; for the CORIMUNO-19 Collaborative Group IMPORTANCE Severe pneumonia with hyperinflammation and elevated interleukin-6 is a common presentation of coronavirus disease 2019 (COVID-19). OBJECTIVE To determine whether tocilizumab (TCZ) improves outcomes of patients hospitalized with moderate-to-severe COVID-19 pneumonia. DESIGN, SETTING, AND PARTICPANTS This cohort-embedded, investigator-initiated, multicenter, open-label, bayesian randomized clinical trial investigating patients with COVID-19 and moderate or severe pneumonia requiring at least 3 L/min of oxygen but without ventilation or admission to the intensive care unit was conducted between March 31, 2020, to April 18, 2020, with follow-up through 28 days. Patients were recruited from 9 university hospitals in France. Analyses were performed on an intention-to-treat basis with no correction for multiplicity for secondary outcomes. INTERVENTIONS Patients were randomly assigned to receive TCZ, 8 mg/kg, intravenously plus usual care on day 1 and on day 3 if clinically indicated (TCZ group) or to receive usual care alone (UC group). Usual care included antibiotic agents, antiviral agents, corticosteroids, vasopressor support, and anticoagulants. MAIN OUTCOMES AND MEASURES Primary outcomes were scores higher than 5 on the World Health Organization 10-point Clinical Progression Scale (WHO-CPS) on day 4 and survival without need of ventilation (including noninvasive ventilation) at day 14. Secondary outcomes were clinical status assessed with the WHO-CPS scores at day 7 and day 14, overall survival, time to discharge, time to oxygen supply independency, biological factors such as C-reactive protein level, and adverse events. RESULTS Of 131 patients, 64 patients were randomly assigned to the TCZ group and 67 to UC group; 1 patient in the TCZ group withdrew consent and was not included in the analysis. Of the 130 patients, 42 were women (32%), and median (interquartile range) age was 64 (57.1-74.3) years. In the TCZ group, 12 patients had a WHO-CPS score greater than 5 at day 4 vs 19 in the UC group (median posterior absolute risk difference [ARD] −9.0%; 90% credible interval [CrI], −21.0 to 3.1), with a posterior probability of negative ARD of 89.0% not achieving the 95% predefined efficacy threshold. At day 14, 12% (95% CI −28% to 4%) fewer patients needed noninvasive ventilation (NIV) or mechanical ventilation (MV) or died in the TCZ group than in the UC group (24% vs 36%, median posterior hazard ratio [HR] 0.58; 90% CrI, 0.33-1.00), with a posterior probability of HR less than 1 of 95.0%, achieving the predefined efficacy threshold. The HR for MV or death was 0.58 (90% CrI, 0.30 to 1.09). At day 28, 7 patients had died in the TCZ group and 8 in the UC group (adjusted HR, 0.92; 95% CI 0.33-2.53). Serious adverse events occurred in 20 (32%) patients in the TCZ group and 29 (43%) in the UC group (P = .21). CONCLUSIONS AND RELEVANCE In this randomized clinical trial of patients with COVID-19 and pneumonia requiring oxygen support but not admitted to the intensive care...

Mycobacterium abscessus is a pathogenic, rapidly growing mycobacterium responsible for pulmonary and cutaneous infections in immunocompetent patients and in patients with Mendelian disorders, such as cystic fibrosis (CF). Mycobacterium abscessus is known to transition from a smooth (S) morphotype with cell surface-associated glycopeptidolipids (GPL) to a rough (R) morphotype lacking GPL. Herein, we show that M. abscessus S and R variants are able to grow inside macrophages and are present in morphologically distinct phagosomes. The S forms are found mostly as single bacteria within phagosomes characterized by a tightly apposed phagosomal membrane and the presence of an electron translucent zone (ETZ) surrounding the bacilli. By contrast, infection with the R form leads to phagosomes often containing more than two bacilli, surrounded by a loose phagosomal membrane and lacking the ETZ. In contrast to the R variant, the S variant is capable of restricting intraphagosomal acidification and induces less apoptosis and autophagy. Importantly, the membrane of phagosomes enclosing the S forms showed signs of alteration, such as breaks or partial degradation. Although not frequently encountered, these events suggest that the S form is capable of provoking phagosome–cytosol communication. In conclusion, M. abscessus S exhibits traits inside macrophages that are reminiscent of slow-growing mycobacterial species.

Background Patients with COVID-19 pneumonia have an excess of inflammation and increased concentrations of cytokines including interleukin-1 (IL-1). We aimed to determine whether anakinra, a recombinant human IL-1 receptor antagonist, could improve outcomes in patients in hospital with mild-to-moderate COVID-19 pneumonia.Methods In this multicentre, open-label, Bayesian randomised clinical trial (CORIMUNO-ANA-1), nested within the CORIMUNO-19 cohort, we recruited patients from 16 University hospitals in France with mild-to-moderate COVID-19 pneumonia, severe acute respiratory syndrome coronavirus 2 infection confirmed by real-time RT-PCR, requiring at least 3 L/min of oxygen by mask or nasal cannula but without ventilation assistance, a score of 5 on the WHO Clinical Progression Scale (WHO-CPS), and a C-reactive protein serum concentration of more than 25 mg/L not requiring admission to the intensive care unit at admission to hospital. Eligible patients were randomly assigned (1:1) using a web-based secure centralised system, stratified by centre and blocked with varying block sizes (randomly of size two or four), to either usual care plus anakinra (200 mg twice a day on days 1-3, 100 mg twice on day 4, 100 mg once on day 5) or usual care alone. Usual care was provided at the discretion of the site clinicians. The two coprimary outcomes were the proportion of patients who had died or needed non-invasive or mechanical ventilation by day 4 (ie, a score of >5 on the WHO-CPS) and survival without need for mechanical or non-invasive ventilation (including high-flow oxygen) at day 14. All analyses were done on an intention-to-treat basis. The trial is registered with ClinicalTrials.gov, NCT04341584, and is now closed to accrual. FindingsBetween April 8 and April 26, 2020, we screened 153 patients. The study was stopped early following the recommendation of the data and safety monitoring board, after the recruitment of 116 patients: 59 were assigned to the anakinra group, and 57 were assigned to the usual care group. Two patients in the usual care group withdrew consent and were not analysed. In the analysable population, the median age was 66 years (IQR 59 to 76) and 80 (70%) participants were men. In the anakinra group, 21 (36%) of 59 patients had a WHO-CPS score of more than 5 at day 4 versus 21 (38%) of 55 in the usual care group (median posterior absolute risk difference [ARD] -2•5%, 90% credible interval [CrI] -17•1 to 12•0), with a posterior probability of ARD of less than 0 (ie, anakinra better than usual care) of 61•2%. At day 14, 28 (47%; 95% CI 33 to 59) patients in the anakinra group and 28 (51%; 95% CI 36 to 62) in the usual care group needed ventilation or died, with a posterior probability of any efficacy of anakinra (hazard ratio [HR] being less than 1) of 54•5% (median posterior HR 0•97; 90% CrI 0•62 to 1•52). At day 90, 16 (27%) patients in the anakinra group and 15 (27%) in the usual care group had died. Serious adverse events occurred in 27 (46%) patients in the anakinra group and 21 (38%) in the usu...

SUMMARY The tuberculosis (TB) bacillus, Mycobacterium tuberculosis (Mtb), and HIV-1 act synergistically; however, the mechanisms by which Mtb exacerbates HIV-1 pathogenesis are not well known. Using in vitro and ex vivo cell culture systems, we show that human M(IL-10) anti-inflammatory macrophages, present in TB-associated microenvironments, produce high levels of HIV-1. In vivo, M(IL-10) macrophages are expanded in lungs of co-infected non-human primates, which correlates with disease severity. Further, HIV-1/Mtb co-infected patients display an accumulation of M(IL-10) macrophage markers (soluble CD163 and MerTK). These M(IL-10) macrophages form direct cell-to-cell bridges, which we identified as tunneling nanotubes (TNTs) involved in viral transfer. TNT formation requires the IL-10/STAT3 signaling pathway, and targeted inhibition of TNTs substantially reduces the enhancement of HIV-1 cell-to-cell transfer and overproduction in M(IL-10) macrophages. Our study reveals that TNTs facilitate viral transfer and amplification, thereby promoting TNT formation as a mechanism to be explored in TB/AIDS potential therapeutics.

Autophagy is a well-conserved lysosomal degradation pathway that plays key roles in bacterial infections. One of the most studied is probably xenophagy, the selective capture and degradation of intracellular bacteria by lysosomes. However, the impact of autophagy goes beyond xenophagy and involves intensive cross-talks with other host defense mechanisms. In addition, autophagy machinery can have non-canonical functions such as LC3-associated phagocytosis. In this review, we intend to summarize the current knowledge on the many functions of autophagy proteins in cell defenses with a focus on bacteria–macrophage interaction. We also present the strategies developed by pathogens to evade or to exploit this machinery in order to establish a successful infection. Finally, we discuss the opportunities and challenges of autophagy manipulation in improving therapeutics and vaccines against bacterial pathogens.

Autophagy is an important innate immune defense mechanism that controls Mycobacterium tuberculosis (Mtb) growth inside macrophages. Autophagy machinery targets Mtb-containing phagosomes via xenophagy after damage to the phagosomal membrane due to the Type VII secretion system Esx-1 or via LC3-associated phagocytosis without phagosomal damage. Conversely, Mtb restricts autophagy-related pathways via the production of various bacterial protein factors. Although bacterial lipids are known to play strategic functions in Mtb pathogenesis, their role in autophagy manipulation remains largely unexplored. Here, we report that the lipid virulence factors sulfoglycolipids (SLs) and phthiocerol dimycocerosates (DIMs) control autophagy-related pathways through distinct mechanisms in human macrophages. Using knock-out and knock-in mutants of Mtb and Mycobacterium bovis BCG (Bacille Calmette Guerin) and purified lipids, we found that (i) Mtb mutants with DIM and SL deficiencies promoted functional autophagy via an MyD88-dependent and phagosomal damage-independent pathway in human macrophages; (ii) SLs limited this pathway by acting as TLR2 antagonists; (iii) DIMs prevented phagosomal damage-independent autophagy while promoting Esx-1-dependent xenophagy; (iv) and DIMs, but not SLs, limited the acidification of LC3-positive Mtb compartments. In total, our study reveals an unexpected and intricate role for Mtb lipid virulence factors in controlling autophagy-related pathways in human macrophages, thus providing further insight into the autophagy manipulation tactics deployed by intracellular bacterial pathogens.

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Autophagy is a lysosomal degradative process that plays essential functions in innate immunity, particularly, in the clearance of intracellular bacteria such as Mycobacterium tuberculosis. The molecular mechanisms involved in autophagy activation and targeting of mycobacteria, in innate immune responses of macrophages, are only partially characterized. Autophagy targets pathogenic M. tuberculosis via a cytosolic DNA recognition- and an ubiquitin-dependent pathway. In this report, we show that non-pathogenic M. smegmatis induces a robust autophagic response in THP-1 macrophages with an up regulation of several autophagy-related genes. Autophagy activation relies in part on recognition of mycobacteria by Toll-like receptor 2 (TLR2). Notably, LC3 targeting of M. smegmatis does not rely on membrane damage, ubiquitination, or autophagy receptor recruitment. Lastly, M. smegmatis promotes recruitment of several autophagy proteins, which are required for mycobacterial killing. In conclusion, our study uncovered an alternative autophagic pathway triggered by mycobacteria which involves cell surface recognition but not bacterial ubiquitination.