASE
 Saliva and gingival crevicular fluid hold promise as diagnostic tools for both oral and systemic diseases .
 The gingival changes associated with periodontitis, including changes in the expression of cytokines and AMPs and products of
tissue and bone destruction are potential targets for oral fluid diagnostics and recent reviews have identified salivary biomarkers
for periodontal disease from these protein categories .
 The potential markers include proteins involved in inflammation (e.g. C-reactive protein, IL-1β, TNFα), collagen breakdown
(MMP-8, MMP-9), bone remodeling (alkaline phosphatase, osteocalcin, osteonectin) and host-defense proteins (e.g. lysozyme,
lactoferrin, histatin).

Protein Concentration
in saliva
(µg/mL
Concentration
in GCF (µg/mL)
Change in periodontal diseas
e
Adrenomedullin 0.06 1.8 Two-fold rise
hNP-1 8.6 0.0012 Upregulated 15-fold in
aggressive periodontitis and
60-fold in chronic periodontitis,
respectivel
hNP-2 5.5 0.0012
hNP-3 0-2.7 0.0012
hNP-4 MS
hBD-1 0.15 +
hBD-3 0.31 +
Cathelicidin/LL-3
7
1.6 + Upregulated in aggressive
periodontitis and chronic
periodontitis
Histatin 1 10.1
Histatin 3 7.3
Statherin 26.5 MS
azeurocidin
 Antimicrobial
peptides
expressed in
saliva and
gingival crevicular
fluid and their role
as biomarkers of
periodontal disease

CONCLUSION
• A wide range of AMPs has been discovered to be expressed in various niches in the oral cavity.
• They have been conserved in evolution and show relatively lower potential to resistance against microbes as they co-evolve
with these pathogens thus potentially help regulate the biofilm environment and progressing gingival and periodontal diseases.
• Not just this but the role of AMPs in controlling the spread of caries has also been documented.
• Challenges such as their design, synthesis, and function at molecular level need to be overcome in the near future so as to open
doors toward the design of potentially effective oral microbial antibiotics. It may be predicted that a better understanding of
how antimicrobial peptides are regulated and how they function will eventually lead to new diagnostic, preventive and/or
therapeutic strategies for periodontal diseases.
• AMPs could also be an interesting way of investigation as periodontal treatment follow-up

REFERRENCES
1. Antimicrobial peptides: The miraculous biological molecules: Siddharth Mallapragada, Ananya Wadhwa,1 Pallavi
Agrawal, Journal of Indian Society of Periodontology - Volume 21, Issue 6, November-December 2017
2. Antimicrobial peptides: key components of the innate immune system,Mukesh Pasupuleti1, Artur Schmidtchen2,
and Martin Malmsten, Critical Reviews in Biotechnology, 2011, 1–29, Early Online © 2011 Informa Healthcare
USA, Inc. ISSN 0738-8551 print/ISSN 1549-7801 online DOI: 10.3109/07388551.2011.594423
3. Role of antimicrobial peptides in periodontal innate defense mechanism,Ashank Mishra, Bagalkotkr Apeksha1,
Pradeep Koppolu, Swapna Amara Lingam2 Departments of Periodontics, 1Pedodontics and 2Oral Medicine and
Radiology, Sri Sai College of Dental Surgery, Hyderabad, Telangana, India © 2015 Journal of Oral Research and
Review | Published by Wolters Kluwer - Medknow

4. Host defense peptides: An insight into the antimicrobial world Shiva Gupta1, Gouri Bhatia2, Anamika
Sharma1, Sameer Saxena2 1Department of Periodontology, Subharti Dental College, Meerut, 2Department of
Periodontology, Teerthanker Mahaveer Dental College and Research Centre, Moradabad, Uttar Pradesh, India
2018 Journal of Oral and Maxillofacial Pathology | Published by Wolters Kluwer – Medknow
5.Antimicrobial peptides and periodontal disease Gorr S-U, Abdolhosseini M. Antimicrobial peptides and
periodontal disease. J Clin Periodontol 2011; 38 (Suppl. 11): 126–141. doi: 10.1111/j.1600-051X.2010.01664.x
6. Understanding the roles of gingival beta-defensins, Ulvi Kahraman Gursoy* and Eija Ko¨no¨nen
Department of Periodontology, Institute of Dentistry, University of Turku, Turku, Finland,Citation: Journal of Oral
Microbiology 2012, 4: 15127 - DOI: 10.3402/jom.v4i0.15127,

8.GCF Adrenomedullin Levels in Healthy and Periodontitis Patients with or without Type 2—Diabetes Mellitus:
Clinicobiochemical Study 1Akanksha Garg, 2A Suchetha, 3N Sapna, 4 SM Apoorva, 5Divya Bhat, 6Lakshmi Puzhankar
World Journal of Dentistry, January-March 2014;5(1):42-46
9. Host defense peptides: An insight into the antimicrobial world: Shiva Gupta1, Gouri Bhatia2, Anamika Sharma1,
Sameer Saxena2 , Journal of Oral and Maxillofacial Pathology | Volume 22 | Issue 2 | May - August 2018
10. Achievements in the Topographic Design of Commercial Titanium Dental Implants: Towards Anti-Peri-Implantitis
Surfaces: J. Clin. Med. 2019, 8, 1982; doi:10.3390/jcm8111982

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