title: B2 but not B1 cells can contribute to CD4+ T-cell-mediated clearance of rotavirus in SCID mice.
abstract: Studies utilizing various immunodeficient mouse models of rotavirus (RV) infection demonstrated significant roles of RV-specific secretory immunoglobulin A (IgA), CD4+ T cells, and CD8+ T cells in the clearance of RV and protection from secondary infection. Secretion of small but detectable amounts of IgA in RV-infected alphabeta T-cell receptor knockout mice (11) and distinctive anatomical localization and physiology of B1 cells suggested that B1 cells might be capable of producing RV-specific intestinal IgA in a T-cell-independent fashion and, therefore, be responsible for ablation of RV shedding. We investigated the role of B1 cells in the resolution of primary RV infection using a SCID mouse model. We found that the adoptive transfer of unseparated peritoneal exudate cells ablates RV shedding and leads to the production of high levels of RV-specific intestinal IgA. In contrast, purified B1 cells do not ablate RV shedding and do not induce a T-cell-independent or T-cell-dependent, RV-specific IgA response but do secrete large amounts of polyclonal (total) intestinal IgA. Cotransfer of mixtures of purified B1 cells and B1-cell-depleted peritoneal exudate cells differing in IgA allotypic markers also demonstrated that B2 cells (B1-cell-depleted peritoneal exudate cells) and not B1 cells produced RV-specific IgA. To our knowledge, this is the first observation that B1 cells are unable to cooperate with CD4+ T cells and produce virus-specific intestinal IgA antibody. We also observed that transferred CD4+ T cells alone are capable of resolving RV shedding, although no IgA is secreted. These data suggest that RV-specific IgA may not be obligatory for RV clearance but may protect from reinfection and that effector CD4+ T cells alone can mediate the resolution of primary RV infection. Reconstitution of RV-infected SCID mice with B1 cells results in the outgrowth of contaminating, donor CD4+ T cells that are unable to clear RV, possibly because their oligoclonal specificities may be ineffective against RV antigens.
authors.affiliation: Department of Biology, University of Pennsylvania, Philadelphia 19104-6018, USA.
authors.forename: N
authors.initials: N
authors.lastname: Kushnir
authors.forename: N A
authors.initials: NA
authors.lastname: Bos
authors.forename: A W
authors.initials: AW
authors.lastname: Zuercher
authors.forename: S E
authors.initials: SE
authors.lastname: Coffin
authors.forename: C A
authors.initials: CA
authors.lastname: Moser
authors.forename: P A
authors.initials: PA
authors.lastname: Offit
authors.forename: J J
authors.initials: JJ
authors.lastname: Cebra
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D004195:Disease Models, Animal; D005434:Flow Cytometry; D006801:Humans; D007071:Immunoglobulin A, Secretory / Q000032:analysis; D007422:Intestines / Q000276:immunology; D008221:Lymphoid Tissue / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D016513:Mice, SCID; D010537:Peritoneum / Q000166:cytology / Q000276:immunology; D012401:Rotavirus / Q000276:immunology* / Q000302:isolation & purification; D012400:Rotavirus Infections / Q000276:immunology* / Q000821:virology
chemical_list: D000914:Antibodies, Viral; D007071:Immunoglobulin A, Secretory