title: Tissue-associated phenotypic heterogeneity of peripheral B cells in mice.
abstract: After their primary differentiation and selection in the bone marrow, the cells of B lineage are distributed to the peripheral lymphoid system. Here we report that, with the use of a novel rat monoclonal antibody (IBL-2), a tissue-related phenotypic difference could be observed in the peripheral B-cell compartment in mouse. The antigen recognized by this antibody is a 25,000/29,000 MW heterodimeric cell surface molecule which is resistant to phosphatidylinositol-phospholipase C treatment, but is sensitive to proteases. The antigen was found to be expressed by the majority of B cells from the spleen, whereas the B cells from other peripheral sources (lymph nodes and Peyer's patches) proved to be negative. The staining pattern of splenic B cells was heterogeneous, containing a substantial dim population (IBL-2lo), and a smaller, intensely stained fraction (IBL-2hi) within the positive subset. Unlike the B cells, the T cells were negative in every peripheral lymphoid tissue analysed. In addition, the ratios between the various IBL-2-reactive B cells (positive to negative and, within the positive population, the IBL-2lo to IBL-2hi, respectively) in the spleen were quite similar to that of B cells in the bone marrow. Furthermore, the levels of L-selectin expressed by the various IBL-2-reactive subpopulations were found to be heterogeneous both in the bone marrow and in the spleen. The bone marrow cells could be resolved into double negative, L-selectin +/-/IBL-2lo, L-selectin--IBL-2lo, and L-selectin-/IBL-2hi populations, respectively. In the spleen, an additional fraction with L-selectin+/IBL-2- phenotype could be detected. In both tissues, the overwhelming majority of IBL-2hi cells were found at the MEL-14- compartment. We conclude that either these findings may reflect a heterogeneous development state within the peripheral B-cell pool, with a substantial fraction of splenic B cells being less differentiated than those in other peripheral lymphoid tissues, or alternatively, the differential reactivity of murine B cells with the IBL-2 monoclonal antibody is due to their tissue location.
authors.affiliation: Immunological and Biotechnological Laboratory, University Medical School of Pécs, Hungary.
authors.forename: P
authors.initials: P
authors.lastname: Balogh
authors.forename: A
authors.initials: A
authors.lastname: Kumánovics
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D001853:Bone Marrow / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D015151:Immunoblotting; D016130:Immunophenotyping / Q000379:methods; D019041:L-Selectin / Q000032:analysis; D008221:Lymphoid Tissue / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D013154:Spleen / Q000276:immunology*; D013156:Splenectomy
chemical_list: D000911:Antibodies, Monoclonal; D019041:L-Selectin