Diebel Specific Acquired Immunity

Question 1

What causes naive lymphocyte to proliferate?

Answer 1

antigen binding

Question 2

Describe humoral immunity:

Answer 2

B cells releasing antibody into tissue fluids, blood and secretions.

Question 3

Describe cell-mediated immunity:

Answer 3

T-cells themselves survey the surface of the body’s cells, looking for ones that have parasites within them or that are dangerously changed or mutated.

Question 4

MHC I is recognized by ______ T-cells?

Answer 4

CD8+ killers

Question 5

MHC II is recognized by ______ T-cells?

Answer 5

CD4+ helpers

Question 6

Another name for MHC molecules:

Answer 6

HLA (human leukocyte antigens)

Question 7

Regions on an antigen that can be recognized by an antibody or by T-cell receptors:

Answer 7

Epitopes

Question 8

Type of cytokine released by activated T-cells that have travelled to the site of infection:

Answer 8

lymphokines

Question 9

An example of a lymphokine is INF-gama. What is its function at the infection site?

Answer 9

Stimulates M1 “angry” macrophages

Question 10

Five subtypes of helper T-cells with CD4 molecular marker:

Answer 10

1. Th1
2. Th2
3. Th17
4. Tfh
5. Treg

Question 11

Cells that recognize antigen and produce lyphokines (INF-gama) to attract thousands of macrophages to wipe out infection or…

a transplanted kidney

Answer 11

Th1 (Type 1 helper T-cells)

Question 12

Similar to Th1’s but more powerfull. Implicated in many serious forms of autoimmunity.

Answer 12

Th17

Question 13

Type of cells that stimulate M2 macrophages

• promote healing
• important in parasite immunity

Answer 13

Th2

Question 14

Cells stimulated by antigen and migrate from T-cell areas of lymph nodes to B-cell follicles
-help B-cells get activated to produce IgM, IgG, IgE, and IgA

Answer 14

Thf (Follicular helper T-cells)

Question 15

Cells that make cytokines (IL-10) to suppress activation of Th1, Th2, and Th17
-keep immune response in check

Answer 15

Treg (Regulatory T-cells)

Question 16

Cells that destroy any body cell they identify as bearing a foreign or abnormal antigen on its surface (MHC-I).
-have CD8 molecular marker

Answer 16

Cytotoxic or Killer T-cells

Question 17

Describe T-cell activation via MHC-I APC:

Adhesion:

Ag-specific activation:

Co-stimulation:

Cytokine signals:

Answer 17

Adhesion: ICAM 1/3 (on APC) —- LFA-1 (T-cell)

Ag-specific activation: CD58 (APC) — CD2 (T-cell)

MHC I —- TCR

MHC I —- CD8

Co-stimulation: B7 (1 or 2) on APC —- CD28 (T-cell)

Cytokine signals: IL-1 (APC) —- IL-1R (T-cell) , paracrine

IL-2 (from other T-cells and self) —- CD25, autocrine/paracrine

Question 18

How does activation of T-cells by APCs differ from MHC-1 to MHC-II?

Answer 18

Co-stimulation is with CD4 — MHC II instead of CD8— MHC I

Question 19

Function of IL-2 and IL-15 with respect to T-cell activation:

Answer 19

general activators

Question 20

Function of IL-12 and IFN-gama with respect to T-cell activation:

Answer 20

Drive T helpers to Th1 subtype

Question 21

Function of IL-4 with respect to T-cell activation:

Answer 21

Drives helper cells to Th2 subtypes

Question 22

Function of IL-10 with respect to T-helpers?

Answer 22

down regulates Th1

Question 23

Function of TGF-beta with respect to T helpers?

Answer 23

down regulates both Th1 and Th2

Question 24

Describe dendrite’s role in activation of T-cells:

Answer 24

• encounters antigen and engulfs it
• travels to spleen or lymph node while digesting antigen and presenting it on its surface in an MHC II molecule
• encounters and activates a T-cell which initiates full blown adaptive immunity

Question 25

Two ways cytotoxic T-cells kill:

Answer 25

1. FAS-FAS ligand interaction induces apoptosis in infected target cell 2. by secreting toxic agents: - TNF- can induce apoptosis - Perforin- pore forming protein - Granzymes- induce apoptosis

Question 26

In negative selection of T-cells in the thymus, what happens if a T-cell recognizes "self" antigen on MHC II of the thymus epithelial cells?

Answer 26

they are driven to apoptosis and die

Question 27

Cluster of differentiation markers present on T-cells:

Answer 27

CD3 (part of TCR complex) CD4 or CD8 CD23

Question 28

Cluster of differentiation markers present on B-cells:

Answer 28

CD1 CD19 CD20 CD23 CD40 (interact with Thf to progress to plasma cells) CD79 (a and b) part of the BCR complex

Question 29

Unlike T-cells which require MHC for activation, B-cells are activated by:

Answer 29

direct binding with antigen via antibodies **now cell can differentiate and proliferate (usually with the help of Tfh)

Question 30

Fully differentiated B-cell is called:

Answer 30

Plasma cell -protein production factory for soluble antibodies

Question 31

Five types of antibodies:

Answer 31

IgA IgD (only on cell surface, not secreted) IgG IgE IgM

Question 32

Most abundant antibody in the body?

Answer 32

IgG **can bind an antigen and activate complement

Question 33

Only Ig that crosses placenta?

Answer 33

IgG

Question 34

Large antibody that is the first to appear in blood after exposure to antigen?

Answer 34

IgM **gets replaced by IgG after a week or two

Question 35

Only real job of IgD?

Answer 35

B-cell membrane antigen binding receptor

Question 36

Most important Ig in secretions like tears, saliva, GU, GI fluids, and milk?

Answer 36

IgA

Question 37

What protects IgA from digestive enzymes?

Answer 37

Secretory component

Question 38

Ig that attaches to Mast cells and causes production of leukotrienes, prosteglandins, and cytokines and release of histamine upon contact with an antigen?

Answer 38

IgE

Question 39

Ig associated with resistance to parasites as well as allergic reactions:

Answer 39

IgE

Question 40

Mucous membrane antibody?

Answer 40

IgA

Question 41

Ig's of deeper tissue like spleen and lymph nodes?

Answer 41

First IgM then later IgG

Question 42

Hypersensitivity mediated by IgE: **release of histamine by mast cells and basophils

Answer 42

Type 1

Question 43

Hypersensitivity of autoimmune origin in which antibodies can react to self antigens (ie. hemolytic disease, myesthenia gravis, Goodpasture's syndrome)?

Answer 43

Type II

Question 44

Hypersensitivity caused by antibody/soluble antigen too small for phagocytosis so complement initiates usual inlflammatory response and tissue damage is caused?

Answer 44

Type III ie. arthritis, SLE

Question 45

Cell mediated hypersensitivity caused by T-cells?

Answer 45

Type IV