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Planas D, Fert A, Zhang Y, Ruiz M, Goulet J, Wiche Salinas T, Cohen E, Routy J, Chomont N, Ancuta P. Antagonism of PPARγ for Th17 mucosal immunity restoration and HIV reservoir purging. J Virus Erad 2019. [DOI: 10.1016/s2055-6640(20)30215-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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2
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Isnard S, Ramendra R, Dupuy F, Mehraj V, Lin J, Kokinov N, Lebouché B, Costiniuk C, Ancuta P, Bernard N, Durand M, Tremblay C, Routy JP. Relevance of Reg3α and I-FABP on microbial translocation, inflammation and reservoir size in people living with HIV. J Virus Erad 2019. [DOI: 10.1016/s2055-6640(20)31030-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Routy JP, Ramendra R, Ghali P, Costiniuk C, Lebouché B, Ponte R, Reinhard R, Sousa J, Chomont N, Cohen E, Ancuta P, Mehraj V. Balancing risk-benefit ratio in donors of gut biopsy samples for HIV persistence research. J Virus Erad 2017. [DOI: 10.1016/s2055-6640(20)30655-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Wacleche V, Ancuta P, Goulet J, Gosselin A, Gaudreau M, Routy J. Pathogenicity of CD16 + monocyte-derived dendritic cells during HIV-1 infection. J Virus Erad 2015. [DOI: 10.1016/s2055-6640(20)31399-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Wacleche V, Cleret-Buhot A, Zhang Y, Planas D, Goulet J, Monteiro P, Niessl J, Gosselin A, Tremblay C, Jenabian M, Routy J, El-Far M, Chomont N, Haddad E, Sekaly R, Ancuta P. The transcriptional program governed by RORγt favors HIV-1 replication in CCR4 + CCR6 + Th17 cells. J Virus Erad 2015. [DOI: 10.1016/s2055-6640(20)31315-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Cubas R, van Grevenynghe J, Wills S, Kardava L, Santich BH, Buckner CM, Muir R, Tardif V, Nichols C, Procopio F, He Z, Metcalf T, Ghneim K, Locci M, Ancuta P, Routy JP, Trautmann L, Li Y, McDermott AB, Koup RA, Petrovas C, Migueles SA, Connors M, Tomaras GD, Moir S, Crotty S, Haddad EK. Reversible Reprogramming of Circulating Memory T Follicular Helper Cell Function during Chronic HIV Infection. J Immunol 2015; 195:5625-36. [PMID: 26546609 DOI: 10.4049/jimmunol.1501524] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 10/06/2015] [Indexed: 11/19/2022]
Abstract
Despite the overwhelming benefits of antiretroviral therapy (ART) in curtailing viral load in HIV-infected individuals, ART does not fully restore cellular and humoral immunity. HIV-infected individuals under ART show reduced responses to vaccination and infections and are unable to mount an effective antiviral immune response upon ART cessation. Many factors contribute to these defects, including persistent inflammation, especially in lymphoid tissues, where T follicular helper (Tfh) cells instruct and help B cells launch an effective humoral immune response. In this study we investigated the phenotype and function of circulating memory Tfh cells as a surrogate of Tfh cells in lymph nodes and found significant impairment of this cell population in chronically HIV-infected individuals, leading to reduced B cell responses. We further show that these aberrant memory Tfh cells exhibit an IL-2-responsive gene signature and are more polarized toward a Th1 phenotype. Treatment of functional memory Tfh cells with IL-2 was able to recapitulate the detrimental reprogramming. Importantly, this defect was reversible, as interfering with the IL-2 signaling pathway helped reverse the abnormal differentiation and improved Ab responses. Thus, reversible reprogramming of memory Tfh cells in HIV-infected individuals could be used to enhance Ab responses. Altered microenvironmental conditions in lymphoid tissues leading to altered Tfh cell differentiation could provide one explanation for the poor responsiveness of HIV-infected individuals to new Ags. This explanation has important implications for the development of therapeutic interventions to enhance HIV- and vaccine-mediated Ab responses in patients under ART.
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Affiliation(s)
- Rafael Cubas
- Vaccine and Gene Therapy Institute of Florida, Port St. Lucie, FL 34987
| | - Julien van Grevenynghe
- Institut National de la Recherche Scientifique, Institut Armand-Frappier, Laval H7V 1B7, Quebec, Canada
| | - Saintedym Wills
- Department of Immunology and the Duke Human Vaccine Institute, Duke University, Durham, NC 27710
| | - Lela Kardava
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Brian H Santich
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Clarisa M Buckner
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Roshell Muir
- Vaccine and Gene Therapy Institute of Florida, Port St. Lucie, FL 34987
| | - Virginie Tardif
- Vaccine and Gene Therapy Institute of Florida, Port St. Lucie, FL 34987
| | - Carmen Nichols
- Vaccine and Gene Therapy Institute of Florida, Port St. Lucie, FL 34987
| | - Francesco Procopio
- Service d'Immunologie et Allergie, Centre Hospitalier Universitaire Vaudois, 1011 Lausanne, Switzerland
| | - Zhong He
- Vaccine and Gene Therapy Institute of Florida, Port St. Lucie, FL 34987
| | - Talibah Metcalf
- Vaccine and Gene Therapy Institute of Florida, Port St. Lucie, FL 34987
| | - Khader Ghneim
- Vaccine and Gene Therapy Institute of Florida, Port St. Lucie, FL 34987
| | - Michela Locci
- Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037
| | - Petronella Ancuta
- Department of Medicine, University of Montreal, Montreal, Quebec H3C 3J7, Canada; Department of Microbiology, Infectiology and Immunology, Faculty of Medicine, University of Montreal, Montreal, Quebec H3C 3J7, Canada
| | - Jean-Pierre Routy
- Chronic Viral Illness Service, McGill University Health Centre, Montreal, Quebec H3H 2R9, Canada; Research Institute, McGill University Health Centre, Montreal, Quebec H3H 2R9, Canada; Division of Hematology, McGill University Health Centre, Montreal, Quebec H3H 2R9, Canada
| | - Lydie Trautmann
- Vaccine and Gene Therapy Institute of Florida, Port St. Lucie, FL 34987
| | - Yuxing Li
- International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037; Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037
| | - Adrian B McDermott
- Immunology Laboratory, Vaccine Research Center, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Rick A Koup
- Immunology Laboratory, Vaccine Research Center, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Constantinos Petrovas
- Immunology Laboratory, Vaccine Research Center, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Steven A Migueles
- HIV-Specific Immunity Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Mark Connors
- HIV-Specific Immunity Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Georgia D Tomaras
- Department of Immunology and the Duke Human Vaccine Institute, Duke University, Durham, NC 27710
| | - Susan Moir
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Shane Crotty
- Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037; Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093; and Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, La Jolla, CA 92037
| | - Elias K Haddad
- Vaccine and Gene Therapy Institute of Florida, Port St. Lucie, FL 34987;
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Jenabian MA, Patel M, Kema I, Vyboh K, Kanagaratham C, Radzioch D, Thébault P, Lapointe R, Gilmore N, Ancuta P, Tremblay C, Routy JP. Soluble CD40-ligand (sCD40L, sCD154) plays an immunosuppressive role via regulatory T cell expansion in HIV infection. Clin Exp Immunol 2014; 178:102-11. [PMID: 24924152 DOI: 10.1111/cei.12396] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2014] [Indexed: 12/22/2022] Open
Abstract
CD40/CD40-ligand (CD40L) signalling is a key stimulatory pathway which triggers the tryptophan (Trp) catabolizing enzyme IDO in dendritic cells and is immunosuppressive in cancer. We reported IDO-induced Trp catabolism results in a T helper type 17 (Th17)/regulatory T cell (Treg ) imbalance, and favours microbial translocation in HIV chronic infection. Here we assessed the link between sCD40L, Tregs and IDO activity in HIV-infected patients with different clinical outcomes. Plasmatic sCD40L and inflammatory cytokines were assessed in anti-retroviral therapy (ART)-naive, ART-successfully treated (ST), elite controllers (EC) and healthy subjects (HS). Plasma levels of Trp and its metabolite Kynurenine (Kyn) were measured by isotope dilution tandem mass spectrometry and sCD14 was assessed by enzyme-linked immunosorbent assay (ELISA). IDO-mRNA expression was quantified by reverse transcription-polymerase chain reaction (RT-PCR). The in-vitro functional assay of sCD40L on Treg induction and T cell activation were assessed on peripheral blood mononuclear cells (PBMCs) from HS. sCD40L levels in ART-naive subjects were significantly higher compared to ST and HS, whereas EC showed only a minor increase. In ART-naive alone, sCD40L was correlated with T cell activation, IDO-mRNA expression and CD4 T cell depletion but not with viral load. sCD40L was correlated positively with IDO enzymatic activity (Kyn/Trp ratio), Treg frequency, plasma sCD14 and inflammatory soluble factors in all HIV-infected patients. In-vitro functional sCD40L stimulation induced Treg expansion and favoured Treg differentiation by reducing central memory and increasing terminal effector Treg proportion. sCD40L also increased T cell activation measured by co-expression of CD38/human leucocyte antigen D-related (HLA-DR). These results indicate that elevated sCD40L induces immunosuppression in HIV infection by mediating IDO-induced Trp catabolism and Treg expansion.
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Affiliation(s)
- M-A Jenabian
- Chronic Viral Illness Service, McGill University Health Centre, Montreal, QC, Canada; Research Institute, McGill University Health Centre, Montreal, QC, Canada
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Routy JP, Angel JB, Patel M, Kanagaratham C, Radzioch D, Kema I, Gilmore N, Ancuta P, Singer J, Jenabian MA. Assessment of chloroquine as a modulator of immune activation to improve CD4 recovery in immune nonresponding HIV-infected patients receiving antiretroviral therapy. HIV Med 2014; 16:48-56. [PMID: 24889179 DOI: 10.1111/hiv.12171] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/09/2014] [Indexed: 01/05/2023]
Abstract
OBJECTIVES Chloroquine (CQ), an anti-inflammatory drug, inhibits Toll-like receptor (TLR) signalling in plasmacytoid dendritic cells (pDCs) and may be beneficial for HIV-infected patients in whom immune activation persists despite effective antiretroviral therapy (ART). The effect of CQ on CD4 T-cell recovery and immune activation in immune nonresponding patients receiving successful ART was therefore studied. METHODS Nineteen adults on ART with CD4 counts ≤ 350 cells/μL and undetectable viral load (VL) orally received CQ at 250 mg/day for 24 weeks. Side effects, CD4 and CD8 T-cell counts, VL, T-cell activation, pDC proportion and plasma inflammatory markers were assessed at baseline, at 24 weeks, and at 12 weeks after CQ discontinuation (clinicaltrial.org registration #NCT02004314). RESULTS CQ was well tolerated and all patients maintained an undetectable VL. The absolute CD4 and CD8 T-cell counts and their percentages, the pDC proportion, T-cell activation, D-dimer and C-reactive protein (CRP) plasma levels and the kynurenine/tryptophan ratio did not change with CQ treatment. Among nine cytokines/chemokines measured, only levels of interferon (IFN)-α2 were significantly increased by CQ treatment. CONCLUSIONS CQ was well tolerated in patients with low CD4 T-cell counts despite long-term effective ART; however, 24 weeks of CQ treatment did not improved CD4 T-cell recovery, lymphoid and myeloid immune activation or inflammatory markers.
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Affiliation(s)
- J-P Routy
- Chronic Viral Illness Service, McGill University Health Centre, Montreal, QC, Canada; Research Institute of McGill University Health Centre, Montreal, QC, Canada; Division of Hematology, McGill University Health Centre, Montreal, QC, Canada
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Gosselin A, Monteiro P, Chomont N, Diaz-Griffero F, Wacleche VS, Said EA, Fonseca S, El-Far M, Boulassel M, Routy J, Sekaly R, Ancuta P. P16-54 LB. Blood CCR6+ Th17 and Th1Th17 but not CCR6neg Th1 cells are targets for HIV replication and their frequency is diminished in HIV-infected subjects. Retrovirology 2009. [PMCID: PMC2767923 DOI: 10.1186/1742-4690-6-s3-p407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Hocini H, Becquart P, Bouhlal H, Chomont N, Ancuta P, Kazatchkine MD, Bélec L. Active and selective transcytosis of cell-free human immunodeficiency virus through a tight polarized monolayer of human endometrial cells. J Virol 2001; 75:5370-4. [PMID: 11333919 PMCID: PMC114943 DOI: 10.1128/jvi.75.11.5370-5374.2001] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We report that both primary and laboratory-adapted infectious human immunodeficiency virus type 1 (HIV-1) isolates in a cell-free form are capable of transcytosis through a tight and polarized monolayer of human endometrial cells. Trancytosis of cell-free HIV occurs in a strain-selective fashion and appears to be dependent on interactions between HIV envelope glycoproteins and lectins on the apical membrane of the epithelial cells. These findings provide new insights into the initial events occurring during heterosexual transmission of the virus.
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Ancuta P, Bakri Y, Chomont N, Hocini H, Gabuzda D, Haeffner-Cavaillon N. Opposite effects of IL-10 on the ability of dendritic cells and macrophages to replicate primary CXCR4-dependent HIV-1 strains. J Immunol 2001; 166:4244-53. [PMID: 11238678 DOI: 10.4049/jimmunol.166.6.4244] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We investigated the effect of IL-10 on replication of primary CXCR4-dependent (X4) HIV-1 strains by monocyte-derived dendritic cells (DCs) and macrophages (M Phis). M Phis efficiently replicated CXCR4-dependent HIV-1 (X4 HIV-1) strains NDK and VN44, whereas low levels of p24 were detected in supernatants of infected DCs. IL-10 significantly increased X4 HIV-1 replication by DCs but blocked viral production by M Phis as determined by p24 levels and semiquantitative nested PCR. IL-10 up-regulated CXCR4 mRNA and protein expression on DCs and M Phis, suggesting that IL-10 enhances virus entry in DCs but blocks an entry and/or postentry step in M Phis. The effect of IL-10 on the ability of DCs and M Phis to transmit virus to autologous CD4(+) T lymphocytes was investigated in coculture experiments. DCs exhibited a greater ability than did M Phis to transmit a vigorous infection to CD4(+) T cells despite their very low replication capacity. IL-10 had no effect on HIV-1 replication in DC:T cell cocultures but markedly decreased viral production in M Phi:T cell cocultures. These results demonstrate that IL-10 has opposite effects on the replication of primary X4 HIV-1 strains by DCs and M Phis. IL-10 increases X4-HIV-1 replication in DCs but does not alter their capacity to transmit virus to CD4(+) T lymphocytes. These findings suggest that increased levels of IL-10 observed in HIV-1-infected patients with disease progression may favor the replication of X4 HIV-1 strains in vivo.
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Affiliation(s)
- P Ancuta
- Unité d'Immunopathologie Humaine, Institut National de la Santé et de la Recherche Médicale, Broussais Hospital, Paris, France.
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Abstract
We previously reported an increased percentage of CD14+CD16++ monocytes in the peripheral blood of HIV-infected patients but the physiopathological role of this monocyte subset remains unclear. Cells with a CD14+CD16++ phenotype may be obtained in vitro by culturing human peripheral blood monocytes in the presence of GM-CSF, IL-4 and IL-10. In the present study, we compared the phenotypic and functional characteristics of monocytes-derived CD14+CD16++ cells with those of macrophages and dendritic cells. We show that the CD14+CD16++ cells express dendritic cell markers: CD40, CD80, CD86, HLA-DR, CD11b, CD11c, CD18, CD1a, and CD83. Using RNase protection assay, we demonstrate that CD14+CD16++ cell subset expresses a low ratio of IL-1beta/IL-1ra mRNA and expresses IL-6, MIP-1alpha, MIP-1beta, MCP-1, IL-8, RANTES and I-309 transcripts, similar to dendritic cells. CD14+CD16++ cells produce IL-12, MCP-1 and IL-8, as assessed by flow cytometry. Moreover, CD14+CD16++ cells pulsed with different recall antigens induce a potent autologous T cell proliferation. Altogether, these results provide evidence that CD14+CD16++ cells differentiated in vitro from peripheral blood monocytes exhibit dendritic cell characteristics.
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Affiliation(s)
- P Ancuta
- Unité d'Immunopathologie Humaine, INSERM U430, Hôpital Broussais, Paris, France
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Weiss L, Ancuta P, Girard PM, Bouhlal H, Roux A, Cavaillon NH, Kazatchkine MD. Restoration of normal interleukin-2 production by CD4+ T cells of human immunodeficiency virus-infected patients after 9 months of highly active antiretroviral therapy. J Infect Dis 1999; 180:1057-63. [PMID: 10479131 DOI: 10.1086/315025] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The present study investigated immune restoration in patients at intermediate stages of human immunodeficiency virus (HIV) disease after initiation of highly active antiretroviral therapy (HAART). A progressive increase in both memory and naive CD4+ T cells was observed from the first weeks of therapy, concomitant with a decrease in the expression of activation markers on CD8+ T cells. The early-activation marker CD69 remained, however, overexpressed on T cells after suboptimal stimulation in vitro, indicative of persistent immune activation. The percentage of interleukin (IL)-2-producing CD4+ T cells significantly increased from 9 months of HAART. In most patients, CD4+ T cells recovered an ability to produce IL-2 on stimulation, similar to that of HIV-seronegative controls. Reversal of T-cell anergy may be a key event in immune restoration for achieving long-term clinical benefit with HAART.
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Affiliation(s)
- L Weiss
- INSERM U 430, Hôpital Broussais, 75014, Paris, France. laurence.
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Ancuta P, Fahmi H, Pons JF, Le Blay K, Chaby R. Involvement of the membrane form of tumour necrosis factor-alpha in lipopolysaccharide-induced priming of mouse peritoneal macrophages for enhanced nitric oxide response to lipopolysaccharide. Immunology 1997; 92:259-66. [PMID: 9415035 PMCID: PMC1364067 DOI: 10.1046/j.1365-2567.1997.00338.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We studied the pathways of macrophage response to lipopolysaccharide (LPS). When mouse macrophages pre-exposed to LPS were restimulated with this agent, reduced tumour necrosis factor-alpha (TNF-alpha) responses (desensitization/endotoxin tolerance) were accompanied by increased (priming) nitric oxide (NO) responses. Priming was also inducible with recombinant interferon-beta (IFN-beta). The requirement of TNF-alpha biosynthesis in the LPS-induced priming was also suggested by the observation that both anti-TNF-alpha serum and pentoxifylline inhibited this effect. However, addition of mouse recombinant TNF-alpha (mrTNF-alpha) did not enhance the priming induced by LPS or IFN-beta, and preincubation with mrTNF-alpha alone, or in association with other cytokines produced by macrophages (interleukin-1 beta, interleukin-6, or leukaemia inhibitory factor), did not induce a priming effect. We found however, that pentoxifylline, which blocked the priming, also decreased the level of membrane-bound TNF-alpha. Furthermore, exposure to compound BB-3103 (a metalloproteinase inhibitor that blocks the processing of membrane-bound TNF-alpha yielding to the secreted cytokine) enhanced the priming effect, the expression of membrane TNF-alpha and the specific binding of LPS. These observations suggest that the membrane form of TNF-alpha is involved in the interaction of LPS with a receptor required for LPS-induced priming.
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Affiliation(s)
- P Ancuta
- Endotoxin Group, URA-1116 of the National Centre for Scientific Research, University of Paris-Sud, Orsay, France
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Fahmi H, Ancuta P, Perrier S, Chaby R. Preexposure of mouse peritoneal macrophages to lipopolysaccharide and other stimuli enhances the nitric oxide response to secondary stimuli. Inflamm Res 1996; 45:347-53. [PMID: 8841836 DOI: 10.1007/bf02252947] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The aim of this study was to compare the regulation of the production of tumor necrosis factor-alpha (TNF-alpha) and secondary nitric oxide (NO) in macrophages submitted to a sequence of two stimulations. Pre-exposure for 18 h of mouse thioglycollate-elicited peritoneal macrophages to low doses (1-10 ng/ml) of lipopolysaccharide (LPS), in the presence or absence of serum, induces on one hand a desensitization (endotoxin tolerance) for secondary TNF-alpha responses to LPS and, on the other hand, a 4 fold increase (priming) of secondary NO responses. Preexposure to components from Gram-positive bacteria (lipoteichoic acid, peptidoglycan) and to a synthetic lipid structurally related to lipid A (compound M4), induced similar effects. In contrast to the desensitization for TNF-alpha secretion, the priming for NO production was not mimicked by sodium nitroprusside, a generator of NO. The results suggest that concomitant but distinct activation pathways induced by LPS and other agents can be dissociated by serum-independent modulation processes elicited by pre-exposure of the cells to LPS itself, or to other stimuli.
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Affiliation(s)
- H Fahmi
- URA-1116 du C.N.R.S., Université de Paris-Sud, Orsay, France
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Ancuta P, Pedron T, Girard R, Sandström G, Chaby R. Inability of the Francisella tularensis lipopolysaccharide to mimic or to antagonize the induction of cell activation by endotoxins. Infect Immun 1996; 64:2041-6. [PMID: 8675305 PMCID: PMC174034 DOI: 10.1128/iai.64.6.2041-2046.1996] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
We studied the ability of the lipopolysaccharide (LPS) extracted from a vaccine strain of Francisella tularensis (LPS-Ft) to mimic LPSs from other gram-negative bacteria for activation of various murine cell types or to antagonize the effects of other LPSs. We found that activation of macrophages for the production of tumor necrosis factor alpha and NO, of pre-B lymphocytes for the expression of surface immunoglobulins, and of bone marrow cells for the expression of LPS-binding sites was either undetectable with LPS-Ft or required concentrations 100 to 1,000 times higher than for standard LPSs. Preexposure of macrophages to LPS-Ft also failed to trigger down-regulation of tumor necrosis factor alpha (desensitization) or up-regulation of NO responses to an endotoxin challenge. In contrast to other atypical LPSs, LPS-Ft was also unable to antagonize any of the endotoxin-induced cellular responses mentioned above, suggesting that this LPS does not interact with LPS receptors.
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Affiliation(s)
- P Ancuta
- Endotoxin Group, URA-1116 of the National Center for Scientific Research, University of Paris-Sud, Orsay, France
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