Recruitment of a distinct but related set of VH sequences into the murine CD21hi/CD23− marginal zone B-cell repertoire to that seen in the class switched antibody response

摘要

Development and maintenance of cells in the murine follicular and marginal zone compartments is thought to involve differing levels of stimulation of the BCR, although it is still not clear which BCR ligands mediate these events. How the delineation between naïve and antigen experienced B-cell populations relates to cell phenotype and how precise or blurred this delineation is, is also not well understood. Here we show, using PCR to analyse the antibody response to phenyl-oxazolone in the mouse, that the antibody repertoire of CD21hi/CD23− marginal zone B-cells shows persistent increase in levels of particular IgM after immunization with foreign antigen. Further, we show that these IgM have different but related VH/CDR3 sequences from those seen in the class-switched response to oxazolone that we have also analysed. We also detect an effect of antigen on the follicular B-cell repertoire that is less persisting. These results provide evidence consistent with the signal strength model of mature B-cell development being extended to include stimulation by foreign antigen, and also further the known zone of influence of foreign antigen on the B-cell compartment.