How are antigens presented by MHC?

The usual process of antigen presentation through the MHC I molecule is based on an interaction between the T-cell receptor and a peptide bound to the MHC class I molecule. There is also an interaction between the CD8+ molecule on the surface of the T cell and non-peptide binding regions on the MHC class I molecule.

What does antigen presentation on MHC I signal to the immune system?

Antigen Presentation with MHC I Molecules MHC I molecules, found on all normal, healthy, nucleated cells, signal to the immune system that the cell is a normal “self” cell.

Is antigen presentation by MHC adaptive?

Major Histocompatibility Complex (MHC) Class I and MHC Class II Proteins: Conformational Plasticity in Antigen Presentation. Antigen presentation by major histocompatibility complex (MHC) proteins is essential for adaptive immunity.

How does the antigen MHC complex work?

The function of MHC molecules is to bind peptide fragments derived from pathogens and display them on the cell surface for recognition by the appropriate T cells. The MHC genes are, in fact, the most polymorphic genes known.

What does an antigen bound to MHC I on the surface of a cell indicate about that cell?

Antigens generated endogenously within these cells are bound to MHC-I molecules and presented on the cell surface. This antigen presentation pathway enables the immune system to detect transformed or infected cells displaying peptides from modified-self (mutated) or foreign proteins.

What is the role of MHC molecules in the recognition of infected cells by NK cells and what is the physiological significance of this recognition?

The loss of inhibitory signaling by MHC-specific receptors is responsible for the capacity of NK cells to attack class I-deficient cells. Because inhibitory receptors discriminate allelic variants of class I molecules, NK cells also attack MHC-different cells.

How antigen is processed and presented on the surface of class MHC?

The route of processing for exogenous antigens for MHC class II presentation begins with endocytosis of the antigen. MHC class II molecules are transported into endocytic vesicles where they bind peptide antigen, and then travel to the cell surface.