Regulation of Mycobacterium tuberculosis-Dependent HIV-1 Transcription Reveals a New Role for NFAT5 in the Toll-Like Receptor Pathway

Tuberculosis (TB) disease in HIV co-infected patients contributes to increased mortality by activating innate and adaptive immune signaling cascades that stimulate HIV-1 replication, leading to an increase in viral load. Here, we demonstrate that silencing of the expression of the transcription factor nuclear factor of activated T cells 5 (NFAT5) by RNA interference (RNAi) inhibits Mycobacterium tuberculosis (MTb)-stimulated HIV-1 replication in co-infected macrophages. We show that NFAT5 gene and protein expression are strongly induced by MTb, which is a Toll-like receptor (TLR) ligand, and that an intact NFAT5 binding site in the viral promoter of R5-tropic HIV-1 subtype B and subtype C molecular clones is required for efficent induction of HIV-1 replication by MTb. Furthermore, silencing by RNAi of key components of the TLR pathway in human monocytes, including the downstream signaling molecules MyD88, IRAK1, and TRAF6, significantly inhibits MTb-induced NFAT5 gene expression. Thus, the innate immune response to MTb infection induces NFAT5 gene and protein expression, and NFAT5 plays a crucial role in MTb regulation of HIV-1 replication via a direct interaction with the viral promoter. These findings also demonstrate a general role for NFAT5 in TLR- and MTb-mediated control of gene expression

Comprehensive lung injury pathology induced by mTOR inhibitors

Molecular Targets in Oncology[Abstract] Interstitial lung disease is a rare side effect of temsirolimus treatment in renal cancer patients. Pulmonary fibrosis is characterised by the accumulation of extracellular matrix collagen, fibroblast proliferation and migration, and loss of alveolar gas exchange units. Previous studies of pulmonary fibrosis have mainly focused on the fibro-proliferative process in the lungs. However, the molecular mechanism by which sirolimus promotes lung fibrosis remains elusive. Here, we propose an overall cascade hypothesis of interstitial lung diseases that represents a common, partly underlying synergism among them as well as the lung pathogenesis side effects of mammalian target of rapamycin inhibitors

Impairment of ß chemokine and cytokine production in patients with HIV related Pneumocystis jerovici pneumonia

Background: Pneumocystis jerovici pneumonia (PJP) remains a frequent opportunistic infection in HIV infected patients which markedly upregulates HIV replication by mechanisms so far poorly elucidated. PJP triggers the production of proinflammatory mediators with activating effects on HIV. However, anti-inflammatory factors with inhibiting effects on HIV are normally produced in parallel. We postulated that an imbalance of mediators normally controlling HIV replication could underlie its marked increase during PJP. Methods: The production of tumour necrosis factor α (TNFα), interleukins IL-6 and IL-10, and ß-chemokine by bronchoalveolar lavage (BAL) cells recovered from HIV infected patients with and without PJP was compared. The pulmonary viral load was determined and correlations with cytokine and chemokine production were examined. Results: TNFα and IL-6 release was similar in patients with and without PJP but IL-10 and ß-chemokine release was markedly lower in the PJP group (IL-10: p<10(-2), RANTES, MIP-1α and MIP-1ß: p<0.001). The pulmonary viral load was markedly higher in patients with PJP (p<0.001) and correlated negatively with levels of MIP-1α, RANTES and IL-10 in BAL fluid cells (p<0.05). Conclusion: Pulmonary IL-10 and ß-chemokine production is markedly defective in HIV infected patients with PJP, while pulmonary TNFα and IL-6 levels are normal. The resulting excess of these latter factors, which are known to upregulate HIV replication, might contribute to the increase in pulmonary viral load and to the more rapid HIV disease progression observed in patients with PJP