title: Impaired interleukin 1 and interleukin 2 production following in vitro abortive infection of murine spleen mononuclear cells by Semliki Forest virus.
abstract: The effect of Semliki Forest virus (SFV) infection of murine spleen mononuclear cells was investigated in vitro. A small percentage of spleen macrophages expressed viral antigens, but no infectious virus particles were released, indicating an abortive-type infection. Wild-type SFV infected a higher percentage of macrophages than the attenuated, demyelinating mutant A7. The proliferation of spleen mononuclear cells under Con A stimulation was inhibited by the viral infection. The supernatant (SN) harvested from infected and Con A-stimulated spleen adherent cells could not stimulate thymocytes in an interleukin 1 (IL-1) assay and indomethacin treatment of infected cultures had no effect. The stimulatory effect of SN from noninfected cultures in the IL-1 assay was reduced when SN from infected cultures was added, suggesting the presence of an IL-1 inhibitor. Interleukin 2 (IL-2) production by splenocytes also decreased after viral infection, but exogenous IL-2 restored the response to Con A stimulation of infected spleen cells. This study demonstrates that abortive SFV infection of spleen macrophages has an immunosuppressive effect which may lead to an aberrant immune regulation.
authors.affiliation: Department of Medical Microbiology and Infectious Diseases, University of Alberta, Edmonton, Canada.
authors.forename: L X
authors.initials: LX
authors.lastname: Wu
authors.forename: J
authors.initials: J
authors.lastname: Ilonen
authors.forename: M J
authors.initials: MJ
authors.lastname: Mäkelä
authors.forename: R
authors.initials: R
authors.lastname: Salonen
authors.forename: R
authors.initials: R
authors.lastname: Marusyk
authors.forename: A A
authors.initials: AA
authors.lastname: Salmi
mesh_terms: D000818:Animals; D000943:Antigens, Differentiation / Q000032:analysis; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D007375:Interleukin-1 / Q000096:biosynthesis*; D007376:Interleukin-2 / Q000096:biosynthesis*; D007963:Leukocytes, Mononuclear / Q000382:microbiology / Q000502:physiology*; D008213:Lymphocyte Activation; D051379:Mice; D012672:Semliki forest virus; D013154:Spleen / Q000166:cytology; D014036:Togaviridae Infections / Q000276:immunology*; D014779:Virus Replication
chemical_list: D000943:Antigens, Differentiation; D007375:Interleukin-1; D007376:Interleukin-2; D003208:Concanavalin A