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Sistem imun 5.
- 1. IMMUNE SYSTEMBy : CiciRizky Y 120210103016 Adha Qiftiyatul M 120210103020 Wulan Anggraeni 120210103048 Tesa Lusidyah 120210103052
- 2. What is theimmune system? The body’s defense against disease causing organisms, malfunctioning cells, and foreign particles
- 3. IMMUNE SYSTEM Adaptive ImmuneSystem (Specific respon) Innate Immune system (Non specific respon) Disorders and disease External Defense Internal Defense -Skin -Mucous membranes -secretorions -Phagocytic cells -Antimicrobial subtance -Inflammatory response -Natural killer cells Limfosit T Limfosit B
- 4. Immune System :2 branches 1. The Innate Immune system = - is present before any exposure to pathogens and is effective from the time of birth 2. The Adaptive Immune System = - develops after exposure to agents such as microbes, toxins, or other foreign substances
- 5. INNATE IMMUNITY Innateimmunity is present before any exposure to pathogens and is effective from the time of birth It involves nonspecific responses to pathogens Innate immunity consists of external barriers plus internal cellular and chemical defenses
- 6. Nonspecific response Skin Mucous membranes Secretions EXTERNAL INNATE IMMUNITY
- 7. - Phagocytic cells Thereare different types of phagocytic cells: - Neutrophils engulf and destroy microbes - Macrophages are part of the lymphatic system and are found throughout the body - Eosinophils discharge destructive enzymes - Dendritic cells stimulate development of acquired immunity Pseudopodia surround microbes. 1 Microbes are engulfed into cell. 2 Vacuole containing microbes forms. 3 Vacuole and lysosome fuse. 4 Toxic compounds and lysosomal enzymes destroy microbes. 5 Microbial debris is released by exocytosis. 6 Microbes MACROPHAGE Vacuole Lysosome containing enzymes INTERNAL INNATE IMMUNITY
- 8. - Antimicrobial substance Peptides and proteins function in innate defense by attacking microbes directly or impeding their reproduction Interferon proteins provide innate defense against viruses and help activate macrophages About 30 proteins make up the complement system, which causes lysis of invading cells and helps trigger inflammation INTERNAL INNATE IMMUNITY
- 9. - Inflammatory response •Inflammation can be either local or systemic (throughout the body) • Fever is a systemic inflammatory response triggered by pyrogens released by macrophages, and toxins from pathogens • Septic shock is a life-threatening condition caused by an overwhelming inflammatory response INTERNAL INNATE IMMUNITY
- 10. Natural killer cells All cells in the body (except red blood cells) have a class 1 MHC protein on their surface. Cancerous or infected cells no longer express this protein; natural killer (NK) cells attack these damaged cells INTERNAL INNATE IMMUNITY
- 11. ADAPTIVE IMMUNITY - developsafter exposure to agents such as microbes, toxins, or other foreign substances
- 12. T-Lymphocytes Mature T-cellshave T cell receptors which have a very similar structure to antibodies and are specific to 1 antigen. They are activated when the receptor comes into contact with the Ag with another host cell (e.g. on a macrophage membrane or an invaded body cell)
- 13. T-Lymphocytes After activationthe cell divides to form: T-helper cells – secrete CYTOKINES help B cells divide stimulate macrophages Cytotoxic T cells (killer T cells) Kill body cells displaying antigen Memory T cells remain in body
- 15. Helper T cells Helper T-cells have receptors for recognizing antigens. If they are presented with an antigen, they release cytokines to stimulate B-cell division. The helper T-cell is the key cell to signal an immune response. If helper T-cells are disabled, as they are in people with AIDS, the immune system will not respond.
- 16. “Killer” T cells While B-cells divide and differentiate, so do T-cells. Some T-cells become cytotoxic, or “killer” T-cells. These T- cells seek out and destroy any antigens in the system, and destroy microbes “tagged” by antibodies. Some cytotoxic T-cells can recognize and destroy cancer cells.
- 17. B cells B-cellsin general produce antibodies. Those with antibodies that bind with the invader’s antigen are stimulated to reproduce rapidly. B-cells differentiate into either plasma cells or memory B-cells. Plasma cells rapidly produce antibodies. Memory cells retain the “memory” of the invader and remain ready to divide rapidly if an invasion occurs again.
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- 19. B -Lymphocytes Someactivated B cells PLASMA CELLS these produce lots of antibodies, < 1000/sec The antibodies travel to the blood, lymph, lining of gut and lungs. The number of plasma cells goes down after a few weeks Antibodies stay in the blood longer but eventually their numbers go down too.
- 20. B -Lymphocytes Someactivated B cells MEMORY CELLS. Memory cells divide rapidly as soon as the antigen is reintroduced. There are many more memory cells than there were clone cells. When the pathogen/infection infects again it is destroyed before any symptoms show.
- 21. B cells recognize antigens, Differentiateinto plasma cells- produce more antibodies Differentiate into memory cells- keep some for later proliferate, and produce specific antibodies.
- 22. Antibodies Also knownas immunoglobulins Globular glycoproteins The heavy and light chains are polypeptides The chains are held together by disulphide bridges Each ab has 2 identical ag binding sites – variable regions. The order of amino acids in the variable region determines the shape of the binding site
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- 24. Type Number of agbinding sites Site of action Functions IgG 2 •Blood •Tissue fluid •CAN CROSS PLACENTA •Increase macrophage activity •Antitoxins •Agglutination IgM 10 •Blood •Tissue fluid Agglutination IgA 2 or 4 •Secretions (saliva, tears, small intestine, vaginal, prostate, nasal, breast milk) •Stop bacteria adhering to host cells •Prevents bacteria forming colonies on mucous membranes IgE 2 Tissues •Activate mast cells HISTAMINE •Worm response
- 25. INTERACTION OF ANTIGENS- ANTIBODIES
- 26. ANTIGEN a substanceor molecule that is recognized by the immune system. The molecule can be from foreign material such as bacteria or viruses. Anything that can trigger this immune response is called an antigen. An antigen can be a microbe such as a virus, or even a part of a microbe. Tissues or cells from another person (except an identical twin) also carry nonself markers and act as antigens.
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- 28. Antigen- binding sitesAntibody A Antigen Antibody B AntibodyC Epitopes (antigenic determinants) An antigen is any foreign molecule That is specifically recognized by lymphocytes and elicits a response from them A lymphocyte actually recognizes and binds To just a small, accessible portion of the antigen called an epitope Picture Source : campbell An antibody is a substance formed immunity in human blood in response to antigenic stimulus and will react specifically with antigen
- 29. Antibodies as Receptors Antibodies can attach to B cells, and serve to recognize foreign antigens.
- 30. Antigens as Effectors Free antibodies can bind to antigens, which “tags” the antigen for the immune system to attack and destroy.
- 31. Antigen Recognition byLymphocytes The vertebrate body is populated by two main types of lymphocytes B lymphocytes (B cells) and T lymphocytes (T cells) Which circulate through the blood The plasma membranes of both B cells and T cells Have about 100,000 antigen receptor that all recognize the same epitope
- 32. Antigen- Binding site b chain Disulfidebridge a chain T cell A T cell receptor consists of one a chain and one b chain linked by a disulfide bridge. (b) Variable regions Constant regions Transmembrane region Plasma membrane Cytoplasm of T cell T Cell Receptors for Antigens and the Role of the MHC Each T cell receptor Consists of two different polypeptide chains Figure 43.8b V V C C Picture Source : campbell
- 33. T cellsbind to small fragments of antigens That are bound to normal cell-surface proteins called MHC molecules MHC molecules Are encoded by a family of genes called the major histocompatibility complex
- 34. Infected cellsproduce MHC molecules Which bind to antigen fragments and then are transported to the cell surface in a process called antigen presentation A nearby T cell Can then detect the antigen fragment displayed on the cell’s surface
- 35. Depending ontheir source Peptide antigens are handled by different classes of MHC molecules
- 36. Figure 43.9a Infected cell Antigen fragment ClassI MHC molecule T cell receptor (a) Cytotoxic T cell A fragment of foreign protein (antigen) inside the cell associates with an MHC molecule and is transported to the cell surface. 1 The combination of MHC molecule and antigen is recognized by a T cell, alerting it to the infection. 2 1 2 Class I MHC molecules, found on almost all nucleated cells of the body Display peptide antigens to cytotoxic T cells Picture Source : campbell
- 37. Class IIMHC molecules, located mainly on dendritic cells, macrophages, and B cells Display antigens to helper T cells 1 2 Figure 43.9b Microbe Antigen- presenting cell Antigen fragment Class II MHC molecule T cell receptor Helper T cell A fragment of foreign protein (antigen) inside the cell associates with an MHC molecule and is transported to the cell surface. 1 The combination of MHC molecule and antigen is recognized by a T cell, alerting it to the infection. 2 (b) Picture Source : campbell
- 38. Clonal Selection ofLymphocytes In a primary immune response Binding of antigen to a mature lymphocyte induces the lymphocyte’s proliferation and differentiation, a process called clonal selection
- 39. Clonal selectionof B cells Generates a clone of short-lived activated effector cells and a clone of long-lived memory cells Figure 43.12 Antigen molecules Antigen receptor B cells that differ in antigen specificity Antibody molecules Clone of memory cells Clone of plasma cells Antigen molecules bind to the antigen receptors of only one of the three B cells shown. The selected B cell proliferates, forming a clone of identical cells bearing receptors for the selecting antigen. Some proliferating cells develop into short-lived plasma cells that secrete antibodies specific for the antigen. Some proliferating cells develop into long-lived memory cells that can respond rapidly upon subsequent exposure to the same antigen. Picture Source : campbell
- 41. PRIMARY AND SECONDARYIMMUNE RESPONSE
- 42. Primary Immune Response >> Inthe event the primary response stimulation, cells divide and hold precursor differentiation into antibody- forming cells that produce IgM and IgG. During the process of memory cells are formed, which are still limited. Secondary Immune Response >> In the event secondary response, the cells sensitive to the antigen that number is growing rapidly increased antibody synthesis, is faster, more durable, and more effective than the previous response. That is because the immune system has been more ready to antigens as memory cells prepared against antigens. These memory cells that will eventually lead to immunological memory.
- 44. ALERGY AND ABNORMALITYOF IMMUNE SYSTEM
- 45. Allergies When theimmune system responds to harmless substances Allergens – antigenic substances which do no real harm Allergens include house dust, animal skin, pollen, house dust mite and its faeces
- 47. Allergies Histamine causesblood vessels to widen and become leaky. Fluid and white blood cells leave capillaries. The area of leakage becomes hot, red and inflamed
- 49. Smallpox Symptoms Red spotscontaining transparent fluid all over body. Spots fill with pus Eyelids swell and become glued together
- 50. Measles Caused byan airborne virus 9th leading cause of death worldwide Causes rash and fever Can have fatal complications Passive immunity from mothers in infants under 8 months Now quite a rare disease in developed countries due to vaccination
- 51. Measles Transmitted easilyin overcrowded, insanitary conditions Mainly affects malnourished infants with vitamin A deficiencies Responsible for many cases of childhood blindness and can cause severe brain damage Herd immunity of 93-95% needed to prevent transmission within a population.
- 52. THANK YOU FORYOUR ATTENTION WASSALAMUALAIKUM WR.WB