The immune system relies on the ability to detect when cells are virally infected, or potentially tumorigenic, and to specifically eliminate these cells. This is achieved by the actions of Major Histocompatibility Complex (MHC) class I molecules, which bind small peptides from the proteolytic turnover of proteins in the cytoplasm, and present these peptides on the cell surface to T lymphocytes. Detection of viral, or non-self, peptides can stimulate the generation of potent anti-viral cytotoxic T lymphocyte responses.
One particular human MHC class I molecule, HLA-B27, is also strongly associated with a type of inflammatory arthritis known as ankylosing spondylitis. The reasons for this association are still unclear, and we are therfore applying our knowledge of MHC class I assembly to this topic.