Marginal zone B cells exhibit unique activation, proliferative and immunoglobulin secretory responses.
Mouse splenic B cells can be separated based on their distinctive expression of cell surface antigens. Marginal zone (MZ) B cells are CD38high CD21high CD23low/-, while follicular (FO) B cells are CD21int CD23int and newly formed (NF) B cells are CD21dim/- CD23-. Exploiting these phenotypic distinctions, we isolated the three B cell subsets and assessed their other phenotypic differences and functional capabilities in vitro. FO B cells proliferate more than the other B cell subsets in response to either IgM or CD38 cross-linking. MZ B cells proliferate better than FO B cells when stimulated with lipopolysaccharide (LPS), sub-optimal levels of LPS and CD38 cross-linking or CD40 ligation. When NF, FO and MZ B cells were stimulated with either LPS or LPS and interleukin-4, MZ B cells secreted more IgM and IgG3 than the other two subsets. Similarly, calcium fluxes measured within MZ B cells are larger in amplitude and more sustained after B cell receptor cross-linking than those found in the other two subsets. Collectively, these results indicate that CD38high CD21high CD23low/- MZ B cells are specially suited to play a unique role in response to antigens delivered to the MZ area.
Oliver
A M
AM
Division of Developmental and Clinical Immunology, University of Alabama at Birmingham, USA.
Martin
F
F
Gartland
G L
GL
Carter
R H
RH
Kearney
J F
JF
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D002118:Calcium / Q000378:metabolism; D002453:Cell Cycle; D015870:Gene Expression; D005803:Genes, Immunoglobulin; D007136:Immunoglobulins / Q000378:metabolism*; D008213:Lymphocyte Activation; D016131:Lymphocyte Subsets / Q000276:immunology*; D008214:Lymphocytes / Q000166:cytology; D051379:Mice; D008807:Mice, Inbred BALB C; D008811:Mice, Inbred DBA; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D013154:Spleen / Q000166:cytology*
D007136:Immunoglobulins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D002118:Calcium