Adaptive Immune Response

Adaptive Immune Response

1. It is specific

2. Immune components are activated only after infection start

3. Response magnitude is higher in the second and subsequent encounter

4. Immunological memory is stored

5. Lymphoid organs

   • Primary
     • Production sites of immune cells
     • Maturation sites for immune cells in the absence of antigen
   • Secondary
     • Maturation sites for antigen-driven immune cells

6. Lymphocyte

   • T cells
     • Mature in thymus
   • B cells
     • Mature in bone marrow
   • Antigen- independence
     • Have surface markers or receptors
       • Bind to antigens
       • Bind to receptors on other cells
       • Transmit and receive messages
     • Receptor molecules
       • Major histocompatibility complex (MHS)
         • Classes
           • Class 1
             • Expressed on all nucleated cells
           • Class 2
             • Antigen-presenting cells
           • Class 3
             • Protein associated with the complement system
       • Cluster of differentiation (CD)
         • CD4
           • Binds to MHS class 2
         • CD8
           • Binds to MHS class 1
       • Antigen-specific receptors
         • Mature T and B cells
           • Carry one specific type of receptors called clones
             • To eliminate lymphocytes that recognize self-antigens
           • T-cell receptors
             • Supported by CD4 and CD8
           • Immunoglobulins (Ig) or antibodies in B cells
             • IgG, IgA, IgM, IgE, IgD

7. T-cell Response

   • T helper cell
     • Activate other cells
   • Memory T cell
     • Store immunological memory
   • Regulatory T cells
     • Prevent excessive inflammation and autoimmunity
   • Cytotoxic T cells
     • Attack infected, cancerous and foreign cells

8. B cells

   • Memory B cells
     • Store immunological memory
   • Regulatory B cells
     • Prevent excessive inflammation and autoimmunity
   • Plasma cells
     • Launch antibodies
       • Neutralisation
       • Opsonisation
       • Agglutination
       • Antitoxin action