Are MHC antigens?

MHC is the tissue-antigen that allows the immune system (more specifically T cells) to bind to, recognize, and tolerate itself (autorecognition). MHC is also the chaperone for intracellular peptides that are complexed with MHCs and presented to T cell receptors (TCRs) as potential foreign antigens.

Why does the body reject blood transfusions?

It is common for patients to make antibodies to HLA antigens in response to transfusions or pregnancy. When platelets are transfused to a patient with corresponding HLA antibodies they are very rapidly cleared from circulation, which is essentially immediate rejection of the transfusion.

What are two unique properties of MHC HLA proteins that make them so critical to match between donor and recipient?

2.4. Normally, T cells are not activated by peptides derived from self-cells, but they are activated by peptides from non-self cells that are displayed by the MHC class I molecules through T cell receptor (TCR). Thereafter, these activated T cells attack non-self cells and prevent the growth of non-autologous cells.

What is an MHC protein and why is it significant immunologically What does MHC stand for?

major histocompatibility complex
major histocompatibility complex (MHC), group of genes that code for proteins found on the surfaces of cells that help the immune system recognize foreign substances. MHC molecules were initially defined as antigens that stimulate an organism’s immunologic response to transplanted organs and tissues.

What does the immune system create to fight against foreign blood cells?

B lymphocytes produce antibodies – proteins (gamma globulins) that recognize foreign substances (antigen) and attach themselves to them. B lymphocytes (or B cells) are each programmed to make one specific antibody.

Why might different MHC I molecules between donor and recipient cells lead to rejection of a transplanted organ or tissue?

Suggest a reason for this. If the MHC class I molecules expressed on donor cells differ from the MHC class I molecules expressed on recipient cells, NK cells may identify the donor cells as not normal and produce enzymes to induce the donor cells to undergo apoptosis, which would destroy the transplanted organ.

What role do antibodies play when a person receives a blood transfusion from an incompatible blood donor?

That means people with type A blood create antibodies against B antigens. A person with type A blood receiving a transfusion of type B or AB blood would have an ABO incompatibility reaction. In an ABO incompatibility reaction, your immune system attacks the new blood cells and destroys them.