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HIV-tuberculosis-associated immune reconstitution inflammatory syndrome is characterized by Toll-like receptor and inflammasome signalling.

Lai RP, Meintjes G, Wilkinson KA, Graham CM, Marais S, Van der Plas H, Deffur A, Schutz C, Bloom C, Munagala I, Anguiano E, Goliath R, Maartens G, Banchereau J, Chaussabel D, O'Garra A, Wilkinson RJ - Nat Commun (2015)

Bottom Line: Here we perform transcriptomic profiling of the blood samples of patients with HIV-associated TB.Inhibition of MyD88 adaptor and group 1 caspases reduces secretion of cytokines including IL-1 in TB-IRIS patients.These data provide insight on the pathogenesis of TB-IRIS and may assist the development of specific therapies.

View Article: PubMed Central - PubMed

Affiliation: The Francis Crick Institute Mill Hill Laboratory, London NW7 1AA, UK.

ABSTRACT
Patients with HIV-associated tuberculosis (TB) initiating antiretroviral therapy (ART) may develop immune reconstitution inflammatory syndrome (TB-IRIS). No biomarkers for TB-IRIS have been identified and the underlying mechanisms are unclear. Here we perform transcriptomic profiling of the blood samples of patients with HIV-associated TB. We identify differentially abundant transcripts as early as week 0.5 post ART initiation that predict downstream activation of proinflammatory cytokines in patients who progress to TB-IRIS. At the characteristic time of TB-IRIS onset (week 2), the signature is characterized by over-representation of innate immune mediators including TLR signalling and TREM-1 activation of the inflammasome. In keeping with the transcriptional data, concentrations of plasma cytokines and caspase-1/5 are elevated in TB-IRIS. Inhibition of MyD88 adaptor and group 1 caspases reduces secretion of cytokines including IL-1 in TB-IRIS patients. These data provide insight on the pathogenesis of TB-IRIS and may assist the development of specific therapies.

No MeSH data available.


Related in: MedlinePlus

Both canonical and non-canonical inflammasomes are activated in TB-IRIS.(a) Patient PBMC from TB-IRIS and non-IRIS (week 2) were treated with pan-group 1 caspase inhibitor or dimethyl sulfoxide (DMSO) vehicle control, followed by stimulation with heat-inactivated H37Rv. An unstimulated background control was included for each treatment per sample. Concentrations of caspase-1 (left, on TC supernatant) and caspase-3 (right, with lysate) are shown as background subtracted (stimulated minus unstimulated) with a value of zero assigned to those negative after background subtraction. Caspase-5 (middle, with lysate) is expressed as fold-change of stimulated samples over unstimulated controls, as a standard curve was not available. The Wilcoxon signed rank test was used for statistical comparisons. The median value of each group was shown and P-value was designated: *P≤0.05, **P≤0.01, ***P≤0.001 and ****P≤0.0001. (b) Reflecting increased concentrations of caspase-1 and caspase-5, concentrations of IL-1β (left) and IL-1α (right) produced by patient PBMCs treated above were measured. Concentrations are expressed as that from MTB-stimulated minus the corresponding unstimulated control.
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f7: Both canonical and non-canonical inflammasomes are activated in TB-IRIS.(a) Patient PBMC from TB-IRIS and non-IRIS (week 2) were treated with pan-group 1 caspase inhibitor or dimethyl sulfoxide (DMSO) vehicle control, followed by stimulation with heat-inactivated H37Rv. An unstimulated background control was included for each treatment per sample. Concentrations of caspase-1 (left, on TC supernatant) and caspase-3 (right, with lysate) are shown as background subtracted (stimulated minus unstimulated) with a value of zero assigned to those negative after background subtraction. Caspase-5 (middle, with lysate) is expressed as fold-change of stimulated samples over unstimulated controls, as a standard curve was not available. The Wilcoxon signed rank test was used for statistical comparisons. The median value of each group was shown and P-value was designated: *P≤0.05, **P≤0.01, ***P≤0.001 and ****P≤0.0001. (b) Reflecting increased concentrations of caspase-1 and caspase-5, concentrations of IL-1β (left) and IL-1α (right) produced by patient PBMCs treated above were measured. Concentrations are expressed as that from MTB-stimulated minus the corresponding unstimulated control.

Mentions: We next investigated TREM1 signalling, the other consistently over-represented pathway in TB-IRIS. The TREM1 activation in TB-IRIS consisted of upregulated messenger RNA expression of TLRs, NLR, NOD, CARD and CASP5 (caspase-5), all of which are involved in canonical and non-canonical inflammasomes. We detected a significantly higher concentration of caspase-1 in the supernatant of MTB-stimulated PBMC cultures from TB-IRIS patients at week 2 (Fig. 7a), suggesting the canonical inflammasome may be involved in mediating TB-IRIS. For the non-canonical inflammasome, PBMC lysates from TB-IRIS were found to have a significantly higher content of caspase-5, compared with non-IRIS (Fig. 7a), indicating that the non-canonical inflammasome is also activated during TB-IRIS. There was no significant difference in the anti-inflammatory apoptotic caspase-3 between TB-IRIS and non-IRIS (Fig. 7a). We next quantified the concentration of IL-1β and IL-1α in tissue culture (TC) supernatant as they are cleaved by caspase-1 and caspase-5, respectively. Significantly higher concentrations of IL-1β and IL-1α were detected in TB-IRIS, compared with non-IRIS (Fig. 7b). Treatment with an irreversible pan-caspase-1/4/5 inhibitor Z-WEHD-FMK significantly reduced the production of IL-1β and IL-1α in both groups, with a greater reduction observed in TB-IRIS. Together, these data suggest that inflammasome activation also contributes to the inflammatory response in TB-IRIS.


HIV-tuberculosis-associated immune reconstitution inflammatory syndrome is characterized by Toll-like receptor and inflammasome signalling.

Lai RP, Meintjes G, Wilkinson KA, Graham CM, Marais S, Van der Plas H, Deffur A, Schutz C, Bloom C, Munagala I, Anguiano E, Goliath R, Maartens G, Banchereau J, Chaussabel D, O'Garra A, Wilkinson RJ - Nat Commun (2015)

Both canonical and non-canonical inflammasomes are activated in TB-IRIS.(a) Patient PBMC from TB-IRIS and non-IRIS (week 2) were treated with pan-group 1 caspase inhibitor or dimethyl sulfoxide (DMSO) vehicle control, followed by stimulation with heat-inactivated H37Rv. An unstimulated background control was included for each treatment per sample. Concentrations of caspase-1 (left, on TC supernatant) and caspase-3 (right, with lysate) are shown as background subtracted (stimulated minus unstimulated) with a value of zero assigned to those negative after background subtraction. Caspase-5 (middle, with lysate) is expressed as fold-change of stimulated samples over unstimulated controls, as a standard curve was not available. The Wilcoxon signed rank test was used for statistical comparisons. The median value of each group was shown and P-value was designated: *P≤0.05, **P≤0.01, ***P≤0.001 and ****P≤0.0001. (b) Reflecting increased concentrations of caspase-1 and caspase-5, concentrations of IL-1β (left) and IL-1α (right) produced by patient PBMCs treated above were measured. Concentrations are expressed as that from MTB-stimulated minus the corresponding unstimulated control.
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f7: Both canonical and non-canonical inflammasomes are activated in TB-IRIS.(a) Patient PBMC from TB-IRIS and non-IRIS (week 2) were treated with pan-group 1 caspase inhibitor or dimethyl sulfoxide (DMSO) vehicle control, followed by stimulation with heat-inactivated H37Rv. An unstimulated background control was included for each treatment per sample. Concentrations of caspase-1 (left, on TC supernatant) and caspase-3 (right, with lysate) are shown as background subtracted (stimulated minus unstimulated) with a value of zero assigned to those negative after background subtraction. Caspase-5 (middle, with lysate) is expressed as fold-change of stimulated samples over unstimulated controls, as a standard curve was not available. The Wilcoxon signed rank test was used for statistical comparisons. The median value of each group was shown and P-value was designated: *P≤0.05, **P≤0.01, ***P≤0.001 and ****P≤0.0001. (b) Reflecting increased concentrations of caspase-1 and caspase-5, concentrations of IL-1β (left) and IL-1α (right) produced by patient PBMCs treated above were measured. Concentrations are expressed as that from MTB-stimulated minus the corresponding unstimulated control.
Mentions: We next investigated TREM1 signalling, the other consistently over-represented pathway in TB-IRIS. The TREM1 activation in TB-IRIS consisted of upregulated messenger RNA expression of TLRs, NLR, NOD, CARD and CASP5 (caspase-5), all of which are involved in canonical and non-canonical inflammasomes. We detected a significantly higher concentration of caspase-1 in the supernatant of MTB-stimulated PBMC cultures from TB-IRIS patients at week 2 (Fig. 7a), suggesting the canonical inflammasome may be involved in mediating TB-IRIS. For the non-canonical inflammasome, PBMC lysates from TB-IRIS were found to have a significantly higher content of caspase-5, compared with non-IRIS (Fig. 7a), indicating that the non-canonical inflammasome is also activated during TB-IRIS. There was no significant difference in the anti-inflammatory apoptotic caspase-3 between TB-IRIS and non-IRIS (Fig. 7a). We next quantified the concentration of IL-1β and IL-1α in tissue culture (TC) supernatant as they are cleaved by caspase-1 and caspase-5, respectively. Significantly higher concentrations of IL-1β and IL-1α were detected in TB-IRIS, compared with non-IRIS (Fig. 7b). Treatment with an irreversible pan-caspase-1/4/5 inhibitor Z-WEHD-FMK significantly reduced the production of IL-1β and IL-1α in both groups, with a greater reduction observed in TB-IRIS. Together, these data suggest that inflammasome activation also contributes to the inflammatory response in TB-IRIS.

Bottom Line: Here we perform transcriptomic profiling of the blood samples of patients with HIV-associated TB.Inhibition of MyD88 adaptor and group 1 caspases reduces secretion of cytokines including IL-1 in TB-IRIS patients.These data provide insight on the pathogenesis of TB-IRIS and may assist the development of specific therapies.

View Article: PubMed Central - PubMed

Affiliation: The Francis Crick Institute Mill Hill Laboratory, London NW7 1AA, UK.

ABSTRACT
Patients with HIV-associated tuberculosis (TB) initiating antiretroviral therapy (ART) may develop immune reconstitution inflammatory syndrome (TB-IRIS). No biomarkers for TB-IRIS have been identified and the underlying mechanisms are unclear. Here we perform transcriptomic profiling of the blood samples of patients with HIV-associated TB. We identify differentially abundant transcripts as early as week 0.5 post ART initiation that predict downstream activation of proinflammatory cytokines in patients who progress to TB-IRIS. At the characteristic time of TB-IRIS onset (week 2), the signature is characterized by over-representation of innate immune mediators including TLR signalling and TREM-1 activation of the inflammasome. In keeping with the transcriptional data, concentrations of plasma cytokines and caspase-1/5 are elevated in TB-IRIS. Inhibition of MyD88 adaptor and group 1 caspases reduces secretion of cytokines including IL-1 in TB-IRIS patients. These data provide insight on the pathogenesis of TB-IRIS and may assist the development of specific therapies.

No MeSH data available.


Related in: MedlinePlus