Grant: Operating Grant

B lymphocytes are an important component of the immune system due to their ability to produce antibodies, molecules that can neutralize pathogens. Such antibody responses occur when B lymphocytes that are specific for the pathogen obtain help from pathogen-specific T lymphocytes. These cellular interactions take place within a complex microenvironment called the Germinal Centre which is located within lymph nodes or the spleen. However, it takes approximately one week to initiate a Germinal Centre response, and this puts the host at risk of succumbing to infection in the early days post-exposure. As a stop-gap, humans have an innate immune system that responds rapidly to microbial exposure. Interestingly, even though B and T lymphocytes are considered part of the adaptive immune system, some B and T lymphocytes have innate properties. This is particularly true in the mucosal tissues (gut, lung, reproductive tract) and in the skin, all of which are locations where pathogens first invade our bodies. We know much less about innate lymphocytes and how they participate in immune response compared to their adaptive counterparts. We are studying innate B cell responses, with particular focus on those innate responses that occur in the gut. In particular, we are interested in how innate B cells produce the mucosal antibody IgA, and whether IgA-secreting B cells may have special properties that allow them to fight off infections.