A subfraction of B220 super(+) cells in murine bone marrow and spleen does not belong to the B cell lineage but has dendritic cell characteristics

• Published in: European journal of immunology 2002-03, Vol.32 (3), p.686-692
• Main Authors: Nikolic, T, Dingjan, G M, Leenen, PJM, Hendriks, R W
• Format: Article
• Language: English
• Subjects: B220 antigen
• ISSN: 0014-2980
• DOI: 10.1002/1521-4141(200203)32:3<686::AID-IMMU686>3.0.CO;2-I

Although CD45R / B220 is commonly used as a pan-B cell marker in the mouse, not all B220 super(+) cells belong to the B cell lineage. Here we report the characterization of a subpopulation of B220 super(+)CD19 super(-) cells in murine bone marrow, which failed to express markers that are present in early CD19 super(-) B cell precursors. Instead, these cells expressed low levels of MHC class II and CD11c, which are typically found on dendritic cells (DC). Moreover, these B220 super(+)CD19 super(-)CD11c super(+) cells expressed Gr-1, indicating that they are related to the recently identified murine plasmacytoid DC or their progenitors. Therefore, we evaluated surface marker expression of the B220 super(+)CD19 super(-)CD11c super(+) cells in lymphoid tissues of C57BL / 6 mice, recombinase activating gene-1 deficient mice, lacking mature B and T lymphocytes, and mice with a targeted disruption of the Ig H chain mu membrane exon ( mu MT), lacking mature B lymphocytes. When comparing bone marrow and spleen, we found that the surface profiles of B220 super(+)CD19 super(-)CD11c super(+) cells were remarkably similar, indicating that they are in a comparable maturation or activation stage in the two lymphoid compartments. In addition, the almost complete absence of peripheral B220 super(+) B-lineage cells in mu MT mice allowed the anatomical localization of the B220 super(+)CD19 super(-)CD11c super(+) cells to the red pulp and the T cell areas in the spleen. Taken together, our findings indicate that the mouse bone marrow contains a recirculating population of B220 super(+)CD19 super(-) CD11c super(+) plasmacytoid DC, the development of which is largely independent of the presence of mature T and B cells.