Herpes simplex virus remodels T-cell receptor signaling, resulting in p38-dependent selective synthesis of interleukin-10.
Herpes simplex virus (HSV)-specific T cells are essential for viral clearance. However, T cells do not prevent HSV latent infection or reactivation, suggesting that HSV has the potential to modulate T-cell function. T-cell receptor (TCR) stimulation is a potent and specific means of activating T cells. To investigate how HSV affects T-cell function, we have analyzed how HSV affects TCR-stimulated intracellular signaling and cytokine synthesis in mock-infected and HSV-infected T cells. Mock-infected T cells stimulated through the TCR synthesized a broad range of cytokines that included the proinflammatory cytokines tumor necrosis factor alpha, gamma interferon, and interleukin-2. In contrast, HSV-infected T cells stimulated through the TCR selectively synthesized interleukin-10, a cytokine that suppresses cellular immunity and favors viral replication. To achieve selective interleukin-10 synthesis, HSV differentially affected TCR signaling pathways. HSV inhibited TCR-stimulated formation of the linker for activation of the T-cell signaling complex, and HSV inhibited TCR-stimulated NF-kappaB activation. At the same time, HSV activated the p38 and JNK mitogen-activated protein kinases as well as the downstream transcription factors ATF-2 and c-Jun. HSV did not inhibit TCR-stimulated activation of STAT3, a transcription factor involved in interleukin-10 synthesis. The activation of p38 was required for interleukin-10 synthesis in HSV-infected T cells. The ability of HSV to differentially target intracellular signaling pathways and transform an activating stimulus into an immunosuppressive response represents a novel strategy for pathogen-mediated immune modulation. Selective, TCR-stimulated interleukin-10 synthesis may play an important role in HSV pathogenesis.
Sloan
Derek D
DD
Department of Laboratory Medicine, University of Washington, Seattle, WA 98195, USA.
Jerome
Keith R
KR
D051698:Activating Transcription Factor 2 / Q000378:metabolism; D002460:Cell Line; D006801:Humans; D016753:Interleukin-10 / Q000096:biosynthesis*; D048670:MAP Kinase Kinase 4 / Q000037:antagonists & inhibitors / Q000378:metabolism; D035683:MicroRNAs; D010766:Phosphorylation; D011948:Receptors, Antigen, T-Cell / Q000819:agonists / Q000378:metabolism*; D050796:STAT3 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction; D018139:Simplexvirus / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology* / Q000821:virology*; D014764:Viral Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*