IgMhighCD21high lymphocytes enriched in the splenic marginal zone generate effector cells more rapidly than the bulk of follicular B cells.
Ag encounter will recruit Ag-specific cells from the pool of mature B lymphocytes in the spleen and activate them to perform effector functions: generation of Ab-forming cells (plasma cells) and presentation of Ag to T cells. We have compared the ability of mature follicular and marginal zone cells to develop into effector B cells. The generation of marginal zone B cells and their localization in the marginal sinus area are T cell and CD40 ligand independent, suggesting that they do not represent a postgerminal center population. Compared with mature recirculating follicular B cells, they express several characteristics of previous antigenic experience, including higher levels of B7.1 (CD80) and B7.2 (CD86) when freshly isolated and following in vitro stimulation. After a brief 6- to 8-h in vitro stimulation with LPS or anti-CD40 Abs, marginal zone B cells become potent APCs. In addition, their ability to proliferate and differentiate into plasma cells in response to low doses of T-independent polyclonal stimuli (LPS) is far greater than that of follicular B cells. These findings indicate a functional heterogeneity within splenic mature B lymphocytes, with marginal zone B cells having the capacity to generate effector cells in early stages of the immune response against particulate Ags scavenged efficiently in this special anatomical site.
Oliver
A M
AM
Division of Developmental and Clinical Immunology, Department of Microbiology, University of Alabama, Birmingham 35294, USA.
Martin
F
F
Kearney
J F
JF
D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000378:metabolism; D016175:B-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D002999:Clone Cells / Q000276:immunology / Q000378:metabolism; D007075:Immunoglobulin M / Q000096:biosynthesis*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D017464:Receptors, Complement 3d / Q000096:biosynthesis*; D017455:Receptors, IgE / Q000096:biosynthesis; D013154:Spleen / Q000166:cytology* / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D015854:Up-Regulation / Q000276:immunology
D000911:Antibodies, Monoclonal; D007075:Immunoglobulin M; D008070:Lipopolysaccharides; D017464:Receptors, Complement 3d; D017455:Receptors, IgE