[HTML][HTML] Interleukin-17 limits hypoxia-inducible factor 1α and development of hypoxic granulomas during tuberculosis

R Domingo-Gonzalez, S Das, KL Griffiths, M Ahmed… - JCI insight, 2017 - ncbi.nlm.nih.gov
R Domingo-Gonzalez, S Das, KL Griffiths, M Ahmed, M Bambouskova, R Gopal, S Gondi
JCI insight, 2017ncbi.nlm.nih.gov
Mycobacterium tuberculosis (Mtb) is a global health threat, compounded by the emergence
of drug-resistant strains. A hallmark of pulmonary tuberculosis (TB) is the formation of
hypoxic necrotic granulomas, which upon disintegration, release infectious Mtb.
Furthermore, hypoxic necrotic granulomas are associated with increased disease severity
and provide a niche for drug-resistant Mtb. However, the host immune responses that
promote the development of hypoxic TB granulomas are not well described. Using a necrotic …
Abstract
Mycobacterium tuberculosis (Mtb) is a global health threat, compounded by the emergence of drug-resistant strains. A hallmark of pulmonary tuberculosis (TB) is the formation of hypoxic necrotic granulomas, which upon disintegration, release infectious Mtb. Furthermore, hypoxic necrotic granulomas are associated with increased disease severity and provide a niche for drug-resistant Mtb. However, the host immune responses that promote the development of hypoxic TB granulomas are not well described. Using a necrotic Mtb mouse model, we show that loss of Mtb virulence factors, such as phenolic glycolipids, decreases the production of the proinflammatory cytokine IL-17 (also referred to as IL-17A). IL-17 production negatively regulates the development of hypoxic TB granulomas by limiting the expression of the transcription factor hypoxia-inducible factor 1α (HIF1α). In human TB patients, HIF1α mRNA expression is increased. Through genotyping and association analyses in human samples, we identified a link between the single nucleotide polymorphism rs2275913 in the IL-17 promoter (–197G/G), which is associated with decreased IL-17 production upon stimulation with Mtb cell wall. Together, our data highlight a potentially novel role for IL-17 in limiting the development of hypoxic necrotic granulomas and reducing disease severity in TB.
ncbi.nlm.nih.gov