Lecture 26 - Transplant Immunology Flashcards
1
Q
Why do we perform transplants
A
- treatment of a variety of medical conditions including end-stage organ failure, chronic diseases, malignancies
2
Q
What antigens are a concern in transplantation
A
- major histocompatibility complex molecules
- ABO blood group antigens
- minor histocompatibility antigens
3
Q
What are class I HLA
A
- polymorphic monomer with B2 microglobulin
- expressed on all nucleated cells and platelets
- expression levels varies on cells
4
Q
What are class II HLA
A
- heterodimer of polymorphic A and B chains
- expressed on antigen presenting cells (b cells)
- can be upregulated on other cells
5
Q
What does class II do in the immune response
A
- expressed on antigen presenting cells
- present peptides derived from exogenous antigens
- restricted to CD4 T cells
6
Q
What does class I do in the immune response
A
- expressed on all nucleated cells and platelets
- present peptides derived from small endogenous proteins, such as viruses or self-protein fragments
- restricted to CD8 T cells
7
Q
What does HLA polymorphism allow for
A
presentation of different repertoires of peptides to T cells
8
Q
How is HLA inherited
A
- follows mendelian inheritance
- antigens are co-dominantly expressed
9
Q
How is HLA recognized by the immune system
A
can be recognized by T cells and B cells
10
Q
What is the indirect pathway
A
- peptides derived from donor HLA presented to recipient T cells by recipient APCs
11
Q
What is the direct pathway
A
- intact donor HLA presented to recipient T cells by donor APCs
