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Govender S, David M, Naicker T. Is the Complement System Dysregulated in Preeclampsia Comorbid with HIV Infection? Int J Mol Sci 2024; 25:6232. [PMID: 38892429 PMCID: PMC11172754 DOI: 10.3390/ijms25116232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 05/27/2024] [Accepted: 05/31/2024] [Indexed: 06/21/2024] Open
Abstract
South Africa is the epicentre of the global HIV pandemic, with 13.9% of its population infected. Preeclampsia (PE), a hypertensive disorder of pregnancy, is often comorbid with HIV infection, leading to multi-organ dysfunction and convulsions. The exact pathophysiology of preeclampsia is triggered by an altered maternal immune response or defective development of maternal tolerance to the semi-allogenic foetus via the complement system. The complement system plays a vital role in the innate immune system, generating inflammation, mediating the clearance of microbes and injured tissue materials, and a mediator of adaptive immunity. Moreover, the complement system has a dual effect, of protecting the host against HIV infection and enhancing HIV infectivity. An upregulation of regulatory proteins has been implicated as an adaptive phenomenon in response to elevated complement-mediated cell lysis in HIV infection, further aggravated by preeclamptic complement activation. In light of the high prevalence of HIV infection and preeclampsia in South Africa, this review discusses the association of complement proteins and their role in the synergy of HIV infection and preeclampsia in South Africa. It aims to identify women at elevated risk, leading to early diagnosis and better management with targeted drug therapy, thereby improving the understanding of immunological dysregulation.
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Affiliation(s)
| | | | - Thajasvarie Naicker
- Optics and Imaging Centre, Doris Duke Medical Research Institute, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa; (S.G.); (M.D.)
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2
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Bermejo-Jambrina M, van der Donk LE, van Hamme JL, Wilflingseder D, de Bree G, Prins M, de Jong M, Nieuwkerk P, van Gils MJ, Kootstra NA, Geijtenbeek TB. Control of complement-induced inflammatory responses to SARS-CoV-2 infection by anti-SARS-CoV-2 antibodies. EMBO J 2024; 43:1135-1163. [PMID: 38418557 PMCID: PMC10987522 DOI: 10.1038/s44318-024-00061-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 01/31/2024] [Accepted: 02/06/2024] [Indexed: 03/01/2024] Open
Abstract
Dysregulated immune responses contribute to the excessive and uncontrolled inflammation observed in severe COVID-19. However, how immunity to SARS-CoV-2 is induced and regulated remains unclear. Here, we uncover the role of the complement system in the induction of innate and adaptive immunity to SARS-CoV-2. Complement rapidly opsonizes SARS-CoV-2 particles via the lectin pathway. Complement-opsonized SARS-CoV-2 efficiently induces type-I interferon and pro-inflammatory cytokine responses via activation of dendritic cells, which are inhibited by antibodies against the complement receptors (CR) 3 and 4. Serum from COVID-19 patients, or monoclonal antibodies against SARS-CoV-2, attenuate innate and adaptive immunity induced by complement-opsonized SARS-CoV-2. Blocking of CD32, the FcγRII antibody receptor of dendritic cells, restores complement-induced immunity. These results suggest that opsonization of SARS-CoV-2 by complement is involved in the induction of innate and adaptive immunity to SARS-CoV-2 in the acute phase of infection. Subsequent antibody responses limit inflammation and restore immune homeostasis. These findings suggest that dysregulation of the complement system and FcγRII signaling may contribute to severe COVID-19.
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Affiliation(s)
- Marta Bermejo-Jambrina
- Department of Experimental Immunology, Amsterdam UMC location AMC, Amsterdam, The Netherlands.
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, Amsterdam, The Netherlands.
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria.
| | - Lieve Eh van der Donk
- Department of Experimental Immunology, Amsterdam UMC location AMC, Amsterdam, The Netherlands
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, Amsterdam, The Netherlands
| | - John L van Hamme
- Department of Experimental Immunology, Amsterdam UMC location AMC, Amsterdam, The Netherlands
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, Amsterdam, The Netherlands
| | - Doris Wilflingseder
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Godelieve de Bree
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, Amsterdam, The Netherlands
- Department of Internal Medicine, Amsterdam UMC location AMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Maria Prins
- Department of Internal Medicine, Amsterdam UMC location AMC, University of Amsterdam, Amsterdam, The Netherlands
- Department of Infectious Diseases, Public Health Service of Amsterdam, GGD, Amsterdam, The Netherlands
| | - Menno de Jong
- Department of Medical Microbiology and Infection Prevention, Amsterdam UMC location AMC University of Amsterdam, Amsterdam, The Netherlands
| | - Pythia Nieuwkerk
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, Amsterdam, The Netherlands
- Department of Infectious Diseases, Public Health Service of Amsterdam, GGD, Amsterdam, The Netherlands
- Department of Medical Psychology (J3-2019-1), Amsterdam UMC location AMC University of Amsterdam, Amsterdam, The Netherlands
| | - Marit J van Gils
- Department of Medical Microbiology and Infection Prevention, Amsterdam UMC location AMC University of Amsterdam, Amsterdam, The Netherlands
| | - Neeltje A Kootstra
- Department of Experimental Immunology, Amsterdam UMC location AMC, Amsterdam, The Netherlands
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, Amsterdam, The Netherlands
| | - Teunis Bh Geijtenbeek
- Department of Experimental Immunology, Amsterdam UMC location AMC, Amsterdam, The Netherlands.
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, Amsterdam, The Netherlands.
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3
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Abstract
PURPOSE OF REVIEW This review summarizes recent studies reporting the induction of vaccinal effects by human immunodeficiency virus (HIV-1) antibody therapy. It also puts into perspective preclinical studies that have identified mechanisms involved in the immunomodulatory properties of antiviral antibodies. Finally, it discusses potential therapeutic interventions to enhance host adaptive immune responses in people living with HIV (PLWH) treated with broadly neutralizing antibodies (bNAbs). RECENT FINDINGS Recent studies in promising clinical trials have shown that, in addition to controlling viremia, anti-HIV-1 bNAbs are able to enhance the host's humoral and cellular immune response. Such vaccinal effects, in particular the induction of HIV-1-specific CD8 + T-cell responses, have been observed upon treatment with two potent bNAbs (3BNC117 and 10-1074) alone or in combination with latency-reversing agents (LRA). While these studies reinforce the idea that bNAbs can induce protective immunity, the induction of vaccinal effects is not systematic and might depend on both the virological status of the patient as well as the therapeutic strategy chosen. SUMMARY HIV-1 bNAbs can enhance adaptive host immune responses in PLWH. The challenge now is to exploit these immunomodulatory properties to design optimized therapeutic interventions to promote and enhance the induction of protective immunity against HIV-1 infection during bNAbs therapy.
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Bertacchi G, Posch W, Wilflingseder D. HIV-1 Trans Infection via TNTs Is Impeded by Targeting C5aR. Biomolecules 2022; 12:biom12020313. [PMID: 35204813 PMCID: PMC8868603 DOI: 10.3390/biom12020313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 02/03/2022] [Accepted: 02/10/2022] [Indexed: 02/04/2023] Open
Abstract
Nonadjacent immune cells communicate through a complex network of tunneling nanotubes (TNTs). TNTs can be hijacked by HIV-1, allowing it to spread between connected cells. Dendritic cells (DCs) are among the first cells to encounter HIV-1 at mucosal sites, but they are usually efficiently infected only at low levels. However, HIV-1 was demonstrated to productively infect DCs when the virus was complement-opsonized (HIV-C). Such HIV-C-exposed DCs mediated an improved antiviral and T-cell stimulatory capacity. The role of TNTs in combination with complement in enhancing DC infection with HIV-C remains to be addressed. To this aim, we evaluated TNT formation on the surface of DCs or DC/CD4+ T-cell co-cultures incubated with non- or complement-opsonized HIV-1 (HIV, HIV-C) and the role of TNTs or locally produced complement in the infection process using either two different TNT or anaphylatoxin receptor antagonists. We found that HIV-C significantly increased the formation of TNTs between DCs or DC/CD4+ T-cell co-cultures compared to HIV-exposed DCs or co-cultures. While augmented TNT formation in DCs promoted productive infection, as was previously observed, a significant reduction in productive infection was observed in DC/CD4+ T-cell co-cultures, indicating antiviral activity in this setting. As expected, TNT inhibitors significantly decreased infection of HIV-C-loaded-DCs as well as HIV- and HIV-C-infected-DC/CD4+ T-cell co-cultures. Moreover, antagonizing C5aR significantly inhibited TNT formation in DCs as well as DC/CD4+ T-cell co-cultures and lowered the already decreased productive infection in co-cultures. Thus, local complement mobilization via DC stimulation of complement receptors plays a pivotal role in TNT formation, and our findings herein might offer an exciting opportunity for novel therapeutic approaches to inhibit trans infection via C5aR targeting.
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5
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Abstract
Complement-opsonized HIV-1 triggers efficient antiviral type I interferon (IFN) responses in dendritic cells (DCs), which play an important role in protective responses at the earliest stages in retroviral infection. In contrast, HIV-1 suppresses or escapes sensing by STING- and MAVS-associated sensors. Here, we identified a complement receptor-mediated sensing pathway, where DCs are activated in CCR5/RLR (RIG-I/MDA5)/MAVS/TBK1-dependent fashion. Increased fusion of complement-opsonized HIV-1 via complement receptor 4 and CCR5 leads to increased incoming HIV-1 RNA in the cytoplasm, sensed by a nonredundant cooperative effect of RIG-I and MDA5. Moreover, complement-opsonized HIV-1 down-modulated the MAVS-suppressive Raf-1/PLK1 pathway, thereby opening the antiviral recognition pathway via MAVS. This in turn was followed by MAVS aggregation and subsequent TBK1/IRF3/NF-κB activation in DCs exposed to complement- but not non-opsonized HIV-1. Our data strongly suggest that complement is important in the induction of efficient antiviral immune responses by preventing HIV-1 suppressive mechanisms as well as inducing specific cytosolic sensors.
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Zaderer V, Posch W, Gstir R, Filipek PA, Bonn GK, Aramwit P, Huber LA, Wilflingseder D. P80 Natural Essence Exerts Efficient Anti-HIV-1- as Well as Adjuvant Effects in DCs. Vaccines (Basel) 2021; 9:976. [PMID: 34579213 PMCID: PMC8472994 DOI: 10.3390/vaccines9090976] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 08/18/2021] [Accepted: 08/26/2021] [Indexed: 12/16/2022] Open
Abstract
Dendritic cells (DCs), as well as complement, play a major role during human immunodeficiency virus 1 (HIV-1) entry and infection at mucosal sites. Together, DCs and complement are key points for understanding host defence against HIV-1 infection and for studying the impact of new drugs on the regulation of innate host-pathogen interactions and adaptive immunity. For this, we evaluated the antiviral effect of the P80 natural essence (Longan extract) on interactions of non- and complement-opsonized HIV-1 with DCs. In viability assays, we first illustrated the effects of P80 natural essence on DC function. We found that P80 concentrations above 1.5% caused increased cell death, while at concentrations between 0.5% and 1% the compound exerted efficient antiviral effects in DCs and illustrated an adjuvant effect regarding DC activation. DC maturation, as well as co-stimulatory capacity, were significantly improved by P80 natural essence via p38 MAPK phosphorylation in presence of the viral challenge independent of the opsonization pattern. These findings might be exploited for future therapeutic options to target DC subsets directly at mucosal sites by P80 natural essence and to block entry of both, non- and complement-opsonized HIV-1.
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Affiliation(s)
- Viktoria Zaderer
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (V.Z.); (W.P.)
| | - Wilfried Posch
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (V.Z.); (W.P.)
| | - Ronald Gstir
- ADSI—Austrian Drug Screening Institute GmbH, 6020 Innsbruck, Austria; (R.G.); (P.A.F.); (G.K.B.); (L.A.H.)
| | - Przemyslaw A. Filipek
- ADSI—Austrian Drug Screening Institute GmbH, 6020 Innsbruck, Austria; (R.G.); (P.A.F.); (G.K.B.); (L.A.H.)
| | - Günther K. Bonn
- ADSI—Austrian Drug Screening Institute GmbH, 6020 Innsbruck, Austria; (R.G.); (P.A.F.); (G.K.B.); (L.A.H.)
| | - Pornanong Aramwit
- Department of Pharmacy Practice, Faculty of Pharmaceutical Sciences and Center of Excellence in Bioactive Resources for Innovative Clinical Applications, Chulalongkorn University, Bangkok 10330, Thailand;
| | - Lukas A. Huber
- ADSI—Austrian Drug Screening Institute GmbH, 6020 Innsbruck, Austria; (R.G.); (P.A.F.); (G.K.B.); (L.A.H.)
- Institute of Cell Biology, Biocenter Innsbruck, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Doris Wilflingseder
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (V.Z.); (W.P.)
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7
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Lafon E, Diem G, Witting C, Zaderer V, Bellmann-Weiler RM, Reindl M, Bauer A, Griesmacher A, Fux V, Hoermann G, Miller C, Zabernigg A, Wöll E, Wilflingseder D, Lass-Flörl C, Posch W. Potent SARS-CoV-2-Specific T Cell Immunity and Low Anaphylatoxin Levels Correlate With Mild Disease Progression in COVID-19 Patients. Front Immunol 2021; 12:684014. [PMID: 34194438 PMCID: PMC8237940 DOI: 10.3389/fimmu.2021.684014] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 05/20/2021] [Indexed: 01/07/2023] Open
Abstract
T cells play a fundamental role in the early control and clearance of many viral infections of the respiratory system. In SARS-CoV-2-infected individuals, lymphopenia with drastically reduced CD4+ and CD8+ T cells correlates with Coronavirus disease 2019 (COVID-19)-associated disease severity and mortality. In this study, we characterized cellular and humoral immune responses induced in patients with mild, severe and critical COVID-19. Peripheral blood mononuclear cells of 37 patients with mild, severe and critical COVID-19 and 10 healthy individuals were analyzed by IFNγ ELISpot and multi-color flow cytometry upon stimulation with peptide pools covering complete immunodominant SARS-CoV-2 matrix, nucleocapsid and spike proteins. In addition SARS-CoV-2 antibody levels, neutralization abilities and anaphylatoxin levels were evaluated by various commercially available ELISA platforms. Our data clearly demonstrates a significantly stronger induction of SARS-CoV-2 specific CD8+ T lymphocytes and higher IFNγ production in patients with mild compared to patients with severe or critical COVID-19. In all patients SARS-CoV-2-specific antibodies with similar neutralizing activity were detected, but highest titers of total IgGs were observed in critical patients. Finally, elevated anaphylatoxin C3a and C5a levels were identified in severe and critical COVID-19 patients probably caused by aberrant immune complex formation due to elevated antibody titers in these patients. Crucially, we provide a full picture of cellular and humoral immune responses of COVID-19 patients and prove that robust polyfunctional CD8+ T cell responses concomitant with low anaphylatoxin levels correlate with mild infections. In addition, our data indicates that high SARS-CoV-2 antibody titers are associated with severe disease progression.
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Affiliation(s)
- Eliott Lafon
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Gabriel Diem
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Christina Witting
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Viktoria Zaderer
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Markus Reindl
- Clinical Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Angelika Bauer
- Clinical Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Andrea Griesmacher
- Central Institute for Medical and Chemical Laboratory Diagnosis, University Hospital Innsbruck, Innsbruck, Austria
| | - Vilmos Fux
- Central Institute for Medical and Chemical Laboratory Diagnosis, University Hospital Innsbruck, Innsbruck, Austria
| | - Gregor Hoermann
- Central Institute for Medical and Chemical Laboratory Diagnosis, University Hospital Innsbruck, Innsbruck, Austria.,Munich Leukemia Laboratory (MLL), Munich, Germany
| | - Carl Miller
- Department of Internal Medicine, Hospital Kufstein, Kufstein, Austria
| | - August Zabernigg
- Department of Internal Medicine, Hospital Kufstein, Kufstein, Austria
| | - Ewald Wöll
- Department of Internal Medicine, Hospital Zams, Zams, Austria
| | - Doris Wilflingseder
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Cornelia Lass-Flörl
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Wilfried Posch
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
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8
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Abstract
The innate immune system is comprised of both cellular and humoral players that recognise and eradicate invading pathogens. Therefore, the interplay between retroviruses and innate immunity has emerged as an important component of viral pathogenesis. HIV-1 infection in humans that results in hematologic abnormalities and immune suppression is well represented by changes in the CD4/CD8 T cell ratio and consequent cell death causing CD4 lymphopenia. The innate immune responses by mucosal barriers such as complement, DCs, macrophages, and NK cells as well as cytokine/chemokine profiles attain great importance in acute HIV-1 infection, and thus, prevent mucosal capture and transmission of HIV-1. Conversely, HIV-1 has evolved to overcome innate immune responses through RNA-mediated rapid mutations, pathogen-associated molecular patterns (PAMPs) modification, down-regulation of NK cell activity and complement receptors, resulting in increased secretion of inflammatory factors. Consequently, epithelial tissues lining up female reproductive tract express innate immune sensors including anti-microbial peptides responsible for forming primary barriers and have displayed an effective potent anti-HIV activity during phase I/II clinical trials.
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9
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Posch W, Bermejo-Jambrina M, Lass-Flörl C, Wilflingseder D. Role of Complement Receptors (CRs) on DCs in Anti-HIV-1 Immunity. Front Immunol 2020; 11:572114. [PMID: 33224139 PMCID: PMC7670068 DOI: 10.3389/fimmu.2020.572114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 10/06/2020] [Indexed: 12/12/2022] Open
Abstract
Upon entry of human immunodeficiency virus 1 (HIV-1) into the host, innate immune mechanisms are acting as a first line of defense, that considerably also modify adaptive immunity by the provision of specific signals. Innate and adaptive immune responses are intimately linked and dendritic cells (DCs) together with complement (C) play an important role in regulation of adaptive immunity. Initially, the role of complement was considered to primarily support – or COMPLEMENT - cytolytic actions of antibodies or antibody-complexed antigens (immune complexes, ICs) or directly kill the pathogens by complement-mediated lysis. Recently, the role of complement was revised and found to significantly augmenting and modulating adaptive immunity, in particular against viruses. Complement and DCs are therefore predestined to open novel avenues for antiviral research and potential therapeutic interventions. Recent studies on interactions of complement-opsonized HIV-1 with DCs demonstrated a high potential of such primed DCs to initiate efficient antiviral and cytotoxic anti-HIV-1 immunity and complement-coated viral particles shift DCs functions via CR3 and CR4 in an antithetic manner. This review will focus on our current knowledge of CR3 and CR4 actions on DCs during HIV-1 binding and the outcome of infection influenced by entry and signaling pathways.
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Affiliation(s)
- Wilfried Posch
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Marta Bermejo-Jambrina
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria.,Department of Experimental Immunology, Amsterdam Infection and Immunity Institute, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Cornelia Lass-Flörl
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Doris Wilflingseder
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
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10
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Kumar NA, Kunnakkadan U, Thomas S, Johnson JB. In the Crosshairs: RNA Viruses OR Complement? Front Immunol 2020; 11:573583. [PMID: 33133089 PMCID: PMC7550403 DOI: 10.3389/fimmu.2020.573583] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 08/24/2020] [Indexed: 12/02/2022] Open
Abstract
Complement, a part of the innate arm of the immune system, is integral to the frontline defense of the host against innumerable pathogens, which includes RNA viruses. Among the major groups of viruses, RNA viruses contribute significantly to the global mortality and morbidity index associated with viral infection. Despite multiple routes of entry adopted by these viruses, facing complement is inevitable. The initial interaction with complement and the nature of this interaction play an important role in determining host resistance versus susceptibility to the viral infection. Many RNA viruses are potent activators of complement, often resulting in virus neutralization. Yet, another facet of virus-induced activation is the exacerbation in pathogenesis contributing to the overall morbidity. The severity in disease and death associated with RNA virus infections shows a tip in the scale favoring viruses. Growing evidence suggest that like their DNA counterparts, RNA viruses have co-evolved to master ingenious strategies to remarkably restrict complement. Modulation of host genes involved in antiviral responses contributed prominently to the adoption of unique strategies to keep complement at bay, which included either down regulation of activation components (C3, C4) or up regulation of complement regulatory proteins. All this hints at a possible “hijacking” of the cross-talk mechanism of the host immune system. Enveloped RNA viruses have a selective advantage of not only modulating the host responses but also recruiting membrane-associated regulators of complement activation (RCAs). This review aims to highlight the significant progress in the understanding of RNA virus–complement interactions.
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Affiliation(s)
- Nisha Asok Kumar
- Viral Disease Biology, Department of Pathogen Biology, Rajiv Gandhi Center for Biotechnology, Thiruvananthapuram, India.,Manipal Academy of Higher Education, Manipal, India
| | - Umerali Kunnakkadan
- Viral Disease Biology, Department of Pathogen Biology, Rajiv Gandhi Center for Biotechnology, Thiruvananthapuram, India.,Department of Biotechnology, University of Kerala, Thiruvananthapuram, India
| | - Sabu Thomas
- Cholera and Biofilm Research Lab, Department of Pathogen Biology, Rajiv Gandhi Center for Biotechnology, Thiruvananthapuram, India
| | - John Bernet Johnson
- Viral Disease Biology, Department of Pathogen Biology, Rajiv Gandhi Center for Biotechnology, Thiruvananthapuram, India
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11
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Bermejo-Jambrina M, Blatzer M, Jauregui-Onieva P, Yordanov TE, Hörtnagl P, Valovka T, Huber LA, Wilflingseder D, Posch W. CR4 Signaling Contributes to a DC-Driven Enhanced Immune Response Against Complement-Opsonized HIV-1. Front Immunol 2020; 11:2010. [PMID: 32922405 PMCID: PMC7457048 DOI: 10.3389/fimmu.2020.02010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 07/24/2020] [Indexed: 12/27/2022] Open
Abstract
Dendritic cells (DCs) possess intrinsic cellular defense mechanisms to specifically inhibit HIV-1 replication. In turn, HIV-1 has evolved strategies to evade innate immune sensing by DCs resulting in suboptimal maturation and poor antiviral immune responses. We previously showed that complement-opsonized HIV-1 (HIV-C) was able to efficiently infect various DC subsets significantly higher than non-opsonized HIV-1 (HIV) and therefore also mediate a higher antiviral immunity. Thus, complement coating of HIV-1 might play a role with respect to viral control occurring early during infection via modulation of DCs. To determine in detail which complement receptors (CRs) expressed on DCs was responsible for infection and superior pro-inflammatory and antiviral effects, we generated stable deletion mutants for the α-chains of CR3, CD11b, and CR4, CD11c using CRISPR/Cas9 in THP1-derived DCs. We found that CD11c deletion resulted in impaired DC infection as well as antiviral and pro-inflammatory immunity upon exposure to complement-coated HIV-1. In contrast, sole expression of CD11b on DCs shifted the cells to an anti-inflammatory, regulatory DC type. We here illustrated that CR4 comprised of CD11c and CD18 is the major player with respect to DC infection associated with a potent early pro-inflammatory immune response. A more detailed characterization of CR3 and CR4 functions using our powerful tool might open novel avenues for early therapeutic intervention during HIV-1 infection.
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Affiliation(s)
- Marta Bermejo-Jambrina
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria.,Department of Experimental Immunology, Amsterdam Infection and Immunity Institute, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Michael Blatzer
- Experimental Neuropathology Unit, Infection and Epidemiology Department, Institute Pasteur, Paris, France
| | - Paula Jauregui-Onieva
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Teodor E Yordanov
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Paul Hörtnagl
- Central Institute for Blood Transfusion and Immunological Department, Innsbruck, Austria
| | - Taras Valovka
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria.,Department of Pediatrics I, Medical University of Innsbruck, Innsbruck, Austria
| | - Lukas A Huber
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Doris Wilflingseder
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Wilfried Posch
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
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12
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Abstract
PURPOSE OF REVIEW The review recalls recent findings regarding the induction of vaccinal effects by HIV-1 broadly neutralizing antibodies (bNAbs) and highlights potential therapeutic strategies to exploit such immunomodulatory properties. RECENT FINDINGS Studies in different animal models have shown that mAbs can generate long-lasting protective immunity. Induction of this vaccinal effect by HIV-1 bNAbs has also been more recently reported in animal models of HIV-1 infection. Notably, bNAbs treatment of macaques infected with the chimeric simian-human immunodeficiency virus (SHIV) improved both humoral and cellular adaptive immune responses that contributed to disease control. Importantly, this concept has been extended to HIV-1-infected patients as enhancement of humoral responses was recently reported in HIV-1 patients treated with bNAbs. Studies aiming at elucidating the mechanisms underlying these immunomodulatory properties of bNAbs have identified a role for immune complexes in shaping immune responses against HIV-1. They also highlight different Fc (fragment crystallizable) region effector functions that might be required for the enhancement of HIV-1 immune responses upon bNAbs treatment. SUMMARY HIV-1 bNAbs can elicit protective adaptive immune responses through mechanisms involving multiple cellular and molecular actors of the immune system. Harnessing these mechanisms will be crucial to achieve protective immunity against HIV-1 infection by bNAbs.
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13
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Dittmer U, Sutter K, Kassiotis G, Zelinskyy G, Bánki Z, Stoiber H, Santiago ML, Hasenkrug KJ. Friend retrovirus studies reveal complex interactions between intrinsic, innate and adaptive immunity. FEMS Microbiol Rev 2019; 43:435-456. [PMID: 31087035 PMCID: PMC6735856 DOI: 10.1093/femsre/fuz012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 05/13/2019] [Indexed: 12/14/2022] Open
Abstract
Approximately 4.4% of the human genome is comprised of endogenous retroviral sequences, a record of an evolutionary battle between man and retroviruses. Much of what we know about viral immunity comes from studies using mouse models. Experiments using the Friend virus (FV) model have been particularly informative in defining highly complex anti-retroviral mechanisms of the intrinsic, innate and adaptive arms of immunity. FV studies have unraveled fundamental principles about how the immune system controls both acute and chronic viral infections. They led to a more complete understanding of retroviral immunity that begins with cellular sensing, production of type I interferons, and the induction of intrinsic restriction factors. Novel mechanisms have been revealed, which demonstrate that these earliest responses affect not only virus replication, but also subsequent innate and adaptive immunity. This review on FV immunity not only surveys the complex host responses to a retroviral infection from acute infection to chronicity, but also highlights the many feedback mechanisms that regulate and counter-regulate the various arms of the immune system. In addition, the discovery of molecular mechanisms of immunity in this model have led to therapeutic interventions with implications for HIV cure and vaccine development.
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Affiliation(s)
- Ulf Dittmer
- Institute for Virology, University Clinics Essen, University of Duisburg-Essen, Virchowstr. 179, 45147 Essen, Germany
| | - Kathrin Sutter
- Institute for Virology, University Clinics Essen, University of Duisburg-Essen, Virchowstr. 179, 45147 Essen, Germany
| | - George Kassiotis
- Retroviral Immunology, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
- Department of Medicine, Faculty of Medicine, Imperial College London, St Mary's Hospital, Praed St, Paddington, London W2 1NY, UK
| | - Gennadiy Zelinskyy
- Institute for Virology, University Clinics Essen, University of Duisburg-Essen, Virchowstr. 179, 45147 Essen, Germany
| | - Zoltán Bánki
- Division of Virology, Medical University of Innsbruck, Peter-Mayrstr. 4b, A-6020 Innsbruck, Austria
| | - Heribert Stoiber
- Division of Virology, Medical University of Innsbruck, Peter-Mayrstr. 4b, A-6020 Innsbruck, Austria
| | - Mario L Santiago
- University of Colorado School of Medicine, 12700E 19th Ave, Aurora, CO 80045, USA
| | - Kim J Hasenkrug
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, NIAID, NIH, 903S 4th Street, Hamilton, MT 59840, USA
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14
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Schönfeld M, Knackmuss U, Chandorkar P, Hörtnagl P, Hope TJ, Moris A, Bellmann-Weiler R, Lass-Flörl C, Posch W, Wilflingseder D. Co- but not Sequential Infection of DCs Boosts Their HIV-Specific CTL-Stimulatory Capacity. Front Immunol 2019; 10:1123. [PMID: 31178863 PMCID: PMC6542955 DOI: 10.3389/fimmu.2019.01123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 05/02/2019] [Indexed: 11/27/2022] Open
Abstract
Pathogenic bacteria and their microbial products activate dendritic cells (DCs) at mucosal surfaces during sexually transmitted infections (STIs) and therefore might also differently shape DC functions during co-infection with HIV-1. We recently illustrated that complement (C) coating of HIV-1 (HIV-C), as primarily found during the acute phase of infection before appearance of HIV-specific antibodies, by-passed SAMHD1-mediated restriction in DCs and therefore mediated an increased DC activation and antiviral capacity. To determine whether the superior antiviral effects of HIV-C-exposed DCs also apply during STIs, we developed a co-infection model in which DCs were infected with Chlamydia spp. simultaneously (HIV-C/Chlam-DCs or HIV/Chlam-DCs) or a sequential infection model, where DCs were exposed to Chlamydia for 3 or 24 h (Chlam-DCs) followed by HIV-1 infection. Co-infection of DCs with HIV-1 and Chlamydia significantly boosted the CTL-stimulatory capacity compared to HIV-1-loaded iDCs and this boost was independent on the opsonization pattern. This effect was lost in the sequential infection model, when opsonized HIV-1 was added delayed to Chlamydia-loaded DCs. The reduction in the CTL-stimulatory capacity of Chlam-DCs was not due to lower HIV-1 binding or infection compared to iDCs or HIV-C/Chlam-DCs, but due to altered fusion and internalization mechanisms within DCs. The CTL-stimulatory capacity of HIV-C in Chlam-DCs correlated with significantly reduced viral fusion compared to iDCs and HIV-C/Chlam-DCs and illustrated considerably increased numbers of HIV-C-containing vacuoles than iDCs. The data indicate that Chlamydia co-infection of DCs mediates a transient boost of their HIV-specific CTL-stimulatory and antiviral capacity, while in the sequential infection model this is reversed and associated with hazard to the host.
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Affiliation(s)
- Manuela Schönfeld
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Ulla Knackmuss
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Parul Chandorkar
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Paul Hörtnagl
- Central Institute for Blood Transfusion and Immunological Department, Medical University of Innsbruck, Innsbruck, Austria
| | - Thomas John Hope
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Arnaud Moris
- Sorbonne Université, INSERM, CNRS, Center for Immunology and Microbial Infections - CIMI-Paris, Paris, France.,Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Rosa Bellmann-Weiler
- Department of Internal Medicine II, Medical University of Innsbruck, Innsbruck, Austria
| | - Cornelia Lass-Flörl
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Wilfried Posch
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Doris Wilflingseder
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
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15
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Fcγ Receptor Type I (CD64)-Mediated Impairment of the Capacity of Dendritic Cells to Activate Specific CD8 T Cells by IgG-opsonized Friend Virus. Viruses 2019; 11:v11020145. [PMID: 30744065 PMCID: PMC6410291 DOI: 10.3390/v11020145] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 01/31/2019] [Accepted: 02/01/2019] [Indexed: 11/18/2022] Open
Abstract
Dendritic cells (DCs) express Fcγ receptors (FcγRs) for the binding immune complexes (ICs) consisting of IgG and antigens (Ags). IC–FcγR interactions have been demonstrated to enhance activation and antigen-presenting functions of DCs. Utilizing Friend virus (FV), an oncogenic mouse retrovirus, we investigated the effect of IgG-opsonization of retroviral particles on the infection of DCs and the subsequent presentation of viral antigens by DCs to virus-specific CD8 T cells. We found that opsonization by virus-specific non-neutralizing IgG abrogated DC infection and as a consequence significantly reduced the capacity of DCs to activate virus-specific CD8 T cells. Effects of IgG-opsonization were mediated by the high-affinity FcγR type I, CD64, expressed on DCs. Our results suggest that different opsonization patterns on the retroviral surface modulate infection and antigen-presenting functions of DCs, whereby, in contrast to complement, IgG reduces the capacity of DCs to activate cytotoxic T cell (CTL) responses.
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16
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Steger M, Bermejo-Jambrina M, Yordanov T, Wagener J, Brakhage AA, Pittl V, Huber LA, Haas H, Lass-Flörl C, Posch W, Wilflingseder D. β-1,3-glucan-lacking Aspergillus fumigatus mediates an efficient antifungal immune response by activating complement and dendritic cells. Virulence 2018; 10:957-969. [PMID: 30372658 PMCID: PMC8647855 DOI: 10.1080/21505594.2018.1528843] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Complement system and dendritic cells (DCs) form - beside neutrophils and macrophages - the first line of defense to combat fungal infections. Therefore, we here studied interactions of these first immune elements with Aspergillus fumigatus lacking ß-1,3-glucans (fks1tetOnrep under repressed conditions) to mechanistically explain the mode of action of echinocandins in more detail. Echinocandins are cell wall active agents blocking β-glucan synthase, making the A. fumigatus fks1tetOn mutant a good model to study immune-modulatory actions of these drugs. We now demonstrate herein, that complement was activated to significantly higher levels by the fks1-deficient strain compared to its respective wild type. This enhanced covalent linking of complement fragments to the A. fumigatus fks1tetOnrep mutant further resulted in enhanced DC binding and internalization of the fungus. Additionally, we found that fks1tetOnrep induced a Th1-/Th17-polarizing cytokine profile program in DCs. The effect was essentially dependent on massive galactomannan shedding, since blocking of DC-SIGN significantly reduced the fks1tetOnrep-mediated induction of an inflammatory cytokine profile.Our data demonstrate that lack of ß-1,3-glucan, also found under echinocandin therapy, results in improved recognition of Aspergillus fumigatus by complement and DCs and therefore not only directly affects the fungus by its fungistatic actions, but also is likely to exert indirect antifungal mechanisms by strengthening innate host immune mechanisms.Abbreviations: C: complement; CR:complement receptor; DC: dendritic cell; iDC: immature dendritic cell; DC-SIGN: Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Non-integrin; ERK: extracellular signal-regulated kinases; JNK : c-Jun N-terminal kinases; MAPK: mitogen-activated protein kinase; NHS: normal human serum; PRR: pattern recognition receptor; Th :T helper; TLR :Toll-like receptor; WT: wild type.
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Affiliation(s)
- Marion Steger
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Marta Bermejo-Jambrina
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Teodor Yordanov
- Division of Cell Biology, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Johannes Wagener
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Germany.,Division of Molecular Biology, Medical University Innsbruck, Innsbruck, Austria
| | - Verena Pittl
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Lukas A Huber
- Division of Cell Biology, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Hubertus Haas
- Department of Microbiology and Molecular Biology, Friedrich Schiller University (FSU), Jena, Germany
| | - Cornelia Lass-Flörl
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Wilfried Posch
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Doris Wilflingseder
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
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17
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Hua CK, Ackerman ME. Increasing the Clinical Potential and Applications of Anti-HIV Antibodies. Front Immunol 2017; 8:1655. [PMID: 29234320 PMCID: PMC5712301 DOI: 10.3389/fimmu.2017.01655] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 11/13/2017] [Indexed: 01/03/2023] Open
Abstract
Preclinical and early human clinical studies of broadly neutralizing antibodies (bNAbs) to prevent and treat HIV infection support the clinical utility and potential of bNAbs for prevention, postexposure prophylaxis, and treatment of acute and chronic infection. Observed and potential limitations of bNAbs from these recent studies include the selection of resistant viral populations, immunogenicity resulting in the development of antidrug (Ab) responses, and the potentially toxic elimination of reservoir cells in regeneration-limited tissues. Here, we review opportunities to improve the clinical utility of HIV Abs to address these challenges and further accomplish functional targets for anti-HIV Ab therapy at various stages of exposure/infection. Before exposure, bNAbs' ability to serve as prophylaxis by neutralization may be improved by increasing serum half-life to necessitate less frequent administration, delivering genes for durable in vivo expression, and targeting bNAbs to sites of exposure. After exposure and/or in the setting of acute infection, bNAb use to prevent/reduce viral reservoir establishment and spread may be enhanced by increasing the potency with which autologous adaptive immune responses are stimulated, clearing acutely infected cells, and preventing cell-cell transmission of virus. In the setting of chronic infection, bNAbs may better mediate viral remission or "cure" in combination with antiretroviral therapy and/or latency reversing agents, by targeting additional markers of tissue reservoirs or infected cell types, or by serving as targeting moieties in engineered cell therapy. While the clinical use of HIV Abs has never been closer, remaining studies to precisely define, model, and understand the complex roles and dynamics of HIV Abs and viral evolution in the context of the human immune system and anatomical compartmentalization will be critical to both optimize their clinical use in combination with existing agents and define further strategies with which to enhance their clinical safety and efficacy.
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Affiliation(s)
- Casey K. Hua
- Department of Microbiology and Immunology, Geisel School of Medicine, Lebanon, NH, United States
| | - Margaret E. Ackerman
- Department of Microbiology and Immunology, Geisel School of Medicine, Lebanon, NH, United States
- Thayer School of Engineering, Dartmouth College, Hanover, NH, United States
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18
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Posch W, Lass-Flörl C, Wilflingseder D. Generation of Human Monocyte-derived Dendritic Cells from Whole Blood. J Vis Exp 2016. [PMID: 28060313 DOI: 10.3791/54968] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Dendritic cells (DCs) recognize foreign structures of different pathogens, such as viruses, bacteria, and fungi, via a variety of pattern recognition receptors (PRRs) expressed on their cell surface and thereby activate and regulate immunity. The major function of DCs is the induction of adaptive immunity in the lymph nodes by presenting antigens via MHC I and MHC II molecules to naïve T lymphocytes. Therefore, DCs have to migrate from the periphery to the lymph nodes after the recognition of pathogens at the sites of infection. For in vitro experiments or DC vaccination strategies, monocyte-derived DCs are routinely used. These cells show similarities in physiology, morphology, and function to conventional myeloid dendritic cells. They are generated by interleukin 4 (IL-4) and granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulation of monocytes isolated from healthy donors. Here, we demonstrate how monocytes are isolated and stimulated from anti-coagulated human blood after peripheral blood mononuclear cell (PBMC) enrichment by density gradient centrifugation. Human monocytes are differentiated into immature DCs and are ready for experimental procedures in a non-clinical setting after 5 days of incubation.
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Affiliation(s)
- Wilfried Posch
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck;
| | - Cornelia Lass-Flörl
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck
| | - Doris Wilflingseder
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck
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19
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Converting monoclonal antibody-based immunotherapies from passive to active: bringing immune complexes into play. Emerg Microbes Infect 2016; 5:e92. [PMID: 27530750 PMCID: PMC5034104 DOI: 10.1038/emi.2016.97] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 07/12/2016] [Accepted: 07/14/2016] [Indexed: 12/13/2022]
Abstract
Monoclonal antibodies (mAbs), which currently constitute the main class of biotherapeutics, are now recognized as major medical tools that are increasingly being considered to fight severe viral infections. Indeed, the number of antiviral mAbs developed in recent years has grown exponentially. Although their direct effects on viral blunting have been studied in detail, their potential immunomodulatory actions have been overlooked until recently. The ability of antiviral mAbs to modulate antiviral immune responses in infected organisms has recently been revealed. More specifically, upon recognition of their cognate antigens, mAbs form immune complexes (ICs) that can be recognized by the Fc receptors expressed on different immune cells of infected individuals. This binding may be followed by the modulation of the host immune responses. Harnessing this immunomodulatory property may facilitate improvements in the therapeutic potential of antiviral mAbs. This review focuses on the role of ICs formed with different viral determinants and mAbs in the induction of antiviral immune responses in the context of both passive immunotherapies and vaccination strategies. Potential deleterious effects of ICs on the host immune response are also discussed.
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20
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Complement-Opsonized HIV-1 Overcomes Restriction in Dendritic Cells. PLoS Pathog 2015; 11:e1005005. [PMID: 26121641 PMCID: PMC4485899 DOI: 10.1371/journal.ppat.1005005] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 06/05/2015] [Indexed: 11/19/2022] Open
Abstract
DCs express intrinsic cellular defense mechanisms to specifically inhibit HIV-1 replication. Thus, DCs are productively infected only at very low levels with HIV-1, and this non-permissiveness of DCs is suggested to go along with viral evasion. We now illustrate that complement-opsonized HIV-1 (HIV-C) efficiently bypasses SAMHD1 restriction and productively infects DCs including BDCA-1 DCs. Efficient DC infection by HIV-C was also observed using single-cycle HIV-C, and correlated with a remarkable elevated SAMHD1 T592 phosphorylation but not SAMHD1 degradation. If SAMHD1 phosphorylation was blocked using a CDK2-inhibitor HIV-C-induced DC infection was also significantly abrogated. Additionally, we found a higher maturation and co-stimulatory potential, aberrant type I interferon expression and signaling as well as a stronger induction of cellular immune responses in HIV-C-treated DCs. Collectively, our data highlight a novel protective mechanism mediated by complement opsonization of HIV to effectively promote DC immune functions, which might be in the future exploited to tackle HIV infection. We here give insight into a substantial novel way of dendritic cell modulation at least during acute HIV-1 infection by triggering integrin receptor signaling. We found that complement-opsonization of the virus is able to relieve SAMHD1 restriction in DCs, thereby initiating strong maturation and co-stimulatory capacity of the cells and stimulating efficient cellular and humoral antiviral immune responses. This newly described way of DC modulation by complement might be exploited to find novel therapeutic targets promoting DC immune functions against HIV.
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21
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Vogelpoel LTC, Baeten DLP, de Jong EC, den Dunnen J. Control of cytokine production by human fc gamma receptors: implications for pathogen defense and autoimmunity. Front Immunol 2015; 6:79. [PMID: 25759693 PMCID: PMC4338787 DOI: 10.3389/fimmu.2015.00079] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 02/10/2015] [Indexed: 01/21/2023] Open
Abstract
Control of cytokine production by immune cells is pivotal for counteracting infections via orchestration of local and systemic inflammation. Although their contribution has long been underexposed, it has recently become clear that human Fc gamma receptors (FcγRs), which are receptors for the Fc region of immunoglobulin G (IgG) antibodies, play a critical role in this process by controlling tissue- and pathogen-specific cytokine production. Whereas individual stimulation of FcγRs does not evoke cytokine production, FcγRs cell-type specifically interact with various other receptors for selective amplification or inhibition of particular cytokines, thereby tailoring cytokine responses to the immunological context. The physiological function of FcγR-mediated control of cytokine production is to counteract infections with various classes of pathogens. Upon IgG opsonization, pathogens are simultaneously recognized by FcγRs as well as by various pathogen-sensing receptors, leading to the induction of pathogen class-specific immune responses. However, when erroneously activated, the same mechanism also contributes to the development of autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus. In this review, we discuss control of cytokine production as a novel function of FcγRs in human innate immune cells in the context of homeostasis, infection, and autoimmunity and address the possibilities for future therapeutic exploitation.
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Affiliation(s)
- Lisa T C Vogelpoel
- Department of Cell Biology and Histology, Academic Medical Center, University of Amsterdam , Amsterdam , Netherlands
| | - Dominique L P Baeten
- Department of Clinical Immunology and Rheumatology, Academic Medical Center, University of Amsterdam , Amsterdam , Netherlands
| | - Esther C de Jong
- Department of Cell Biology and Histology, Academic Medical Center, University of Amsterdam , Amsterdam , Netherlands
| | - Jeroen den Dunnen
- Department of Cell Biology and Histology, Academic Medical Center, University of Amsterdam , Amsterdam , Netherlands
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22
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Wilflingseder D, Schroll A, Hackl H, Gallasch R, Frampton D, Lass-Flörl C, Pancino G, Saez-Cirion A, Lambotte O, Weiss L, Kellam P, Trajanoski Z, Geijtenbeek T, Weiss G, Posch W. Immediate T-Helper 17 Polarization Upon Triggering CD11b/c on HIV-Exposed Dendritic Cells. J Infect Dis 2015; 212:44-56. [PMID: 25583169 DOI: 10.1093/infdis/jiv014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 12/29/2014] [Indexed: 12/14/2022] Open
Abstract
Early on in human immunodeficiency virus (HIV) type 1 infection, gut T-helper (Th) 17 cells are massively depleted leading eventually to compromised intestinal barrier function and excessive immune activation. In contrast, the functional Th17 cell compartment of the gut is well-maintained in nonpathogenic simian immunodeficiency virus infection as well as HIV-1 long-term nonprogressors. Here, we show that dendritic cells (DCs) loaded with HIV-1 bearing high surface complement levels after incubation in plasma from HIV-infected individuals secreted significantly higher concentrations of Th17-polarizing cytokines than DCs exposed to nonopsonized HIV-1. The enhanced Th17-polarizing capacity of in vitro-generated and BDCA-1(+) DCs directly isolated from blood was linked to activation of ERK. In addition, C3a produced from DCs exposed to complement-opsonized HIV was associated with the higher Th17 polarization. Our in vitro and ex vivo data, therefore, indicate that complement opsonization of HIV-1 strengthens DC-mediated antiviral immune functions by simultaneously triggering Th17 expansion and intrinsic C3 formation via DC activation.
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Affiliation(s)
| | - Andrea Schroll
- Department of Internal Medicine VI, Clinical Immunology and Infectious Diseases
| | - Hubert Hackl
- Division of Bioinformatics, Biocenter, Medical University of Innsbruck, Austria
| | - Ralf Gallasch
- Division of Bioinformatics, Biocenter, Medical University of Innsbruck, Austria
| | - Dan Frampton
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge University College London, Windeyer Institute, United Kingdom
| | | | | | | | - Olivier Lambotte
- INSERM U1012, Régulation de la Réponse Immune, Infection VIH1 et Autoimmunité, Université Paris Sud APHP, Service de Médecine Interne, Hôpitaux Universitaires Paris Sud Faculté de Médecine Paris Sud, Le Kremlin Bicêtre, France
| | - Laurence Weiss
- Unité de Régulation des Infections Rétrovirales APHP Hôpital Européen Georges Pompidou, Paris
| | - Paul Kellam
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge University College London, Windeyer Institute, United Kingdom
| | - Zlatko Trajanoski
- Division of Bioinformatics, Biocenter, Medical University of Innsbruck, Austria
| | - Teunis Geijtenbeek
- Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, The Netherlands
| | - Günter Weiss
- Department of Internal Medicine VI, Clinical Immunology and Infectious Diseases
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23
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Cure of HIV infection: is the long wait over? J Allergy Clin Immunol 2014; 134:20-2. [PMID: 25117800 DOI: 10.1016/j.jaci.2014.04.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 04/16/2014] [Indexed: 11/23/2022]
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24
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Posch W, Pfaller K, Lass-Flörl C, Wilflingseder D. The viral make-up makes a world of difference. AIDS Res Hum Retroviruses 2014; 30:642-3. [PMID: 24984236 DOI: 10.1089/aid.2014.0061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Wilfried Posch
- Division of Hygiene and Medical Microbiology, Innsbruck Medical University, Innsbruck, Austria
| | - Kristian Pfaller
- Division of Embryology and Histology, Innsbruck Medical University, Innsbruck, Austria
| | - Cornelia Lass-Flörl
- Division of Hygiene and Medical Microbiology, Innsbruck Medical University, Innsbruck, Austria
| | - Doris Wilflingseder
- Division of Hygiene and Medical Microbiology, Innsbruck Medical University, Innsbruck, Austria
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25
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Saez-Cirion A, Jacquelin B, Barré-Sinoussi F, Müller-Trutwin M. Immune responses during spontaneous control of HIV and AIDS: what is the hope for a cure? Philos Trans R Soc Lond B Biol Sci 2014; 369:20130436. [PMID: 24821922 PMCID: PMC4024229 DOI: 10.1098/rstb.2013.0436] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
HIV research has made rapid progress and led to remarkable achievements in recent decades, the most important of which are combination antiretroviral therapies (cART). However, in the absence of a vaccine, the pandemic continues, and additional strategies are needed. The 'towards an HIV cure' initiative aims to eradicate HIV or at least bring about a lasting remission of infection during which the host can control viral replication in the absence of cART. Cases of spontaneous and treatment-induced control of infection offer substantial hope. Here, we describe the scientific knowledge that is lacking, and the priorities that have been established for research into a cure. We discuss in detail the immunological lessons that can be learned by studying natural human and animal models of protection and spontaneous control of viraemia or of disease progression. In particular, we describe the insights we have gained into the immune mechanisms of virus control, the impact of early virus-host interactions and why chronic inflammation, a hallmark of HIV infection, is an obstacle to a cure. Finally, we enumerate current interventions aimed towards improving the host immune response.
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Affiliation(s)
| | | | | | - M. Müller-Trutwin
- Institut Pasteur, Unité de Régulation des Infections Rétrovirales, Paris, France
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26
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Chinen J, Notarangelo LD, Shearer WT. Advances in basic and clinical immunology in 2012. J Allergy Clin Immunol 2013; 131:675-82. [DOI: 10.1016/j.jaci.2013.01.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2012] [Accepted: 01/07/2013] [Indexed: 01/29/2023]
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