Immunity and Immune cells Dr. Sadaf Mumtaz 16/01/12

Immunity Body’s ability to resist or eliminate potentially harmful foreign material or abnormal cells Innate Immunity Non-specific Acquired Immunity Specific

Immune cells Neutrophils Eosinophils Basophils Monocytes Lymphocytes B Lymphocytes T Lymphocytes

Innate Immunity Inflammation----neutrophils and macrophages Interferons—defend against viral infection NK cells – Lymphocyte like cells The complementary system

Phagocyte secreted chemicals in inflammation Neutrophils Lactoferin binds tightly with iron Kallikren converts specific plasma protein precursors produced by the liver into kinins activate nearby nerve endings Powerful chemotaxis of more neutrophils Mast cells & Basophils Histamine and heparin Macrophages NO toxic to near by microbes Endogenous pyrogens-fever IL-1--- fever & proliferation of B & T lymphocytes Leucocyte endogenous mediator Decreases plasma concentration of iron--Anemia Stimulates synthesis and release of neutrophils from bone marrow

Fever Augments phagocytosis Increase the rate of many enzyme dependent inflammatory activities Interfere with bacterial multiplication by increasing bacterial requirements for iron

Interferons Named for its ability to ‘interfere’ Provides non-specific resistance to viral infection

NK cells NK cells Cytotoxic T cells Lymphocyte like cells Lymphocytes Non-specifically destroy virus infected and cancer Specific destruction of virus infected and cancer Immediate assault Require a maturation period Less in number More abundant

Acquired immunity

B cell mediated immunity

Primary and secondary immune responses

Antibodies IgM IgG IgE IgA IgD Secreted in early stages of plasma cell response IgG Most abundant Ig in the blood, produced copiously upon second exposure IgE Protects against parasitic worms, antibody mediator for common allergic responses such as hay fever, asthma, hives IgA Found in secretions e.g digestive, genitourinary, milk , tears, saliva etc IgD Function is uncertain

Structure of Antibody

How Antibodies work

Complement System

Activation of T cells

Processing of MHC self-antigen and foreign antigen complex

Regulation of immune system

Cytotoxic T cell

Helper cell types IL-12 IL-4 TH 1 TH 2 Cell mediated immunity B-cell mediated immunity

MHC1 & MHC 11

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