Transplantation Flashcards
autologous graft
aka isograft
transplanted from an individual to the same individual
syngenic graft/syngraft
transplant between 2 genetically identical individuals like identical twins
allogenic graft
transplant between 2 genetically dissimilar individuals of the same species
xenogeneic graft
transplant between members of 2 different species
orthotopic transplant
graft placed in its normal anatomical location
heterotopic transplant
placed in an anatomically different site
first set rejection
rejected in 7-10 days, similar to primary immune response
second set rejection
transplanted again, rejected in 2-3 days, similar to secondary immune response
privileged immune sites perks
- extracellular fluid here doesnt leave through the lymphatic system
- TGF-B an inhibitory cytokine is produced
- Fas ligand that reacts with Fas on lymphocytes to induce apoptosis
2 types of acute rejection
takes place within 1 month of transplantation
- acute humoral rejection: antibody & complement mediated
- acute cellular: lysis via CTLs, NK cells, and macrophages
alloreactivity
most important mechanism for T helper cell activation
t cell recognized unprocessed allogeneic MHC mcl on graft APC
step 1 alloreactivity
- direct & indirect dentritic cell presentation of alloantigens
- stimulates CD4 alloreactive t cells to be activated
step 2 alloreactivity
- CD4 t helper cells provide IL-2 and IFN gamma to CD8 cells to produce CTLs
- CTLs lyse graft cells
- alloreactive B cells produce anti graft antibodies
corticosteroids
lyse immature thymocytes
block release of cytokines from macrophages
inhibit leukocyte migration
cyclosporine
drug for immunosuppression
inhibits IL-2 and IFN-gamma
prevents activation of cell mediated immunity
