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  • 1
    In: Microbiology Spectrum, American Society for Microbiology, Vol. 11, No. 1 ( 2023-02-14)
    Abstract: In the search for control of human immunodeficiency virus type 1 (HIV-1) infection without antiretroviral therapy, posttreatment controllers (PTCs) are models of HIV remission. To better understand their mechanisms of control, we characterized the HIV blood reservoirs of 8 PTCs (median of 9.4 years after treatment interruption) in comparison with those of 13 natural HIV infection controllers (HICs) (median of 18 years of infection) and with those of individuals receiving efficient antiretroviral therapy initiated during either primary HIV infection (PHIs; n  = 8) or chronic HIV infection (CHIs; n  = 6). This characterization was performed with single-genome amplification and deep sequencing. The proviral diversity, which reflects the history of past viral replication, was lower in the PTCs, PHIs, and aviremic HICs than in the blipper HICs and CHIs. The proportions of intact and defective proviruses among the proviral pool in PTCs were not significantly different from those of other groups. When looking at the quantities of proviruses per million peripheral blood mononuclear cells (PBMCs), they had similar amounts of intact proviruses as other groups but smaller amounts of defective proviruses than CHIs, suggesting a role of these forms in HIV pathogenesis. Two HICs but none of the PTCs harbored only proviruses with deletion in nef ; these attenuated strains could contribute to viral control in these participants. We show, for the first time, the presence of intact proviruses and low viral diversity in PTCs long after treatment interruption, as well as the absence of evolution of the proviral quasispecies in subsequent samples. This reflects low residual replication over time. Further data are necessary to confirm these results. IMPORTANCE Most people living with HIV need antiretroviral therapy to control their infection and experience viral relapse in case of treatment interruption, because of viral reservoir (proviruses) persistence. Knowing that proviruses are very diverse and most of them are defective in treated individuals, we aimed to characterize the HIV blood reservoirs of posttreatment controllers (PTCs), rare models of drug-free remission, in comparison with spontaneous controllers and treated individuals. At a median time of 9 years after treatment interruption, which is unprecedented in the literature, we showed that the proportions and quantities of intact proviruses were similar between PTCs and other individuals. Unlike 2/7 spontaneous controllers who harbored only nef -deleted proviruses, which are attenuated strains, which could contribute to their control, no such case was observed in PTCs. Furthermore, PTCs displayed low viral genetic diversity and no evolution of their reservoirs, indicating very low residual replication, despite the presence of intact proviruses.
    Type of Medium: Online Resource
    ISSN: 2165-0497
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2023
    detail.hit.zdb_id: 2807133-5
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  • 2
    In: Journal of Clinical Microbiology, American Society for Microbiology, Vol. 56, No. 6 ( 2018-06)
    Abstract: The diagnosis of nocardiosis, a severe opportunistic infection, is challenging. We assessed the specificity and sensitivity of a 16S rRNA Nocardia PCR-based assay performed on clinical samples. In this multicenter study (January 2014 to April 2015), patients who were admitted to three hospitals and had an underlying condition favoring nocardiosis, clinical and radiological signs consistent with nocardiosis, and a Nocardia PCR assay result for a clinical sample were included. Patients were classified as negative control (NC) (negative Nocardia culture results and proven alternative diagnosis or improvement at 6 months without anti- Nocardia treatment), positive control (PC) (positive Nocardia culture results), or probable nocardiosis (positive Nocardia PCR results, negative Nocardia culture results, and no alternative diagnosis). Sixty-eight patients were included; 47 were classified as NC, 8 as PC, and 13 as probable nocardiosis. PCR results were negative for 35/47 NC patients (74%). For the 12 NC patients with positive PCR results, the PCR assay had been performed with respiratory samples. These NC patients had chronic bronchopulmonary disease more frequently than did the NC patients with negative PCR results (8/12 patients [67%] versus 11/35 patients [31%] ; P = 0.044). PCR results were positive for 7/8 PC patients (88%). There were 13 cases of probable nocardiosis, diagnosed solely using the PCR results; 9 of those patients (69%) had lung involvement (consolidation or nodule). Nocardia PCR testing had a specificity of 74% and a sensitivity of 88% for the diagnosis of nocardiosis. Nocardia PCR testing may be helpful for the diagnosis of nocardiosis in immunocompromised patients but interpretation of PCR results from respiratory samples is difficult, because the PCR assay may also detect colonization.
    Type of Medium: Online Resource
    ISSN: 0095-1137 , 1098-660X
    RVK:
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2018
    detail.hit.zdb_id: 1498353-9
    SSG: 12
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  • 3
    In: Journal of Clinical Microbiology, American Society for Microbiology, Vol. 43, No. 8 ( 2005-08), p. 4215-4217
    Abstract: Using commercially available herpes simplex virus (HSV) type-specific serological diagnostic tests, HSV type 2 (HSV-2) antibody prevalence was assessed in two parallel prospective studies including 534 human immunodeficiency virus type 1 (HIV-1)-infected outpatients living in two areas of northern France. In the first cohort of 434 subjects, 223 (51%) individuals demonstrated a positive HSV-2 serological status while 66 (66%) of 100 subjects in the second cohort were seropositive for HSV-2 (51 versus 66%; P = 0.08). Among the 223 HSV-2-seropositive subjects identified in the first study cohort, only 22 (10%) had suffered from recurrent anogenital lesions during the past 12 months while 154 (69%) had no clinical history of herpesvirus infection. Our findings demonstrate high proportions of subclinical and undiagnosed HSV-2 infection in HIV-1-infected individuals and suggest that HSV type-specific serological testing in the French HIV-1-infected subpopulation could be an efficient strategy to diagnose clinically asymptomatic HSV-2 infections.
    Type of Medium: Online Resource
    ISSN: 0095-1137 , 1098-660X
    RVK:
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2005
    detail.hit.zdb_id: 1498353-9
    SSG: 12
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  • 4
    In: Infection and Immunity, American Society for Microbiology, Vol. 76, No. 7 ( 2008-07), p. 3027-3036
    Abstract: Mycobacterium tuberculosis possesses a diversity of potential virulence factors including complex branched lipids such as the phenolic glycolipid PGL-tb. PGL-tb expression by the clinical M. tuberculosis isolate HN878 has been associated with a less efficient Th1 response and increased virulence in mice and rabbits. It has been suggested that the W-Beijing family is the only group of M. tuberculosis strains with an intact pks1 - 15 gene, required for the synthesis of PGL-tb and capable of producing PGL-tb. We have found that some strains with an intact pks1 - 15 do not produce PGL-tb while others may produce a variant of PGL-tb. We examined the early host cytokine response to infection with these strains in vitro to better understand the effect of PGL-tb synthesis on immune responses. In addition, we generated a PGL-tb-producing H37Rv in order to determine the effect of PGL-tb production on the host immune response during infection by a strain normally devoid of PGL-tb synthesis. We observed that PGL-tb production by clinical M. tuberculosis isolates affected cytokine production differently depending on the background of the strain. Importantly, while ectopic PGL-tb production by H37Rv suppressed the induction of several pro- and anti-inflammatory cytokines in vitro in human monocytes, it did not lead to increased virulence in infected mice and rabbits. Collectively, our data indicate that, while PGL-tb may play a role in the immunogenicity and/or virulence of M. tuberculosis , it probably acts in concert with other bacterial factors which seem to be dependent on the background of the strain.
    Type of Medium: Online Resource
    ISSN: 0019-9567 , 1098-5522
    RVK:
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2008
    detail.hit.zdb_id: 1483247-1
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  • 5
    In: Infection and Immunity, American Society for Microbiology, Vol. 77, No. 12 ( 2009-12), p. 5651-5658
    Abstract: Depletion of dendritic cells (DC) in secondary lymphoid organs is a hallmark of sepsis-induced immune dysfunction. In this setting, we investigated if Toll-like receptor (TLR)-dependent signaling might modulate the maturation process and the survival of DC. Using a model of sublethal polymicrobial sepsis induced by cecal ligation and puncture, we investigated the quantitative and functional features of spleen DC in wild-type, TLR2 −/− , TLR4 −/− , and TLR2 −/− TLR4 −/− mice. By 24 h, a decrease in the relative percentage of CD11c high spleen DC occurred in wild-type mice but was prevented in TLR2 −/− , TLR4 −/− , and TLR2 −/− TLR4 −/− mice. In wild-type mice, sepsis dramatically affected both CD11c + CD8α + and CD11c + CD8α − subsets. In all three types of knockout mice studied, the CD11c + CD8α + subset followed a depletion pattern similar to that for wild-type mice. In contrast, the loss of CD11c + CD8α − cells was attenuated in TLR2 −/− and TLR4 −/− mice and completely prevented in TLR2 −/− TLR4 −/− mice. Accordingly, apoptosis of spleen DC was increased in septic wild-type mice and inhibited in knockout mice. In addition we characterized the functional features of spleen DC obtained from septic mice. As shown by increased expression of major histocompatibility complex class II and CD86, polymicrobial sepsis induced maturation of DC, with subsequent increased capacity to prime T lymphocytes, similarly in wild-type and knockout mice. In response to CpG DNA stimulation, production of interleukin-12 was equally impaired in DC obtained from wild-type and knockout septic mice. In conclusion, although dispensable for the DC maturation process, TLR2 and TLR4 are involved in the mechanisms leading to depletion of spleen DC following polymicrobial sepsis.
    Type of Medium: Online Resource
    ISSN: 0019-9567 , 1098-5522
    RVK:
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2009
    detail.hit.zdb_id: 1483247-1
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  • 6
    In: Infection and Immunity, American Society for Microbiology, Vol. 79, No. 5 ( 2011-05), p. 1848-1854
    Abstract: NF-κB is a critical regulator of gene expression during severe infections. NF-κB comprises homo- and heterodimers of proteins from the Rel family. Among them, p50 and p65 have been clearly implicated in the pathophysiology of sepsis. In contrast, the role of cRel in sepsis is still controversial and has been poorly studied in single-pathogen infections. We aimed to investigate the consequences of cRel deficiency in a cecal ligation and puncture (CLP) model of sepsis. We have approached the underlying mechanisms of host defense by analyzing bacterial clearance, systemic inflammation, and the distribution of spleen dendritic cell subsets. Moreover, by using a genome-wide technology, we have also analyzed the CLP-induced modifications in gene expression profiles both in wild-type (wt) and in rel −/− mice. The absence of cRel enhances mortality due to polymicrobial sepsis. Despite normal pathogen clearance, cRel deficiency leads to an altered systemic inflammatory response associated with a sustained loss of the spleen lymphoid dendritic cells. Furthermore, a whole-blood microarray study reveals that the differential outcome between wt and rel −/− mice during sepsis is preceded by remarkable changes in the expression of hundreds of genes involved in aspects of host-pathogen interaction, such as host survival and lipid metabolism. In conclusion, cRel is a key NF-κB member required for host antimicrobial defenses and a regulatory transcription subunit that controls the inflammatory and immune responses in severe infection.
    Type of Medium: Online Resource
    ISSN: 0019-9567 , 1098-5522
    RVK:
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2011
    detail.hit.zdb_id: 1483247-1
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  • 7
    In: Antimicrobial Agents and Chemotherapy, American Society for Microbiology, Vol. 52, No. 6 ( 2008-06), p. 2283-2284
    Type of Medium: Online Resource
    ISSN: 0066-4804 , 1098-6596
    RVK:
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2008
    detail.hit.zdb_id: 1496156-8
    SSG: 12
    SSG: 15,3
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  • 8
    In: Antimicrobial Agents and Chemotherapy, American Society for Microbiology, Vol. 46, No. 7 ( 2002-07), p. 2061-2068
    Abstract: The effects of a series of dihydroethano- and ethenoanthracene derivatives on chloroquine (CQ) accumulation in CQ-susceptible strain 3D7 and CQ-resistant clone W2 were assessed. The levels of CQ accumulation increased little or none in CQ-susceptible strain 3D7 and generally increased markedly in CQ-resistant strain W2. At 10 μM, 28 compounds yielded cellular accumulation ratios (CARs) greater than that observed with CQ alone in W2. At 10 μM, in strain W2, 21 of 31 compounds had CQ CARs two or more times higher than that of CQ alone, 15 of 31 compounds had CQ CARs three or more times higher than that of CQ alone, 13 of 31 compounds had CQ CARs four or more times higher than that of CQ alone, and 9 of 31 compounds had CQ CARs five or more times higher than that of CQ alone. At 1 μM, 17 of 31 compounds had CQ CARs two or more times higher than that of CQ alone, 12 of 31 compounds had CQ CARs three or more times higher than that of CQ alone, 6 of 31 compounds had CQ CARs four or more times higher than that of CQ alone, and 3 of 31 compounds had CQ CARs five or more times higher than that of CQ alone. At 1 μM, 17 of 31 compounds were more potent inducers of CQ accumulation than verapamil and 12 of 31 compounds were more potent inducers of CQ accumulation than promethazine. The nature of the basic group seems to be associated with increases in the levels of CQ accumulation. At 1 and 10 μM, 10 of 14 and 13 of 14 compounds with amino group (amines and diamines), respectively, had CARs ≥3, while at 1 and 10 μM, only 1 of the 13 derivatives with amido groups had CARs ≥3. Among 12 of the 31 compounds which were more active inducers of CQ accumulation than promethazine at 1 μM, 10 had amino groups and 1 had an amido group.
    Type of Medium: Online Resource
    ISSN: 0066-4804 , 1098-6596
    RVK:
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2002
    detail.hit.zdb_id: 1496156-8
    SSG: 12
    SSG: 15,3
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  • 9
    In: Antimicrobial Agents and Chemotherapy, American Society for Microbiology, Vol. 43, No. 2 ( 1999-02), p. 418-420
    Abstract: The 50% inhibitory concentration (IC 50 s) of benflumetol (range, 12.5 to 240 nM; mean, 55.1 nM) for 158 Senegalese isolates were evaluated. Ten isolates (6%) showed decreased susceptibility to benflumetol. Benflumetol was slightly more potent against chloroquine-resistant isolates ( P 〈 0.025). No correlation or weak correlations in the responses to benflumetol and pyrimethamine, chloroquine, amodiaquine, artemether, quinine, and pyronaridine were observed, and these correlations are insufficient to suggest cross-resistance. Benflumetol may be an important alternative drug for the treatment of chloroquine-resistant malaria.
    Type of Medium: Online Resource
    ISSN: 0066-4804 , 1098-6596
    RVK:
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 1999
    detail.hit.zdb_id: 1496156-8
    SSG: 12
    SSG: 15,3
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  • 10
    Online Resource
    Online Resource
    American Society for Microbiology ; 2011
    In:  Journal of Virology Vol. 85, No. 14 ( 2011-07-15), p. 7402-7410
    In: Journal of Virology, American Society for Microbiology, Vol. 85, No. 14 ( 2011-07-15), p. 7402-7410
    Abstract: After fusing with the plasma membrane, enveloped poxvirus virions form actin-filled membranous protrusions, called tails, beneath themselves and move toward adjacent uninfected cells. While much is known about the host and viral proteins that mediate formation of actin tails, much less is known about the factors controlling release. We found that the phosphoinositide 5-phosphatase SHIP2 localizes to actin tails. Localization requires phosphotyrosine, Abl and Src family tyrosine kinases, and neural Wiskott-Aldrich syndrome protein (N-WASP) but not the Arp2/Arp3 complex or actin. Cells lacking SHIP2 have normal actin tails but release more virus. Moreover, cells infected with viral strains with mutations in the release inhibitor A34 release more virus but recruit less SHIP2 to tails. Thus, the inhibitory effects of A34 on virus release are mediated by SHIP2. Together, these data suggest that SHIP2 and A34 may act as gatekeepers to regulate dissemination of poxviruses when environmental conditions are conducive.
    Type of Medium: Online Resource
    ISSN: 0022-538X , 1098-5514
    Language: English
    Publisher: American Society for Microbiology
    Publication Date: 2011
    detail.hit.zdb_id: 1495529-5
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