DC-SIGN Induction in Alveolar Macrophages Defines Privileged Target Host Cells for Mycobacteria in Patients with Tuberculosis

BACKGROUND: Interplays between Mycobacterium tuberculosis, the etiological agent of tuberculosis (TB) in human and host professional phagocytes, namely macrophages (Mφs) and dendritic cells (DCs), are central to immune protection against TB and to TB pathogenesis. We and others have recently shown that the C-type lectin dendritic cell–specific intercellular adhesion molecule-3 grabbing nonintegrin (DC-SIGN; CD209) mediates important interactions between mycobacteria and human monocyte-derived DCs (MoDCs) in vitro. METHODS AND FINDINGS: In order to explore the possible role of DC-SIGN in M. tuberculosis infection in vivo, we have analysed DC-SIGN expression in broncho-alveolar lavage (BAL) cells from patients with TB (n = 40) or with other non-mycobacterial lung pathologies, namely asthma (n = 14) and sarcoidosis (n = 11), as well as from control individuals (n = 9). We show that in patients with TB, up to 70% of alveolar Mφs express DC-SIGN. By contrast, the lectin is barely detected in alveolar Mφs from all other individuals. Flow cytometry, RT-PCR, and enzyme-linked immunosorbent assay analyses of BAL-derived fluids and cells indicated that M. tuberculosis infection induces DC-SIGN expression in alveolar Mφs by a mechanism that is independent of Toll-like receptor-4, interleukin (IL)-4, and IL-13. This mechanism most likely relies on the secretion of soluble host and/or mycobacterial factors that have yet to be identified, as both infected and uninfected bystander Mφs were found to express DC-SIGN in the presence of M. tuberculosis. Immunohistochemical examination of lung biopsy samples from patients with TB showed that the bacilli concentrate in pulmonary regions enriched in DC-SIGN-expressing alveolar Mφs in vivo. Ex vivo binding and inhibition of binding experiments further revealed that DC-SIGN–expressing alveolar Mφs constitute preferential target cells for M. tuberculosis, as compared to their DC-SIGN(−) counterparts. In contrast with what has been reported previously in MoDCs in vitro, ex vivo DC-SIGN ligation by mycobacterial products failed to induce IL-10 secretion by alveolar Mφs, and IL-10 was not detected in BALs from patients with TB. CONCLUSION: Altogether, our results provide further evidence for an important role of DC-SIGN during TB in humans. DC-SIGN induction in alveolar Mφs may have important consequences on lung colonization by the tubercle bacillus, and on pulmonary inflammatory and immune responses in the infected host

Cytokines et maladies pulmonaires granulomateuses et fibrosantes

PARIS5-BU Méd.Cochin (751142101) / SudocPARIS-BIUM (751062103) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

Alveolar CD11b⁺ Cells Over-Express DC-SIGN in Patients with TB

<div><p>(A) BAL cells from a patient with TB (upper four panels) and from a patient with sarcoidosis (lower two panels) were analyzed by flow cytometry. Expression of CD3 and CD4 was analyzed on cells from R1. CD11b and DC-SIGN expression was analyzed on cells from R2.</p> <p>(B) Distribution of the proportion of CD11b⁺DC-SIGN⁺ cells in BALs according to pathology and age. Black circles indicate ≤15 y of age; black triangles indicate ≥20 y; NC, no case.</p> <p>(C) DC-SIGN (upper panels) and <i>M. tuberculosis</i> (lower panels) immunodetection in serial sections of a lung biopsy from a patient with TB. The pictures are representative of results obtained with samples from a total of four patients. G, granuloma.</p> <p>(D) DC-SIGN immunodetection in a lung biopsy from a patient with sarcoidosis. The pictures are representative of results obtained with samples from a total of three patients.</p> <p>In (C) and (D), magnification in left panels is 100×, and regions in squares are shown at higher magnification in right panels.</p></div

DC-SIGN Mediates <i>M. tuberculosis</i> Binding to Alveolar Mϕs from Patients with TB

<div><p>(A) Alveolar Mϕs from a patient with TB were infected with GFP-expressing <i>M. tuberculosis,</i> in the absence (ø; upper left panel) or the presence of control isotype (upper right panel), anti-CD11b (lower left panel), or -DC-SIGN (lower right panel) blocking antibodies. In the upper panels, cells were then stained with fluorescent PE-conjugated anti-DC-SIGN and APC-conjugated anti-CD11b antibodies. In lower panels, fluorescent antibodies were added together with blocking antibodies (same clones).</p> <p>(B) Proportion of GFP⁺ cells in DC-SIGN⁻ (open bars) and DC-SIGN⁺ (grey bars) alveolar Mϕs as calculated from (A) using BALs from two patients with TB. THP1 Mϕs expressing or not expressing DC-SIGN (THP1::DC-SIGN) were used in a binding experiment with <i>M. tuberculosis</i> H37Rv, in the presence or absence of anti-DC-SIGN antibodies.</p> <p>(D) Confocal microscopy examination of adherent DC-SIGN⁺ cells infected with GFP-expressing <i>M. tuberculosis</i> for various times.</p></div

Alveolar DC-SIGN⁺ Cells in Patients with TB Are Mϕs

<div><p>(A) Total BAL cells from a patient with TB were allowed to adhere to the plastic for 1 h at 37 °C in complete medium. CD11b and DC-SIGN expression was analyzed by flow cytometry before (left) and after (right) adherence.</p> <p>(B) Surface and intracellular DC-SIGN (red) expression by an adherent alveolar cell examined under the confocal microscope.</p> <p>(C) Flow cytometry analysis of surface expression of BDCA-1 (CD1c), BDCA-2, BDAC-3, CD1a, CD11b, CD11c, CD14, CD68, CD83, and CD123 in DC-SIGN⁺ BAL cells from a patient with TB.</p> <p>(D) Flow cytometry analysis of surface expression of CD40, CD86, HLA-DR, CD11b, CD11c, CD206, CD16, CD32, CD40, CD64, TLR2, TLR4, and TLR9 in DC-SIGN⁺ BAL cells from a patient with TB.</p> <p>In (C) and (D), analysis was performed on DC-SIGN–expressing cells in R2, as shown in <a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.0020381#pmed-0020381-g001" target="_blank">Figure 1</a>.</p></div

DC-SIGN Is Induced on Resident Alveolar Mϕs upon <i>M. tuberculosis</i> Infection

<div><p>(A) Flow cytometry analysis of CD11b and DC-SIGN expression by PBMCs from a healthy donor (upper panels) and a patient with TB (lower panels).</p> <p>(B) Adherent DC-SIGN⁻ alveolar Mϕs from a non-tuberculous patient were infected with a GFP-expressing strain of <i>M. tuberculosis</i> at a MOI of one bacterium per cell, or treated with IL-4, TNF-α, or LPS, or left untreated (ø control). After 48 h at 37 °C, cells were recovered and DC-SIGN expression was analyzed by flow cytometry. In <i>M. tuberculosis</i> panel, the grey area corresponds to GFP⁺ (infected) cells, and the plain line corresponds to GFP⁻ (uninfected) cells.</p> <p>(C) Cells infected with <i>M. tuberculosis</i> at a MOI of 1 for 1, 2, 4, or 24 h were analysed by RT-PCR for DC-SIGN and GAPDH mRNAs.</p></div

Expansion of Circulating CD49b+LAG3+ Type 1 Regulatory T Cells in Human Chronic Graft-Versus-Host Disease

International audienceNo abstract availabl

COMET: a multicomponent home-based disease-management programme versus routine care in severe COPD

The COPD Patient Management European Trial (COMET) investigated the efficacy and safety of a home-based COPD disease management intervention for severe COPD patients. The study was an international open-design clinical trial in COPD patients (forced expiratory volume in 1 s <50% of predicted value) randomised 1:1 to the disease management intervention or to the usual management practices at the study centre. The disease management intervention included a self-management programme, home telemonitoring, care coordination and medical management. The primary end-point was the number of unplanned all-cause hospitalisation days in the intention-to-treat (ITT) population. Secondary end-points included acute care hospitalisation days, BODE (body mass index, airflow obstruction, dyspnoea and exercise) index and exacerbations. Safety end-points included adverse events and deaths. For the 157 (disease management) and 162 (usual management) patients eligible for ITT analyses, all-cause hospitalisation days per year (mean +/- SD) were 17.4 +/- 35.4 and 22.6 +/- 41.8, respectively (mean difference -5.3, 95% CI -13.7 to -3.1; p=0.16). The disease management group had fewer per-protocol acute care hospitalisation days per year (p=0.047), a lower BODE index (p=0.01) and a lower mortality rate (1.9% versus 14.2%; p<0.001), with no difference in exacerbation frequency. Patient profiles and hospitalisation practices varied substantially across countries. The COMET disease management intervention did not significantly reduce unplanned all-cause hospitalisation days, but reduced acute care hospitalisation days and mortality in severe COPD patients

Prevalence and characteristics of TERT and TERC mutations in suspected genetic pulmonary fibrosis

International audienceTelomerase reverse transcriptase (TERT) or telomerase RNA (TERC) gene mutation is a major monogenic cause of pulmonary fibrosis. Sequencing of TERT/TERC genes is proposed to patients with familial pulmonary fibrosis. Little is known about the possible predictors of this mutation and its impact on prognosis. We retrospectively analysed all the genetic diagnoses made between 2007-2014 in patients with pulmonary fibrosis. We evaluated the prevalence of TERT/TERC disease-Associated variant (DAV), factors associated with a DAV, and the impact of the DAV on survival. 237 patients with pulmonary fibrosis (153 with familial pulmonary fibrosis, 84 with telomere syndrome features without familial pulmonary fibrosis) were tested for TERT/TERC DAV. DAV was diagnosed in 40 patients (16.8%), including five with non-idiopathic interstitial pneumonia. Prevalence of TERT/TERC DAV did not significantly differ between patients with familial pulmonary fibrosis or with only telomere syndrome features (18.2% versus 16.4%). Young age, red blood cell macrocytosis, and low platelet count were associated with the presence of DAV; the probability of DAV was increased for patients 40-60 years. Transplant-free survival was lower with than without TERT/TERC DAV (4.2 versus 7.2 years; p=0.046). TERT/TERC DAV were associated with specific clinical and biological features and reduced transplantfree survival. ©ERS 2016