HLA-B77

HLA-B

HLA-B77 is a human leukocyte antigen (HLA) serotype within the HLA-B locus. The HLA-B77 serotype identifies the gene products of the HLA-B*77 allele. This allele is part of the major histocompatibility complex (MHC) class I molecules, which play a critical role in the immune system by presenting peptides to T cells.

Structure

HLA-B77, like other HLA class I molecules, is composed of a heavy chain and a light chain. The heavy chain is encoded by the HLA-B gene and is approximately 45 kDa in size. It is non-covalently associated with beta-2 microglobulin, a 12 kDa light chain. The heavy chain consists of three extracellular domains (α1, α2, and α3), a transmembrane domain, and a cytoplasmic tail.

Function

The primary function of HLA-B77 is to present endogenous peptides, typically derived from intracellular proteins, to CD8+ T cells. This interaction is crucial for the immune system's ability to recognize and eliminate infected or malignant cells. The peptide-binding groove of HLA-B77 can accommodate a diverse array of peptides, allowing for the presentation of a wide variety of antigens.

Genetics

The HLA-B77 allele is one of many alleles within the HLA-B locus. The HLA-B gene is located on the short arm of chromosome 6 at position 6p21.3. The HLA-B77 allele is relatively rare compared to other HLA-B alleles. The diversity of HLA alleles, including HLA-B77, is a result of evolutionary pressures to enhance immune defense mechanisms.

Clinical Significance

HLA-B77, like other HLA alleles, can be involved in various immune system-related conditions. These include autoimmune diseases, infectious diseases, and transplant rejection. The specific role of HLA-B77 in these conditions is an area of ongoing research. Understanding the distribution and function of HLA-B77 can aid in the development of personalized medical treatments and improve outcomes in organ transplantation.

See Also

• HLA-B
• Major histocompatibility complex
• T cell receptor
• Autoimmune disease
• Organ transplantation