Immune System By: Wyatt Ainslie & Colin Marsh

Lesson Plan O Present O Present poster/model O Handout wrkst O Do Wrkst

Immunology O Immunology is a science that examines the structure and function of the immune system. O Originates from medicine and early studies on causes of immunity to disease. O In the 18 th century Pierre-Louis Moreau de Maupertuis made experiments with scorpion venom and observed that certain dogs and mice were immune to it. O This was later exploited by Louis Pastuer in the development of vaccination. O Viruses were confirmed as human pathogens in 1901, with the discovery of the yellow fever.

Immunology Cont. O Immunology made a great advance towards the end of the ninetenth century in the study of humoral immunity and cellular immunity. O Paul Ehrlich proposed the side-chain theory to explain the antigen-antibody reaction; which he an the founder of cellular immunology were awarded the Nobel Prize.

Layered Defense O The immune system protects organisms from infection with layered defenses of increasing specificity. O Physical barriers prevent pathogens such as bacteria and viruses from entering the organism. O If a pathogen breaches these barriers, the innate immune system provides an immediate response. O Innate and adaptive immunity depend on the ability of the immune system to distinguish from substances

Innate Immune System O Microorganism’s or toxin’s that successfully enter the cells and mechanism’s of this system O Response is usually triggered when microbes are identified by pattern recognition receptors. O The defense systems respond to pathogen in a generic way. O The innate immune system is the dominant system of host defense in most organism O Surface barriers protect organisms from infection. O Inflammation is one of the first responses of the immune system to infection. O Complement system is a biological cascade that attacks the surfaces of foreign cells.

Adaptive Immune System O The adaptive immune system evolved in early vertebrates and allows for a stronger immune response. O The adaptive immune response is antigen specific and requires the recognition of antigens during antigen presentation. O Lymphocytes are cells which have special types of leukocytes called lymphocytes. O Natural killer cells are a component which does not attack invading microbes. O Killer t cells are a sub-group of t-cells that are infected with viruses. O Helper t-cells regulate both the innate and adaptive immune responses and help determine which responses the body. O Phagocytosis is an important feature of cellular innate immunity that engulf great pathogens.

Immunological Memory O When b cells and t cells are activated and begin to replicate and some of there offspring become memory cells. O Immunological memory can be in the form of either passive short-term memory or active long-term memory. O Passive memory have several layers of protection provided by the mother. O During pregnancy the antibody IgG is transported from mother to baby directly across the placenta.

Alternate Adaptive Immune System O Evolution of the adaptive immune system occurred in an ancestor of the jawed vertebrates O Lamprey and Hagfish have a distinct lymphocyte derived molecule. O These molecules are believed to bind pathogenic antigens in a similar way to antibodies.

Active Memory and Immunization O Long-term active memory is acquired following infection by activation of b and t cells O Active immunity can also be generated artificially, through vaccination. O Vaccination introduces an antigen from a pathogen in order to stimulate the immune system and develop specific immunity. O Most viral vaccines are based on live attenuated viruses, while many bacterial vaccines are based on acellular components.

Disorders of Immunity O Immunodefiences- occur when one or more of the components of the immune system are inactive. Malnutrition is one of these causes. O Autoimmunity-Immune system fails to distinguish self and non-self and attacks itself. O Hypersensitivety- immune response that damages the body’s own tissues.

Tumor Immunology O Role is to identify and eliminate tumors. O The antigens expressed by tumors have several sources like oncogenic viruses like human papillomavirus. O The main response of the immune system to tumors is to destroy the abnormal cells using killer t-cells.

Physiological Regulation O Hormones act as immunomodulaters, altering the sensitivity of the immune system. O The immune system is affected by sleep and rest, and sleep deprivation is detrimental to immune function.

Any Questions?

Bibliography O Beck,Gregory; Gail Habicht(november1996).Immunity and the Invertebrates” Scientific American O “Inflammatory Cells and Cancer”, Lisa M. Coussens and Zena Werb, Journal of Experimental Medicine, March 19, O “Chronic Immune Activation and Inflammation”, K.J. O’Bryne and A.G. Dalgleish, British Journal of Cancer, August 2010 O Retief FP, Cilliers L. “The Epidemic of Athens, O Major Walter Reed, Medical Corps, U.S. Army Walter Reed Army Medical Center.