Adaptive Immunity: Specific Defenses of the host Ch 17

Immunity: ability of the body to resist pathogens Innate resistance Immunity: ability of the body to resist pathogens Due to production of specific lymphocytes and antibodies Acquired immunity Naturally – active immunity – get it, get over it Passive immunity – Mother to child, AB from mother (short term)

Dual Nature of Adaptive Immunity Figure 17.8

Dual Nature of Adaptive Immunity T and B cells develop from stem cells in red bone marrow Humoral immunity B cells mature in the bone marrow Chickens: Bursa of Fabricius Due to antibodies Cellular immunity Due to T cells T cells mature in the thymus ANIMATION Humoral Immunity: Overview

Artificially acquired immunity Vaccination Antiserum Gamma globulin (IgG purified)

Fig 17-17

Antigen, anything that can cause an immunological response Examples

Humoral vs.. cell mediated immunity Humoral is serum immunity Cell mediated depends on T cells

Antibody Structure The monomer is bivalent 4 ppt chains, 2 light and 2 heavy All contain a V region where antibody binding occurs Y or T shaped know where ab binds, know constant region. Fc or constant region binds to host cell or complement.

17.3

Epitopes

Haptens: example penicillin Haptens are usually below 10kd mw or lower. Can produce and imune response is combine with a host protein, then the response can happened without the carrier molecule. Such as penicillon Figure 17.2

Classes of Immunoglobulin IgG serum, passive immunity, neutralize, precipitate, opsonize IgM 5monomers on a chain, agglutination and complement IgA monomer in serum, dimmers in mucus, protects outer surfaces. IgD antigen receptors on B cells IgE antigen receptors on mast cells and basophiles.

Apoptosis: programmed cell death, Lymphocytes that are no longer needed destroy themselves. Clonal selection: during fetal development, self reacting AB is destroyed. During sickness more AB is produced (will review later)

Types of WBC Granulocytes: Basophil, Neutrophil, eosinophil contain substances and histamine. True phagocytes monocytes, macrophage Lymphocyte. Antibody production. And Cell mediated immunity

Clonal Selection and differentiation of B cells

Results of antigen binding Neutralize Opsonizaiton Agglutination Fixing complement Precipitation

Immunological memory Ab titer Plasma cells Memory cells

Fig 17.15

Replace with fig 17.10

Monoclonal Antibodies Immortal cells that produce an antibody that binds to one haptin.

Production of Monoclonal AB (fig 18.2)

Antibodies can now be manufactured Used to tread diseases like cancer How are antibodies treated so that they do not produce an immune response?

All of the previous activities are due to B cells.

T cells and cell mediated Immunity Differentiate in the thymus gland (and others) Classified by cell surface receptors (CD4) Binds to antigen and APC by MHC

Practical applications of Immunology (ch 19) Vaccines Heard immunity: if > 85% are immune to a disease, the pathogen has difficulty spreading Types Attenuated whole agent – non pathogenic Inactivated whole agent – dead Toxoids – inactivated toxin Subunit vaccine –purified protein Conjugated vaccine DNA vaccine – MHC1 associated responses

How to make vaccines Animals Cell culture Chick embryos Recombinant vaccines are much safer

Disorders of the Human immune system

Defects Hay fever Transplant rejection Autoimmunity Infection carriers

Hypersensitivity Rx that lead to tissue damage Occur when person is sensitized 4 types

Autoimmune disease From loss of self tolerance Self tolerance occurs during fetal development Clonal deletion Clonal anergy Graves disease Myasthenia gravis Systemic lupus Rheumatoid arthritis Hashimotas disease Insulin dependent diabetes

Types of T cells Classified by certain glycoproteins on surface (clusters of differentiation (CD)) Th –T helper-CD4 Recognise an antigen presented on the surface of a macrophage and activate it. Tc – Cytotoxic T cells –CD8 When activated by cytokines from the Th cell will change to kill self altered cells

Tr – Regulatory T cells – (turn down immune response)

Cytotoxic T cells are transformed into CTL’s by a cell with markers on it. Same as 17.10

The MHC antigen complex induces a toll-like receptor

Organisms like large paracites that are too large for ingestion by phagocytic cells must be attacked externally