The expression of B cell surface receptors. III. The murine low-affinity IgE Fc receptor is not expressed on Ly 1 or 'Ly 1-like' B cells

Abstract

The distribution of IgE FcR (FcεR)-positive and -negative B celIs was examined in normal adult mice. Using three-color flow cytometry, the expression of the FcεR was analyzed on various B-cell subsets present in the peritoneum and spleen. The results demonstrate that in the peritoneal cavity, the FcεR is not expressed on the large majority of Ly 1+ B cells and Ly 1-, Mac 1+ sister B cells, The receptor is present, however, on the small number of conventional B cells residing in the peritoneum. Although interleukin 4 (IL-4) can increase the levels of the FcεR on conventional B cells, incubation of Ly 1 and sister B cells with IL-4 did not result in the expression of the FcεR. When examining B cells present in the spleen, a small subset of B cells was consistently found to be FcεR-. These FcεR- cells were IgM-bright, IgD-dull and largely Ly 1- and Mac 1-negative. Staining of spienic tissue sections revealed that the FcεR- B cells were primarily localized to the marginal zones, whereas the FcεR+ B cells were found in the follicies. Taken together, the results indicate that the FcεR may be a useful marker in delineating the various B-cell subsets. In the peritoneum, the FcεR appears to discriminate conventional B cells from those of the Ly 1/sister lineage, and in the spleen it is likely to distinguish resting follicular B cells from Ly 1/sister and marginal zone B cells. © 1991 Oxford University Press.