1. OUR IMMUNE SYSTEM

2. What is our immune system?
A system of biological structures and processes within an organism that protects against disease.
Must detect a wide variety of agents, known as pathogens, from viruses to parasitic worms, and distinguish them from the organism's own healthy tissue.

3. Immunology
Branch of biomedical science that covers the study of all aspects of the immune system in all organisms.

4. Two parts to the immune system
Innate
Adaptive

5. Innate Immune System The body’s first line of defense
A non-specific series of defense mechanisms in our body utilized to fight off infections when it first occurs
Recognizes pathogens from healthy tissue and acts right away

6. What are some examples we can think of?
Surface
Skin, exoskeleton (on insects), mucus, our own bacteria
Inflammation
First sign of infection, increased blood flow to site of damaged tissue – bringing white and red blood cells for protection and repair against pathogens
Cell protection
Natural Killer cells
Cells which recognize damaged cells (virus infected, tumorous etc.) and eliminate them

7. Innate immune system
Kicks in for the first 0-12h following an infection
If pathogen persists past that point, our body utilizes our Adaptive Immune system to begin fighting off infection

8. Adaptive Immune System
Acquired immune system
Comprised of a series of highly systematic cells utilized to fighting off, eliminating, and recognizing pathogens.

9. Adaptive Immune System
Produces cells which are highly specific to different pathogens
Comprised of B-Cells, and T-Cells

10. B-Cells Produce our antibodies (IgA, IgG, IgE, IgM, IgD)
Each antibody is specific to a certain pathogen.
Antibodies circulate our system until it finds it’s specific antigen.

11. B-Cells
Once pathogen has been recognized, B-cell produces more antibodies to neutralize pathogens
B-cells then display the antigen on it’s surface so that T-cells can then recognize the antigen and get to work.
Antigen is the part of a foreign substance which elicits an immune response

13. T-Cells Originate from the thymus 5 different types of T-cells Helper
Cytotoxic
Memory
Regulatory
Natural Killer

14. Helper T-Cells
Assist white blood cells with the immunological processes
Developing Memory B-Cells
Produce cytokines which aid in the active immune response

15. Cytotoxic T-Cells
Destroy virus-infected cells and tumor cells, and are also implicated in transplant rejection

16. Memory T-Cells
Antigen-specific T cells that persist long-term after an infection has resolved
Provides immune system with “memory” of past infections

17. Regulatory T-Cells Immunological tolerance
Keeps our immune system from “over-reacting”
Allergies
Host bacteria
Autoimmune disorders

18. Natural Killer T-Cells
Not to be confused with NK cells of innate immune system
Purpose is to eliminate cells displaying antigens
Can recognize tumor cells, and cells infected with the herpes virus.