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Kozlowski PA, Aldovini A. Mucosal Vaccine Approaches for Prevention of HIV and SIV Transmission. CURRENT IMMUNOLOGY REVIEWS 2019; 15:102-122. [PMID: 31452652 PMCID: PMC6709706 DOI: 10.2174/1573395514666180605092054] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 04/19/2018] [Accepted: 05/30/2018] [Indexed: 02/06/2023]
Abstract
Optimal protective immunity to HIV will likely require that plasma cells, memory B cells and memory T cells be stationed in mucosal tissues at portals of viral entry. Mucosal vaccine administration is more effective than parenteral vaccine delivery for this purpose. The challenge has been to achieve efficient vaccine uptake at mucosal surfaces, and to identify safe and effective adjuvants, especially for mucosally administered HIV envelope protein immunogens. Here, we discuss strategies used to deliver potential HIV vaccine candidates in the intestine, respiratory tract, and male and female genital tract of humans and nonhuman primates. We also review mucosal adjuvants, including Toll-like receptor agonists, which may adjuvant both mucosal humoral and cellular immune responses to HIV protein immunogens.
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Affiliation(s)
- Pamela A. Kozlowski
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
| | - Anna Aldovini
- Department of Medicine, and Harvard Medical School, Boston Children’s Hospital, Department of Pediatrics, Boston MA, 02115, USA
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2
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Poles J, Alvarez Y, Hioe CE. Induction of intestinal immunity by mucosal vaccines as a means of controlling HIV infection. AIDS Res Hum Retroviruses 2014; 30:1027-40. [PMID: 25354023 DOI: 10.1089/aid.2014.0233] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
CD4(+) T cells in the mucosa of the gastrointestinal (GI) tract are preferentially targeted and depleted by HIV. As such, the induction of an effective anti-HIV immune response in the mucosa of the GI tract-through vaccination-could protect this vulnerable population of cells. Mucosal vaccination provides a promising means of inducing robust humoral and cellular responses in the GI tract. Here we review data from the literature about the effectiveness of various mucosal vaccination routes--oral (intraintestinal/tonsilar/sublingual), intranasal, and intrarectal--with regard to the induction of immune responses mediated by cytotoxic T cells and antibodies in the GI mucosa, as well as protective efficacy in challenge models. We present data from the literature indicating that mucosal routes have the potential to effectively elicit GI mucosal immunity and protect against challenge. Given their capacity for the induction of anti-HIV immune responses in the GI mucosa, we propose that mucosal routes, including the nonconventional sublingual, tonsilar, and intrarectal routes, be considered for the delivery of the next generation HIV vaccines. However, further studies are necessary to determine the ideal vectors and vaccination regimens for these routes of immunization and to validate their efficacy in controlling HIV infection.
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Affiliation(s)
- Jordan Poles
- Department of Microbiology, New York University School of Medicine, New York, New York
| | - Yelina Alvarez
- VA New York Harbor Healthcare System–Manhattan Campus and Department of Pathology, New York University School of Medicine, New York, New York
| | - Catarina E. Hioe
- VA New York Harbor Healthcare System–Manhattan Campus and Department of Pathology, New York University School of Medicine, New York, New York
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3
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Regulatory T-cell vaccination independent of auto-antigen. Exp Mol Med 2014; 46:e82. [PMID: 24626168 PMCID: PMC3972794 DOI: 10.1038/emm.2014.4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Accepted: 12/06/2013] [Indexed: 12/21/2022] Open
Abstract
To date, efforts to treat autoimmune diseases have primarily focused on the disease symptoms rather than on the cause of the disease. In large part, this is attributed to not knowing the responsible auto-antigens (auto-Ags) for driving the self-reactivity coupled with the poor success of treating autoimmune diseases using oral tolerance methods. Nonetheless, if tolerogenic approaches or methods that stimulate regulatory T (Treg) cells can be devised, these could subdue autoimmune diseases. To forward such efforts, our approach with colonization factor antigen I (CFA/I) fimbriae is to establish bystander immunity to ultimately drive the development of auto-Ag-specific Treg cells. Using an attenuated Salmonella vaccine expressing CFA/I fimbriae, fimbriae-specific Treg cells were induced without compromising the vaccine's capacity to protect against travelers' diarrhea or salmonellosis. By adapting the vaccine's anti-inflammatory properties, it was found that it could also dampen experimental inflammatory diseases resembling multiple sclerosis (MS) and rheumatoid arthritis. Because of this bystander effect, disease-specific Treg cells are eventually induced to resolve disease. Interestingly, this same vaccine could elicit the required Treg cell subset for each disease. For MS-like disease, conventional CD25+ Treg cells are stimulated, but for arthritis CD39+ Treg cells are induced instead. This review article will examine the potential of treating autoimmune diseases without having previous knowledge of the auto-Ag using an innocuous antigen to stimulate Treg cells via the production of transforming growth factor-β and interleukin-10.
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Lewis GK. Live-attenuatedSalmonellaas a prototype vaccine vector for passenger immunogens in humans: are we there yet? Expert Rev Vaccines 2014; 6:431-40. [PMID: 17542757 DOI: 10.1586/14760584.6.3.431] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
It has been nearly 20 years since the first Phase I clinical trial of a live-attenuated bacterial vaccine was created by recombinant DNA methods, opening the door to the use of these organisms as mucosal delivery vehicles for passenger antigens. Over this time, a number of animal studies have indicated the feasibility of this approach. These include studies showing that bacteria can deliver antigens expressed by the bacterium itself and that bacteria can deliver DNA vaccines to be expressed in target eukaryotic cells. Concomitant studies have identified a number of attenuating mutations that render the bacterial vectors both safe and immunogenic in humans. Both avenues of research indicate the significant promise of this approach to mucosal vaccine development; however, this promise remains largely unrealized at the level of human clinical trials. This review sketches the history of this problem and points toward possible solutions using Salmonella vaccine vectors as the prototypes.
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Affiliation(s)
- George K Lewis
- Division of Basic Science and Vaccine Research, Institute of Human Virology, University of Maryland Biotechnology Institute and University of Maryland Baltimore, 725 W. Lombard Street, Baltimore, MD 21218, USA.
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Chin'ombe N, Ruhanya V. Recombinant Salmonella Bacteria Vectoring HIV/AIDS Vaccines. Open Virol J 2013; 7:121-6. [PMID: 24478808 PMCID: PMC3905348 DOI: 10.2174/1874357901307010121] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 11/13/2013] [Accepted: 11/18/2013] [Indexed: 11/29/2022] Open
Abstract
HIV/AIDS is an important public health problem globally. An affordable, easy-to-deliver and protective HIV
vaccine is therefore required to curb the pandemic from spreading further. Recombinant Salmonella bacteria can be
harnessed to vector HIV antigens or DNA vaccines to the immune system for induction of specific protective immunity.
These are capable of activating the innate, humoral and cellular immune responses at both mucosal and systemic
compartments. Several studies have already demonstrated the utility of live recombinant Salmonella in delivering
expressed foreign antigens as well as DNA vaccines to the host immune system. This review gives an overview of the
studies in which recombinant Salmonella bacteria were used to vector HIV/AIDS antigens and DNA vaccines. Most of
the recombinant Salmonella-based HIV/AIDS vaccines developed so far have only been tested in animals (mainly mice)
and are yet to reach human trials.
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Affiliation(s)
- Nyasha Chin'ombe
- Department of Medical Microbiology, University of Zimbabwe, Harare, Zimbabwe ; Division of Medical Virology, University of Cape Town, Cape Town, South Africa
| | - Vurayai Ruhanya
- Department of Medical Microbiology, University of Zimbabwe, Harare, Zimbabwe
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6
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Faisal SM, Yan F, Chen TT, Useh NM, Guo S, Yan W, Wang SJ, Glaser AL, McDonough SP, Singh B, Chang YF. Evaluation of a Salmonella vectored vaccine expressing Mycobacterium avium subsp. paratuberculosis antigens against challenge in a goat model. PLoS One 2013; 8:e70171. [PMID: 23950909 PMCID: PMC3739776 DOI: 10.1371/journal.pone.0070171] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 06/14/2013] [Indexed: 12/21/2022] Open
Abstract
Johnes disease (JD), caused by Mycobacterium avium subsp paratuberculosis (MAP), occurs worldwide as chronic granulomatous enteritis of domestic and wild ruminants. To develop a cost effective vaccine, in a previous study we constructed an attenuated Salmonella strain that expressed a fusion product made up of partial fragments of MAP antigens (Ag85A, Ag85B and SOD) that imparted protection against challenge in a mouse model. In the current study we evaluated the differential immune response and protective efficacy of the Sal-Ag vaccine against challenge in a goat model as compared to the live attenuated vaccine MAP316F. PBMCs from goats vaccinated with Sal-Ag and challenged with MAP generated significantly lower levels of IFN-γ, following in vitro stimulation with either Antigen-mix or PPD jhonin, than PBMC from MAP316F vaccinated animals. Flow cytometric analysis showed the increase in IFN-γ correlated with a significantly higher level of proliferation of CD4, CD8 and γδT cells and an increased expression of CD25 and CD45R0 in MAP316F vaccinated animals as compared to control animals. Evaluation of a range of cytokines involved in Th1, Th2, Treg, and Th17 immune responses by quantitative PCR showed low levels of expression of Th1 (IFN-γ, IL-2, IL-12) and proinflammatory cytokines (IL-6, IL-8, IL-18, TNF-α) in the Sal-Ag immunized group. Significant levels of Th2 and anti-inflammatory cytokines transcripts (IL-4, IL-10, IL-13, TGF-β) were expressed but their level was low and with a pattern similar to the control group. Over all, Sal-Ag vaccine imparted partial protection that limited colonization in tissues of some animals upon challenge with wild type MAP but not to the level achieved with MAP316F. In conclusion, the data indicates that Sal-Ag vaccine induced only a low level of protective immunity that failed to limit the colonization of MAP in infected animals. Hence the Sal-Ag vaccine needs further refinement to increase its efficacy.
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Affiliation(s)
- Syed M Faisal
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
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Pascual DW, Suo Z, Cao L, Avci R, Yang X. Attenuating gene expression (AGE) for vaccine development. Virulence 2013; 4:384-90. [PMID: 23652809 PMCID: PMC3714130 DOI: 10.4161/viru.24886] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Live attenuated vaccines are adept in stimulating protective immunity. Methods for generating such vaccines have largely adopted strategies used with Salmonella enterica. Yet, when similar strategies were tested in other gram-negative bacteria, the virulence factors or genes responsible to incapacitate Salmonella often failed in providing the desired outcome. Consequently, conventional live vaccines rely on prior knowledge of the pathogen's virulence factors to successfully attenuate them. This can be problematic since such bacterial pathogens normally harbor thousands of genes. To circumvent this problem, we found that overexpression of bacterial appendages, e.g., fimbriae, capsule, and flagella, could successfully attenuate wild-type (wt) Salmonella enterica serovar Typhimurium. Further analysis revealed these attenuated Salmonella strains conferred protection against wt S. Typhimurium challenge as effectively as genetically defined Salmonella vaccines. We refer to this strategy as attenuating gene expression (AGE), a simple efficient approach in attenuating bacterial pathogens, greatly facilitating the construction of live vaccines.
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Affiliation(s)
- David W Pascual
- Department of Infectious Diseases and Pathology, College of Veterinary Medicine, University of Florida, Gainesville, FL USA.
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8
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Chandra S, Faisal SM, Chen JW, Chen TT, McDonough SP, Liu S, Moreira MAS, Akey BL, Chang CF, Chang YF. Immune response and protective efficacy of live attenuated Salmonella vaccine expressing antigens of Mycobacterium avium subsp. paratuberculosis against challenge in mice. Vaccine 2012; 31:242-51. [PMID: 23000222 DOI: 10.1016/j.vaccine.2012.09.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 08/31/2012] [Accepted: 09/10/2012] [Indexed: 11/25/2022]
Abstract
Mycobacterium avium subsp. paratuberculosis (MAP) causes chronic granulomatous enteritis in ruminants that leads to diarrhea and eventually death. Existing vaccines have proven useful in limiting disease progression but have not been effective in preventing infection. To address this problem we constructed an attenuated Salmonella (ΔyejE; ΔssaV) strain harboring a plasmid that expressed a fusion protein comprised of the Salmonella Type III secretion system (T3SS) effector SopE and MAP antigens (85A, 85B, SOD, 74F) and evaluated its potential as vaccine candidate against MAP infection in mice. Of various SopE-MAP fusion proteins analyzed, only SopE104-Ag85A C-terminal(202-347)-SOD N-terminal(1-72)-Ag85B C-terminal(173-330) and SopE104-74F(1-148+669-786)were successfully expressed and secreted into culture media as revealed by western blot analysis. Mice immunized with attenuated Salmonella (ΔyejE; ΔssaV) harboring the SopE104-Ag85A C-terminal(202-347)-SOD N-terminal(1-72)-Ag85B C-terminal(173-330) and SopE104-74F(1-148+669-786)plasmid generated a potent and long lasting Th1 response characterized by production of IFN-γ. The cytokine profile varied at various time points after immunization and challenge, which showed down regulation of Th2 cytokines (IL-4, IL-10) and up-regulation of proinflammatory cytokines (IL-12 and IL-17). Further, the immune response correlated with protection as revealed by reduced bacterial load and improved histopathology of spleen and liver, which showed fewer granulomas and lower numbers of acid-fast bacilli as compared to PBS controls. Interestingly, vaccination with antigens mixed with Ribi adjuvant (Agmix+Ribi) imparted better protection than the attenuated salmonella vectored vaccine. Thus, priming with a live recombinant Salmonella strain that secretes MAP antigens represents a promising approach that could lead to development of an efficacious and cost effective vaccine for Johne's disease.
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Affiliation(s)
- Subhash Chandra
- Department of Population Medicine and Diagnostic Sciences, Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
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9
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Abstract
Efforts to make vaccines against infectious diseases as well as immunotherapies for cancer, autoimmune diseases and allergy have utilized a variety of heterologous expression systems, including viral and bacterial vectors, as well as DNA and RNA constructs. This review explores the immunologic rationale and provides an update of insights obtained from preclinical and clinical studies of such vaccines.
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Bachtiar EW, Coloe PJ, Smooker PM. Construction and immunogenicity of Salmonella vaccine vector expressing HIV-1 antigen and MCP3. Acta Microbiol Immunol Hung 2009; 56:403-15. [PMID: 20038492 DOI: 10.1556/amicr.56.2009.4.10] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
UNLABELLED This study aims to determine the efficacy of Salmonella enterica serovar Typhimurium STM-1 bearing MCP-3 gene as a delivery vehicle for the HIV gag gene (in particular p24 gene) and HIV env gene. The STM1 delivery HIV-p24 vaccination was carried out in the form of a recombinant or a DNA vaccine whereas only a DNA vaccine was used for HIV env . Naked DNA vaccination was also tested and immune responses were evaluated following immunisation in mouse model. RESULTS vaccination cellular immune responses induced by recombinant p24 STM1 (STM1/pHly-p24) were greater than those elicited by the p24 DNA vaccine in STM1 (STM1/VR-p24), (but statistically not significant) than those induced by oral vaccination. However, IgA responses induced by oral vaccination with either a recombinant or DNA vaccine of p24 in STM1 are higher than those induced by IP vaccination. In addition, the numbers of cells secreting IL4 are reduced after oral vaccination with STM1/VR-p24/MCP3. However, for the HIV p24 antigen, STM1/MCP3 preferentially induces IFNgamma-secreting splenocytes. CONCLUSIONS This result confirms other studies that Salmonella was able to deliver HIV antigens to the immune system and induced specific immune responses to the HIV antigen and for the HIV p24 antigen, STM1/MCP3 induces secretion of IFNgamma.
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Affiliation(s)
- E W Bachtiar
- Biotechnology and Environmental Biology, RMIT University, Victoria, Australia.
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Abstract
It has been demonstrated that HIV-1 gp120 resembles several important properties of immunoglobulins allowing it strong influence on the human immune system, especially through induction of the deceptive imprinting and deregulation of the immune network. On the other hand there are many unanswered questions concerning properties and control of the genetically modified viruses and bacteria used as vectors in AIDS vaccines. This situation opens a serious question about the safety of vectored AIDS vaccine and the ethics of their trials in humans.
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Affiliation(s)
- Veljko Veljkovic
- Center for Multidisciplinary Research, Institute of Nuclear Sciences VINCA, Belgrade, Yugoslavia.
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12
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Chin'ombe N, Bourn WR, Williamson AL, Shephard EG. Oral vaccination with a recombinant Salmonella vaccine vector provokes systemic HIV-1 subtype C Gag-specific CD4+ Th1 and Th2 cell immune responses in mice. Virol J 2009; 6:87. [PMID: 19555490 PMCID: PMC2708135 DOI: 10.1186/1743-422x-6-87] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Accepted: 06/25/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Recombinant Salmonella vaccine vectors may potentially be used to induce specific CD4+ T cell responses against foreign viral antigens. Such immune responses are required features of vaccines against pathogens such as human immunodeficiency virus type 1 (HIV-1). The aim of this study was to investigate the induction of systemic HIV-1-specific CD4+ T helper (Th) responses in mice after oral immunization with a live attenuated Salmonella vaccine vector that expressed HIV-1 subtype C Gag. Groups of BALB/c mice were vaccinated orally three times (4 weeks apart) with this recombinant Salmonella. At sacrifice, 28 days after the last immunization, systemic CD4+ Th1 and Th2 cytokine responses were evaluated by enzyme-linked immunospot assay and cytometric bead array. HIV-1 Gag-specific IgG1 and IgG2a humoral responses in the serum were determined by enzyme-linked immunosorbent assay. RESULTS Mice vaccinated with the recombinant Salmonella elicited both HIV-1-specific Th1 (interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha)) and Th2 (interleukin-4 (IL-4) and interleukin-5 (IL-5)) cytokine responses. The vaccine induced 70 (IFN-gamma) spot-forming units (SFUs)/10e(6) splenocytes and 238 IL-4 SFUs/10e(6) splenocytes. Splenocytes from vaccinated mice also produced high levels of Th1 and Th2 cytokines upon stimulation with a Gag CD4 peptide. The levels of IFN-gamma, TNF-alpha, IL-4 and IL-5 were 7.5-, 29.1-, 26.2- and 89.3-fold above the background, respectively. Both HIV-1 Gag-specific IgG1 and IgG2a antibodies were detected in the sera of vaccinated mice. CONCLUSION The study highlights the potential of orally-delivered attenuated Salmonella as mucosal vaccine vectors for HIV-1 Subtype C Gag to induce Gag-specific CD4+ Th1 and Th2 cellular immune responses and antibodies which may be important characteristics required for protection against HIV-1 infection.
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Affiliation(s)
- Nyasha Chin'ombe
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Observatory 7925, Cape Town, South Africa.
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Affiliation(s)
- Camille N Kotton
- Infectious Diseases Division, Massachusetts General Hospital, Boston, Massachusetts 02114, USA.
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Dunstan SJ, Simmons CP, Strugnell RA. In vitro and in vivo stability of recombinant plasmids in a vaccine strain of Salmonella enterica var. Typhimurium. FEMS IMMUNOLOGY AND MEDICAL MICROBIOLOGY 2003; 37:111-9. [PMID: 12832114 DOI: 10.1016/s0928-8244(03)00065-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This study examined the ability of different plasmid vectors encoding H(C) fragment, the non-toxic binding portion of tetanus toxin, to be stably retained by Salmonella enterica var. Typhimurium (Salmonella typhimurium) vaccine strain BRD509 and, upon immunisation, to induce an antibody response against the carried antigen. The H(C) fragment expression cassette containing the transcription/translation signals, H(C) fragment open reading frame and the downstream TrpA terminator, was excised from pTETtac4 and incorporated into the plasmids pIC20H, pBR322, pACYC184 and pRSF1010. The resulting constructs were transferred into attenuated S. typhimurium, BRD509, and the level of H(C) fragment expression was examined by Western blot analysis. The relative stability of each plasmid in S. typhimurium was determined in vitro in the absence of antibiotic selection, and in vivo following immunisation. The ability of each H(C) fragment-expressing strain to induce lipopolysaccharide- and tetanus toxoid-specific antibody responses was assayed by an enzyme-linked immunosorbent assay. These studies showed that all the vaccine vector constructs, except the S. typhimurium carrying the expression vector based on pIC20H, were able to elicit a high titre immune response. The level of tetanus toxoid-specific antibody induced by S. typhimurium directly correlated with the level of in vitro and in vivo stability of the H(C) fragment expression plasmid carried by the bacterium, and not with an increased copy number of the parent plasmid vector.
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Affiliation(s)
- Sarah J Dunstan
- Department of Microbiology and Immunology, The University of Melbourne, Parkville, Vic. 3052, Australia
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Abstract
Twenty years after the discovery of HIV, there is still no vaccine. This year, an envelope vaccine aimed at stimulating neutralizing antibodies was unable to protect against infection in phase 3 trials. But more than 20 HIV vaccines designed to stimulate T-cell responses are being developed. Will any of them work?
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Affiliation(s)
- Andrew J McMichael
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford OX3 9D5, UK.
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Abstract
HIV/AIDS has become the most devastating pandemic in recorded history. It has killed 40 million people in the last 20 years and the World Health Organisation estimated that at least 14,000 new infections occurred daily in 2001. There will be up to 100 million new infections in the next 10 years (for current updates, visit http://www.unaids.org/epidemic_update/). Most HIV infections occur in the developing world, and the adverse social and economic impact of the HIV/AIDS pandemic, particularly in the developing world, is unprecedented. Highly active antiretroviral therapy (HAART) has had significant effects on HIV/AIDS in the developed world. The drugs have acted to prolong survival, reduce the viral load, and to alleviate suffering. However, the incidence of side effects and resistance is high and the drugs are unaffordable and unavailable in the developing world. HAART regimens are difficult to comply with. Public health efforts to modify the behaviour, attitude and culture that accelerate the spread of HIV/AIDS have had only modest success. There is urgent need for a prophylactic and/or therapeutic HIV vaccine. This is a review of the obstacles and current trends in HIV vaccine development.
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Affiliation(s)
- Matilu Mwau
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
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17
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Garmory HS, Brown KA, Titball RW. Salmonella vaccines for use in humans: present and future perspectives. FEMS Microbiol Rev 2002; 26:339-53. [PMID: 12413664 DOI: 10.1111/j.1574-6976.2002.tb00619.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
In recent years there has been significant progress in the development of attenuated Salmonella enterica serovar Typhi strains as candidate typhoid fever vaccines. In clinical trials these vaccines have been shown to be well tolerated and immunogenic. For example, the attenuated S. enterica var. Typhi strains CVD 908-htrA (aroC aroD htrA), Ty800 (phoP phoQ) and chi4073 (cya crp cdt) are all promising candidate typhoid vaccines. In addition, clinical trials have demonstrated that S. enterica var. Typhi vaccines expressing heterologous antigens, such as the tetanus toxin fragment C, can induce immunity to the expressed antigens in human volunteers. In many cases, the problems associated with expression of antigens in Salmonella have been successfully addressed and the future of Salmonella vaccine development is very promising.
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Affiliation(s)
- Helen S Garmory
- Department of Biomedical Sciences, Dstl Chemical and Biological Sciences, Porton Down, Salisbury SP4 0JQ, UK.
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18
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Affiliation(s)
- A M Schultz
- International AIDS Vaccine Initiative, New York, New York, USA.
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19
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Devico AL, Fouts TR, Shata MT, Kamin-Lewis R, Lewis GK, Hone DM. Development of an oral prime-boost strategy to elicit broadly neutralizing antibodies against HIV-1. Vaccine 2002; 20:1968-74. [PMID: 11983256 DOI: 10.1016/s0264-410x(02)00080-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Given the increasing incidence of HIV-1 infection world-wide, an affordable, effective vaccine is probably the only way that this virus will be contained. Accordingly, our group is developing an oral prime-boost strategy with the primary goal of eliciting broadly neutralizing antibodies against HIV-1 to provide sterilizing immunity for this virus. Our secondary goal is to elicit broadly cross-reactive anti-viral CD8(+) T cells by this strategy to blunt any breakthrough infections that occur after vaccination of individuals who fail to develop sterilizing immunity. This article describes our progress in the use of the live attenuated intracellular bacteria, Salmonella and Shigella, as oral delivery vehicles for DNA vaccines and the development of conformationally constrained HIV-1 Env immunogens that elicit broadly neutralizing antibodies.
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MESH Headings
- AIDS Vaccines/administration & dosage
- AIDS Vaccines/immunology
- Administration, Oral
- Animals
- Bacterial Vaccines/administration & dosage
- Bacterial Vaccines/immunology
- CD4 Antigens/chemistry
- CD4 Antigens/metabolism
- CD8-Positive T-Lymphocytes/immunology
- HIV Antibodies/biosynthesis
- HIV Antibodies/immunology
- HIV Envelope Protein gp120/chemistry
- HIV Envelope Protein gp120/immunology
- HIV Envelope Protein gp120/metabolism
- HIV-1/immunology
- Humans
- Immunity, Mucosal
- Immunization, Secondary
- Macaca mulatta
- Mice
- Models, Molecular
- Protein Conformation
- Protein Interaction Mapping
- Protein Structure, Tertiary
- Receptors, CCR5/metabolism
- Recombinant Fusion Proteins/chemistry
- Recombinant Fusion Proteins/immunology
- Salmonella typhi/immunology
- Salmonella typhimurium/immunology
- Shigella flexneri/immunology
- Vaccination/methods
- Vaccines, Attenuated/administration & dosage
- Vaccines, Attenuated/immunology
- Vaccines, DNA/administration & dosage
- Vaccines, DNA/immunology
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Affiliation(s)
- Anthony L Devico
- Division of Vaccine Research, Institute of Human Virology, University of Maryland Biotechnology Institute, 725 W. Lombard Street, Baltimore, MD 21201, USA
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20
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Shata MT, Hone DM. Vaccination with a Shigella DNA vaccine vector induces antigen-specific CD8(+) T cells and antiviral protective immunity. J Virol 2001; 75:9665-70. [PMID: 11559798 PMCID: PMC114537 DOI: 10.1128/jvi.75.20.9665-9670.2001] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A prototype Shigella human immunodeficiency virus type 1 (HIV-1) gp120 DNA vaccine vector was constructed and evaluated for immunogenicity in a murine model. For comparative purposes, mice were also vaccinated with a vaccinia virus-env (vaccinia-env) vector or the gp120 DNA vaccine alone. Enumeration of the CD8(+)-T-cell responses to gp120 after vaccination using a gamma interferon enzyme-linked spot assay revealed that a single intranasal dose of the Shigella HIV-1 gp120 DNA vaccine vector elicited a CD8(+) T-cell response to gp120, the magnitude of which was comparable to the sizes of the analogous responses to gp120 that developed in mice vaccinated intraperitoneally with the vaccinia-env vector or intramuscularly with the gp120 DNA vaccine. In addition, a single dose of the Shigella gp120 DNA vaccine vector afforded significant protection against a vaccinia-env challenge. Moreover, the number of vaccinia-env PFU recovered in mice vaccinated intranasally with the Shigella vector was about fivefold less than the number recovered from mice vaccinated intramuscularly with the gp120 DNA vaccine. Since the Shigella vector did not express detectable levels of gp120, this report confirms that Shigella vectors are capable of delivering passenger DNA vaccines to host cells and inducing robust CD8(+) T-cell responses to antigens expressed by the DNA vaccines. Furthermore, to our knowledge, this is the first documentation of antiviral protective immunity following vaccination with a live Shigella DNA vaccine vector.
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Affiliation(s)
- M T Shata
- Division of Vaccine Research, Institute of Human Virology, University of Maryland Biotechnology Institute, Baltimore, Maryland 21201, USA
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21
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Carbonetti NH, Tuskan RG, Lewis GK. Stimulation of HIV gp120-specific cytolytic T lymphocyte responses in vitro and in vivo using a detoxified pertussis toxin vector. AIDS Res Hum Retroviruses 2001; 17:819-27. [PMID: 11429123 DOI: 10.1089/088922201750252016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
CD8+ cytolytic T lymphocytes (CTL) are almost certainly an important component of a potentially protective immune response to HIV. To test the ability of pertussis toxin (PT) to deliver an HIV-derived major histocompatibility complex (MHC) class I peptide for CTL stimulation, we constructed a fusion of the gp120 P18-I10 CTL epitope with a genetically detoxified derivative of PT (PT9K/129G) and assayed this fusion for its ability to stimulate a gp120-specific CTL response in vitro and in vivo. Antigen-presenting cells incubated with this fusion protein were lysed by P18-I10-specific CTL in vitro and this activity was shown to be MHC class I restricted. The activity was inhibited by brefeldin A but was not inhibited by proteasome inhibitors, possibly because PT undergoes retrograde intracellular transport through the Golgi apparatus to the endoplasmic reticulum and delivers epitopes directly to nascent class I molecules. Mice immunized intraperitoneally with a single dose of the fusion protein without adjuvant raised a strong gp120-specific CTL response in the spleen. This CTL response was dependent on (1) the dose of fusion administered, (2) the fusion of the epitope with the toxin (since coadministration of peptide and toxin gave no response), and (3) the activity of CD8+ cells. These data demonstrate that this detoxified derivative to PT, which is already a component of a licensed vaccine for humans, could represent a useful vaccine vector molecule for stimulation of HIV-specific CTL responses.
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Affiliation(s)
- N H Carbonetti
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
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22
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Pascual DW, Hone DM, Hall S, van Ginkel FW, Yamamoto M, Walters N, Fujihashi K, Powell RJ, Wu S, Vancott JL, Kiyono H, McGhee JR. Expression of recombinant enterotoxigenic Escherichia coli colonization factor antigen I by Salmonella typhimurium elicits a biphasic T helper cell response. Infect Immun 1999; 67:6249-56. [PMID: 10569734 PMCID: PMC97026 DOI: 10.1128/iai.67.12.6249-6256.1999] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Protective immunity to enterotoxigenic Escherichia coli (ETEC) is antibody (Ab) dependent; however, oral immunization with purified ETEC fimbriae fails to elicit protective immunity as a consequence of antigenic alteration by the gastrointestinal (GI) tract. Unless unaltered ETEC fimbriae can reach the inductive lymphoid tissues of the GI tract, immunity to ETEC cannot be induced. To produce immunity, live vectors, such as Salmonella typhimurium, can effectively target passenger antigens to the inductive lymphoid tissues of the GI tract. By convention, oral immunizations with Salmonella vectors induce CD4(+) T helper (Th) cell responses by gamma interferon (IFN-gamma)-dominated pathways both to the vector and passenger antigen, resulting in serum immunoglobulin G2a (IgG2a) and modest mucosal IgA Ab responses. In the present study, mice orally immunized with a Salmonella vector engineered to stably express ETEC colonization factor antigen I (CFA/I) showed initially elevated serum IgG1 and mucosal IgA anti-CFA/I Ab responses. As expected, mice orally immunized with an E. coli-CFA/I construct elicited poor anti-CFA/I Ab responses. In fact, the addition of cholera toxin during oral E. coli-CFA/I immunization failed to greatly enhance mucosal IgA Ab responses. Seven days after immunization with the Salmonella-CFA/I construct, cytokine-specific ELISPOT showed induction of predominant Th2-type responses in both mucosal and systemic immune compartments supporting the early IgG1 and IgA anti-CFA/I Abs. By 4 weeks, the Th cell response became Th1 cell dominant from the earlier Th2-type responses, as evidenced by increased mucosal and systemic IFN-gamma-producing T cells and a concomitant elevation of serum IgG2a Ab responses. This biphasic response offers an alternative strategy for directing Salmonella vector-induced host immunity along a Th2 cell-dependent pathway, allowing for early promotion of mucosal and systemic Abs.
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Affiliation(s)
- D W Pascual
- Veterinary Molecular Biology, Montana State University, Bozeman, Montana 59717-3610, USA.
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23
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Fromen-Romano C, Drevet P, Robert A, Ménez A, Léonetti M. Recombinant Staphylococcus strains as live vectors for the induction of neutralizing anti-diphtheria toxin antisera. Infect Immun 1999; 67:5007-11. [PMID: 10496871 PMCID: PMC96846 DOI: 10.1128/iai.67.10.5007-5011.1999] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have investigated whether the nonpathogenic gram-positive bacteria Staphylococcus xylosus and S. carnosus can display a whole domain of a toxic protein on their surface and if such vectors are suitable for immunization of BALB/c mice. The nucleotide sequence encoding the receptor-binding domain (DTR; amino acids 382 to 535) of diphtheria toxin (DT) was inserted into plasmids pSE'mp18ABPXM and pSPPmABPXM, which were designed to display heterologous proteins on S. xylosus and S. carnosus cell surfaces, respectively. Western blot analysis of the resulting bacterial lysates indicates that DTR is produced by each expression system. However, analysis of rabbit anti-DTR antisera binding to the transformed live bacteria shows that DTR is not displayed on the surface of S. xylosus cells whereas it is efficiently exposed on S. carnosus. A significant anti-DT antibody response was raised in BALB/c mice immunized intraperitoneally with S. carnosus displaying DTR, and the antisera abolished DT cytotoxicity on Vero cells. Thus, only S. carnosus can display a whole domain of a toxic protein and represents a potential vector for humoral vaccination.
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Affiliation(s)
- C Fromen-Romano
- CEA, Département d'Ingénierie et d'Etudes des Protéines (DIEP), Centre d'Etude de Saclay, 91191 Gif-Sur-Yvette Cedex, France
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24
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Pasetti MF, Anderson RJ, Noriega FR, Levine MM, Sztein MB. Attenuated deltaguaBA Salmonella typhi vaccine strain CVD 915 as a live vector utilizing prokaryotic or eukaryotic expression systems to deliver foreign antigens and elicit immune responses. Clin Immunol 1999; 92:76-89. [PMID: 10413655 DOI: 10.1006/clim.1999.4733] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Attenuated Salmonella typhi strain CVD 915, harboring a deletion in guaBA that interrupts the biosynthesis of guanine nucleotides, was evaluated as a live vector vaccine for delivering foreign antigens utilizing prokaryotic or eukaryotic expression systems. Plasmids pTETnir15 and pcDNA3tetC encoding fragment C (Frag C) of tetanus toxin under the control of prokaryotic or eukaryotic promoters, respectively, were introduced into CVD 915 and administered intranasally to mice. Purified pcDNA3tetC and Frag C were given intramuscularly. High titers of serum IgG1, IgG2a, and IgG2b antibodies against Frag C were elicited by CVD 915(pTETnir15) and CVD 915(pcDNA3tetC). These responses were significantly higher than those induced by pcDNA3tetC. Proliferative responses and IL-2 and IFN-gamma production were observed in splenocytes exposed to S. typhi antigens and Frag C. We conclude that CVD 915 is a highly efficient live vector to carry foreign genes under eukaryotic or prokaryotic control and elicit potent immune responses.
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Affiliation(s)
- M F Pasetti
- Department of Pediatrics, University of Maryland, School of Medicine, Baltimore, Maryland 21201, USA
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25
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Wu S, Pascual DW, Lewis GK, Hone DM. Induction of mucosal and systemic responses against human immunodeficiency virus type 1 glycoprotein 120 in mice after oral immunization with a single dose of a Salmonella-HIV vector. AIDS Res Hum Retroviruses 1997; 13:1187-94. [PMID: 9310285 DOI: 10.1089/aid.1997.13.1187] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Previous studies from our group showed that a Salmonella-HIV vector vaccine that expressed recombinant HIV-1 envelope protein gp120 stably in the vector cytoplasm elicited type 1 helper T cell (Th1) responses to gp120. Despite the promise of such vaccines, a major limitation in their use was that multiple immunizations were required to elicit even small responses. For this reason, we sought a modified vector configuration that would induce more potent gp120-specific T cell responses exhibiting a broader spectrum of effector functions after a single inoculation. In this article we describe the construction and immunogenicity of a Salmonella-HIV vector that displays a truncated derivative of HIV-1(IIIB) envelope in the periplasm of the vector. A single oral dose of this Salmonella vector, called H683(pW58-asd+), generated a gp120-specific proliferation response in the spleen 14 days after immunization. In agreement with our previous findings, the gp120-specific splenic CD4+ T cells elicited by H683(pW58-asd+) displayed a Th1 phenotype; however, gp120-specific splenic CD4+ Th2 cells were also evident. In addition, this strain induced strong gp120-specific IgA antibody-secreting cell (ASC) responses in the intestinal lamina propria and mesenteric lymph nodes. As many as 2% of the total lamina propria and mesenteric lymph node IgA ASCs were found to be specific for gp120 28 days after a single oral dose of H683(pW57-asd+). Because the proliferative response following a single dose of H683(pW58-asd+) was comparable to that seen previously after three doses of an analogous construct expressing recombinant gp120 in the cytoplasm, these observations suggest that Salmonella-vectored secreted HIV-1 antigens elicit higher T cell responses than their cytoplasmically bound analogs.
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Affiliation(s)
- S Wu
- Division of Infectious Diseases and Gastroenterology, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21202, USA
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Affiliation(s)
- S Russo
- Institute of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Milan, Italy
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Mann BJ, Burkholder BV, Lockhart LA. Protection in a gerbil model of amebiasis by oral immunization with Salmonella expressing the galactose/N-acetyl D-galactosamine inhibitable lectin of Entamoeba histolytica. Vaccine 1997; 15:659-63. [PMID: 9178467 DOI: 10.1016/s0264-410x(96)00236-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Infection with the enteric parasite Entamoeba histolytica can result in colitis and dysentery as well as abscesses at extra-intestinal sites. An effective vaccine must be able to protect against both mucosal and systemic disease. In this study an attenuated Salmonella strain that expressed a portion of the GalNAc lectin of E, histolytica was used to orally immunize gerbils. Animals were challenged by intrahepatic injection of amebic trophozoites. A significant decrease in size of amebic liver abscesses was observed in orally immunized animals. Oral immunization with a Salmonella-based vaccine was as effective as systemic immunization for protection against systemic challenge.
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Affiliation(s)
- B J Mann
- Department of Internal Medicine, University of Virginia, School of Medicine, Charlottesville 22908, USA
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28
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Hone DM, Wu S, Powell RJ, Pascual DW, Van Cott J, McGhee J, Fouts TR, Tuskan RG, Lewis GK. Optimization of live oral Salmonella-HIV-1 vaccine vectors for the induction of HIV-specific mucosal and systemic immune responses. J Biotechnol 1996; 44:203-7. [PMID: 8717405 DOI: 10.1016/0168-1656(95)00151-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Recent evidence suggests that live oral Salmonella-HIV vaccine vectors have the potential to elicit HIV-specific T cell-mediated immunity in both the mucosal and systemic compartments. We are using the mouse-typhoid model to identify Salmonella::HIV vaccine vector constructs that elicit HIV-specific mucosal and systemic immune responses. Oral immunization of mice with a Salmonella strain that expresses recombinant gp120 (rgp120) in the cytoplasm of the vector elicits a modest gp120-specific T cell proliferation response in the spleen. However, such Salmonella constructs did not stimulate the development of gp120-specific serum IgG or cytotoxic T lymphocytes (CTLs). Interestingly, the majority of cytoplasmically-expressed rgp120 forms inclusion bodies in Salmonella. We believe that in this form rgp120 is highly susceptible to protease degradation by the vector. As such, cytoplasmic rgp120 may not persist in the host after vaccination, resulting in the modest immunogenicity of rgp120 in these constructs. To circumvent this problem we constructed Salmonella strains that express rgp120 on the surface of the vector. Preliminary data suggest that surface-expressed rgp120 is significantly more immunogenic in both the mucosal and systemic compartments than cytoplasmic rgp120. These results, therefore, support the proposal that Salmonella vectors will be a safe and inexpensive means for delivery of HIV antigens to, and the elicitation of HIV-specific T cells in, the mucosal and systemic compartments.
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Affiliation(s)
- D M Hone
- Vaccine Vector Group, School of Medicine, University of Maryland at Baltimore, USA
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