title: The early protective thymus-independent antibody response to foot-and-mouth disease virus is mediated by splenic CD9+ B lymphocytes.
abstract: Infection of mice with cytopathic foot-and-mouth disease virus (FMDV) induces a rapid and specific thymus-independent (TI) neutralizing antibody response that promptly clears the virus. Herein, it is shown that FMDV-infected dendritic cells (DCs) directly stimulate splenic innate-like CD9(+) B lymphocytes to rapidly (3 days) produce neutralizing anti-FMDV immunoglobulin M antibodies without T-lymphocyte collaboration. In contrast, neither follicular (CD9(-)) B lymphocytes from the spleen nor B lymphocytes from lymph nodes efficiently respond to stimulation with FMDV-infected DCs. The production of these protective neutralizing antibodies is dependent on DC-derived interleukin-6 (IL-6) and on CD9(+) cell-derived IL-10 secretion. In comparison, DCs loaded with UV-inactivated FMDV are significantly less efficient in directly stimulating B lymphocytes to secrete TI antibodies. A critical role of the spleen in the early production of anti-FMDV antibodies in infected mice was also demonstrated in vivo. Indeed, either splenectomy or functional disruption of the marginal zone of the spleen delays and reduces the magnitude of the TI anti-FMDV antibody response in infected mice. Together, these results indicate that in addition to virus localization, the FMDV-mediated modulation of DC functionality is a key parameter that collaborates in the induction of a rapid and protective TI antibody response against this virus.
authors.affiliation: Instituto de Virologia, Centro de Investigaciones en Ciencias Veterinarias, INTA-Castelar, Buenos Aires, Argentina.
authors.forename: Matias
authors.initials: M
authors.lastname: Ostrowski
authors.forename: Monica
authors.initials: M
authors.lastname: Vermeulen
authors.forename: Osvaldo
authors.initials: O
authors.lastname: Zabal
authors.forename: Patricia I
authors.initials: PI
authors.lastname: Zamorano
authors.forename: Ana M
authors.initials: AM
authors.lastname: Sadir
authors.forename: Jorge R
authors.initials: JR
authors.lastname: Geffner
authors.forename: Osvaldo J
authors.initials: OJ
authors.lastname: Lopez
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D015703:Antigens, CD / Q000032:analysis; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology; D004195:Disease Models, Animal; D005536:Foot-and-Mouth Disease / Q000276:immunology*; D029544:Foot-and-Mouth Disease Virus / Q000276:immunology*; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D016753:Interleukin-10 / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis; D008562:Membrane Glycoproteins / Q000032:analysis; D051379:Mice; D008807:Mice, Inbred BALB C; D009500:Neutralization Tests; D013154:Spleen / Q000166:cytology / Q000276:immunology*; D060245:Tetraspanin 29; D013950:Thymus Gland / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D015703:Antigens, CD; C554870:Cd9 protein, mouse; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D015850:Interleukin-6; D008562:Membrane Glycoproteins; D060245:Tetraspanin 29; D016753:Interleukin-10