overview of immunology

Question 1

Describe the role of immune system in host defense

Answer 1

defense against foreign antigens: Innate immunity, Adaptive immunity

Question 2

Explain tolerance and consequences of loss of tolerance

Answer 2

Tolerance: recognize self from nonself.

Loss of tolerance: autoimmunity. Self is attacked

Question 3

Describe properties of antigens and which types of molecules are most immunogenic

Answer 3

1. Foreign
2. Chemically complex
3. MW >6kD
   Immunogenicity: Proteins, polysaccharides, nucleic acids, lipids (highest to lowest)

Question 4

3 terms that are used to refer to the component of the antigen with which receptors on immune cells interact

Answer 4

1. Epitope
2. Antigenic Determinant
3. Determinant

Question 5

3 chemical barriers

Answer 5

1. Lysozyme: present in secretions (tears, sweat, saliva) splits the cell wall of bacteria
2. Spermine: in semen to destroy bacteria to protect sperm
3. Acid pH in the stomach: destroy bacteria

Question 6

2 physical barriers

Answer 6

Skin and mucosal linings

Question 7

Name the four defining characteristics of innate and adaptive immune system

Answer 7

Adaptive: Exquisite Specificity
                  Lag time for first exposure
                  Memory
                  Adaptivity
Innate has none of these things

Question 8

List cells of Innate and Adaptive immunity

Answer 8

Innate cells: Macrophages, Neutrophils, NK cells, dendritic cells. Mast cells, basophils, eosinophils (cytokines, chemokines)
Adaptive cells: T cells and B cells

Question 9

explain the role of each primary lymphoid tissues

Answer 9

Bone Marrow: makes B cells, eosinophils, basophils, monocytes, granulocytes, dendritic cells, mast cells.
Thymus: makes T cells.
These have central tolerance induction: if B/T cells have antigen receptors for self are destroyed on the spot. they never leave.
Peripheral tolerance: cells that escape and have these self antigen receptors need to be deleted.

Question 10

Explain the role of secondary lymphoid tissues

Answer 10

Lymph nodes, tonsils/adenoids, Spleen, MALT: sites of action against antigens (adaptive response)

Question 11

Lymph Nodes

Answer 11

primary follicles-B cells mature resting
secondary follicles- have germinal centers, active B cells.
- there are also macrophages, dendritic cells, follicular dendritic cells in the cortex.

Paracortex: mostly T cells with some dendritic cells
Medulla: macrophages, dendritic cells, and Plasma cells

Question 12

Spleen

Answer 12

encapsulated, red pulp, white pulp.
White pulp=functions as the secondarylymph tissue.
PALS (periarterial lymphatic sheath surrounds central arteries/arterioles is rich in T cells. 1* and 2* follicles are outgrowths from PALS and are rich in B cells. Marginal zone contains dendritic and macrophages.

Question 13

MALT (mucosa), GALT (Gut), BALT (Bronchus)

Answer 13

these regions have gaps that allows microbes to penetrate lining. They enter via M cells to enter Lamina Propria. LP is the site of follicles, phagocytic cells, dendritic cells, lymphocytes.
Follicle associated epithelium: has M cells (no goblet cells)
M cells have few lysosomes indicating that ther are not phagocytic cells. They have lots of vescicles so they are for transport.

Question 14

3 examples of sites of entry

Answer 14

Peyers Patches is the GALT
Lymph Nodes in Lymph
Spleen for Blood

Question 15

Cytokines/chemokines

Answer 15

small peptides secreted mainly by activated leukocytes. different cytokines can produce same response (functional redundancy)(pleitropic)

chemokines: cause leukocytes accumulation,
* Chemokines are chemoattractants but not all chemoattractants are chemokines.

Question 16

Compliment

Answer 16

term for a family of proteins that facilitate elimination of microorganism. Most of the proteins are made in the liver and circulate as dormant enzymes serving as substrates for other complement proteins that have themselves been activated.