Core Immunology - MHC and Transplantation (14)

Question 1

Blood groups - anti

Answer 1

Naturally occuring anti-A/anti-B isoagglutinins

Question 2

Isoagglutinin

Answer 2

Causes agglutination of RBC of another individual of same species

Question 3

Peter Alfred Gorer

Answer 3

Tumour transplantation between mouse strains (discovery MHC)

Question 4

Sir Peter Medawar

Answer 4

Skin allograft rejection in burns victims (discovery MHC)

Question 5

MHC (Major Histocompatibility Complex)

Answer 5

Set of genes found in all vertebrae

Question 6

MHC have role in

Answer 6

Immune function, disease susceptibility, reproductive success, histocompatibility and graft survival (membrane bound glycoproteins)

Question 7

Proteins encoded by MHC

Answer 7

Expressed at cell surface and function to present as ‘self and non-self’ antigens for inspection by T cell antigen receptors

Question 8

HLA complex (Human leukocyte antigen) =

Answer 8

MHC

Question 9

MHC class 1

Answer 9

Found on all nucleated cells (transplantation)

Question 10

MHC class 2

Answer 10

Expressed on antigen presenting cells (B cells, dendritic) expression can be induced on T cells (transplantation)

Question 11

Inheritance of MHC

Answer 11

Mendelian inheritance, inherited two antigens at a given locus, co-dominant expression (all inherited antigens displaced on cell surface)

Question 12

HLA polymorphism

Answer 12

Highly polymorphic, large number of allelic variants at each locus (survival advantage), important in capacity of individual to mount immune response to antigen

Question 13

Semi-direct recognition of foreign tissue in transplantation

Answer 13

Involved only in vitro

Question 14

Direct recognition of foreign tissue in transplantation

Answer 14

(Shouldn’t occur), WBC of donor migrate into recipient, interact directly with recipient T cell > recognise donor cell surface as HLA > T cell proliferation > immune response > migrate back to graft > damage (occurs immediately on transplantation)

Question 15

Indirect recognition of foreign tissue in transplantation

Answer 15

Foreign protein picked up by recipients WBC/dendritic, broken down and presented MHC > damage graft (normal response)

Question 16

Sensitisation

Answer 16

Event which elicits HLA directed immune response (pregnancy, blood transfusion, transplantation)

Question 17

Tests for sensitisation

Answer 17

Serum screening (monitor determine HLA), cross-matching (final check)

Question 18

Flow cross match

Answer 18

T cell suppress HLA on surface, add patient serum, if Ab will bind to foreign HLA on surface, add reporter molecular and laser

Question 19

Hyperacute rejection

Answer 19

Carry out transplant despite rejection, Ab bind > activate clotting cascade and complement pathway, lose integrity of vascular endothelium > leaky > organs necrotic > fatal