title: HIV-infected CD4+ T Cells Use T-bet-dependent Pathway for Production of IL-10 Upon Antigen Recognition.
abstract: Interleukin (IL)-10 has been implicated in persistence of pathogens in a number of chronic infections. Infected CD4+ cells upon reactivation with HIV antigens were also shown to produce IL-10, which might contribute to their persistence. Hence, it is crucial to determine mechanisms regulating IL-10 production after activation with HIV antigens for devising effective blocking strategies. In this study, ERK-, T-bet- and FoxP3-dependent pathways were evaluated for their possible roles in IL-10 production by infected CD4+ cells after reactivation with HIV Env. Intracellular and secreted IL-10 levels were determined by flow cytometry and Bioplex assay after treating PBMCs with PD98059, tipifarnib and cyclosporin A for blocking of ERK-, T-bet-and FoxP3-dependent pathways, respectively. Baseline levels of T-bet, pERK were higher in P24+ CD4+ cells as compared to uninfected CD4+ cells, which increased further after activation with Env. Inhibition of T-bet resulted in 2.3-fold reduction of IL-10 expression whereas ERK and FoxP3 inhibition failed to cause suppression of IL-10 expression. Conversely, IL-10 secreted by PBMCs was inhibited maximally after ERK inhibition suggesting its role in regulation of cytokine secretory pathway. IFN-γ was found to be suppressed after treatment with inhibitors of all these pathways. Thus, the study highlighted need for IL-10 blockade along with the use of antigens for therapeutic vaccinations or latency reversal and identified the T-bet-dependent pathway as an important pathway regulating IL-10 production by infected CD4+ cells. However, simultaneous blockade of IFN-γ precludes use of inhibitor of this pathway as an IL-10 blocking strategy.
authors.affiliation: National AIDS Research Institute, Pune, India.
authors.forename: A
authors.initials: A
authors.lastname: Shete
authors.affiliation: National AIDS Research Institute, Pune, India.
authors.forename: P
authors.initials: P
authors.lastname: Suryawanshi
authors.affiliation: National AIDS Research Institute, Pune, India.
authors.forename: S
authors.initials: S
authors.lastname: Godbole
authors.affiliation: National AIDS Research Institute, Pune, India.
authors.forename: J
authors.initials: J
authors.lastname: Pawar
authors.affiliation: National AIDS Research Institute, Pune, India.
authors.forename: R
authors.initials: R
authors.lastname: Paranjape
authors.affiliation: National AIDS Research Institute, Pune, India.
authors.forename: M
authors.initials: M
authors.lastname: Thakar
mesh_terms: D000328:Adult; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000821:virology; D002478:Cells, Cultured; D016572:Cyclosporine / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors; D005260:Female; D005419:Flavonoids / Q000494:pharmacology; D051858:Forkhead Transcription Factors / Q000037:antagonists & inhibitors; D016655:HIV Core Protein p24 / Q000378:metabolism; D015658:HIV Infections / Q000276:immunology* / Q000821:virology; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D016753:Interleukin-10 / Q000096:biosynthesis* / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D008875:Middle Aged; D015363:Quinolones / Q000494:pharmacology; D020825:T-Box Domain Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D055815:Young Adult; D000098815:T-bet Transcription Factor
chemical_list: C418974:FOXP3 protein, human; D005419:Flavonoids; D051858:Forkhead Transcription Factors; D016655:HIV Core Protein p24; C508609:IL10 protein, human; D015363:Quinolones; D020825:T-Box Domain Proteins; D000098815:T-bet Transcription Factor; D016753:Interleukin-10; D007371:Interferon-gamma; D016572:Cyclosporine; D048049:Extracellular Signal-Regulated MAP Kinases; C402769:tipifarnib; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one