CD8+ T cells immune Responses to Cytosolic Antigens

Question 1

Dendritic Cell encounters

Answer 1

exogenous antigen in circulation, it is endocytosis, processing and presentation en route to secondary lymphoid tissue

Question 2

Dendritic cells present

Answer 2

peptide MHC class II to CD4+Thp that secrete IL-2

Question 3

Clonal expansion happens after

Answer 3

Thp following IL-2 to IL2R

Question 4

cross presentation of endocytosed antigen leads to

Answer 4

peptide-MHC class I on antigen presenting cell hence presentation to pCTL

Question 5

Cross priming of

Answer 5

pCTL

Question 6

pCTL interactions

Answer 6

CD2 and LFA1 interact with dendritic cell LFA-3 and ICAM 1,2

Question 7

IL-2:IL2R interaction leads to

Answer 7

proliferation of the activated pCTL

Question 8

Proliferation =

Answer 8

clonal expansion

Question 9

Maturation from pCTL to CTL requies

Answer 9

7-10 days, IL-2 IFN-gamma

Question 10

Mature CTL functions in

Answer 10

immunosurveillance

Question 11

IL2R=

Answer 11

CD25

Question 12

Processing and Presentation to CD4+ T cells starts with

Answer 12

endocytosis of antigen into endosome, lysosome fuses with endosome and enzymes degrade the antigen

Question 13

Endosome lysosome vesicle fuses with

Answer 13

vesicle transporting class II MHC/invariant chain in vesicle and the lysosome degrades invariant chain

Question 14

Peptides bind to groove in

Answer 14

MHC class II

Question 15

Binding of peptide to MHC class I in

Answer 15

a vacuole and transport to the cell surface and then it is expressed on cell surface

Question 16

Presentation to pCTL=

Answer 16

Cross Priming

Question 17

Target cells of Mature CTLs have

Answer 17

antigenic peptide-MHC class I molecules on their cell surface

Question 18

antigen for mature CTL mustpresent in

Answer 18

target cell cytosol

Question 19

antigen destroyed by proteosome fragments presented to

Answer 19

TAP-1 and TAP-2 bind to MHC class I in endoplasmic reticulum, golgi vesicle transport complext to the cell membrane

Question 20

MHC class I peptide expressed on target cell surface is

Answer 20

recognized by circulating mature CTLs that are doing immunosurveillance(they have differentiated becasue of the same antigen)

Question 21

Interaction of the CTL with target cell leads to

Answer 21

destruction of target cell with perforin and granzymes

Question 22

after destroying a target cell a CTL will

Answer 22

continue with immunosurveillance

Question 23

Most activate CTLs will undergo

Answer 23

apoptosis but some will survive as memory cells.

Question 24

Virus is outside the cell when

Answer 24

released form cells or duing infectivity stage

Question 25

Host defenses when outside the cell

Answer 25

phagocytes, dendritic cells, B cells

Question 26

Dendritic cells when virus are outside the cell become

Answer 26

APCS for CD4+ Thp cells and cross presentation to CD8+ pCTL

Question 27

when virus is inside the cell, the cell

Answer 27

produces and secretes IFN Alpha

Question 28

IFN alpha binds to

Answer 28

cognate receptors on neighboring cells which leads to production of 25oligoadenylate synthetase

Question 29

2,5-OAS leads to

Answer 29

activation of RNaseL which degrades the viral and cellular RNA

Question 30

Host defenses when virus is inside the cell

Answer 30

NK cells and Cytotoxic T cells

Question 31

Plasma cells secrete

Answer 31

IgG antibodies that play a role in phagocytosis and NK cell mediated ADCC

Question 32

increased MHC expression on Target

Answer 32

reduces the likelihood that the infected cell will be destroyed by NK cells and strengthens the likelihood of desturction by CTLs

Question 33

decreased MHC expression on target

Answer 33

strengthens likelihood of destruction by NK cells and reduces for destruction by CTLs

Question 34

Human Immunodeficiency Virus infection receptor on target cells

Answer 34

GP120 on HIV binds to CD4 on target cells

Question 35

Target cells for HIV

Answer 35

CD4+ T cells, dendritic cells, macrophages

Question 36

Coreceptors on target cell for HIV

Answer 36

CXCR4 required for M-tropic strains of HIB and CCR5 required by T-tropic strains of HIV