What is the Difference Between HLA and MHC?
🆚 Go to Comparative Table 🆚The human leukocyte antigen (HLA) system and the major histocompatibility complex (MHC) are essentially the same, as HLA is the name given to the MHC in humans. Both terms refer to a group of genes that encode cell surface markers, antigen-presenting molecules, and other proteins involved in immune function. The main differences between HLA and MHC are:
- Species: MHC is a term used to describe the same set of genes in animals, while HLA is specific to humans.
- Naming Conventions: In different species, MHC is known by different names, such as H-2 in mice and HLA in humans.
Both HLA and MHC are divided into three main regions, designated as class I, class II, and class III based on the structure and function of gene products. The main functions of HLA/MHC include antigen presentation, T-cell recognition, and immune regulation.
Comparative Table: HLA vs MHC
The table below outlines the differences between HLA (Human Leukocyte Antigen) and MHC (Major Histocompatibility Complex):
| Feature | HLA | MHC |
|---|---|---|
| Definition | HLA is a gene complex present in humans that encodes for MHC molecules. | MHC molecules play a major role in the recognition of foreign substances, such as antigens. |
| Location | HLA is located on the short arm of chromosome 6 (6p21.3) in humans. | MHC molecules are found in many vertebrates, including humans. |
| Classes | HLA consists of three regions designated as class I, class II, and class III, based on the structure and function of gene products. | MHC molecules are of two main classes: MHC class I and MHC class II. |
| Function | The main function of HLA class I gene products (HLA-A, -B, and -C) is to present endogenous peptides to responding CD8+ T cells. HLA class II gene products (-DP, -DQ, and -DR) present exogenous peptides to CD4+ helper T cells. | MHC class I molecules present endogenous antigens, while MHC class II molecules present exogenous antigens. |
| Alleles | HLA has a number of different alleles, resulting in a diverse antigen presentation and varying susceptibility to infections and autoimmunity. | MHC molecules have conserved structures, allowing them to recognize foreign antigens. |
| Applications | HLA typing is used to match organ and tissue transplants, as well as to study associations between HLA and autoimmune diseases, infections, or cancer. | MHC molecules are used in transplantation, autoimmune diseases, and infectious diseases. |
| Naming | HLA alleles are named with a letter (A, B, C, D, etc.) and followed by a number representing a specific allele (e.g., HLA-B27, HLA-DQB1*03:01). | MHC molecules are named based on their class and the species they are found in (e.g., HLA-DR for human MHC class II). |
In summary, HLA is a gene complex that encodes for MHC molecules in humans, while MHC molecules are involved in the recognition of foreign antigens and presenting them to the immune system. Both HLA and MHC molecules have class I and class II subtypes, but their functions differ in presenting endogenous and exogenous antigens, respectively.
- MHC I vs II
- Major vs Minor Histocompatibility Antigens
- Hapten vs Antigen
- O vs H Antigen
- T Cells vs B Cells
- MLA vs MLC
- Antibodies vs T Cells
- Humoral vs Cell Mediated Immunity
- Immunocytochemistry vs Immunohistochemistry
- Macrophages vs Dendritic Cells
- HTLV vs HIV
- Immunofluorescence vs Immunohistochemistry
- T Helper vs T Cytotoxic Cells
- Memory T Cells vs Memory B Cells
- HLH vs MAS
- Hypersensitivity vs Autoimmunity
- T Lymphocytes vs B Lymphocytes
- Lymphocytes vs Leucocytes
- Self vs Non Self Antigens