IL-24 modulates IFN-gamma expression in patients with tuberculosis.
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.
Wu
Bo
B
Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, United States.
Huang
Chunhong
C
Kato-Maeda
Midori
M
Hopewell
Philip C
PC
Daley
Charles L
CL
Krensky
Alan M
AM
Clayberger
Carol
C
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
D051858:Forkhead Transcription Factors; D007371:Interferon-gamma; D007378:Interleukins; D012333:RNA, Messenger; D000099180:Interleukin-24; C418974:FOXP3 protein, human