title: Antiviral T-cell-independent type 2 antibody responses induced in vivo in the absence of T and NK cells.
abstract: Polyomavirus (PyV) infection induces protective T-cell-independent (TI) IgM and IgG responses in T-cell-deficient (TCR beta x delta-/-) mice. In this study, we show that PyV is a TI -2 antigen: B cells with a mutated Bruton's tyrosine kinase (Xid mutants) do not respond to PyV with antibody secretion in the absence of T cells. We also demonstrate that NK-cell-mediated "help" is not absolutely required for the induction of the TI-2 antibodies to PyV; thus for the first time, we provide evidence for protective IgM and IgG responses against a viral infection induced in mice lacking T and NK cells (CD3Etg). Comparison of the antibody responses observed in T- and NK-cell-deficient mice with those of mice lacking only T cells, however, suggests that NK cells may promote isotype switching to IgG2a. This effect is probably mediated by IFN gamma secretion. In support of this idea, studies on the antibody responses of PyV-infected SCID mice that had been reconstituted with IFN gamma R-/- B cells or wild-type B cells demonstrated the IFN gamma dependence of PyV-specific TI IgG2a secretion and provided evidence that IFN gamma acting directly on B cells plays an important role in TI pathways of isotype switching to IgG2a in vivo.
authors.affiliation: Department of Pathology, University of Massachusetts Medical Center, Worcester, Massachusetts 01655, USA. Eva.Szomolanyi-Tsuda@umassmed.edu
authors.forename: E
authors.initials: E
authors.lastname: Szomolanyi-Tsuda
authors.forename: J D
authors.initials: JD
authors.lastname: Brien
authors.forename: J E
authors.initials: JE
authors.lastname: Dorgan
authors.forename: R L
authors.initials: RL
authors.lastname: Garcea
authors.forename: R T
authors.initials: RT
authors.lastname: Woodland
authors.forename: R M
authors.initials: RM
authors.lastname: Welsh
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology*; D000955:Antigens, T-Independent / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology; D017252:CD3 Complex; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology*; D008212:Lymphocyte Depletion; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D016513:Mice, SCID; D008822:Mice, Transgenic; D011120:Polyomavirus / Q000276:immunology*; D027601:Polyomavirus Infections / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000276:immunology; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology; D017471:Receptors, Interferon / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D014412:Tumor Virus Infections / Q000276:immunology; D000096743:Interferon gamma Receptor
chemical_list: D000914:Antibodies, Viral; D000955:Antigens, T-Independent; D017252:CD3 Complex; D007074:Immunoglobulin G; D011948:Receptors, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta; D017471:Receptors, Interferon; D000096743:Interferon gamma Receptor; C115335:CD3E protein, human