title: Rapid response of marginal zone B cells to viral particles.
abstract: Marginal zone (MZ) B cells are thought to be responsible for the first wave of Abs against bacterial Ags. In this study, we assessed the in vivo response of MZ B cells in mice immunized with viral particles derived from the RNA phage Qbeta. We found that both follicular (FO) and MZ B cells responded to immunization with viral particles. MZ B cells responded with slightly faster kinetics, but numerically, FO B cells dominated the response. B1 B cells responded similarly to MZ B cells. Both MZ and FO B cells underwent isotype switching, with MZ B cells again exhibiting faster kinetics. In fact, almost all Qbeta-specific MZ B cells expressed surface IgG by day 5. Histological analysis demonstrated that a population of activated B cells remain associated with the MZ, probably due to the elevated integrin levels expressed by these cells. Thus, both MZ and FO B cells respond with rapid proliferation to viral infection and both populations undergo isotype switching, but MZ B cells remain in the MZ and may be responsible for local Ab production, opsonizing pathogens entering the spleen.
authors.affiliation: Cytos Biotechnology AG, Zurich-Schlieren, Switzerland.
authors.forename: Dominique
authors.initials: D
authors.lastname: Gatto
authors.forename: Christiane
authors.initials: C
authors.lastname: Ruedl
authors.forename: Bernhard
authors.initials: B
authors.lastname: Odermatt
authors.forename: Martin F
authors.initials: MF
authors.lastname: Bachmann
mesh_terms: D017908:Allolevivirus / Q000276:immunology* / Q000378:metabolism; D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis; D016175:B-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000378:metabolism / Q000821:virology*; D015415:Biomarkers / Q000032:analysis; D005260:Female; D005434:Flow Cytometry; D018858:Germinal Center / Q000166:cytology / Q000276:immunology / Q000378:metabolism / Q000821:virology; D017578:Immunoglobulin Class Switching; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D039041:Integrin alpha4beta1 / Q000096:biosynthesis; D008211:Lymphocyte Cooperation / Q000276:immunology; D016169:Lymphocyte Function-Associated Antigen-1 / Q000096:biosynthesis; D008562:Membrane Glycoproteins / Q000096:biosynthesis; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011991:Receptors, Virus / Q000378:metabolism; D013154:Spleen / Q000166:cytology / Q000276:immunology* / Q000378:metabolism / Q000821:virology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology / Q000821:virology; D060245:Tetraspanin 29; D013997:Time Factors; D015854:Up-Regulation / Q000276:immunology; D014771:Virion / Q000276:immunology* / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D015415:Biomarkers; C554870:Cd9 protein, mouse; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D039041:Integrin alpha4beta1; D016169:Lymphocyte Function-Associated Antigen-1; D008562:Membrane Glycoproteins; D011991:Receptors, Virus; D060245:Tetraspanin 29