Cell-mediate Immune Response & Humoral/Antibody-mediate Immune Response

An easy-to-memorize form of essay:

Cell-mediate Immune Response

• Macrophage first engulf & digest bacteria into small fragments.
• Antigen fragments combine with class II MHC found on surface of macrophage.
• Macrophage becomes APC(antigen-presenting cell).
• APC binds to helper T cell, bond is enhanced by CD4.
• CD4 binds to class II MHC. This stimulate APC to secrete interleukin-1.
• Interleukin-1stimulate helper T cell to produce interleukin-2(in large amounts).
• Interleukin-2 stimulates helper T cell to multiply into cytotoxic T cell.
• Cytotoxic T cell attach to infected/cancerous cell and release perforin to puncture holes on target cell.
• Target cell undergoes lysis and is destroyed.

Humoral/Antibody-mediate Immune Response

• B lympocyte binds to antigens of pathogen.
• Pathogen is engulfed by B cell by endocytosis and digested.
• Antigens bind with class II MHC & move to cell surface.
• B cell becomes APC(antigen-presenting cell).
• APC binds to helper T cell, T cell secrete interleukin-2 which activates B cell.
• B cell divide repeatedly into plasma cells & memory B cells.
• Plasma cells produce antibodies that kill the antigen.