lecture 17- transplantation immunology

Question 1

what is an example of an immunologically privileged site

Answer 1

cornea

Question 2

define autograft

Answer 2

grafts exchanged from one part to another part of the same individual

Question 3

define isograft

Answer 3

graft exchanged between different individuals of identical genetic constitutions

Question 4

define allograft

Answer 4

graft exchanged between nonidentical members of the same species

Question 5

define xenograft

Answer 5

graft exchange between members of different species

Question 6

graft rejection is mediated by ______

Answer 6

lymphocytes

Question 7

describe direct allorecognition

Answer 7

T cell recognizes unprocessed allogeneic MHC molecule on graft APCs

Question 8

describe indirect allorecognition

Answer 8

T cell recognizes processed peptide of allogeneic MHC molecule bound to self MHC molecule on host APC

Question 9

when is indirect allorecognition particularly important

Answer 9

during chronic rejection

Question 10

define chronic rejection

Answer 10

when the number of donor professional APCs is too low to stimulate a direct immune response

Question 11

what is the cause of hyper acute rejection

Answer 11

performed antidonor antibodies and complement

Question 12

what is the cause of accelerated rejection

Answer 12

reactivation of sensitized T cells

Question 13

what is the cause of acute rejection

Answer 13

primary activation of T cells

Question 14

_____ plays an important role in triggering acute rejection

Answer 14

Donor DCs

Question 15

what does clotting cascade generate

Answer 15

fibrin and fibrinopeptides

Question 16

what do fibrinopeptides do

Answer 16

increase local vascular permeability and serve as chemoattractant for neutrophils and macrophages

Question 17

what does the kinin cascade produce

Answer 17

bradykinin that causes vasodilation, smooth muscle contraction, increased vascular permeability

Question 18

what is ABO matching NOT important for

Answer 18

corneal transplantation, heart valve transplantation, bone and tendon grafts

Question 19

what is cross-matching used for

Answer 19

to test the recipient serum for preformed Abs against donor’s HLAs

Question 20

what are lymphocytes from the recipient that are intact called

Answer 20

responder cells

Question 21

what is proliferation of responder cells measured by

Answer 21

incorporation of tritiated thymidine

Question 22

describe host-versus graft disease

Answer 22

when a kidney is transplanted, the recipient’s T cells attack the transplant

Question 23

describe graft-versus host disease

Answer 23

when bone marrow is transplanted, the T cells in the transplant attack the recipients tissues

Question 24

what type of T cells and cytokines are involved in humoral graft rejection

Answer 24

Th2 (IL-4, IL-5, and IL-10)

Question 25

what type of T cell and cytokines is involved in cellular graft rejection

Answer 25

Th1 (IL-2, IFN-gamma)

Question 26

what is GVHD caused by

Answer 26

reaction of grafted mature T cells in the tissue transplant with allo-Ags of the host

Question 27

describe acute GVHD

Answer 27

epithelial cell death in the skin, liver and GI

Question 28

describe chronic GVHD

Answer 28

fibrosis and atrophy of affected organ