Published on

basic immunity and the oral cavity

Published in: Health & Medicine
  • Be the first to comment

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide


  2. 2.  The nomenclature of Immunology  Types of immunity (innate and adaptive; active and passive; humoral and cell-mediated)  Features of immune responses  The major cells of the immune system  Immunity in the oral cavity
  3. 3. Definitions • Immunity: protection against infections • Immune system: molecules, cells and tissues that mediate responses to foreign substances • Antigens: substances recognized by the cells and molecules of the immune system and to which the system responds
  4. 4. Innate and adaptive immunity Innate immunity: always present (ready to attack); many pathogenic microbes have evolved to resist innate immunity Adaptive immunity: stimulated by exposure to microbe; more potent
  5. 5. Properties of adaptive immune responses The two features that best distinguish adaptive and innate immunity are specificity and memory
  6. 6. Primary and secondary immune responses illustrate specificity and memory in adaptive immunity
  7. 7. The concept of clonal selection Lymphocytes with highly specific and diverse antigen receptors develop prior to exposure to antigens
  8. 8. Active and passive immunity Active immunity: long-lasting protection (memory), multiple effector mechanisms activated, lag time Passive immunity: rapid protection, short duration
  9. 9. Cells of the immune system • Lymphocytes – Mediators of adaptive immune responses; only cells with specific receptors for antigens • Antigen-presenting cells (APCs) – Specialized to capture, concentrate, and display antigens for recognition by lymphocytes – Dendritic cells; macrophages, B cells; follicular dendritic cells • Effector cells – Function to eliminate microbes; include lymphocytes, granulocytes (neutrophils, eosinophils), macrophages
  10. 10. Development of B and T lymphocytes Congenital immunodeficiency diseases are often caused by blocks at different stages of lymphocyte maturation
  11. 11. Classes of lymphocytes
  12. 12. The CD Nomenclature • Structurally defined leukocyte surface molecule that is expressed on cells of a particular lineage (“differentiation”) and recognized by a group (“cluster”) of cell-specific antibodies is called a member of a cluster of differentiation (CD) • CD molecules (CD antigens, CD markers) are: • • • Used to classify leukocytes into functionally distinct subpopulations, e.g. helper T cells are CD4+CD8-, CTLs are CD8+CD4Often involved in leukocyte functions Antibodies against various CD molecules are used to: • • • Identify and isolate leukocyte subpopulations Study functions of leukocytes Eliminate particular cell populations
  13. 13. Types of adaptive immunity Different types of immune responses are mediated by different classes of lymphocytes and defend against different types of microbes
  14. 14. Phases of adaptive immune responses Need for proliferation and differentiation results in delay (typically 4-7 days) in the adaptive immune response
  15. 15. Stages in the life history of lymphocytes Proliferation: expands number of antigen-specific cells Differentiation: converts lymphocytes into effective defenders
  16. 16. Naïve, effector and memory lymphocytes • Naïve lymphocytes – Mature lymphocytes that have not previously encountered antigen; function -- antigen recognition – Preferential migration to peripheral lymphoid organs (lymph nodes), the sites where antigens are concentrated and immune responses start
  17. 17. Naïve, effector and memory lymphocytes • Naïve lymphocytes – Mature lymphocytes that have not previously encountered antigen; function -- antigen recognition – Preferential migration to peripheral lymphoid organs (lymph nodes), the sites where antigens are concentrated and immune responses start • Effector lymphocytes – Activated lymphocytes capable of performing the functions required to eliminate microbes („effector functions”) – Effector T lymphocytes: cytokine secretion (helper cells), killing of infected cells (CTLs) – B lymphocytes: antibody-secreting plasma cells
  18. 18. Naïve, effector and memory lymphocytes • • Naïve lymphocytes – Mature lymphocytes that have not previously encountered antigen; function -- antigen recognition – Preferential migration to peripheral lymphoid organs (lymph nodes), the sites where antigens are concentrated and immune responses start Effector lymphocytes – Activated lymphocytes capable of performing the functions required to eliminate microbes („effector functions”) – Effector T lymphocytes: cytokine secretion (helper cells), killing of infected cells (CTLs) – B lymphocytes: antibody-secreting cells (e.g. plasma cells) • Memory lymphocytes – Long-lived, functionally silent cells; mount rapid responses to antigen challenge (secondary responses)
  19. 19. Naïve, effector and memory lymphocytes • • • Naïve lymphocytes – Mature lymphocytes that have not previously encountered antigen; function -- antigen recognition – Preferential migration to peripheral lymphoid organs (lymph nodes), the sites where antigens are concentrated and immune responses start Effector lymphocytes – Activated lymphocytes capable of performing the functions required to eliminate microbes („effector functions”) – Effector T lymphocytes: cytokine secretion (helper cells), killing of infected cells (CTLs) – B lymphocytes: antibody-secreting cells (e.g. plasma cells) Memory lymphocytes – Long-lived, functionally silent cells; mount rapid responses to antigen challenge (secondary responses)
  20. 20. MHC  MAJOR HISTOCOMPATIBILITY COMPLEX  The histocompatibility antigens are cell surface antigens that induce an immune responses.  In human beings, human leukocyte antigens (HLA) (alloantigens), were found to be the major histocompatibility antigens.  The ability to respond immunologically to an antigen is conditioned by specific genes called the immune response (Ir) genes.
  21. 21.  HLA molecules:  HLA class I antigens (A, B and C) are found on the surface of virtually all nucleated cells.  They are the principal antigens involved in graft rejection and cell mediated cytolysis.  May function as components of hormone receptors.
  22. 22. HLA class II antigens  Are more restricted in distribution -- found only on cells of the immune system-macrophages, dendritic cells, activated T cells, and particularly on B cells.  HLA class II molecules are primarily responsible for the graft-versus-host response and the mixed leucocyte reaction (MLR)
  23. 23. HLA class III antigens  They include complement components linked to the formation of - C3 convertases. - Heat shock proteins and - Tumour necrosis factors.
  24. 24.  Many critical interactions among cells of the immune system are controlled by soluble mediators called cytokines.  Cytokines produced by lymphocytes are known as lymphokines, whereas those produced by monocytes or macrophages are called monokines. Cytokines -( Interleukins, Interferons, Growth factors)
  25. 25. Types: Interleukin I (Leucocyte Activating Factor): -IL -I , IL-I -Stimulation of T Cells -B cell proliferation, antibody synthesis -Chemotaxis, Phagocytosis
  26. 26. Interleukin – 2 :(T cell growth factor) -Powerful Mediator of immune response Interleukin – 3 :(Multi colony stimulating factor) -Growth factor for bone marrow stem cells
  27. 27. Interleukin – 4:( B cell growth factor I) -Growth factor for T cell, mast cells Interleukin – 5 :(B cell growth factor II) -Proliferation of activated B cells, Maturation of Eosinophils
  28. 28. Interleukin – 6 : - Immunoglobulin synthesis -Stimulatory effects Colony stimulating factors: -Stimulates pluripotent stem cells -Treating haemtopoitic dysfunction Tumor necrosis factors TNF: -A serum factor found to induce hemorrhagic necrosis in tumours -Cachectin, TNF (activated macrophages) -TNF (Lymphotoxin)
  29. 29. Interferons:IFN -IFN (Leucocytes) -IFN (Fibroblasts) -IFN (T cells) -Macrophage activation -Antitumour activity
  30. 30. Antigens Antigen (Ag) – the molecule an antibody (Ab) binds to • • • • usually a foreign substance each antigen has different sites that antibodies can bind to, so that one antigen can be bound by several different antibodies examples in the case of allergy could be pollen, cat dander, or a chemical in soap The two attributes of antigenicity are: (1) Induction of an immune response (immunogenicity), and (2) specific reaction with antibodies.
  31. 31.  Complete antigen is able to induce antibody formation and  Haptens are substances which are incapable of inducing  The smallest unit of antigenicity is known as the antigenic determinant or epitope. produce a specific and observable reaction with the antibody so produced. antibody formation by themselves but can react specifically with antibodies. The combining area on the antibody molecule, corresponding to the epitope, is called the paratope.
  32. 32. ANTIBODY  An immunoglobulin that is capable of combining with specificity to the antigen that elicited its production. Each is made of two identical heavy and two identical light amino acid chains, held together by disulfide bonds
  33. 33. variable regions of the light chain (grey) and the heavy chain (yellow) form the antigen binding site - light chain constant region is blue while heavy chain constant region is red. The two chains are joined by carbohydrate (purple).
  34. 34. How, Why and Where are Antibodies Produced?  Produced in Vertebrate Cells in response to a „non-self‟ substance termed an antigen.  The process begins with macrophages roaming in the bloodstream. Macrophages engulf „non-self‟ molecules and then display portions of the engulfed molecules on their outer plasma membranes.  After many recognition steps B-cells are stimulated to produce specific antibodies.  The antibodies then go off and bind to the foreign substance thereby marking the substance for destruction.
  35. 35. How an Antibody Works Antibody binds to target antigen Receptor for constant region of antibody on NK cell recognizes a bound antibody After binding, the NK cell is signaled to kill the target cell The target cell dies by apoptosis and/or membrane damage
  36. 36. Primary Response 1.Is slow, sluggish and short-lived, 2.Long lag phase SecondaryResponse 1.Is prompt, powerful and prolonged. 2. Short or Negligible lag phase 3.Low titre of antibodies 3. Much higher level of antibodies that lasts that does not persist for long periods. for long. 4. Antibody IgG. 4. Antibody - IgM
  38. 38. Stages of development of immunoglobulin  In humans - Peyer's patches develop and lymphoid cells appear in the spleen and lymph nodes by the 20th week of gestation.  From then on the fetus is able to produce IgM and IgD.  It receives maternal IgG, (but IgA and IgE are not present).  At birth IgM production is enhanced, but IgG level falls steadily, to reach miminum levels by the 3rd month.  IgG production then picks up and becomes adequate by 2-3 years.  Full immunocompetence is attained only after the first decade of life.
  39. 39. I. IgG Structure: Monomer Percentage serum antibodies: 80% Location: Blood, lymph, intestine Half-life in serum: 23 days Complement Placental Known Fixation: Yes Transfer: Yes Functions: Enhances phagocytosis, neutralizes toxins and viruses, protects fetus and newborn.
  40. 40. II. IgM Structure: Pentamer Percentage serum antibodies: 5- 10% Location: Blood, lymph, B cell surface (monomer) Half-life in serum: 5 days Complement Placental Known Fixation: Yes Transfer: No Functions: First antibodies produced during an infection. Effective against microbes and agglutinating antigens.
  41. 41. III. IgA Structure: Dimer Percentage serum antibodies: 10- 15% Location: Secretions (tears, saliva, intestine, milk), blood and lymph. Half-life in serum: 6 days Complement Placental Known Fixation: No Transfer: No Functions: Localized protection of mucosal surfaces. Provides immunity to infant digestive tract.
  42. 42. IV. IgD  Structure: Monomer  Percentage serum antibodies: 0.2%  Location: B-cell surface, blood, and  Half-life in serum: 3 days lymph  Complement  Placental  Known Fixation: No Transfer: No Functions: In serum function is unknown. On B cell surface, initiate immune response.
  43. 43. V. IgE Structure: Monomer Percentage serum antibodies: 0.002% Location: Bound to mast cells and basophils throughout body. Blood. Half-life in serum: 2 days Complement Placental Known Fixation: No Transfer: No Functions: Allergicreactions. Possibly lysis of worms.
  44. 44. THE COMPLEMENT SYSTEM  Complement was initially described as a substance in peritoneal fluid and sera that cooperated with antibodies in the lytic destruction of bacteria (Bacteriolysis Pfeiffer‟s phenomenon) NOMENCLATURE  C1q, C1r, C1s, C4, C2, C3, C5, C6, C7, C8, C9.  Enzymatically active form – C1r  Suffix letters a , b etc represents clevage products  Small intial clevage fragment – „a‟ fragment and the large - „b‟ fragment eg.C3a, C3b
  45. 45. GENERAL FEATURES  Present in all normal mammalian sera  Complement activation by antibody antigen is possible only with IgM(CH4), IgG1, IgG3(CH2)  Classic activation pathway – cytolytic destruction of membrane sensitive antigens  Alternate pathway (properdin pathway)  Kinin formation, chemotaxis, opsonisation, anaphylotoxin formation and immune adherance
  46. 46. Functions  Lysis- cells, bacteria, and enveloped viruses.  Opsonization- foreign cells, bacteria, viruses are prepared for phagocytosis.  Generation of peptide fragments that regulate features of infammatory and immune responses.
  47. 47. Overview of the Immune Response
  48. 48. IMMUNOLOGICAL TOLERANCE  Is the condition in which contact with an antigen specifically abolishes the capacity to mount an immune response against that particular antigen when it is administered subsequently.  The unresponsiveness of individuals to self antigens was due to the contact of the immature immunological system with self antigens during embryonic life.  Can occur in adults also.  Tolerance may be - total or partial. - short-lived or long-lasting. The induction, degree and duration of tolerance depend on the species and immunocompetence of the host, nature and dose of the antigen and the route of administration.
  49. 49. Immunodifficiency Diseases - Conditions where the defence mechanisms of the body are impaired, leading to repeated microbial infections of varying severity and sometimes enhanced susceptibility to malignancies Classification : a.Primary immunodeficiencies: -Abnormalities in the development of the immune mechanisms b.Secondary immunodeficiencies: -Diseases, drugs, Nutritional inadequacies
  50. 50. Classification of primary immunodeficiency syndrome A.Disorders of specific immunity I. Humoral immunodeficiencies (B cell defects) a.X – linked agammaglobulinemia b.Transient, hypogammaglobulinemia of infancy c.Common variable immunodeficiency d. Immunodeficiencies with hyper IgM e.Selective immunoglobuin deficiency (IgA, IgM, IgG
  51. 51. II.Cellular immuodeficiencies ( T cell defects) a.Thymic hypoplasia (DiGeorge‟s syndrome b.Chronic mucocutaneus candidiasis III.Combined immunodeficiencies(B and T cell defects) a.Cellular immunodeficiency with abnormal imunoglobulin synthesis(Nezelof syndrome) b.Ataxia telengictasia c.Wiskott aldrich syndrome d.Immunodeficiency with thymoma e.Immunodeficiency with short- limbed dwarfism f.Episodic lymphopenia with lymphocytotoxin
  52. 52. B.Disorders of complement a.Complement component deficiency b.Complemnt inhibitor defeciencies C.Disorders of phagocytosis a.Chronic granulomatos diseases b.Myloperoxide deficiencies C.Chediac higashi syndrome d.Leucocyte G6PD defecie Secondry immunodeficiencies: Malnutrition, malignancy, infections, metobolic disorders, cytotoxic drugs
  53. 53. Immunity in the oral cavity
  54. 54. DEVELOPMENT OF ORAL IMMUNE SYSTEMS DURING INFANCY  During the mid 1960 s Secretory IgA (SlgA) became recognized as the primary immune mediator of specific host defenses on mucosal surfaces, specially equipped with four binding sites and secretory component .  during first years of life the infant‟s oral cavity receives immune components from several sources :  maternal milk  maternal serum ( igg via placental transfer)  infant saliva  infant serum ( via gcf and teething )
  55. 55. INFANT SALIVARY SOURCES : SALIVARY IgA:  By 4 to 8 weeks of age , saliva from essentially all immunologically sufficient infants contains detectable quantities of IgA .  IgA concentration, yields a peak at about 2 to 3 months. Following this early burst of IgA secretion, salivary IgA concentrations level off during the middle of the first year.  Concentrations then gradually increase through early childhood .Adult levels of salivary IgA are not reached until at least 5 years of age.
  56. 56.  Secretory IgA has been identified in the meconium of newborn infants, a substance that is not considered to be maternally derived.  Low concentrations of IgA (and IgM antibody) to poliovirus (PV) and E. coli 0 antigens have also been detected in the saliva of neonates delivered from normal mothers and from mothers with hypogammaglobulinemia.  These antibodies were synthesized in utero to placentally transferred maternal IgG antiidiotypic antibodies to these antigens.
  57. 57. SALIVARY IgG  IgG is not considered to be a significant product of adult major salivary gland tissues.  During fetal life. IgG -producing cells are absent from salivary tissue. In the neo-natal period, IgG has been found in saliva.Salivary mucosa is temporarily permeable to the nonspecific passage of macromolecules from serum.  The presence of serum-derived IgG in saliva at birth could provide the neonate with passive immunity in the oral cavity because most of this IgG is maternally derived.  However, this source of protection is transitory because salivary IgG concentrations and the percentage of infants in whom these concentrations can be detected rapidly decrease to essentially zero during the first 2 months of life.  IgG then remains absent from the oral cavity until teeth begin to erupt.
  58. 58. SALIVARY IgD  Salivary IgD is detected in nearly half of the saliva samples of children up to 1 month of age.  Salivary IgD detected in these young infants may be locally produced because IgD concentration does not correlate with other salivary components presumed to be serum derived (e.g., IgG and albumin).  The initial elevated frequency of infants with salivary IgD has been reported to fall such that after 5 months of age, IgD could only occasionally be detected in the saliva of children up to 3 years old.  Source : Parotid gland
  59. 59. IgM  Like IgA, IgM does not possess the appropriate Fc configuration to be transferred to the fetus via the all IgM in neonatal circulation is synthesized de novo. During the first 1 to 2 months after birth significant concentrations of IgM are present in the saliva  These immunoglobulins exist in much lower concentrations than IgA in these pure glandular secretions  Palatine minor salivary glands are relatively enriched in IgM compared to other major and minor gland salivary glands 
  60. 60. THE ORAL CAVITY AS AN IMMUNOLOGICAL ENTITY SALIVARY ENVIRONMENT Components of Innate Immunity  Mucins  Lactoferrin  Salivary peroxidase  Lysozyme  Other Salivary Components-Histidine rich proteins, Proline rich peptides, Beta-2microglobulins & Fibronectin
  61. 61. MUCIN  Mucus secreting cells located mainly in submandibular ,sublingual & minor salivary glands  Lubrication  IgA combines with mucins  Mucin oligosaccharides mimic tissue receptors recognized by bacteria LACTOFERRIN  Serous cells of salivary gland  PMNs also secrete them  High afinity to Fe  Carboxy anion interaction with bacterial surface  OH- radical generation
  62. 62. SALIVARY PEROXIDASES  PAROTID + SUMBANDIBULAR.,PMNs  H2O2 , Thiocyanate ions  Hypothiocyanate ions LYSOZYME (muramidase)  Ductal epithelium  N-acetyl muramic acid + Nacetylglucoseamine linkage of peptidoglycan layer of bacterial cellwall is cleaved
  63. 63. COMPONENTS OF THE ANTIBODY MEDIATED IMMUNITY Secretory IgA -Stable complexes -Virus Neutralization, Immune exclusion, „Disposal‟ of bacteria -Bacterial Enzyme Inhibition IgM - „IgM COMPENSATION‟ -Opsonization, Complement mediated Lysis IgG & IgD -Occurs in low conc.
  64. 64.  Another function associated with SIgA activity is bacterial enzyme inhibition.  Salivary IgA antibody has been shown to inhibit the function of a group of enzymes (glucosyltransferases) from cariogenic mutans streptococci that synthesize glucans involved in plaque formation.  Inhibition of this process may also change the diffusion characteristics of plaque, thus allowing bacterial acids to diffuse more readily out of plaque.  SIgA antibody could interfere with bacterial metabolism by inhibiting enzymes involved in transport phenomena.
  65. 65. GCF ENVIRONMENT  CELLULAR COMPONENTS  Polymorhonuclear neutrophils -Realeses Granules containing LYSOSOMAL ENZYMES  Lymphocytes -B & T Lymphocytes (1%-2%)  Monocytes & Macrophages -Supplement the antibacterial activity of PMN  Others -Lipopolysaccharides -Bacterial proteases -Prostaglandins Immunoglobulins:(IgG, IgA, IgM) Complement:(C3, C4:Additional activated components During disease)
  66. 66. COMPLEMENT  In periodontally healthy subjects, C3 and C4 can be detected.  If inflammation occurs, concentrations of GCF C3 and C4 decrease with respect to serum, and activated complement components such as C3a, C3b, and C5a appear, indicating that complement activation has occurred in the gingival crevice.  This activation is likely to be in response to the increased bacterial load associated with the inflammation. Both classic and alternate complement pathways can be activated.  The biologically active polypeptides released by complement activation have a variety of antibacterial eftects.
  67. 67. PMN‟s  In the GCF environment PMNs defend against bacterial invasion of the gingival tissue through phagocytic and bactericidal mechanisms.  The activity of PMNs results in the release of granules containing lysosomal enzymes that can disengage bacterial plaque adherent to the tooth.  These enzymes also have the potential to damage host tissue if present in high enough concentrations.
  68. 68. LYMPHOCYTES , MONOCYTES MACROPHAGES  Both T and B lymphocytes appear in the GCF, comprising 1 % to 2% of the cells found therein.  Approximately three times as many B cells as T cells are present in GCF, which is the converse of their ratio in blood.  Monocytes and macrophages: Approximately 2% to 3% of the remainder of the immune cells in the GCF are monocytes. These cells may supplement the antibacterial activity of the PMNs
  69. 69. IMMUNOLOGICAL ASPECTS OF DENTAL CARIES  At least six species of microorganisms constitute this mutans group. The two most prominent species in humans are S. mutans (serotypes c, e, and f) and Streptococcus sobrinus (serotypes d, g, and h).  Most individuals are colonized by mutans streptococci of the c serotype.  High levels of serum IgG antibody to mutans streptococcal cells or antigens are associated with low levels of caries in young adults. Serum antibody from caries-free young adults inhibits Glucosyltransferases from mutans streptococci to a greater extent than serum from caries-prone individuals.
  70. 70.    Studies suggested that low numbers of mutans streptococci in dental plaque are associated with relative elevations in serum IgG antibody in children approximately 2 to 5 years old. Serum IgG antibody to mutans streptococcal antigens is associated with lower caries experience. CARIES VACCINE : “Wagner” was the 1st person to successfully vaccinate rats against caries. Interestingly S. fecalis was used as the immunogen
  71. 71. SYSTEMIC ACTIVE IMMUNIZATION  Gregory and Filler observed that ingestion of a vaccine containing killed Streptococcus mutans daily for ten consecutive days induced an increased level of specific secretary IgA antibodies to Streptococcus mutans cells.  This resulted in reduction in number of viable Streptococcus mutans organism in dental plaque and whole saliva
  72. 72. SYSTEMIC PASSIVE IMMUNIZATION  Michalek, et al. used a multivalent vaccine consisting of whole cell antigen of Streptococcus mutans (serotype a, b, c, d, g), to hyperimmunize a group of pregnant cows.  They observed low plaque scores decreased number of streptococci in plaque and decreased caries actually as compared to the control.  Role of Probiotics …..
  74. 74. CONCLUSION  STUDENT- It is dry .It goes above head .It is difficult to understand.  RESEARCH SCIENTIST- when I don’t know the cause ,I put the blame on immunology.  PRACTITIONERS- I use it as a weapon to escape when my treatment fails.  But actually it is a war between the pathogens and the host defense system which ends in the “SURVIVAL OF THE FITTEST” .
  75. 75. conclusion  Immune system is a complex functioning system Acting against various invading pathogens and preventing the diseases – protective  Helpful in various diagnostic investigations  Acting against the own body tissues – destructive. IMMUNE SYSTEM , THUS COULD BE A
  76. 76. References:  Janis kuby, Immunology, 1st Edition, W.H.Freeman &company, 1992.  Daniel P. Stites, Aba Terr, Tristram G. Parslow Basic and clinical immunology, 8 th Edition, Prentice-hall international inc,1994.  Ivan Roitt, Jonathan Brostoff, David Male, Immunology, 3rd Edition, Mosby Publication, 1994.  James T Barsel ,Text book of immunology, 5th edition, mosby publication,1998  Jawetz and Melnick, Text book of medical microbiology 3rd edition,elsevier science publishing company,1999  Gerard.J.Tortora &Grabowski Principles Of Anatomy and physiology,10 thEdition,john Wiley & son’s inc Publication,2000  Barrot ,Basic immunology and its medical applications ,4 th edition,2000  Harsh Mohan “Essential Pathology for Dental Students 2nd Edition. Jaypee Brothers Medical Publishers (P) Ltd. New Delhi. 2002.  Ananthanarayan & panissker’s text book of microbiology, 7th edition, orient longman private limited, 2005.
  77. 77.  Alan Hgowenlock, Varley‟s ,Practical clinical biochemistry,6th edition,2005  Textbook of medical physiology –18th edition by Guyton  Robbins & Cotran pathologic basis of diseases, 7th edition ,Elsevier Publications , 2006.  .Contemporary oral microbiology and immunology.By Slot and Taubmann  Cellular and molecular immunology. Abul K. Abbas, Andrew H. Litchman; 5 th edition  . Immunology : Roitt, Brostoff, Male 6 th edition.  J Virol. 2005 Nov;79(22):14318-29. Human beta-defensins suppress human immunodeficiency virus infection: potential role in mucosal protection. Sun L et al,  ABIKO .Y et al;Med Electron Microsc. 2003 Dec;36(4):247-52. Defensins in saliva and the salivary glands.  . E.E. LeClair;Four Reasons to Consider a Novel Class of Innate Immune Molecules in the Oral Epithelium. ; J Dent Res 82(12):944-950, 2003  . M. Murakami et al.;Cathelicidin Antimicrobial Peptides are Expressed in Salivary Glands and Saliva. J Dent Res 81(12):845-850, 2002