death

Question 1

Compare MHC 1 and MHC 2

Answer 1

MHC 1: beta microglobulin (Non constant) , 8-10 aa , alpha chain, cytoplasmic chain , non convelantly bonded, a2 a1joined by peptide bonding groove , C8 interacts with a3 MHC 2: alpha and Beta Chain , CD4 interacts with bata 2

Question 2

Whats the role of IL8?

Answer 2

Chemotactic for neutrophils

Question 3

whats the role of IL6?

Answer 3

mediator for acute phase proteins

Question 4

Whats teh role of IL12 ?

Answer 4

Directs adaptive immune response Activates NK Cells

Question 5

Whats teh role of TNF alpha ?

Answer 5

alarm cytokine

Question 6

Whats the role of IL1 ?

Answer 6

Fever, alarm cytokine

Question 7

What are C3 and C5a ?

Answer 7

Anaphylatoxins

Question 8

How to CTL kill cells?

Answer 8

Fas and FasL ( TCL cells) perforin allows granzyme to enter Upregulate CASPASES

Question 9

What does IFN - gamma do ?

Answer 9

cytokine againsts viral bacterial infections

Question 10

How do T cells mature ?

Answer 10

Precursors progenitor cells made in BM then migrate to thymus mature in cortex to medulla of thymus Originally they are CD4- and CD8- Cortex express TCr precursor Medulla: different ab TCR are made via gene rearrrangement

Question 11

75. Distinguish between the exogenous and the endogenous antigen presentation pathways and the T-cells involved

Answer 11

MHC 2 = exogenous antigen , peptide cleaved by proteases , MHC transported to RER and associated with invariant chain, MHC2-IC-complex moved to golgi in endosome, IC ingested by CLIP (C2 associated invariant chain peptide), CLIP exchanged for antigenic peptide MHC1= endogenous antigen, cleaved via proteosome, taken to RER via TAP ( transporter associated with antigen presentation) , Golgi trafficks to surface

Question 12

Whats the main differnce between TH1 and Th2?

Answer 12

TH1= cell mediated, make IFN-gamma, boost intacellular esponse,macrophage activation , DTH reactions, dwon regulate th 2 responses Th2= multicellular organism , b cell proliferation, produce IL4 IL5 and IL13

Question 13

How does central tolerance occur in B cells

Answer 13

• if immature B cell in BM encounters antigen in a form where it can crosslink IgM apoptossi occurs - In BM if maturaing B cell bind to antiegn apoptosis –> apooptosis x proloferation - stromal cells display all self antigens

Question 14

TCR structure

Answer 14

Question 15

AID enzyme

Answer 15

GC –> AT

c –> U bases