Major histocompatibility complex (MHC)

Definition

Major Histocompatibility Complex (MHC) proteins are essential for the immune system to recognize foreign molecules. They play a critical role in antigen presentation to T cells.

5 Must Know Facts For Your Next Test

1. MHC molecules are divided into two main classes: MHC class I and MHC class II.
2. MHC class I molecules present antigens from intracellular pathogens to CD8+ T cells.
3. MHC class II molecules present antigens from extracellular pathogens to CD4+ T cells.
4. The genes encoding MHC molecules are highly polymorphic, allowing for a wide range of antigen presentation.
5. Each individual has a unique set of MHC alleles, which influences their immune response.

Review Questions

• What are the two main classes of MHC molecules and their primary functions?
• How do MHC polymorphisms benefit the immune system?
• Which types of T cells interact with MHC class I and II molecules?

Related terms

Antigen-Presenting Cells (APCs):

Cells that process and present antigens on their surface using MHC molecules.

CD8+ T Cells: A type of T cell that interacts with MHC class I molecules to kill infected cells.

CD4+ T Cells: A type of T cell that interacts with MHC class II molecules to help coordinate the immune response.