Major Histocompatibility Complex (MHC)

These flashcards cover key concepts related to the Major Histocompatibility Complex and its role in immunology, antigen presentation, and immune response.

Major Histocompatibility Complex (MHC)

A gene cluster that encodes glycoproteins (MHC molecules) for antigen presentation.

Antigen-Presenting Cells (APCs)

Cells that utilize MHC molecules to present antigens to T cells.

MHC restriction

The requirement that an antigen must bind to an MHC molecule to trigger an immune response.

Class I MHC Molecules

MHC molecules presented on all nucleated cells; they present endogenous antigens to CD8+ T cells.

Class II MHC Molecules

MHC molecules present only on professional antigen-presenting cells; they present exogenous antigens to CD4+ T cells.

Endogenous pathway

The process by which MHC Class I molecules present peptides derived from proteins synthesized within the cell.

Exogenous pathway

The process by which MHC Class II molecules present peptides derived from external proteins that are internalized by APCs.

Polymorphism in MHC

The existence of multiple alleles of MHC genes that allows diverse immune responses to different antigens.

Heterozygote advantage

The phenomenon where heterozygous individuals have a greater immune response to a wider range of pathogens than homozygous individuals.

CLIP (Class II Associated Invariant peptide)

A peptide that occupies the binding groove of MHC Class II molecules until a more appropriate antigenic peptide replaces it.