1
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Sui Y, Meyer TJ, Fennessey CM, Keele BF, Dadkhah K, Ma C, LaBranche CC, Breed MW, Kramer JA, Li J, Howe SE, Ferrari G, Williams LD, Cam M, Kelly MC, Shen X, Tomaras GD, Montefiori D, Greten TF, Miller CJ, Berzofsky JA. Innate protection against intrarectal SIV acquisition by a live SHIV vaccine. JCI Insight 2024; 9:e175800. [PMID: 38912579 DOI: 10.1172/jci.insight.175800] [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: 09/15/2023] [Accepted: 05/08/2024] [Indexed: 06/25/2024] Open
Abstract
Identifying immune correlates of protection is a major challenge in AIDS vaccine development. Anti-Envelope antibodies have been considered critical for protection against SIV/HIV (SHIV) acquisition. Here, we evaluated the efficacy of an SHIV vaccine against SIVmac251 challenge, where the role of antibody was excluded, as there was no cross-reactivity between SIV and SHIV envelope antibodies. After 8 low-dose intrarectal challenges with SIVmac251, 12 SHIV-vaccinated animals demonstrated efficacy, compared with 6 naive controls, suggesting protection was achieved in the absence of anti-envelope antibodies. Interestingly, CD8+ T cells (and some NK cells) were not essential for preventing viral acquisition, as none of the CD8-depleted macaques were infected by SIVmac251 challenges. Initial investigation of protective innate immunity revealed that protected animals had elevated pathways related to platelet aggregation/activation and reduced pathways related to interferon and responses to virus. Moreover, higher expression of platelet factor 4 on circulating platelet-leukocyte aggregates was associated with reduced viral acquisition. Our data highlighted the importance of innate immunity, identified mechanisms, and may provide opportunities for novel HIV vaccines or therapeutic strategy development.
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Affiliation(s)
| | - Thomas J Meyer
- CCR Collaborative Bioinformatics Resource, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | | | | | - Kimia Dadkhah
- Single Cell Analysis Facility, Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Chi Ma
- Thoracic and GI Malignancies Branch, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | - Celia C LaBranche
- Duke Human Vaccine Institute and
- Department of Surgery, Duke University School of Medicine, Durham, North Carolina, USA
| | - Matthew W Breed
- Laboratory Animal Sciences Program, Frederick National Laboratory for Cancer Research, Bethesda, Maryland, USA
| | - Josh A Kramer
- Laboratory Animal Sciences Program, Frederick National Laboratory for Cancer Research, Bethesda, Maryland, USA
| | | | | | | | - LaTonya D Williams
- Duke Human Vaccine Institute and
- Department of Surgery, Duke University School of Medicine, Durham, North Carolina, USA
- Duke Center for Human Systems Immunology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Maggie Cam
- CCR Collaborative Bioinformatics Resource, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | - Michael C Kelly
- Single Cell Analysis Facility, Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Xiaoying Shen
- Duke Human Vaccine Institute and
- Department of Surgery, Duke University School of Medicine, Durham, North Carolina, USA
- Duke Center for Human Systems Immunology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Georgia D Tomaras
- Duke Human Vaccine Institute and
- Department of Surgery, Duke University School of Medicine, Durham, North Carolina, USA
- Duke Center for Human Systems Immunology, Duke University School of Medicine, Durham, North Carolina, USA
| | - David Montefiori
- Duke Human Vaccine Institute and
- Department of Surgery, Duke University School of Medicine, Durham, North Carolina, USA
| | - Tim F Greten
- Thoracic and GI Malignancies Branch, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | - Christopher J Miller
- Center for Comparative Medicine, University of California, Davis, Davis, California, USA
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2
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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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3
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Simian Immunodeficiency Virus Targeting of CXCR3 + CD4 + T Cells in Secondary Lymphoid Organs Is Associated with Robust CXCL10 Expression in Monocyte/Macrophage Subsets. J Virol 2017; 91:JVI.00439-17. [PMID: 28424283 DOI: 10.1128/jvi.00439-17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 04/11/2017] [Indexed: 01/12/2023] Open
Abstract
Glycosylation of Env defines pathogenic properties of simian immunodeficiency virus (SIV). We previously demonstrated that pathogenic SIVmac239 and a live-attenuated, quintuple deglycosylated Env mutant (Δ5G) virus target CD4+ T cells residing in different tissues during acute infection. SIVmac239 and Δ5G preferentially infected distinct CD4+ T cells in secondary lymphoid organs (SLOs) and within the lamina propria of the small intestine, respectively (C. Sugimoto et al., J Virol 86:9323-9336, 2012, https://doi.org/10.1128/JVI.00948-12). Here, we studied the host responses relevant to SIV targeting of CXCR3+ CCR5+ CD4+ T cells in SLOs. Genome-wide transcriptome analyses revealed that Th1-polarized inflammatory responses, defined by expression of CXCR3 chemokines, were distinctly induced in the SIVmac239-infected animals. Consistent with robust expression of CXCL10, CXCR3+ T cells were depleted from blood in the SIVmac239-infected animals. We also discovered that elevation of CXCL10 expression in blood and SLOs was secondary to the induction of CD14+ CD16+ monocytes and MAC387+ macrophages, respectively. Since the significantly higher levels of SIV infection in SLOs occurred with a massive accumulation of infiltrated MAC387+ macrophages, T cells, dendritic cells (DCs), and residential macrophages near high endothelial venules, the results highlight critical roles of innate/inflammatory responses in SIVmac239 infection. Restricted infection in SLOs by Δ5G also suggests that glycosylation of Env modulates innate/inflammatory responses elicited by cells of monocyte/macrophage/DC lineages.IMPORTANCE We previously demonstrated that a pathogenic SIVmac239 virus and a live-attenuated, deglycosylated mutant Δ5G virus infected distinct CD4+ T cell subsets in SLOs and the small intestine, respectively (C. Sugimoto et al., J Virol 86:9323-9336, 2012, https://doi.org/10.1128/JVI.00948-12). Accordingly, infections with SIVmac239, but not with Δ5G, deplete CXCR3+ CCR5+ CD4+ T (Th1) cells during the primary infection, thereby compromising the cellular immune response. Thus, we hypothesized that distinct host responses are elicited by the infections with two different viruses. We found that SIVmac239 induced distinctly higher levels of inflammatory Th1 responses than Δ5G. In particular, SIVmac239 infection elicited robust expression of CXCL10, a chemokine for CXCR3+ cells, in CD14+ CD16+ monocytes and MAC387+ macrophages recently infiltrated in SLOs. In contrast, Δ5G infection elicited only modest inflammatory responses. These results suggest that the glycosylation of Env modulates the inflammatory/Th1 responses through the monocyte/macrophage subsets and elicits marked differences in SIV infection and clinical outcomes.
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4
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Berry N, Manoussaka M, Ham C, Ferguson D, Tudor H, Mattiuzzo G, Klaver B, Page M, Stebbings R, Das AT, Berkhout B, Almond N, Cranage MP. Role of Occult and Post-acute Phase Replication in Protective Immunity Induced with a Novel Live Attenuated SIV Vaccine. PLoS Pathog 2016; 12:e1006083. [PMID: 28002473 PMCID: PMC5176322 DOI: 10.1371/journal.ppat.1006083] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 11/21/2016] [Indexed: 01/24/2023] Open
Abstract
In order to evaluate the role of persisting virus replication during occult phase immunisation in the live attenuated SIV vaccine model, a novel SIVmac239Δnef variant (SIVrtTA) genetically engineered to replicate in the presence of doxycycline was evaluated for its ability to protect against wild-type SIVmac239. Indian rhesus macaques were vaccinated either with SIVrtTA or with SIVmac239Δnef. Doxycycline was withdrawn from 4 of 8 SIVrtTA vaccinates before challenge with wild-type virus. Unvaccinated challenge controls exhibited ~107 peak plasma viral RNA copies/ml persisting beyond the acute phase. Six vaccinates, four SIVmac239Δnef and two SIVrtTA vaccinates exhibited complete protection, defined by lack of wild-type viraemia post-challenge and virus-specific PCR analysis of tissues recovered post-mortem, whereas six SIVrtTA vaccinates were protected from high levels of viraemia. Critically, the complete protection in two SIVrtTA vaccinates was associated with enhanced SIVrtTA replication in the immediate post-acute vaccination period but was independent of doxycycline status at the time of challenge. Mutations were identified in the LTR promoter region and rtTA gene that do not affect doxycycline-control but were associated with enhanced post-acute phase replication in protected vaccinates. High frequencies of total circulating CD8+T effector memory cells and a higher total frequency of SIV-specific CD8+ mono and polyfunctional T cells on the day of wild-type challenge were associated with complete protection but these parameters were not predictive of outcome when assessed 130 days after challenge. Moreover, challenge virus-specific Nef CD8+ polyfunctional T cell responses and antigen were detected in tissues post mortem in completely-protected macaques indicating post-challenge control of infection. Within the parameters of the study design, on-going occult-phase replication may not be absolutely required for protective immunity. Development of an HIV vaccine remains a global health priority. In non-human primates live-attenuated SIV induces a potent vaccine effect. Following disappearance of vaccine virus from the peripheral circulation replication persists in lymphoid tissue. To address whether this occult replication is critical to the generation of protective immunity we used a novel construct (SIVrtTA) based on the prototypic live attenuated SIVmac239Δnef but which requires the presence of the antibiotic doxycycline to replicate. Protection appeared independent of doxycycline status at the time of virulent virus challenge suggesting that occult replication may not be absolutely necessary for persistence of immunity; however, stronger protection was observed in monkeys vaccinated with SIVrtTA where vaccine replication persisted for longer after peak viraemia. Moreover, some evidence of very low level breakthrough of vaccine virus replication was seen and protection was weaker than that obtained with SIVmac239Δnef. Both vaccination and challenge perturbed circulating T cell populations, but only the frequency of SIV-specific CD8+ polyfunctional T cells measured on the day of challenge was associated with protection. Replication-conditional mutants such as SIVrtTA have great potential in unlocking the complex interactions between the vaccine virus and host responses in the generation of potent anti-viral protection in vivo.
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Affiliation(s)
- Neil Berry
- Division of Virology, National Institute for Biological Standards and Control, South Mimms, United Kingdom
- * E-mail:
| | - Maria Manoussaka
- Institute for Infection & Immunity, St George’s, University of London, London, United Kingdom
| | - Claire Ham
- Division of Virology, National Institute for Biological Standards and Control, South Mimms, United Kingdom
| | - Deborah Ferguson
- Division of Virology, National Institute for Biological Standards and Control, South Mimms, United Kingdom
| | - Hannah Tudor
- Division of Virology, National Institute for Biological Standards and Control, South Mimms, United Kingdom
| | - Giada Mattiuzzo
- Division of Virology, National Institute for Biological Standards and Control, South Mimms, United Kingdom
| | - Bep Klaver
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Mark Page
- Division of Virology, National Institute for Biological Standards and Control, South Mimms, United Kingdom
| | - Richard Stebbings
- Division of Biotherapeutics, National Institute for Biological Standards and Control, South Mimms, United Kingdom
| | - Atze T. Das
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Ben Berkhout
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Neil Almond
- Division of Virology, National Institute for Biological Standards and Control, South Mimms, United Kingdom
| | - Martin P. Cranage
- Institute for Infection & Immunity, St George’s, University of London, London, United Kingdom
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5
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Tian RR, Zhang MX, Zhang LT, Zhang XL, Zheng HY, Zhu L, Pang W, Zhang GH, Zheng YT. High immune activation and abnormal expression of cytokines contribute to death of SHIV89.6-infected Chinese rhesus macaques. Arch Virol 2015; 160:1953-66. [DOI: 10.1007/s00705-015-2455-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Accepted: 05/11/2015] [Indexed: 11/28/2022]
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6
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Brown J, Excler JL, Kim JH. New prospects for a preventive HIV-1 vaccine. J Virus Erad 2015; 1:78-88. [PMID: 26523292 PMCID: PMC4625840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The immune correlates of risk analysis and recent non-human primate (NHP) challenge studies have generated hypotheses that suggest HIV-1 envelope may be essential and, perhaps, sufficient to induce protective antibody responses against HIV-1 acquisition at the mucosal entry. New prime-boost mosaic and conserved-sequence, together with replicating vector immunisation strategies aiming at inducing immune responses or greater breadth, as well as the development of immunogens inducing broadly neutralising antibodies and mucosal responses, should be actively pursued and tested in humans. Whether the immune correlates of risk identified in RV144 can be extended to other vaccines, other populations, or different modes and intensity of transmission, and against increasing HIV-1 genetic diversity, remains to be demonstrated. Although NHP challenge studies may guide vaccine development, human efficacy trials remain key for answering the critical questions leading to the development of a global HIV-1 vaccine for licensure.
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Affiliation(s)
| | - Jean-Louis Excler
- US Military HIV Research Program,
Bethesda,
MD,
USA,The Henry M Jackson Foundation for the Advancement of Military Medicine,
Bethesda,
MD,
USA,Corresponding author: Jean-Louis Excler,
US Military HIV Research Program,
6720-A Rockledge Drive, Suite 400Bethesda,
MD20817,
USA
| | - Jerome H Kim
- US Military HIV Research Program,
Walter Reed Army Institute of Research,
Silver Spring,
MD,
USA
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7
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Tuero I, Robert-Guroff M. Challenges in mucosal HIV vaccine development: lessons from non-human primate models. Viruses 2014; 6:3129-58. [PMID: 25196380 PMCID: PMC4147690 DOI: 10.3390/v6083129] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 07/21/2014] [Accepted: 07/23/2014] [Indexed: 12/23/2022] Open
Abstract
An efficacious HIV vaccine is urgently needed to curb the AIDS pandemic. The modest protection elicited in the phase III clinical vaccine trial in Thailand provided hope that this goal might be achieved. However, new approaches are necessary for further advances. As HIV is transmitted primarily across mucosal surfaces, development of immunity at these sites is critical, but few clinical vaccine trials have targeted these sites or assessed vaccine-elicited mucosal immune responses. Pre-clinical studies in non-human primate models have facilitated progress in mucosal vaccine development by evaluating candidate vaccine approaches, developing methodologies for collecting and assessing mucosal samples, and providing clues to immune correlates of protective immunity for further investigation. In this review we have focused on non-human primate studies which have provided important information for future design of vaccine strategies, targeting of mucosal inductive sites, and assessment of mucosal immunity. Knowledge gained in these studies will inform mucosal vaccine design and evaluation in human clinical trials.
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Affiliation(s)
- Iskra Tuero
- Vaccine Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Marjorie Robert-Guroff
- Vaccine Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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8
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Moreno-Fernandez ME, Joedicke JJ, Chougnet CA. Regulatory T Cells Diminish HIV Infection in Dendritic Cells - Conventional CD4(+) T Cell Clusters. Front Immunol 2014; 5:199. [PMID: 24847325 PMCID: PMC4021135 DOI: 10.3389/fimmu.2014.00199] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 04/22/2014] [Indexed: 01/04/2023] Open
Abstract
Formation of immunological synapses (IS) between dendritic cells (DCs) and conventional CD4(+) T cells (Tcon) is critical for productive immune responses. However, when DCs are HIV-infected such synapses are critical to establish HIV infection. As regulatory T cells (Treg) control DC-Tcon interactions, we inquired whether Treg might interfere with DC to Tcon HIV infection. We developed a model, using monocyte-derived DC infected with R5-HIV, and cultured with Tcon in the presence or absence of autologous Treg, using the physiological ratio of 1 Treg for 10 Tcon. Cultures containing Treg significantly decreased HIV infection in DC:T cell clusters. Notably, Treg appear to have an effect on the quality of the IS, as Treg decreased actin polymerization and DC maturation. Importantly, Treg decreased the trafficking of HIV punctate to the IS. Further, CD152 and cyclic adenosine monophosphate were critical Treg effector molecules, as their individual or simultaneous blockade abolished Treg activity, however no additive effect was found. Together, these data suggest that Treg can reduce HIV dissemination, which may be beneficial to the host in the early stages of infection.
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Affiliation(s)
- Maria E Moreno-Fernandez
- Division of Immunobiology, Department of Pediatrics, Cincinnati Children's Hospital Research Foundation , Cincinnati, OH , USA ; Immunology Graduate Program, College of Medicine, University of Cincinnati , Cincinnati, OH , USA
| | - Jara J Joedicke
- Institute for Virology, University Hospital Essen, University Duisburg-Essen , Essen , Germany
| | - Claire A Chougnet
- Division of Immunobiology, Department of Pediatrics, Cincinnati Children's Hospital Research Foundation , Cincinnati, OH , USA
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9
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Abdulhaqq SA, Martinez MI, Kang G, Foulkes AS, Rodriguez IV, Nichols SM, Hunter M, Sariol CA, Ruiz LA, Ross BN, Yin X, Speicher DW, Haase AT, Marx PA, Li Q, Kraiselburd EN, Montaner LJ. Serial cervicovaginal exposures with replication-deficient SIVsm induce higher dendritic cell (pDC) and CD4+ T-cell infiltrates not associated with prevention but a more severe SIVmac251 infection of rhesus macaques. J Acquir Immune Defic Syndr 2014; 65:405-13. [PMID: 24226059 PMCID: PMC3943721 DOI: 10.1097/qai.0000000000000047] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Intravaginal exposure to simian immunodeficiency virus (SIV) acutely recruits interferon-alpha (IFN-α) producing plasmacytoid dendritic cells (pDC) and CD4 T-lymphocyte targets to the endocervix of nonhuman primates. We tested the impact of repeated cervicovaginal exposures to noninfectious, defective SIV particles over 72 hours on a subsequent cervicovaginal challenge with replication competent SIV. METHODS Thirty-four female Indian Rhesus macaques were given a 3-day twice-daily vaginal exposures to either SIVsmB7, a replication-deficient derivative of SIVsmH3 produced by a T lymphoblast CEMx174 cell clone (n = 16), or to CEM supernatant controls (n = 18). On the fourth day, animals were either euthanized to assess cervicovaginal immune cell infiltration or intravaginally challenged with SIVmac251. Challenged animals were tracked for plasma viral load and CD4 counts and euthanized at 42 days after infection. RESULTS At the time of challenge, macaques exposed to SIVsmB7, had higher levels of cervical CD123 pDCs (P = 0.032) and CD4 T cells (P = 0.036) than those exposed to CEM control. Vaginal tissues showed a significant increase in CD4 T-cell infiltrates (P = 0.048) and a trend toward increased CD68 cellular infiltrates. After challenge, 12 SIVsmB7-treated macaques showed 2.5-fold greater daily rate of CD4 decline (P = 0.0408), and viral load rise (P = 0.0036) as compared with 12 control animals. CONCLUSIONS Repeated nonproductive exposure to viral particles within a short daily time frame did not protect against infection despite pDC recruitment, resulting instead in an accelerated CD4 T-cell loss with an increased rate of viral replication.
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Affiliation(s)
- Shaheed A Abdulhaqq
- *Department of Immunology, The Wistar Institute, Philadelphia, PA; †Caribbean Primate Research Center and Animal Resources Center, University of Puerto Rico (UPR), San Juan, PR; ‡University of Minnesota Medical School, Minneapolis, MN; §Division of Biostatistics and Epidemiology, University of Massachusetts, Amherst, MA; ‖Tulane National Primate Research Center, Covington, LA; Departments of ¶Microbiology and #Internal Medicine, UPR Medical School, San Juan, PR; and **School of Biological Sciences and ††Nebraska Center for Virology, University of Nebraska, Lincoln, NE
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10
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Excler JL, Robb ML, Kim JH. HIV-1 vaccines: challenges and new perspectives. Hum Vaccin Immunother 2014; 10:1734-46. [PMID: 24637946 DOI: 10.4161/hv.28462] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The development of a safe and effective preventive HIV-1 vaccine remains a public health priority. Despite scientific difficulties and disappointing results, HIV-1 vaccine clinical development has, for the first time, established proof-of-concept efficacy against HIV-1 acquisition and identified vaccine-associated immune correlates of risk. The correlate of risk analysis showed that IgG antibodies against the gp120 V2 loop correlated with decreased risk of HIV infection, while Env-specific IgA directly correlated with increased risk. The development of vaccine strategies such as improved envelope proteins formulated with potent adjuvants and DNA and vectors expressing mosaics, or conserved sequences, capable of eliciting greater breadth and depth of potentially relevant immune responses including neutralizing and non-neutralizing antibodies, CD4+ and CD8+ cell-mediated immune responses, mucosal immune responses, and immunological memory, is now proceeding quickly. Additional human efficacy trials combined with other prevention modalities along with sustained funding and international collaboration remain key to bring an HIV-1 vaccine to licensure.
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Affiliation(s)
- Jean-Louis Excler
- U.S. Military HIV Research Program; Division of Retrovirology; Walter Reed Army Institute of Research; Bethesda, MD USA; Henry M. Jackson Foundation for the Advancement of Military Medicine; Bethesda, MD USA
| | - Merlin L Robb
- U.S. Military HIV Research Program; Division of Retrovirology; Walter Reed Army Institute of Research; Bethesda, MD USA; Henry M. Jackson Foundation for the Advancement of Military Medicine; Bethesda, MD USA
| | - Jerome H Kim
- U.S. Military HIV Research Program; Division of Retrovirology; Walter Reed Army Institute of Research; Bethesda, MD USA
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11
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Abstract
PURPOSE OF REVIEW The development of a preventive HIV vaccine remains an unresolved challenge. Animal models that can predict the results of HIV vaccine efficacy trials and identify the immune mechanisms responsible for vaccine protection would be most useful for HIV vaccine development. The purpose of the current review is to critique recent developments in the use of animal models of HIV infection in preclinical studies of AIDS vaccines and to describe how the use of improved animal models can inform the development of an HIV vaccine. RECENT FINDINGS The results of preclinical experiments with candidate HIV vaccines can vary with the SIV challenge virus used. It is now known that there is considerable variability in the neutralization sensitivity and that the level of viral sequence diversity within the challenge stocks varies. This has allowed more realistic preclinical vaccine studies with heterologous vaccine antigens and challenge viruses. Further, the dose of challenge virus and the route of virus challenge can modify the efficacy of candidate vaccines in preclinical studies. SUMMARY Recent experiments demonstrate that nonhuman primate models of AIDS can reproduce the complex biology of HIV transmission, recapitulate the results of HIV vaccine efficacy trials in humans and be used to identify correlates of protection.
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12
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Sui Y, Gordon S, Franchini G, Berzofsky JA. Nonhuman primate models for HIV/AIDS vaccine development. ACTA ACUST UNITED AC 2013; 102:12.14.1-12.14.30. [PMID: 24510515 DOI: 10.1002/0471142735.im1214s102] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The development of HIV vaccines has been hampered by the lack of an animal model that can accurately predict vaccine efficacy. Chimpanzees can be infected with HIV-1 but are not practical for research. However, several species of macaques are susceptible to the simian immunodeficiency viruses (SIVs) that cause disease in macaques, which also closely mimic HIV in humans. Thus, macaque-SIV models of HIV infection have become a critical foundation for AIDS vaccine development. Here we examine the multiple variables and considerations that must be taken into account in order to use this nonhuman primate (NHP) model effectively. These include the species and subspecies of macaques, virus strain, dose and route of administration, and macaque genetics, including the major histocompatibility complex molecules that affect immune responses, and other virus restriction factors. We illustrate how these NHP models can be used to carry out studies of immune responses in mucosal and other tissues that could not easily be performed on human volunteers. Furthermore, macaques are an ideal model system to optimize adjuvants, test vaccine platforms, and identify correlates of protection that can advance the HIV vaccine field. We also illustrate techniques used to identify different macaque lymphocyte populations and review some poxvirus vaccine candidates that are in various stages of clinical trials. Understanding how to effectively use this valuable model will greatly increase the likelihood of finding a successful vaccine for HIV.
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Affiliation(s)
- Yongjun Sui
- Vaccine Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland.,These authors contributed equally
| | - Shari Gordon
- Vaccine Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland.,These authors contributed equally
| | - Genoveffa Franchini
- Vaccine Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland.,These authors contributed equally
| | - Jay A Berzofsky
- Vaccine Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland.,These authors contributed equally
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13
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Regulatory T cells in HIV infection: can immunotherapy regulate the regulator? Clin Dev Immunol 2012; 2012:908314. [PMID: 23251223 PMCID: PMC3509372 DOI: 10.1155/2012/908314] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Accepted: 08/28/2012] [Indexed: 12/25/2022]
Abstract
Regulatory T cells (Tregs) have a dominant role in self-tolerance and control of autoimmune diseases. These cells also play a pivotal role in chronic viral infections and cancer by limiting immune activation and specific immune response. The role of Tregs in HIV pathogenesis remains poorly understood as their function, changes according to the phases of infection. Tregs can suppress anti-HIV specific responses and conversely can have a beneficial role by reducing the deleterious impact of immune activation. We review the frequency, function and homing potential of Tregs in the blood and lymphoid tissues as well as their interaction with dendritic cells in the context of HIV infection. We also examine the new insights generated by recombinant IL-2 and IL-7 clinical trials in HIV-infected adults, including the immunomodulatory effects of Tregs. Based on their detrimental role in limiting anti-HIV responses, we propose Tregs as potential targets for immunotherapeutic strategies aimed at decreasing Tregs frequency and/or immunosuppressive function. However, such approaches require a better understanding of the time upon infection when interfering with Treg function may not cause a deleterious state of hyperimmune activation.
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