HLA-C (HLAC)

HLA-C (HLAC)

Definition: HLA-C (HLAC) is a specific class of Human Leukocyte Antigen (HLA) that is part of the Major Histocompatibility Complex (MHC) class I molecules. It plays a crucial role in the immune system by presenting endogenous peptides to CD8+ cytotoxic T cells, which are essential for detecting and eliminating infected or malignant cells.

Importance of HLA-C

• Immune Response: HLA-C molecules present peptide fragments from proteins synthesized within the cell, facilitating the activation of CD8+ T cells. This process is vital for the immune system’s ability to recognize and respond to intracellular pathogens and tumors.
• Transplant Compatibility: HLA-C matching is important in organ transplantation, as compatibility between donor and recipient HLA types can significantly affect transplant success and the risk of rejection.
• Disease Association: Certain HLA-C alleles have been associated with susceptibility to various diseases, including autoimmune disorders and infectious diseases.

Genetic Basis

HLA-C is encoded by the HLA-C gene, which is located on chromosome 6. The gene exhibits high polymorphism, leading to a variety of HLA-C alleles within the population. This diversity enhances the immune system’s ability to respond to a wide range of pathogens but complicates organ transplantation due to increased chances of incompatibility.

Clinical Relevance

• Transplantation: HLA-C typing is performed before organ transplants to ensure compatibility between donors and recipients, reducing the risk of transplant rejection.
• Immunotherapy: Understanding HLA-C interactions can improve cancer immunotherapy strategies by enhancing T cell recognition of tumor antigens.
• Infectious Diseases: Research has shown that certain HLA-C alleles may influence susceptibility to infections, such as COVID-19, HIV.

Conclusion

HLA-C is a critical component of the immune system that facilitates the recognition of infected or cancerous cells by T cells. Its role in transplant compatibility and disease susceptibility underscores its significance in both health and disease management.

References

1. Neefjes J, et al. “Towards a comprehensive understanding of MHC class I antigen presentation.” Nature Reviews Immunology. 2011; 11(12): 823-835. DOI: 10.1038/nri3085
2. Kawai T, et al. “HLA matching for kidney transplantation.” The New England Journal of Medicine. 2008; 358(25): 2749-2761. DOI: 10.1056/NEJMoa0800594
3. Alachkar H, et al. “The role of HLA in autoimmune diseases.” Nature Reviews Rheumatology. 2015; 11(2): 99-106. DOI: 10.1038/nrrheum.2014.174