HLA-DRB3 is a human leukocyte antigen (HLA) gene located on chromosome 6. It codes for a polymorphic cell surface glycoprotein known as the DRB3 molecule. This molecule is a member of the MHC class II family of immune-related proteins and is expressed on the surface of antigen presenting cells.
HLA-DRB3 is involved in the recognition of foreign antigens by the immune system and plays an important role in the initiation and regulation of the adaptive immune response. This gene is highly polymorphic and variation in its sequence determines the specificity of the DRB3 molecule for different antigens.
Mutations in the HLA-DRB3 gene are associated with an increased risk of developing autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus. In addition, some polymorphisms in this gene are associated with an increased risk of developing certain types of cancer.
HLA-DRB3 is also involved in the recognition of peptides derived from self-antigens and the regulation of self-tolerance. This gene is involved in the development of immunologic memory and plays an important role in the generation of long-term protective immunity.
Overall, the HLA-DRB3 gene plays a key role in the immune system and its polymorphisms are associated with a wide range of diseases. Further research is needed to better understand the role of this gene in the development, progression and treatment of these diseases.