What type of antigen is present in the Major Histocompatibility Complex (MHC)?

The Human Leukocyte Antigen (HLA) is the one type of antigen present in the Major Histocompatibility Complex (MHC). It plays a crucial role in the MHC’s function. 

There are various types of HLA present in MHC Class I and MHC Class II. 

• The three types of HLAs present in MHC Class I are HLA-A, HLA-B and HLA-C. 
• The three types of HLAs present in MHC Class II are HLA-DR, HLA-DQ, and HLA-DP.

HLA is responsible for identifying foreign substances within the body. It first detects whether a substance is foreign. If the substance originates from the body, the appropriate HLA signals MHC Class I. If the substance is a foreign antigen that has not originated from the body, the HLA signals MHC Class II, triggering an immune response.