New methods to analyze B cell immune responses to the thymus dependent antigen sheep red blood cells

摘要

B cells contribute critically to an effective immune response by producing antigen-specific antibodies. During the immune response to so-called thymus dependent antigens, activated B cells seek T cell help and form germinal centers. In contrast, thymus independent antigens generally do not induce germinal center formation. In the germinal center, B cells undergo somatic-hypermutation, affinity based clonal expansion and differentiation to produce plasma cells and memory B cells. Valuable insight into these processes has been gained by using model hapten-carrier complexes or sheep red blood cells. Sheep red blood cells induce robust germinal center formation in mice. Therefore this antigen is commonly used to study germinal center responses. In contrast to haptenated antigens, it has thus far been difficult to measure the titer of antigen-specific antibodies or the expansion of antigen-specific B cells after immunization with sheep red blood cells. We have developed new, simple methods to access these parameters, thus providing new tools to study germinal center and antibody responses.