major histocompatibility complex, class II, DR beta 1

Normal function

The HLA-DRB1 gene provides instructions for making a protein that plays a critical role in the immune system. The HLA-DRB1 gene is part of a family of genes called the human leukocyte antigen (HLA) complex. The HLA complex helps the immune system distinguish between the body's own proteins and the proteins made by foreign invaders such as viruses and bacteria.

The HLA complex is the human version of the major histocompatibility complex (MHC), a gene family that occurs in many species. The HLA-DRB1 gene belongs to a group of MHC genes called MHC class II. MHC class II genes provide instructions for making proteins that are present on the surface of certain immune system cells. These proteins attach to protein fragments (peptides) outside the cell. MHC class II proteins display these peptides to the immune system. If the immune system recognizes the peptides as foreign, it triggers a response to attack the invading viruses or bacteria.

The protein produced from the HLA-DRB1 gene, called the beta chain, attaches (binds) to another protein called the alpha chain, which is produced from the HLA-DRA gene. Together, they form a functional protein complex called the HLA-DR antigen-binding heterodimer. This complex displays foreign peptides to the immune system to trigger an immune response.

The wide variety within MHC class II genes allows the immune system to react to a range of foreign invaders. Researchers have identified hundreds of different versions of the HLA-DRB1 gene, each of which is given a particular number (such as HLA-DRB1*04:01).

Conditions referring to this gene or chromosome

• Crohn disease

• Idiopathic pulmonary fibrosis

• Narcolepsy

• Psoriatic arthritis

• Idiopathic inflammatory myopathy

• Juvenile idiopathic arthritis

• Type 1 diabetes

• Multiple sclerosis

• Hashimoto thyroiditis

• Graves disease

• Rheumatoid arthritis

• Autoimmune Addison disease

• Alopecia areata

• Lyme disease

• Rosacea

Other names

HLA class II histocompatibility antigen, DR-1 beta chain

HLA-DR1B

HLA-DRB

human leucocyte antigen DRB1

lymphocyte antigen DRB1

major histocompatibility complex, class II, DR beta 1 precursor

MHC class II antigen

MHC class II HLA-DR beta 1 chain

MHC class II HLA-DR-beta cell surface glycoprotein