![Five Classes[subclasses]
of Immunoglobulins:
1. IgG [subclass IgG1,
IgG2, IgG3, IgG4]
2. IgA [subclass IgA1,
IgA2]
3. IgM
4. IgD
5. IgE
IMMUNOGLOBULIN
CLASSES](https://image.slidesharecdn.com/immunity-sandeep-180515180510/85/Immunity-in-OMFS-14-320.jpg)
Immunity in OMFS
- 1. IMMUNITY PRESENTED BY: GIRIRAJ SANDEEP PG OMFS RRDCH
- 2. CONTENTS •INTRODUCTION •HISTORY OF IMMUNITY •DEFINITION OF IMMUNITY •ANTIGEN •ANTIBODY •IMMUNE SYSTEM •BARRIER DEFENSES •CLASSIFICATION OF IMMUNITY •INNATE IMMUNITY •ADAPTIVE / ACTIVE IMMUNITY •AUTO IMMUNITY •APPLIED ASPECTS •TREATMENT OPTIONS FOR IMMUNE DEFICIENCY •CARIES VACCINE •CONCLUSION •REFERENCE
- 3. INTRODUCTION • Immunity is the balanced state of having adequate biological defenses to fight infection, disease, or other unwanted biological invasion, to avoid allergy and autoimmune diseases.
- 4. HISTORY OF IMMUNITY • The earliest known reference to immunity was during the Plague of Athens in 430 BC. • In the 18th century, Pierre-Louis made experiments with scorpion venom and observed that certain dogs and mice were immune to this venom.
- 5. DEFINITION • The term immunity refers to the resistance exhibited by the host towards infection caused by micro organisms and their products(toxins).
- 6. ANTIGEN: • Any substance foreign to the body that evokes an immune response either alone or after forming a complex with a larger molecule (such as a protein) and that is capable of binding with a product (such as an antibody or T cell) of the immune response. ANTIBODY: • Large number of proteins of high molecular weight that are produced normally by specialized B cells after stimulation by an antigen and act specifically against that antigen in an immune response. • Antibodies are also called as immunoglobulins.
- 7. ANTIGEN/IMMUNOGEN Any substance capable of provoking lymphoid tissues to respond by a reaction specifically directed against inducing substance.
- 8. 1. A Complete Antigen:- Substances which can induce antibody formation by themselves and can react specifically with these antibodies. 2. Haptens:- Substances unable to induce antibody formation on its own but can become can induce antibodies when linked to proteins called carrier proteins. CLASSIFICATION OF ANTIGEN
- 9. 9 Haptens Haptens are of 2 types : 1. Complete Hapten:- can combine with specific antibodies to form precipitates. 2. Simple Hapten:-Combine with specific antibodies but no precipitate is produced.
- 10. EPITOPE Smallest unit of antigenicity against which all immune activity is directed Each antibody recognizes one epitope rather than the whole antigen
- 11. • Immunoglobins which are formed in the serum and tissue fluids in response to an antigen and react with that antigen specifically. ANTIBODIES/IMMUNOGLOBULINS
- 12. • Antibodies have 2 roles to play (a) To bind antigen (B) To interact with host tissues and effector systems to remove the antigen
- 13. STRUCTURE OF ANTIBODIES • Both L and H chains consist of 2 proteins each having : A variable region at amino terminal. A constant region at carboxy terminal . • Antigens combine at the amino terminal.
- 14. Five Classes[subclasses] of Immunoglobulins: 1. IgG [subclass IgG1, IgG2, IgG3, IgG4] 2. IgA [subclass IgA1, IgA2] 3. IgM 4. IgD 5. IgE IMMUNOGLOBULIN CLASSES
- 15. • Major serum (Constitute 70-75% of total immunoglobulin pool) • IgG molecules are synthesized and secreted by Plasma B cells. • Normal serum concentration : 8 to 16 mg/ml (Molecular wt 150,000) • Half life 23 days • Transported through placenta provides the neonate with humoral immunity before its own immunity developes. IgG
- 16. Protects body surfaces • Normal serum conc. 0.6 – 4.2 mg/ml (Half life 6-8 days) • Mol wt 1,60,000 2 forms • Structure: Dimer formed by 2 monomer units joined together by a glycoprotein named J chain. IgA SECRETORY IgA ( mol wt 160,000) . Found on mucosal surfaces SERUM Ig A ( mol wt 400,000) present in secretions such as milk, saliva, tears etc
- 17. Protects blood stream • 5 -8 % of serum Igs • Serum conc. 0.5 – 2 mg/ml • Half life 5 days • Present on the surface of immature B cells. • Earliest Ig formed by foetus • Structure: pentamer ( J chain joining the basic 5 monomer units) • Appears early in response to infection before IgG. Hence its presence in serum indicates recent infection. • Cannot cross placenta IgM
- 18. • Serum conc. 3mg per 100 ml • Mostly intravascularly present • Mol wt 1,80,000 • Half life 3 days • Present on the surface of B cells • Structure similar to Ig G IgD
- 19. Mediates Reaginic Hypersensitivity • Only Ig which is heat labile • Serum contains only traces • Mostly distributed extravascularly • Mol wt 190,000 • Half life 2-3 days • Structure resembles Ig G • Mainly produced in the linings of respiratory and intestinal tracts • Mediates type 1 anaphylactic hypersensitivity reaction via mast cells sensitization • Cannot cross placental barrier IgE
- 21. ANTIGEN ANTIBODY REACTIONS Antigen combines with its specific antibody in an observable manner Uses In the Body (In vivo) Forms the basis of immunity against infectious diseases. In the laboratory ( in vitro) Serological reactions: For diagnosis of infections Detects the quantity of antigens or antibodies. i)Precipitation reaction ii)Agglutination reaction iii)ELISA
- 22. Serological reactions Precipitation Reaction. • When a soluble antigen combines with its antibody in the presence of electrolytes at a suitable temperature & pH, the antigen – antibody form an insoluble precipitate, this is called precipitation reaction. • When, instead of sedimenting, the precipitate remains suspended as floccules its known as flocculation reaction. Application: – Slide test –VDRL test for syphilis. – Tube test– Kahn test for syphilis is tube flocculation. – Immunodiffusion(Precipitation in Gel) – Elek’s test for toxicity in Diptheria Bacilli.
- 23. IMMUNE SYSTEM • It is a system of biological structures and processes within an organism that protects against disease. • Immune system detects a wide variety of agents, from viruses to parasitic worms. • The immune system recognizes foreign bodies and resulting in production of immune cells and proteins. • Barriers prevent the entry of disease causing micro organisms into the body thus acts as protective barrier to the body.
- 24. BARRIER DEFENSES • The barriers prevent the entry of pathogens to resist infection. • The various non specific defense mechanisms are present. 1. Anatomical and physical barriers 2. Physiological and chemical barriers 3. Biological barriers 4. General barriers
- 25. Anatomical and Physical barriers • These include Ex; Skin Mucous membrane, Coughing and sneezing, etc.
- 26. Mucous membrane -The respiratory , GIT etc. lined by mucous membrane -It blocks the micro organisms because of its sticky nature. Coughing and Sneezing -The mechanical actions may help in driving out the foreign particles that enter the digestive and respiratory tracts.
- 27. Physiological and chemical barriers • Human milk: This is very rich in anti bacterial substances. Ex:IgA, lacto ferritin etc. they fight against E.coli and Staphylococci. • Secretions from the digestive tract: -Stomach has microbicidal effect. -This is due to the presence of Hcl in the gastric juice. - This Hcl is secreted by oxyntic cell lining stomach. • Nasal secretion and saliva • Interferons • Complement System
- 28. Biological barriers • These includes mono nuclear phagocytic system which was originally called reticulo-endothelial system(RES). • Biological barriers include endocytosis. • Endocytosis: it is the process in which cells absorb materials from the out side of the environment by engulfing them with their cell membrane. Types: the absorbing of material from the out side of the environment of cell is commanly divided in to 2 types. 1.Phagocytosis. 2.Pinocytosis
- 29. General barriers • Age : - The very young and very old are most susceptable to infections. Ex: 1. Fetus is protected by placental barriers. 2. At old stage people have reduce or loss the host defences. • Racial immunity, Ex- In some parts of Africa resistance to Plasmodium falciparum malaria is seen. • Individual immunity, Ex- Several factors such as age, hormones and nutrition influence the level of innate immunity in an individual
- 30. Structure and Function of Immune System • Lymphoreticular cells consist of lymphoid & reticuloendothelial cells Lymphoid cells Reticulo-endothelial Cells Lymphocytes Plasma cells PMN cells Macrophages (concerned with specific immune response) (concerned with the non-specific immunity) The immune response to an antigen can be of 2 types: I ). Humoral or Antibody mediated immunity II ). Cellular mediated immunity. • Humoral immunity is mediated by antibodies produced by plasma cells & present in blood & body fluids. • Cell mediated immunity by sensitized lymphocytes.
- 31. • Lymphoid organ is classified into central and peripheral lymphoid organs. Central lymphoid organs: Produces mature cells of the immune system. – Bone marrow. – Thymus. Peripheral lymphoid organs: -Major sites of interaction of mature circulating lymphocytes with antigen, and with each other. -Contain lots of B and T cells as well as accessory cells. – Lymph nodes. – Tonsils and adenoids. – Spleen. – MALT or GALT (Mucosal OR Gut-Associated Lymphoid Tissue)
- 32. Central lymphoid organ • Central (primary) lymphoid organs are the sites for generation and early maturation of lymphocytes (B and T cells) • T cells mature in the thymus • B cells mature in the bone marrow
- 33. Peripheral lymphoid organs • Traps antigens. • These are the sites for initiation of most immune response. • Provide signals for recirculation of lymphocytes.
- 34. CLASSIFICATION
- 35. INNATE IMMUNITY • It Is the natural resistances with which a person is born. • Microbes first encounter the epithelial layers, physical barriers that line skin and mucous membranes. • Due to this, inflammatory response stimulates general defenses -Stimulates chemical signals (CYTOKINES) -Antimicrobial Substances, -Fever, -Phagocytic activity • Through these approaches, innate immunity can prevent the colonization, entry and spread of microbes.
- 36. ANTIMICROBIAL PEPTIDES AND PROTEINS • Peptides and proteins function in innate defense by attacking microbes directly or preventing their reproduction. • Interferon activates macrophages to fight against viruses.
- 37. Fig. 43-7 Adenoid Tonsil Lymph nodes Spleen Peyer’s patches (small intestine) Appendix Lymphatic vessels Lymph node Masses of defensive cells Blood capillary Lymphatic vessel Tissue cells Interstitial fluid
- 38. Inflammatory Responses • Following an injury, mast cells release histamine, which promotes changes in blood vessels; this is part of the inflammatory response. • These changes increase local blood supply and allow more phagocytes and antimicrobial proteins to enter tissues leads to the formation of PUS. • Pus, a fluid rich in white blood cells, dead microbes, and cell debris, accumulates at the site of inflammation.
- 39. Complement System • System of some non-specific proteins present in normal human serum,which are activated characteristically by antigen-antibody reaction.
- 40. Complement activation • Activation occur either by i) Classic pathway through antigen- antibody complexes ii) Alternate pathway via non-immunologic agents such as bacterial toxins, cobra venoms .
- 41. Humoral Response • By antibodies circulating in blood • Characteristic pattern of antibody production: • Lag phase: immediate stage following antigenic stimulus during which no antibody is detectable in circulation • Log phase: steady rise in titre of antibodies • Plateau: equilibrium between antibody synthesis and catabolism • Decline phase: catabolism exceeds production, titre falls
- 42. Cell Mediated Immune Response (CMI) • Specific response which do not involve antibodies • Mediated by sensitised T cells. • CMI play important role in : -Delayed hypersensitivity, -Immunity against infectious diseases caused by viruses, -Graft versus host response -Immunity against cancer -Pathogenesis of autoimmune diseases
- 43. Active immunity • It is the production of immunity against particular organisms after exposure. Natural active immunity: This immunity develops by natural processes like infections. Ex:the infection like small pox are cured by the active function of the immune system. Artificial active immunity: - Here instead of natural infections. - Infection is created artificially by using various types of vaccines. Ex: polio vaccine, cholera vaccine etc.
- 44. Key Points -Active immunity takes several weeks to become active but passive is immediate. -Memory cells are only produced in active immunity. Natural active immunity is Sub divided into: Naturally acquired active immunity: - Occurs when a person is exposed to a live pathogen and developing a primary immune response, which leads to immunological memory. - This type of immunity is “natural” because it is not induced by deliberate exposure. Naturally acquired passive immunity: - - Maternal passive immunity is a variant of it. -It refers to antibody-mediated immunity conveyed to a fetus by its mother during pregnancy through placenta. - IgG is the only antibody that can pass through the placenta.
- 45. MECHANISM OF ACTION OF VACCINE VACCINE PRIMARY RESPONSE B &T LYMPHOCYTE STIMULATION MEMORY CELLS SECONDARY RESPONSE AS A RESULT OF EXPOSURE TO ANTIGEN
- 46. ARTIFICIAL ACQUIRED IMMUNITY Artificially acquired active immunity: - It can be induced by a vaccine, a substance that contains antigen. - A vaccine stimulates a primary response against the antigen without causing symptoms of the disease. Artificially acquired passive immunity: - It is a short-term immunization induced by the transfer of antibodies, which can be administered in several forms; a) as human or animal blood plasma, as pooled human immunoglobulin for intravenous (IVIg) or intramuscular (IG) use, and in the form of monoclonal antibodies (MAb). ***Immunity derived from passive immunization lasts for only a short period of time, and there is also a potential risk for hypersensitivity reactions.
- 47. Auto Immunity • A condition in which structural & functional damage is produced by the action of antibodies against the normal constituents of the body Conditions of Auto Immunity: • An elevated level of immunoglobulins or demonstrable antibodies. • Deposition of immunoglobulins or their derivatives &lymphocytes & plasma cells at the site of lesion. Genetic predisposition & female predominance. Benefit from corticosteroid or immunosuppressive drugs.
- 48. Aetiology for auto immunity: • Normal Cells or tissue may undergo antigenic variation by physical, chemical & biological influences, Such altered or neo antigens may elicit an immune response. • Physical agents or irradiation • Several drugs & chemicals. • Infectious agents particularly viruses and bacterial enzymes.
- 49. Classification HEMOCYTOLYTIC AUTOIMMUNE DISEASES • AUTOIMMUNE HAEMOLYTIC ANAEMIA • AUTOIMMUNE THROMBOCYTOPENIA & LEUCOPENIA LOCALISED (ORGAN SPECIFIC AUTOIMMUNE DISESASES) • HASHIMOTO’S DISEASE (LYMPHADENOID GOITRE) • THYROTOXICOSIS (GRAVE’S DIEASE) • ADDISON’S DISEASE • MYASTHENIA GRAVIS SYSTEMIC AUTOIMMUNE DISEASES • SYSTEMIC LUPUS ERYTHAMATOSUS • RHEUMATOID ARTHRITIS
- 50. Treatment • Glucocorticoids. • Anti cancer drugs like nitrogen mustards,nitros ureas. (cyclophosphamide being the most potent) • Antimetabolites –Folic acid analogues such as methotrexate –Purine analogues like azathioprine –Pyrimidine analogues like fluorouracil
- 51. APPLIED ASPECTS
- 52. DIAGNOSIS OF DISEASE- Antigen antibody reactions- used for the purpose of diagnosis of many diseases a) VDRL - syphilis - precipitation test b) WIDAL - typhoid - agglutination test c) ELISA - HIV,TB
- 53. THERAPEUTIC RESPONSE • To check for increasing or decreasing Ag-Ab titre • Test repeated in a week or 10 days • Example- VDRL (syphilis) Widal (typhoid)
- 54. PREVENTION & TREATMENT OF DISEASES- • Active and Passive immunization against many diseases by vaccines & immunoglobulins.
- 55. BLOOD TRANSFUSION SEROLOGY- Grouping, typing and cross matching in transfusion.
- 56. TISSUE TYPING & HISTOCOMPATIBILITY TESTING Necessary for successful transplantations
- 58. Immune Deficiency Diseases • Occur due to lack of some components or some defective components of immune system. • Opportunistic organisms which takes advantage of defective immune system. • Two types – Congenital- Inherited and occur due to defects in B cell, or T cell or both – Acquired- Occur due to infection of some organisms
- 59. Immunodeficiency Disorder Involving T-cells • Di- george syndrome- heart defects, poor immune system function, a cleft palate, behavioural and emotional problems. • Chronic mucocutaneous candidiasis- chronic infections with Candida that are limited to mucosal surfaces, skin and nails. • Acquired T-cell Immunodeficiency syndrome- lymphocytopenia of T cells or by decreased function of individual T cells.
- 60. - It is caused by infection with HIV. • HIV disrupts the immune process by directly infecting the helper T-cells. • Once the infected helper T-cells are activated, they work to create new viruses . • In addition, many helper T-cells are destroyed in the HIV replication process. Acquired Immune Deficiency Syndrome (AIDS)
- 61. Laboratory tests to diagnose an immune disorder include: Blood tests. -HIV test. -Immunoglobulin levels in the blood. -T (thymus derived) lymphocyte count. -White blood cell count. Prenatal testing -Samples of the amniotic fluid, blood or cells from the tissue that will become the placenta (chorion) are tested for abnormalities. Genetical Disorders In some cases, DNA testing is done to test for a genetic defect. Test results make it possible to prepare for treatment soon.
- 63. • Any type of major surgery can stress the body and suppress the immune system. • It can take a couple of weeks to many months for the immune system to recover fully. • During this time, patients are more prone to infections that can affect any area of the body, such as the sinuses, throat, mouth, lungs, skin, and urinary tract.
- 64. Factors that relates with the increased risk of infection, are: • The extent of surgery (number and size of incisions) • Any complications during surgery, such as excessive bleeding • Other medical problems, such as diabetes or heart or lung problems • Previous cancer treatments, such as chemotherapy or radiation
- 66. Immunoglobulin therapy It consists of antibody proteins needed to fight infections. -It can either be injected IV or IM -IV treatment is needed every few weeks. -IM is needed once or twice a week.
- 67. • Gamma interferon therapy- - Interferons are naturally occuring substances that fight viruses and stimulate immune system cells. • Growth factors- -When immune deficiency is caused by a deficiency of white blood cells, growth factor therapy stimulates the levels of white blood cells.
- 68. CARIES VACCINE
- 69. PRINCIPLE • Production of enzyme inhibiting antibodies • Prevention of bacterial accumulation on teeth Best time – age of one (after teeth have emerged but before colonization of streptococcus mutans)
- 70. TOPICAL APPLICATION HAS BEEN SUGGESTED: Mouthrinse or Painting tooth with antibodies. IF ANTIBODIES ARE TO BE EFFECTIVE, THEY HAVE TO HOST GENERATED TO ENSURE A CONTINUOUS SUPPLY. ROUTE OF ADMINISTRATION
- 71. • ORAL VACCINE HAS BEEN SUGGESTED TO BE SAFER THAN AN INJECTED VACCINE. ENCAPSULATED PILL WHOSE CONTENT IS NOT RELEASED UNTIL IT REACHES PEYER’S PATCHES.
- 72. TARGETTING MICROORGANISMS • Streptococcus mutans • Streptococcus sobrinus TARGETTED IMMUNOGLOBULINS • IgA • IgG • IgM
- 74. Healthcare Personnel Vaccination Recommendations Hepatitis B Influenza MMR Varicella (chickenpox) Tetanus, diphtheria, pertussis Meningococcal
- 75. CONCLUSION • It is the immune system that determines the level of resistance an individual possess to an external stimuli. • The immune system is like a double edged sword. It renders an individual ineffective to any disease or infection, on the other hand a compromised or exaggerated immune response would lead to fatal results.
- 76. REFERENCES • Textbook Of Medical Physiology-Guyton And Hall • Textbook Of Microbiology By C.P. Baveja • Textbook Of Pathology By Harsh Mohan • Textbook Of Physiology By Prof A.K. Jain
Editor's Notes
- #21: The antigens may combine with an antibody to form antigen antibody complex
- #23: Lance-grouping beta hemolytic bacteria based on the carbohydrate composition of bacterial antigens found on their cell walls
- #32: loosely organized lymphoid follicles known as the mucosa-associated lymphoid tissue (MALT)
- #60: Cmc-also associated with HPV] 22q11.2 deletion syndrome