B-Lymphocyte Heterogeneity: Ontogenetic Development and Organ Distribution of B-Lymphocyte Populations Defined by their Density of Surface Immunoglobulin.

摘要

The density of total Ig and of IgM, IgG(1), IgG(2), and IgA on the surface of adult murine splenic B lymphocytes was measured using the technique of rapid flow microfluorometry. In addition, the density of total surface Ig and of IgM on B lymphocytes derived from adult bone marrow, lymph nodes, and Peyer's patches, and from neonatal spleen was determined. Adult spleen and lymph node B lymphocytes are characterized by the presence of a large population of cells with a low-to-intermediate density of total surface Ig, which is seen as a peak in the fluorescence profiles when these cells are labeled with fluorescein-conjugated (F1) anti-Ig. This peak is not detected when neonatal spleen or adult bone marrow are examined; the development of this peak among spleen cells occurs during the first 4 wk of life. Although the characteristic fluorescence intensity peak is not seen when adult spleen cells are labeled with F1 anti-mu, changes in the density of surface IgM do occur during the first few weeks of life and are detected as a decrease in the frequency of cells which have relatively large amounts of surface IgM. The differences seen in the fluorescence patterns of adult spleen cells labeled with F1 anti-Ig and F1 anti-mu may be due to the appearance of IgD on the surface of mature splenic B lymphocytes. This is supported by the similarity of the fluorescence profiles of adult bone marrow cells stained with F1 anti-Ig and F1 anti-mu, as the latter population of cells is reported to lack surface IgD. (Author)