MHC Restriction Flashcards
What does negative selection test for
To make sure cells are not self reactive
What is the direct pathway for allorecognition
An APC From the donor presents a peptide to the T helper cell of the recipient. This induces an immune response to the donors cells
Which antigens mediate allograft tissue rejection
Major histocompatibility molecules
Minor histocompatibility molecules
Other alloantigens
Immunity to grafted tissue has memory
T cell mediated immunity
Antibody-mediated immunity
NK cell mediated mechanisms
What is the cause of hyper acute transplant rejection and what is the time frame
Pre existing antibodies to ABO or donor HLA class I
Minutes to hours
What is the cause of acute transplant reaction and what is the time frame
Involvement of alloreactive T cells
Days to weeks
What is the cause of chronic organ transplantation and what is the time frame
Alloreactive T cells via indirect recognition
Months to years
What you call identical animal/donor
Syngeneic
What you call a mismatch of donor/recipient
Fully allogeneic
If a donor is B and a recpient is A and B would it be accepted?
Accepted
If a donor is A and B and the recipient is A, would the graft be accepted or rejected
It would be rejected
What do corticosteroids do
Inhibit inflammatory protein synthesis (NFkB)
Low doses affect AC
High doses affect T cells
What does cyclosporine and FK506 do
Inhibits calcineurin (Ca++ signaling) impairs production of IL-2 (T cell growth factor
What does Rapamycin do
Inhibits mTOR and T cell proliferation
What is t he riskiest type of transplantation
Stem cells
GVHD is associated with
Stem cell tranpslantation when the donors T cells react
What do PMNs protect you from
Sepsis
What do T cells protect you from
Intracellular and fungal infections
What do B cells protect you from
Encapsulated bacteria
What is the mechanism of immunosuppressive therapy to prevent chronic rejection generated from an immune response
T lymphocyte activity
A patient has low CD4 levels and normal CD8 and B cells. Whhat is most likely the T lymphocyte activity deficiency in this patient
MHC-II
In chronic rejection, what is the immunologic effector mechanism?
CD8 lymphocytes
