Transplant (Review) Flashcards
Transplant Rejection
Alloantigen – a genetically determined antigen present in some but not all individuals of a species that is capable of inducing an ____.
class I/class II = alloantigen (classic version) > they are self molecules, but they all differ from one another; not the natural purpose/function of MHC molecules
why transplants are rejected > recognizes non-self class I/II molecules
bone marrow transplant > used to reconstitute immune system in disseminated tumors
they’re treated by radiation/chemo before they get the transplant > donor cells that react against the host cells (graft vs. host disease)
immune response
Patterns of Graft Rejection
skin graft experiments
acute rejection> what happened in that siutation was an activation of ____ (mainly a ____ form of immunity); in organ transplants this is the issue > activation of CD4 and CD8 reacting against foreign MHC molecules
hyperacute > recipient of graft has a prexisting population of ____ that can bind to molecules on surfaces of donated cells > antibody directed against ____ or ____ or ____ antigens; as soon as BV of recipient are connected to BV of donor organ (kidney) and blood flows through grafted tissue > Ab binds ot molecules on surfaces of endothelial cells > and other surfaces once endothelium is broken down; example of where Ab binding to own cells can activate ____ (activating MAC and osmotic lysis); you can ____ this happen before your eyes (not reversible); avoid by doing blood-type matching (no difference in ABO types, no Rh incompataibility) and if they have circulating antibody against MHC molecules
chronic > takes longer to manifest (____); due to recognition of different group of histcompatbiilty antigens (____) > with immunosuppressive protocols this isn’t common
any 3 are potential outcomes when talking transplant; recipient against graft, or cellular transplant can be cells of graft against recipient
T cells
cell-mediated
Ab MHC complex RH ABO blood group complement SEE
months
minor
Direct vs. Indirect Recognition
T cells of recipient recognize foreign MHC molecules with a peptide in them…
if the configurations look similar, it can interact with ____ (direct recognition)
other possibiltiy, APC take up MHC molecules are grafted tissues are dying and process and present normally, and so foreign MHC is introduced into the ____ (indirect)
what actually occurs in the combo of both mechanisms
non self-MHC
self-MHC
Transplant Rejection
immunosuprressive protocols > cyclosporine, and FK5O6 (takrolimice) > if take drugs can induce drug induced ____; mechanism is to block activation of T cells; inhibit ____ and the ____ (from helper T)
most immunosuppressive protocols are directed at the inhibition of ____
gingival overgwoth
IL2
IL2R
T cells