SPECIFIC HOST DEFENSES

I. Types of immunity

    A. Innate immunity
 

    B. Acquired immunity

        1. Natural

            a) natural active

            b) natural passive
 

        2. Artificial

            a) artificial active

            b) artificial passive

                temporary protection

        3.  Vaccines

            a)  killed (inactivated) microorganism

            b)  attenuated microorganism

            c)  toxoid

            d)  microbial component

            e)  recombinant

            f)  DNA

            g)  plant derived
 

II. Introduction to the Immune Response

    A. Host Cells Involved

        1.  Lymphocytes

            T cells

            B cells

            NK cells

            lymphocytosis

            lymphopenia

        2. Plasma cells
  

    B.  Two types of immune response

        1.  Antibody mediated immunity
 

        2.  Cell-mediated immunity
 

    C.  Characteristics of the immune system

        1.  Specificity
 

        2.  Memory
 

        3.  Recognition
 

III.  Antigens and Antibodies

    A.  Antigens (Ags)

        1. Chemical composition

            haptens
 

        2.  Antigenic determinants

            MO have many Ag sites

            each Ag can have different epitopes

            valence

           
 

        3. Specificity
 

    B.  Antibodies (aka. immunoglobulins and gamma-globlulins)

        1.  Chemical composition

            variable region (Fab)

            constant region (Fc)

            domains

           
 

        2.  Antibody function
 

        3.  Classes of Ab

            a)  IgG
 

            b)  IgM
 

            c)  IgA
 

            d)  IgE
 

            e)  IgD
 
 

IV.  Cytokines

    A.  Introduction
 

    B.  Examples

            monokines

            lymphokines

            interleukin

            interferons
 

V.  Mechanism of Antibody Mediated Immunity

    A.  Contact and recognition of Immunogen
 

    B.  Activation of B Lymphocytes

        1.  T-dependent Ag

            APC presents Ag and its own class II MHC

             T-dependant response, helper T cells (CD4+)

        2.  T-independent Ag triggering
 

        3.  Memory cells
 

    C.  Immune response curve

        anamnestic response
 

    D.  Diagnostic use of Ab (serology)
 
 

VI.  Mechanism of CMI

    A.  Contact and recognition of Ag
 

    B.  Types of T cells

        1.  Th cells (CD4+)

        2.  Ts cells (CD8+)


 

        3.  Tc cells (CD8+)


 

        4.  Activation of monocytes/macrophages

           

        5.  Natural killer (NK) cells

    C.  Summary
 
 

    D. Dx uses of CMI

         skin testing:  indicates previous exposure only
 
 

    E. Tolerance

        tolerance arises during embryonic development

        1. Clonal deletion
 

        2. Functional inactivation
 

        3. Clonal anergy
 
 


 


Last updated January 26, 2007.