BS: Cell-Mediated Immunity

Question 1

Differences between T-cell and antibodies

Answer 1

1. T-cells recognize different antigens then antibodies
2. T-cells require the antigens to be peptides
3. T-cells require antigens be presented on the surface of other cells via MHC

Question 2

Similarities between T-cells and antibodies

Answer 2

1. Diversity in antigen binding
2. Generated in a similar manner
3. Purpose is to recognize antigens

Question 3

Cell mediated immunity cells

Answer 3

T-cells

Question 4

T-cell place of maturation

Answer 4

Thymus

Question 5

Classes of T-cells

Answer 5

CD4, CD8

Question 6

Precursor cells to T-cells

Answer 6

Lymophocyte

Question 7

T-cell receptor structure

Answer 7

Contains both alpha and beta chains that variable domains

Question 8

T-cell receptor variability in relation to antibody variability

Answer 8

T-cell variability is two orders greater than antibodies

Question 9

How “self” is indicated in the body

Answer 9

A cell surface protein aggregate, MHC

Question 10

MHC

Answer 10

Major histocompatibility complexes, previously known as HLAs

Question 11

Classes of MHCs

Answer 11

MHC-I and MHC-II

Question 12

Expression of MHC genes

Answer 12

Co-dominant; creates high variation

Question 13

MHC-II expressing cells

Answer 13

Dendritic cells, macrophages, B-cells

Question 14

MHC-I expressing cells

Answer 14

All nucleated cells (all cells except RBCs)

Question 15

Two steps required to activate T-cell

Answer 15

1. CD4 binding to MHC-II

2. T cell receptor recognizing the peptide that’s presented by the MHC-II

Question 16

CD4 (another name)

Answer 16

T-helper cells

Question 17

CD8 (another name)

Answer 17

Cytotoxic killer cells

Question 18

CD4 (functions)

Answer 18

Support macrophages, send out chemokines, chemotaxis, promote inflammation, make memory cells, promote immunity

Question 19

CD8

Answer 19

Killer cells, kill infected cells; eliminate reservoirs of infection

Question 20

CD4 (type of pathway)

Answer 20

Antigen-presenting cells display cell to trigger immune response

Question 21

CD8 (type of pathway)

Answer 21

Regular cell present antigen to trigger destruction

Question 22

T-Regs (description)

Answer 22

T-regulatory cells; can inhibit immune activity

Question 23

T-Regs (derived from)

Answer 23

Self-reactive T-cells

Question 24

AIRE

Answer 24

Protein in thymus that enables thymic expression of proteins from other tissues (allows thymus to test T-cell reactivity)

Question 25

Types of T-cells killed by thymus

Answer 25

1. Strong reactivity to both MHC-I and MHC-II | 2. No reactivity to either MHC-I and MHC-II

Question 26

CD28

Answer 26

Co-stimulator of CD4, binds to a protein called B7; required for full activation of T-helper cell

Question 27

Full T-helper cell activation requires:

Answer 27

1. APC presents MHC-II with an antigen peptide to CD4 | 2. APCs has B7 that binds to T-helper cell's CD28

Question 28

B7

Answer 28

Modulates T-helper cell response; as the infection develops the amount of B7 expressed by APCs increases

Question 29

CTLA4

Answer 29

Binds B7 and prevents CD28 from binding, preventing full T-cell response

Question 30

PD-1

Answer 30

Binds B7 to prevent full T-cell response