Coronavirus transmissible gastroenteritis virus-mediated induction of IFN alpha-mRNA in porcine leukocytes requires prior synthesis of soluble proteins.
We studied the expression of interferon alpha (IFN alpha)-mRNA in porcine non-adherent peripheral blood mononuclear cells (PBMC) after induction by the coronavirus transmissible gastroenteritis virus (TGEV). We found that protein synthesis inhibition by cycloheximide (CHX) blocked IFN alpha-mRNA expression, except when PBMC were preincubated with a conditioned medium as a potential source of cytokines. These data indicate that IFN alpha-mRNA induction by TGEV requires de novo synthesis of proteins. Moreover, they suggest that IFN alpha-mRNA induction in porcine leukocytes by TGEV involves mechanisms identical to those described for the herpes simplex virus in humans. In addition, experiments performed with a TGEV mutant, dm 49-4, previously characterized for its low ability to induce IFN alpha, showed that addition of a conditioned medium could not normalize its IFN alpha-inducing ability. Therefore, the defect of the dm49-4 mutant may be at the level of the final triggering signal to PBMC.
Charley
B
B
INRA, Laboratorie de Virologie et Immunologie Moléculaires, Jouy-en-Josas, France.
Lavenant
L
L
Lefèvre
F
F
D000199:Actins / Q000096:biosynthesis / Q000235:genetics; D000818:Animals; D015152:Blotting, Northern; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D003513:Cycloheximide / Q000494:pharmacology; D016207:Cytokines / Q000502:physiology; D015967:Gene Expression Regulation, Viral; D016898:Interferon-alpha / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000382:microbiology*; D012333:RNA, Messenger / Q000096:biosynthesis*; D013552:Swine; D005760:Transmissible gastroenteritis virus / Q000276:immunology*; D014764:Viral Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis*
D000199:Actins; D017077:Culture Media, Conditioned; D016207:Cytokines; D016898:Interferon-alpha; D012333:RNA, Messenger; D014764:Viral Proteins; D003513:Cycloheximide