1. Ch 15: The Immune System

2. SLOs List 6 types of leukocytes and explain their functions in the IS
Compare and contrast innate (nonspecific) and acquired (specific) immunity
Compare and contrast humoral immunity and cell-mediated immunity Compare and contrast 1° and 2° responses
Describe self-tolerance and the consequence of its breakdown

3. 3 Major Functions Protection from disease causing invaders (such as ?)
Removal of dead /damaged tissues & cells
Recognition & removal of abnormal cells

4. The Concept of Immunity
Immunity: Ability to ______________________.
Susceptibility: Lack of ________________to a disease.
specific

5. Activation of Innate Immunity
1st line of Defense: Physical & chemical barriers keep pathogens out. E.g.: ___________________________ Example of 2nd line of Defense: Host cells have Toll-like receptors (TLRs) they attach to Pathogen-associated molecular patterns (PAMPs) Binding to TLRs induces release of cytokines  regulate intensity and duration of immune responses

6. TLRs
= ?
PAMPs recognition

7. Immune Cells     
6 types of blood and tissue cells involved in IS: 1) 2) 3) 4) 5) 6)
Which ones are APCs?
Which ones are phagocytes?

8. Antigen Presenting Cells
3 types of APCs:
__________ _________
_________
Also stationary Ms:
In lung:
In liver:
In bone:
In brain:
etc.

9. Phagocytosis
Patrolling and stationary WBCs attack and destroy pathogens/foreign molecules nonspecifically
Fig 15-1

10. Adaptive (Specific) Immunity
Antigen (pathogen) specific Overlaps with innate immunity 1o cell type involved? __________________ two subgroups: 1) ___________ 2) ___________ Is systemic (= whole body involved) Has ___________ Uses cytokines (e.g. interleukins & interferons) for communication

11. 2 Branches of Acquired Immune System:
Humoral or ___________ mediated
Cellular or ______ mediated

12. Humoral Immunity Memory cells Effector cells
Virgin (naïve) B Lymphocyte
Compare to Fig 15-7
Memory cells
Effector cells

13. Antibodies = Immunoglobulins
Fig 15-8
Heterogenous group of molecules: 5 subclasses

14. Fig 15-9

15. 5 subclasses of Igs:
Ig G: main ab in serum; + main ab during 2o response
Ig A: main ab is external secretions
Ig E: main ab in allergic reactions
Ig M: ab on virgin B-cells; + main ab during 1o response
Ig D: ab on virgin B-cells

16. 2 immune response: stronger & more rapid
Mostly Ig Ms
2 immune response: stronger & more rapid
Importance of Immunizations!!
due to??
< 2 h
Ig Gs
Fig 15-20

17. Antibody functions by “working against foreign body”

18. B lymphocytes ________ cellular immunity humoral vs. review
T lymphocytes
cytotoxic (killer)
helper
memory
review

19. T-Cell Development TCR cannot bind free ag!
Ag must be presented by APC in connection with MHC molecule
TCRs can only bind to MHC-ag complex
Tc activated by
Th activated by

20. Importance of MHC molecules
High # of MHC alleles in population (Transplant rejection in case of incompatible MHC) MHC class I: found on surface of all nucleated cells – used to present peptides from intracellular invaders or cancer cells T-cytotoxic cell recognizes MHC I MHC class II: found on surface of APCs T-helper cell recognizes MHC II

21. TC Action: one of 2 Mechanisms
1) Perforin molecules
create protein channels
in target cell membrane
Granzymes enter and trigger
apoptosis in target cell
Youtube

22. Viral Infections require Tc-cells
Initial response similar to bacterial infection, then
Intracellular defense mechanisms needed once virus enters host cell. Tc → reacts to viral ag presented by MHC __ complex
Activated M release - interferons. These induce ________________________

23. Active vs. Passive Immunity
Active: Exposure to ___________ Passive: Transfer of antibodies or immune cells into non-immune host

24. Allergy Inflammatory immune responses to non-pathogenic antigens
Symptoms range from mild tissue damage to fatal
Immediate Hypersensitivity: e.g.: ___________ _______________ ab mediated (Ig___)
Delayed Hypersensitivity: e.g.: _______________ due to T-cell abnormality

25. Sensitization phase = 1o immune response.
What is an allergen?
Strong genetic predisposition
Sensitization phase = 1o immune response.
Reexposure: 2o immune response
Anaphylaxis  Hives, bronchoconstriction and widespread vasodilation  ?
Fig
Immediate
Type HS

26. Poison Oak
Delayed
Type HS
Tc cells (attracted by lymphokines) release lytic enzymes and perforins  destroy allergen and skin cells.

27. Immune Response Pathways: 4) Organ & Tissue Transplants
MHC (= HLA) are the 1º tissue antigens Establishment of “self tolerance” during T cell development ABO (and Rh) blood typing (AA, AO, BB, BO, AB, OO) Blood transfusion problems due to antibodies in plasma  Transfusion reaction with hemolysis and possible kidney damage

28. Recognition of Self the end
Important function of IS: Self-tolerance through clonal ______________
Failure of self tolerance: _______________
the end