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Immune System
By: Wyatt Ainslie & Colin Marsh
Lesson Plan
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Immunology
O Immunology is a science that examines the structure and
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function of the immune system.
Originates from medicine and early studies on causes of
immunity to disease.
In the 18th century Pierre-Louis Moreau de Maupertuis made
experiments with scorpion venom and observed that certain
dogs and mice were immune to it.
This was later exploited by Louis Pastuer in the development of
vaccination.
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
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mechanism’s of this system
Response is usually triggered when microbes are identified by
pattern recognition receptors.
The defense systems respond to pathogen in a generic way.
The innate immune system is the dominant system of host
defense in most organism
Surface barriers protect organisms from infection.
Inflammation is one of the first responses of the immune
system to infection.
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
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allows for a stronger immune response .
The adaptive immune response is antigen specific and
requires the recognition of antigens during antigen
presentation.
Lymphocytes are cells which have special types of leukocytes
called lymphocytes.
Natural killer cells are a component which does not attack
invading microbes.
Killer t cells are a sub-group of t-cells that are infected with
viruses.
Helper t-cells regulate both the innate and adaptive immune
responses and help determine which responses the body.
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
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and the Invertebrates” Scientific American
“Inflammatory Cells and Cancer”, Lisa M. Coussens
and Zena Werb, Journal of Experimental Medicine,
March 19, 2001.
“Chronic Immune Activation and Inflammation”, K.J.
O’Bryne and A.G. Dalgleish, British Journal of Cancer,
August 2010
Retief FP, Cilliers L. “The Epidemic of Athens,
Major Walter Reed, Medical Corps, U.S. Army Walter
Reed Army Medical Center.