title: Peritoneal B-2 cells comprise a distinct B-2 cell population with B-1b-like characteristics.
abstract: B-1 and B-2 cells are lymphocyte populations that differ in development, surface marker expression, tissue localization, and function. Though mainly found in the spleen, lymph nodes, and circulation of mice, small numbers of B-2 cells are found in the peritoneal cavity, a site predominantly populated by B-1 cells. Here, we characterized peritoneal B-2 cells, and determined their relationship to B-1 cells. We found that peritoneal B-2 cells appear to be intermediate between splenic B-2 and peritoneal B-1 cells in terms of surface marker expression of B220, CD80, and CD43, expression of several marker genes, and in vitro viability and IgM secretion. Adoptive transfer of peritoneal B-2 cells into severe combined immunodeficiency mice resulted in the acquisition of a phenotype reminiscent of B-1b cells, as shown by up-regulation of Mac-1 and CD43, and down-regulation of CD23. Moreover, adoptively transferred peritoneal B-2 cells recapitulated B-1 cell function by producing natural IgM in recipient mice. These data suggest that peritoneal B-2 cells express some characteristics of B-1b cells and that this similarity increases with additional time in the peritoneal cavity.
authors.affiliation: Department of Microbiology, Boston University School of Medicine, Boston, MA, USA.
authors.forename: William D
authors.initials: WD
authors.lastname: Hastings
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Tumang
authors.forename: Timothy W
authors.initials: TW
authors.lastname: Behrens
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Rothstein
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D016175:B-Lymphocyte Subsets / Q000276:immunology / Q000502:physiology*; D018122:B7-1 Antigen / Q000032:analysis; D020869:Gene Expression Profiling; D007075:Immunoglobulin M / Q000096:biosynthesis; D016130:Immunophenotyping; D051917:Leukosialin / Q000032:analysis; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C
chemical_list: D018122:B7-1 Antigen; D007075:Immunoglobulin M; D051917:Leukosialin