title: IL-24 modulates IFN-gamma expression in patients with tuberculosis.
abstract: IL-24 is a newly described member of the IL-10 family. We previously demonstrated that PBMC from TB patients exhibited low levels of IL-24 and IFN-gamma compared to subjects with latent tuberculosis infection (LTBI). In order to investigate the role of IL-24 in IFN-gamma expression in TB patients, we stimulated PBMC from individuals with LTBI or TB patients with the Mtb-specific antigen, early secretory antigenic target-6 (ESAT-6) and measured cytokine expression using quantitative real-time PCR (qPCR). Exogenous IL-24 increased IFN-gamma expression in PBMC obtained from TB patients while neutralization of IL-24 reduced IFN-gamma expression in PBMC from subjects with LTBI. Exogenous IL-24 enhanced IFN-gamma expression by increasing expression of IL-12 family cytokines, including IL-12alpha, IL-12beta, IL-23alpha and IL-27, and by reducing FOXP3 expression in PBMC from TB patients. This is the first demonstration that IL-24 may play an important role in IFN-gamma expression following infection with Mtb.
authors.affiliation: Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, United States.
authors.forename: Bo
authors.initials: B
authors.lastname: Wu
authors.forename: Chunhong
authors.initials: C
authors.lastname: Huang
authors.forename: Midori
authors.initials: M
authors.lastname: Kato-Maeda
authors.forename: Philip C
authors.initials: PC
authors.lastname: Hopewell
authors.forename: Charles L
authors.initials: CL
authors.lastname: Daley
authors.forename: Alan M
authors.initials: AM
authors.lastname: Krensky
authors.forename: Carol
authors.initials: C
authors.lastname: Clayberger
mesh_terms: D051858:Forkhead Transcription Factors / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007371:Interferon-gamma / Q000235:genetics / Q000378:metabolism*; D007378:Interleukins / Q000096:biosynthesis / Q000378:metabolism / Q000494:pharmacology*; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000276:immunology; D012333:RNA, Messenger / Q000378:metabolism; D014397:Tuberculosis, Pulmonary / Q000276:immunology*; D015854:Up-Regulation; D000099180:Interleukin-24
chemical_list: D051858:Forkhead Transcription Factors; D007371:Interferon-gamma; D007378:Interleukins; D012333:RNA, Messenger; D000099180:Interleukin-24; C418974:FOXP3 protein, human