1. Immune System

2. What It’s All About – the BASICS
Defend the body against pathogens
Recognize self from non-self
Specific and Non-specific
“Bottom line”:
Fight infection through the production of cells that inactivate foreign substances/cells

3. Protection Pathogens Infectious disease Toxic Reproduce in the host
GERMS
Koch’s postulate

4. Koch came up with these rules to identify a pathogen that causes a specific disease

5. 4 ways of getting sick
Contact an infected person directly

6. 4 ways of getting sick
Contact an infected person INdirectly

7. 4 ways of getting sick
Eat infected food or drink infected water

8. 4 ways of getting sick
Get bitten by an infected animal

9. Bubonic Plague
Bubonic plague is an infectious disease, circulating mainly among small rodents and their fleas. Without treatment, the bubonic plague kills about two thirds of infected humans within 4 days. Swollen lymph glands are typical symptoms of the plague. During the 14th century, 25 million people in Europe were belived to have died (around 40% of the entire population).

10. Immune System Anatomy Lymphatic System Lymph (fluid with WBCs)
Lymph nodes (store WBCs)
Tonsils, thymus, spleen, appendix, red bone marrow, adenoids

12. Line up the Troops First line of defense is non-specific
Blocks anything from entering body system

13. First Line of Defense Examples
Skin: wall that blocks pathogens
Sweat: acidic, salty, contains enzymes
Mucus: coats openings to body
Tears: wash out pathogens entering eye

14. If that didn’t work…. Second line of defense: Inflammatory Response
When the pathogen enters the body
Injured cells release HISTAMINE
Capillaries expand so blood flow increases
Fluid leaks out into space between cells
Swelling, redness, pain, heat
What can you do to relieve these symptoms? (Take an ANTI histamine)

15. SPECIFIC DEFENSE IMMUNE RESPONSE Specific for pathogen
Most effective if you’ve been infected before
Through entire body
Triggered by substance in pathogen = antigen
Can be defense in body fluids (humoral) OR defense against abnormal cells or pathogens (cell-mediated)

16. Cells Involved White Blood cells = LEUKOCYTES
They are made in the bone marrow
Some develop in bone marrow, others in the thymus
The picture is of a phagocyte – a wbc that engulfs and digests a pathogen

17. Cells Specifics Non-specific:
Phagocytes: engulf (eat) and digest pathogens
Macrophages are the biggest
Specific:
Lymphocytes: B-cells and T-cells

18. Humoral Immunity – Immunity against pathogens in body fluids
Some B cells recognize specific pathogen
B cells mature in Bone marrow
Antibodies from B-cells
Some B cells remember specific antigens & will produce antibodies whenever the pathogen reappears (memory cells)
Antibodies:
Attach to antigen and attract macrophages

19. B cell immune response 10 to 17 days for full response
B cells + antibodies Y
invader (foreign antigen)
tested by B cells
(in blood & lymph)
memory cells
“reserves” Y Y
recognition Y
captured invaders Y
clone
1000s of clone cells
plasma cells
release antibodies Y Y

20. Lymphocytes: B-cell

21. Cell-Mediated Immunity
Cells directly attack and destroy Ag (antigen)
Cancer cells, infected body cells, invading cells
T cells involved
Born in bone marrow but mature in Thymus
3 types: killer, helper, suppressor

22. T cells Killer T cells Helper T cells (aka T4) Suppressor T cells
Attack Ag (puncture cell membrane)
Helper T cells (aka T4)
Stimulate Killer Ts to divide, stimulate B cells to divide and release Antibodies
Suppressor T cells
Stop the activity of other T cells

23. T cell response killer T cell activate killer T cells
infected cell
helper T cell
helper T cell or
stimulate B cells & antibodies Y
activated
macrophage
helper T cell Y

24. Lymphocytes From Stem Cells

25. Lymphocytes: T-cell

26. Memory Cells Primary response: new pathogen,
new response (5-10 days until max production
of B and T cells)
Secondary Response: same pathogen,
old response (1-2 days, so you don’t even get sick!)
Memory cells can last your entire life!!
You get “booster” vaccines to reactivate the memory cells

27. Vaccinations Immune system exposed to harmless version of pathogen
triggers active immunity
stimulates immune system to produce antibodies to invader
rapid response if future exposure
Most successful against viral diseases

28. Immune response pathogen invasion antigen exposure skin skin
free antigens in blood
antigens on infected cells
macrophages
(APC)
humoral response
cellular response
B cells
helper T cells
T cells
plasma B cells
memory B cells
memory T cells
cytotoxic T cells Y
antibodies

29. HIV and AIDS HIV attacks T4 cells (Helper T cells)
Body can’t defend against any Ags!
Known as an STD: transported in semen, blood, breast milk
Once T4 count is so low that body can’t fight disease, we say the person has AIDS
Takes about 10 years to develop AIDS

30. AIDS Infection

31. Huge Outbreak in Africa
African Children Orphaned by AIDS

33. Allergies

34. Allergies Histamine released even though antigen is harmless
If blood vessels dilate too much: ANAPHYLACTIC SHOCK

35. Autoimmune Disorders Immune system attack SELF cells
Multiple Sclerosis: T cells destroy nerve cells
Maybe Type 1 Diabetes is attack on pancreas

36. Multiple Sclerosis