1. Overview of the Immune System

2. Teaching objectives Recognize the significance of the immune system
What is the role/purpose?
What are the mechanisms of protection?
Distinguish between the innate and adaptive immune response
What are the key features differentiating these two arms of the immune system?

3. Overview of the immune system
Purpose:
Protection from pathogens
Intracellular (viruses, some bacteria and parasites)
Extracellular (most bacteria, fungi, and parasites)
Eliminate modified or altered “self”
Cancer or transformed cells
Methods of defense: mechanical, cellular, humoral

4. Overview of the immune system
Innate (nonspecific)
1st line of defense
Cellular components
Humoral components
Adaptive
(specific)
2nd line of defense

5. Cells of the immune system
Myeloid cells
Granulocytic
Neutrophils
Basophils
Eosinophils
Monocytic
Macrophages
Kupffer cells
Dendritic cells
Lymphoid cells
T cells
Helper cells
Suppressor cells
Cytotoxic cells
B cells
Plasma cells
NK cells

6. Phases of the immune response
Pathogen recognition
Innate response is the same to repeated exposures of the same pathogen
Adaptive response matures over time; repeated exposure leads to faster response
Pathogen removal
Early response: innate
Later response: lymphocytes generate adaptive immune response and memory

7. Comparison of innate and adaptive immune response
Innate immunity
No time lag
Not antigen specific
No memory
Adaptive immunity
A lag period
Antigen specific
Development of memory

8. Effects of the immune system
Beneficial
Protection from invader
Elimination of altered self
Detrimental
Inflammation (local damage and discomfort)
Damage to self (hypersensitivity or autoimmunity)

9. Balance Disease = (bolus of infection x virulence)/immunity infection