cooperation

Question 1

Endo cytosolic antigens 1) name the processes 2)name the enzymes

Answer 1

Class 1 MHC 1) Synthesis of class I, Assoc of peptide with class I, Transport from ER, Expression of MHC 1 peptide at cell surface 2) Peptide transporter protein, TAP and proteasome, which degrades antigen to peptides

Question 2

exogenous antigens 1) name the steps 2) another name for the class 3) how does peptide enter ER

Answer 2

1) Synthesis of class II, assembly of classII (invariant li chain blocks peptide binding site in Er), Transport from ER, Peptide associates with class II, displaces li, Expression of MHC 2 2) Class 2 isknown as APCs 3) The antigen enters via endocytosis, protein degradation

Question 3

How are T cells activated

Answer 3

When their TCR binds peptide antigens displayed on MHC molecules

Question 4

CD8+ cytotoxic lymphocytes present what class?

Answer 4

class 1, so from endogenous antigens

Question 5

CD4+ Helper T lymphocytes present what class?

Answer 5

Class 2 MHC

Question 6

The antigen presenting cell must do what to activate naive T cells?

Answer 6

Acquire and process antigen in compartments which gain access to MHC1 and MHC2 pathways

Question 7

What are the 3 signals for the effective activation of naive T cells

Answer 7

1) Present MHC associated peptides to T cells 2) Provide co stimulation for T cell expansion 3) Induce T cell differentiation

Question 8

What are the best antigen presenting cells?

Answer 8

Dendritic

Question 9

How do APCs become activated?

Answer 9

By binding PAMPs

Question 10

Once the APC has become activate, what happens?

Answer 10

They migrate to local lymph nodes to present the antigen to T cells

Question 11

Dendritic cells in non inflammed tissues are highly efficient at what but are also poor what and why

Answer 11

Efficient at capturing an antigen but very poor as stimulators of naive T cells. They are active in noticing their surrounding environment due to mannose and FcR receptors. But migration to the draining lymph nodes is restricted, low level of MHC 2 on plasma membrane. Secrete TGF beta

Question 12

Dendritic cell maturation is essential for what 1)initiated how? 2) signalling occurs following ligation of?

Answer 12

for activation of naive t cells 1) initiated by binding of pathogens 2) signalling by PRR on the DC following ligation with molecular patterns PAMPS on pathogens

Question 13

DC maturation event are indued by?

Answer 13

PAMPs

Question 14

Binding PAMPs to dendritic cell PRR induces what 7 things

Answer 14

Migration of DC to the lymphoid tissue via lymphatics. Inreased antigen processing. Increased surface expression of MHC 1 and 11. Increased surface expression of adhesion moelcules. Expression of costimulatory molecules (cd80, cd86). Secretion of cytokines, TGF beta, IL6, IL12

Question 15

Maturing DCs loose capacity to what?

Answer 15

capture antigen

Question 16

What are the 3 signals of licensed DCs

Answer 16

Display pathogen peptides on MHC -S1 upregulate expression of adhesion (eg ICAM-1) molecules and express co- stimulatory molecules (eg CD80, CD86) – Signal 2 Secrete selected cytokines Signal 3

Question 17

Adhesion between T cells and APC is essential and how does this ocur and give example

Answer 17

Involves specific receptor ligand interactions and these result in firm binding. ICAM1 on APCs and LFA1 on T cells

Question 18

Descrive the activation of CD4 T cells due to the induction of CD80 and CD86, so describe the first 2 signals

Answer 18

signal 1) Binding the TCR to MHC peptide signal 2) Ligation of CD28 on the T cells by CD80, CD86 on the mature dendritic cell provies signals to induce activation and proliferation of the naive antigen specific T cell

Question 19

After recieiving signal 1 and 2, the activated CD4 Tcell now 1) expresses what? 2) Expresses and secretes what? 3) what is signal 3 4) Signal 3 facilitates activated CD4 TH to what?

Answer 19

1) CD40L 2) Expressed IL2R and secretes IL2 and proliferates 3) Signal 3, differentiates to perfom its effector function so it helps neuts, B cells, CD8 T cells 4) causes the T helper cells to differentiate along several possible pathways

Question 20

Describe the pathways for the T helper cell

Answer 20