Introductory immunity
Chien-Ming Li MD, Ph.D
Categories of immunity
1. Innate immunity
2. Adaptive immunity
3. Passive immunity: vaccination
Innate immunity
• Skin and mucosa
• Macrophages, dendritic cells
• Complement system
– Trigger inflammation
– Attract macrophages to the war zone
– Coat pathogens
Adaptive immunity: lymphocytes-B
and T cells
1. Humoral immunity
2. Cell-mediated immunity
1. Antigen presentation
1. Bacteria are eaten by macrophages
2. Parts of the bacteria are presented onto the surface of
the macrophages
3. Helper T (Th) cells identify the signals
4. Th cells are activated as killer cells.
Humoral immunity
• B cells identify an antigen that is matches its
receptors
• Th cells activate these B cells
• B cells divide and produce plasma cells and
memory cells
• Plasma cells produce antibodies attacking any
cells with this antigen
• Macrophages eat these marked intruders
• Memory cells activate faster than ever in the
aftermath
Antibody or immunoglobulins
1.
2.
3.
4.
5.
IgG
IgD
IgE
IgA
IgM