Blood Bank Lec. 3 MHC

What are MHCs?

• Proteins found on CELL SURFACES for:

  • Self recognition

  • Antigen Presentation

Where is the gene that codes for MHC molecules located?

SHORT ARM of chromosome

What are the 3 CLASS 1 MHC Molecules?

REMEMBER - CLASS 1 you learn your ABC

1. HLA-A

2. HLA-B

3. HLA-C

Where are MHC 1 molecules FOUND

ALL NUCLEATED CELLS

• MOST PROMINENT on lymphocytes and myeloid cells

What is the STRUCTUE of MHC 1 Molecules?

REMEMBER THEY ARE PROTEINS

• Glycoprotein DIMERS

• NON-COVALENTY linked

• More alpha than beta

What do MHC 1 Molecules Process?

Processes ENDOGENOUS ANTIGENS

• Antigen made within the body

• TUMORS, viral proteins made, SELF proteins

To which cells do MHC 1 Molecules present antigens to?

CD8+ T CELLS

Which cell DESTROYS target cells?

CD8+ Tc

Tc binds to the ANTIGEN-MHC1 COMPLEX and releases enzymes that DESTROY TARGET CELL

What are the 3 MHC 2 Molecules?

1. HLA-DP

2. HLA-DQ

3. HLA-DR

Where are MHC 2 Molecules PRIMARILY FOUND?

• ON ANTIGEN PRESENTING CELLS

  • Macrophages and Dendritic Cells

What is the Structure of the MHC2 molecules?

• Two noncovalently bound polypeptides

• EQUAL alpha and beta

What do MHC 2 molecules process?

• Process EXOGENOUS ANTIGENS

  • Antigens from bacteria OUTER INFECTIONS

To which cells do MHC 2 Molecules present antigens to?

• Present outer antigens to CD4+ HELPER CELLS (Th)

What do CD4+ Helper T cells do?

STIMULATE B cells to differentiate to PLASMA CELLS

HELP PLASMA CELL FORMATIION