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Schindewolf C, Menachery VD. Middle East Respiratory Syndrome Vaccine Candidates: Cautious Optimism. Viruses 2019; 11:E74. [PMID: 30658390 PMCID: PMC6356267 DOI: 10.3390/v11010074] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 01/10/2019] [Accepted: 01/12/2019] [Indexed: 12/28/2022] Open
Abstract
Efforts towards developing a vaccine for Middle East respiratory syndrome coronavirus (MERS-CoV) have yielded promising results. Utilizing a variety of platforms, several vaccine approaches have shown efficacy in animal models and begun to enter clinical trials. In this review, we summarize the current progress towards a MERS-CoV vaccine and highlight potential roadblocks identified from previous attempts to generate coronavirus vaccines.
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Affiliation(s)
- Craig Schindewolf
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, 77555 TX, USA.
| | - Vineet D Menachery
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, 77555 TX, USA.
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Intratumoral delivery of CD154 homolog (Ad-ISF35) induces tumor regression: analysis of vector biodistribution, persistence and gene expression. Cancer Gene Ther 2012; 19:336-44. [PMID: 22402624 DOI: 10.1038/cgt.2012.6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Ad-ISF35 is an adenovirus (Ad) vector that encodes a mouse-human chimeric CD154. Ad-ISF35 induces activation of chronic lymphocytic leukemia (CLL) cells converting them into CLL cells capable of promoting immune recognition and anti-leukemia T-cell activation. Clinical trials in humans treated with Ad-ISF35-transduced leukemia cells or intranodal injection of Ad-ISF35 have shown objective clinical responses. To better understand the biology of Ad-ISF35 and to contribute to its clinical development, we preformed studies to evaluate biodistribution, persistence and toxicity of repeat dose intratumoral administration of Ad-ISF35 in a mouse model. Ad-ISF35 intratumoral administration induced tumor regression in more than 80% of mice bearing A20 tumors. There were no abnormalities in the serum chemistry. Mice receiving Ad-ISF35 presented severe extramedullary hematopoiesis and follicular hyperplasia in the spleen and extramedullary hematopoiesis with lymphoid hyperplasia in lymph nodes. After Ad-ISF35 injection, the vector was found primarily in the injected tumors with a biodistribution pattern that showed a rapid clearance with no evidence of Ad-ISF35 accumulation or persistence in the injected tumor or peripheral organs. Furthermore, pre-existing antibodies against Ad-5 did not abrogate Ad-ISF35 anti-tumor activity. In conclusion, intratumoral administration of Ad-ISF35 induced tumor regression in A20 tumor bearing mice without toxicities and with no evidence of vector accumulation or persistence.
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Norup LR, Dalgaard TS, Pedersen AR, Juul-Madsen HR. Assessment of Newcastle disease-specific T cell proliferation in different inbred MHC chicken lines. Scand J Immunol 2011; 74:23-30. [PMID: 21332569 DOI: 10.1111/j.1365-3083.2011.02534.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this study, we have described the establishment of an antigen-specific T cell proliferation assay based on recall stimulation with Newcastle disease (ND) antigen; further, we have described the results obtained after recall stimulation of animals containing different major histocompatibility complex (MHC) haplotypes, vaccinated against ND. First optimization of the assay was performed to lower unspecific proliferation and to enhance antigen-specific T cell proliferation. These two issues were achieved using ethylene diamine tetra acetic acid as stabilizing agent in blood samples and autologous immune serum in culture medium. The optimized assay was used to screen chickens with different MHC haplotypes for their ability to perform T cell proliferation. Results showed that the antigen-specific response of CD4(+) and CD8(+) T cells from B12 chickens was generally low, whereas B13, B130 and B201 chickens were medium in CD4(+) or CD8(+) T cell responses. High responses were seen only in few animals of each haplotype and not in general. A polymorphism in the chicken CD8α gene was found in our experimental chicken lines, resulting in incapability to detect CD8α(+) T cells using antibodies from the CT8 clone. Screening chickens with alternative antibodies showed that antibodies from the 2-398 clone were able to discriminate all CD8α(+) cells from CD8α(-) cells, and consequently this antibody was used in a second vaccination experiment performed with chickens of the haplotypes B13 and B130. This experiment showed a significant difference in antigen-specific proliferation of CD4(+) T cells between the two lines, but not in CD8α(+) T cell proliferation.
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Affiliation(s)
- L R Norup
- Department of Animal Health and Bioscience, Faculty of Agricultural Sciences, Aarhus University, Tjele, Denmark.
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Lanzi A, Ben Youssef G, Perricaudet M, Benihoud K. Anti-adenovirus humoral responses influence on the efficacy of vaccines based on epitope display on adenovirus capsid. Vaccine 2010; 29:1463-71. [PMID: 21184856 DOI: 10.1016/j.vaccine.2010.12.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 11/26/2010] [Accepted: 12/09/2010] [Indexed: 11/30/2022]
Abstract
The efficacy of recombinant adenoviruses (Ads) vaccine vectors is diminished by the high prevalence of anti-Ad antibodies (Abs) that hampers gene transfer. Epitope display on Ad capsid constitutes an alternative approach to bypass anti-Ad Ab capacity from blocking antigen expression. To understand the role of the epitope insertion site, an ovalbumin-derived epitope was genetically inserted into either Ad hexon or fiber proteins. Hexon-modified Ads triggered higher anti-ovalbumin Ab responses after one injection but surprisingly fiber-modified Ads were by far more potent after two or several administrations. Our data unravel a role for anti-Ad humoral immunity in controlling anti-epitope humoral responses.
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Affiliation(s)
- Anastasia Lanzi
- CNRS UMR 8203, Vectorologie et thérapeutiques anticancéreuses, Institut Gustave Roussy, 39 rue Camille Desmoulins, 94805 Villejuif Cedex, France
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Ranki T, Hemminki A. Serotype chimeric human adenoviruses for cancer gene therapy. Viruses 2010; 2:2196-2212. [PMID: 21994616 PMCID: PMC3185575 DOI: 10.3390/v2102196] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 08/16/2010] [Accepted: 09/22/2010] [Indexed: 11/16/2022] Open
Abstract
Cancer gene therapy consists of numerous approaches where the common denominator is utilization of vectors for achieving therapeutic effect. A particularly potent embodiment of the approach is virotherapy, in which the replication potential of an oncolytic virus is directed towards tumor cells to cause lysis, while normal cells are spared. Importantly, the therapeutic effect of the initial viral load is amplified through viral replication cycles and production of progeny virions. All cancer gene therapy approaches rely on a sufficient level of delivery of the anticancer agent into target cells. Thus, enhancement of delivery to target cells, and reduction of delivery to non-target cells, in an approach called transductional targeting, is attractive. Both genetic and non-genetic retargeting strategies have been utilized. However, in the context of oncolytic viruses, it is beneficial to have the specific modification included in progeny virions and hence genetic modification may be preferable. Serotype chimerism utilizes serotype specific differences in receptor usage, liver tropism and seroprevalence in order to gain enhanced infection of target tissue. This review will focus on serotype chimeric adenoviruses for cancer gene therapy applications.
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Affiliation(s)
- Tuuli Ranki
- Cancer Gene Therapy Group, Molecular Cancer Biology Program, University of Helsinki, P.O. Box 63, 00014 University of Helsinki, Finland; E-Mail:
- HUSLAB, Helsinki University Central Hospital, P.O. Box 100, 00029 HUS, Helsinki, Finland
- Haartman Institute & Transplantation Laboratory, University of Helsinki, P.O. Box 21, 00014 University of Helsinki, Finland
- Finnish Institute for Molecular Medicine, University of Helsinki, P.O.Box 20, 00014 University of Helsinki, Finland
| | - Akseli Hemminki
- Cancer Gene Therapy Group, Molecular Cancer Biology Program, University of Helsinki, P.O. Box 63, 00014 University of Helsinki, Finland; E-Mail:
- HUSLAB, Helsinki University Central Hospital, P.O. Box 100, 00029 HUS, Helsinki, Finland
- Haartman Institute & Transplantation Laboratory, University of Helsinki, P.O. Box 21, 00014 University of Helsinki, Finland
- Finnish Institute for Molecular Medicine, University of Helsinki, P.O.Box 20, 00014 University of Helsinki, Finland
- Author to whom correspondence should be addressed; E-Mail: ; Tel. +358-9-1912 5464; Fax: +358-9-1912 5465
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Zaiss AK, Machado HB, Herschman HR. The influence of innate and pre-existing immunity on adenovirus therapy. J Cell Biochem 2010; 108:778-90. [PMID: 19711370 DOI: 10.1002/jcb.22328] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Recombinant adenovirus serotype 5 (Ad5) vectors have been studied extensively in preclinical gene therapy models and in a range of clinical trials. However, innate immune responses to adenovirus vectors limit effectiveness of Ad5 based therapies. Moreover, extensive pre-existing Ad5 immunity in human populations will likely limit the clinical utility of adenovirus vectors, unless methods to circumvent neutralizing antibodies that bind virus and block target cell transduction can be developed. Furthermore, memory T cell and humoral responses to Ad5 are associated with increased toxicity, raising safety concerns for therapeutic adenovirus vectors in immunized hosts. Most preclinical studies have been performed in naïve animals; although pre-existing immunity is among the greatest hurdles for adenovirus therapies, it is also one of the most neglected experimentally. Here we summarize findings using adenovirus vectors in naïve animals, in Ad-immunized animals and in clinical trials, and review strategies proposed to overcome innate immune responses and pre-existing immunity.
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Affiliation(s)
- Anne K Zaiss
- Department of Biological Chemistry, David Geffen School of Medicine, UCLA, Los Angeles, California 90095, USA
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Zaiss AK, Vilaysane A, Cotter MJ, Clark SA, Meijndert HC, Colarusso P, Yates RM, Petrilli V, Tschopp J, Muruve DA. Antiviral Antibodies Target Adenovirus to Phagolysosomes and Amplify the Innate Immune Response. THE JOURNAL OF IMMUNOLOGY 2009; 182:7058-68. [DOI: 10.4049/jimmunol.0804269] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Matthews QL, Yang P, Wu Q, Belousova N, Rivera AA, Stoff-Khalili MA, Waehler R, Hsu HC, Li Z, Li J, Mountz JD, Wu H, Curiel DT. Optimization of capsid-incorporated antigens for a novel adenovirus vaccine approach. Virol J 2008; 5:98. [PMID: 18718011 PMCID: PMC2535600 DOI: 10.1186/1743-422x-5-98] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Accepted: 08/21/2008] [Indexed: 12/31/2022] Open
Abstract
Despite the many potential advantages of Ad vectors for vaccine application, the full utility of current Ad vaccines may be limited by the host anti-vector immune response. Direct incorporation of antigens into the adenovirus capsid offers a new and exciting approach for vaccination strategies; this strategy exploits the inherent antigenicity of the Ad vector. Critical to exploiting Ad in this new context is the placement of antigenic epitopes within the major Ad capsid protein, hexon. In our current study we illustrate that we have the capability to place a range of antigenic epitopes within Ad5 capsid protein hexon hypervariable regions (HVRs) 2 or 5, thus producing viable Ad virions. Our data define the maximal incorporation size at HVR2 or HVR5 as it relates to identical antigenic epitopes. In addition, this data suggests that Ad5 HVR5 is more permissive to a range of insertions. Most importantly, repeated administration of our hexon-modified viruses resulted in a secondary anti-antigen response, whereas minimal secondary effect was present after administration of Ad5 control. Our study describes antigen placement and optimization within the context of the capsid incorporation approach of Ad vaccine employment, thereby broadening this new methodology.
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Affiliation(s)
- Qiana L Matthews
- Division of Human Gene Therapy, Department of Medicine, University of Alabama at Birmingham, Birmingham, USA.
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Sapinoro R, Volcy K, Rodrigo WWSI, Schlesinger JJ, Dewhurst S. Fc receptor-mediated, antibody-dependent enhancement of bacteriophage lambda-mediated gene transfer in mammalian cells. Virology 2008; 373:274-86. [PMID: 18191979 DOI: 10.1016/j.virol.2007.12.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Revised: 09/11/2007] [Accepted: 12/03/2007] [Indexed: 12/23/2022]
Abstract
Lambda phage vectors mediate gene transfer in cultured mammalian cells and in live mice, and in vivo phage-mediated gene expression is increased when mice are pre-immunized with bacteriophage lambda. We now show that, like eukaryotic viruses, bacteriophage vectors are subject to Fc receptor-mediated, antibody-dependent enhancement of infection in mammalian cells. Antibody-dependent enhancement of phage gene transfer required FcgammaRI, but not its associated gamma-chain, and was not supported by other FcgammaR family members (FcgammaRIIA, FcgammaRIIB, and FcgammaRIII). Studies using chlorpromazine and latrunculin A revealed an important role for clathrin-mediated endocytosis (chlorpromazine) and actin filaments (latrunculin A) in antibody-enhanced phage gene transfer. This was confirmed by experiments using inhibitors of endosomal acidification (bafilomycin A1, monensin) and by immunocytochemical colocalization of internalized phage particles with early endosome-associated protein-1 (EAA1). In contrast, microtubule-targeting agents (nocodazole, taxol) increased the efficiency of antibody-enhanced phage gene transfer. These results reveal an unexpected antibody-dependent, FcgammaRI-mediated enhancement of phage transduction in mammalian cells, and suggest new approaches to improve bacteriophage-mediated gene transfer.
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Affiliation(s)
- Ramil Sapinoro
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, USA
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Krause A, Joh JH, Hackett NR, Roelvink PW, Bruder JT, Wickham TJ, Kovesdi I, Crystal RG, Worgall S. Epitopes expressed in different adenovirus capsid proteins induce different levels of epitope-specific immunity. J Virol 2007; 80:5523-30. [PMID: 16699033 PMCID: PMC1472137 DOI: 10.1128/jvi.02667-05] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
On the basis of the concept that the capsid proteins of adenovirus (Ad) gene transfer vectors can be genetically manipulated to enhance the immunogenicity of Ad-based vaccines, the present study compared the antiantigen immunogenicity of Ad vectors with a common epitope of the hemagglutinin (HA) protein of the influenza A virus incorporated into the outer Ad capsid protein hexon, penton base, fiber knob, or protein IX. Incorporation of the same epitope into the different capsid proteins provided insights into the correlation between epitope position and antiepitope immunity. Following immunization of three different strains of mice (C57BL/6, BALB/c, and CBA) with either an equal number of Ad particles (resulting in a different total HA copy number) or different Ad particle numbers (to achieve the same HA copy number), the highest primary (immunoglobulin M [IgM]) and secondary (IgG) anti-HA humoral and cellular CD4 gamma interferon and interleukin-4 responses against HA were always achieved with the Ad vector carrying the HA epitope in fiber knob. These observations suggest that the immune response against an epitope inserted into Ad capsid proteins is not necessarily dependent on the capsid protein number and imply that the choice of incorporation site in Ad capsid proteins in their use as vaccines needs to be compared in vivo.
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Affiliation(s)
- Anja Krause
- Department of Genetic Medicine, Weill Medical College of Cornell University, 515 East 71st Street, New York, NY 10021, USA
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Leopold PL, Wendland RL, Vincent T, Crystal RG. Neutralized adenovirus-immune complexes can mediate effective gene transfer via an Fc receptor-dependent infection pathway. J Virol 2006; 80:10237-47. [PMID: 17005701 PMCID: PMC1617312 DOI: 10.1128/jvi.00512-06] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Neutralization of adenovirus (Ad) by anti-Ad neutralizing antibodies in serum involves formation of Ad-immune complexes that prevent the virus from interacting with target cells. We hypothesized that Ad-immune complexes likely contain viable Ad vectors which, although no longer capable of gaining access to receptors on target cells, may be able to express transgenes in cells bearing Fc receptors for immunoglobulins, i.e., that antibody-based "neutralization" of Ad vectors may be circumvented by the Fc receptor pathway. To test this hypothesis, we expressed the Fcgamma receptor IIA (FcgammaR) in A549 lung epithelial cells or human dermal fibroblasts and evaluated gene transfer in the presence of human neutralizing anti-Ad serum. FcgammaR-expressing cells bound and internalized copious amounts of Ad, with a distinct population of internalized Ad trafficking to the nucleus. The dose-response curves for inhibition of gene transfer revealed that FcgammaR-expressing cells required a more-than-10-fold higher concentration of anti-Ad serum to achieve 50% inhibition of Ad-encoded beta-galactosidase expression compared with non-FcgammaR-expressing cells. The discrepancy between neutralization of Ad during infection of FcgammaR-expressing cells and neutralization of Ad during infection of non-FcgammaR-expressing cells occurred with either heat-inactivated or non-heat-inactivated sera, was blocked by addition of purified Fc domain protein, and did not require the cytoplasmic domain of FcgammaR, suggesting that immune complex internalization proceeded via endocytosis rather than phagocytosis. FcgammaR-mediated infection by Ad-immune complexes did not require expression of the coxsackie virus-Ad receptor (CAR) since similar data were obtained when CAR-deficient human dermal fibroblasts were engineered to express FcgammaR. However, interaction of the Ad penton base with cell surface integrins contributed to the difference in neutralization between FcgammaR-expressing and non-FcgammaR-expressing cells. The data indicate that complexes formed from Ad and anti-Ad neutralizing antibodies, while compromised with respect to infection of non-FcgammaR-expressing target cells, maintain the potential to transfer genes to FcgammaR-expressing cells, with consequent expression of the transgene. The formation of Ad-immune complexes that can target viable virus to antigen-presenting cells may account for the success of Ad-based vaccines administered in the presence of low levels of neutralizing anti-Ad antibody.
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Affiliation(s)
- Philip L Leopold
- Weill Medical College of Cornell University, Department of Genetic Medicine, 1300 York Avenue, W401, New York, NY 10021, USA.
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Cotter MJ, Zaiss AK, Muruve DA. Neutrophils interact with adenovirus vectors via Fc receptors and complement receptor 1. J Virol 2006; 79:14622-31. [PMID: 16282462 PMCID: PMC1287577 DOI: 10.1128/jvi.79.23.14622-14631.2005] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Neutrophils are effectors of the innate immune response to adenovirus vectors. Following the systemic administration of Cy2-labeled AdLuc in mice, flow cytometry and PCR analysis of liver leukocytes revealed that 25% of recruited neutrophils interacted with adenovirus vectors. In vitro, flow cytometry of human neutrophils incubated with Cy2-labeled AdLuc also demonstrated a significant interaction with adenovirus vectors. Fluorescence and electron microscopy confirmed vector internalization by neutrophils. The AdLuc-neutrophil interaction reduced vector transduction efficiency by more than 50% in coincubation assays in epithelium-derived cells. Adenovirus vector uptake by neutrophils occurred independently of coxsackievirus adenovirus receptor (CAR) and capsid RGD motifs, since neutrophils do not express CAR and uptake of the RGD-deleted vector AdL.PB* was similar to that of AdLuc. Furthermore, both AdLuc and AdL.PB* activated neutrophils and induced similar degrees of L-selectin shedding. Neutrophil uptake of AdLuc was dependent on the presence of complement and antibodies, since the interaction between AdLuc and neutrophils was significantly reduced when they were incubated in immunoglobulin G-depleted or heat-inactivated human serum. Blocking of complement receptor 1 (CD35) but not complement receptor 3 (CD11b/CD18) significantly reduced neutrophil uptake of AdLuc. Blocking of Fc gammaRI (CD64), Fc gammaRII (CD32), and Fc gammaRIII (CD16) individually or together also reduced neutrophil uptake of AdLuc, although less than blocking of CD35 alone. Combined CR1 and Fc receptor blockade synergistically inhibited neutrophil-AdLuc interactions close to baseline. These results demonstrate opsonin-dependent adenovirus vector interactions with neutrophils and their corresponding receptors.
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Affiliation(s)
- Matthew J Cotter
- Department of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada
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Meier O, Gastaldelli M, Boucke K, Hemmi S, Greber UF. Early steps of clathrin-mediated endocytosis involved in phagosomal escape of Fcgamma receptor-targeted adenovirus. J Virol 2005; 79:2604-13. [PMID: 15681460 PMCID: PMC546601 DOI: 10.1128/jvi.79.4.2604-2613.2005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Adenovirus type 2 (Ad2) and Ad5 enter epithelial cells via the coxsackievirus B Ad receptor (CAR) and alpha(v) integrin coreceptors. In the absence of CAR, they can be directed to the Fcgamma receptor 1 of hematopoietic cells by an adaptor comprising the extracellular CAR domain and the Fc portion of a human immunoglobulin G (CARex-Fc). This gives rise to Ad aggregates and single particles which together enhance gene delivery up to 250-fold compared to adaptor-less viruses. A small interfering RNA knockdown of the clathrin heavy chain and quantitative electron microscopy of hematopoietic leukemia cells showed that the majority of Ads were phagocytosed as clusters of 1 to 3 microm in diameter and that about 10% of the particles entered cells by clathrin-mediated endocytosis. The clathrin knockdown did not affect phagocytosis but, surprisingly, inhibited viral escape from phagosomes. Similarly, blocking an early stage of clathrin-coated pit assembly inhibited phagosomal escape and infection but not aggregate uptake, unlike blocking of a late stage of clathrin-coated pit formation. We propose a cooperative interaction of clathrin-mediated endocytosis and phagocytosis triggering phagosomal lysis and infection.
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Affiliation(s)
- Oliver Meier
- Zoologisches Institut, University of Zürich, 8057 Zürich, Switzerland
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