Transfer of small resting B cells into immunodeficient hosts results in the selection of a self-renewing activated B cell population.
We studied the role of bone marrow B cell production in the renewal of peripheral B cells and the feedback mechanisms that control the entry of newly formed B cells into the peripheral B cell pools. When resting lymph node B cells are injected into B cell-deficient hosts, a fraction of the transferred cells expands and constitutes a highly selected population that survives for prolonged periods of time by continuous cell renewal at the periphery. Although the number of donor B cells recovered is low, a significant fraction shows an activated phenotype, and the serum immunoglobulin (Ig)M levels are as in normal mice. This population of activated B cells is resistant to replacement by a new cohort of B cells and is able to feedback regulate both the entry of newly formed B cells into the peripheral pool and terminal differentiation. These findings suggest that peripheral B cell selection follows the first come, first served rule and that IgM-secreting cells are generated from a pool of stable activated B cells with an independent homeostasis.
Agenès
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Laboratoire des Dynamiques Lymphocytaires, Centre National de la Recherche Scientifique, Unité de Recherche Associée 1961, Institut Pasteur, 75724 Paris, cedex 15, France.fagenes@pasteur.fr
Freitas
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AA
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D001973:Bromodeoxyuridine / Q000378:metabolism; D002452:Cell Count; D005434:Flow Cytometry; D007072:Immunoglobulin D / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D008198:Lymph Nodes / Q000276:immunology; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D013154:Spleen / Q000276:immunology
D007072:Immunoglobulin D; D007075:Immunoglobulin M; D001973:Bromodeoxyuridine