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Hull-Nye D, Meadows T, Smith? SR, Schwartz EJ. Key Factors and Parameter Ranges for Immune Control of Equine Infectious Anemia Virus Infection. Viruses 2023; 15:v15030691. [PMID: 36992401 PMCID: PMC10058099 DOI: 10.3390/v15030691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 02/28/2023] [Accepted: 03/03/2023] [Indexed: 03/09/2023] Open
Abstract
Equine Infectious Anemia Virus (EIAV) is an important infection in equids, and its similarity to HIV creates hope for a potential vaccine. We analyze a within-host model of EIAV infection with antibody and cytotoxic T lymphocyte (CTL) responses. In this model, the stability of the biologically relevant endemic equilibrium, characterized by the coexistence of long-term antibody and CTL levels, relies upon a balance between CTL and antibody growth rates, which is needed to ensure persistent CTL levels. We determine the model parameter ranges at which CTL and antibody proliferation rates are simultaneously most influential in leading the system towards coexistence and can be used to derive a mathematical relationship between CTL and antibody production rates to explore the bifurcation curve that leads to coexistence. We employ Latin hypercube sampling and least squares to find the parameter ranges that equally divide the endemic and boundary equilibria. We then examine this relationship numerically via a local sensitivity analysis of the parameters. Our analysis is consistent with previous results showing that an intervention (such as a vaccine) intended to control a persistent viral infection with both immune responses should moderate the antibody response to allow for stimulation of the CTL response. Finally, we show that the CTL production rate can entirely determine the long-term outcome, regardless of the effect of other parameters, and we provide the conditions for this result in terms of the identified ranges for all model parameters.
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Affiliation(s)
- Dylan Hull-Nye
- Department of Mathematics, Washington State University, Pullman, WA 99164, USA
| | - Tyler Meadows
- Department of Mathematics and Statistics, Queen’s University, Kingston, ON K7L 3N6, Canada
| | - Stacey R. Smith?
- Department of Mathematics, Faculty of Medicine, The University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Elissa J. Schwartz
- Department of Mathematics and Statistics, School of Biological Sciences, Washington State University, Pullman, WA 99164, USA
- Correspondence:
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2
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Tan MP, Mohamed Alitheen NB, Tan WS, Yap WB. Expression of Influenza M2e-NP Recombinant Fusion Protein in Escherichia coli BL21 (DE3) and Its Binding to Antibodies. Vaccines (Basel) 2022; 10:vaccines10122066. [PMID: 36560475 PMCID: PMC9784878 DOI: 10.3390/vaccines10122066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 11/28/2022] [Accepted: 11/29/2022] [Indexed: 12/03/2022] Open
Abstract
The current influenza vaccines only confer protection against the circulating influenza subtypes, therefore universal vaccines are needed to prevent upcoming influenza outbreaks caused by emerging influenza subtypes. The extracellular domain of influenza A M2 protein (M2e) is highly conserved among different subtypes of influenza A viruses, and it is able to elicit protective immunity against the viruses. The influenza nucleoprotein (NP) was used to display the M2e in this study due to its promising T-cell response and adjuvanticity. The M2e gene was fused to the 5'-end of the NP gene and then cloned into pRSET B vector. The DNA sequencing analysis revealed six point mutations in the M2e-NP fusion gene, including one mutation in the M2e peptide and five mutations in the NP. The mutations were reverted using PCR site-directed mutagenesis. The recombinant plasmids (pRSET B-M2e-NP and pRSET B-mM2e-NP) were introduced into Escherichia coli (E. coli) BL21 (DE3) for protein expression. The mutated and non-mutated proteins were subsequently expressed and named mM2e-NP and M2e-NP, respectively. The expression of mM2e-NP and M2e-NP was not affected by the mutations. The binding of anti-M2e antibody to the purified native mM2e-NP and M2e-NP also remained active. However, when the anti-NP antibody was tested, the signal produced by mM2e-NP was very weak. The results implied that the amino acid changes in the NP had adversely impacted on the conformation of mM2e-NP and subsequently affected the antibody binding. In light of the remarkable antibody binding to the M2e-NP fusion protein, this study highly recommends the potential of M2e-NP as a universal influenza vaccine candidate.
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Affiliation(s)
- Mei Peng Tan
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang 43400, Malaysia
| | - Noorjahan Banu Mohamed Alitheen
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang 43400, Malaysia
| | - Wen Siang Tan
- Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang 43400, Malaysia
| | - Wei Boon Yap
- Center for Toxicology and Health Risk Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, Kuala Lumpur 50300, Malaysia
- Biomedical Science Program, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, Kuala Lumpur 50300, Malaysia
- Correspondence: ; Tel.: +603-92897920
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3
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On the irrationality of rational design of an HIV vaccine in light of protein intrinsic disorder. Arch Virol 2021; 166:1283-1296. [PMID: 33606110 PMCID: PMC7892713 DOI: 10.1007/s00705-021-04984-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 12/19/2020] [Indexed: 12/18/2022]
Abstract
The lack of progress in finding an efficient vaccine for a human immunodeficiency virus (HIV) is daunting. In fact, this search has spanned nearly four decades without much success. There are several objective reasons for such a failure, which include the highly glycosylated nature of HIV-1, the presence of neotopes, and high mutation rates. This article argues that the presence of highly flexible and intrinsically disordered regions in both human anti-HIV-1 antibodies and the major HIV-1immunogen, its surface glycoprotein gp120, represent one of the major causes for the lack of success in utilization of structure-based reverse vaccinology.
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4
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Lin Y, Wang XF, Wang Y, Du C, Ren H, Liu C, Zhu D, Chen J, Na L, Liu D, Yang Z, Wang X. Env diversity-dependent protection of the attenuated equine infectious anaemia virus vaccine. Emerg Microbes Infect 2021; 9:1309-1320. [PMID: 32525460 PMCID: PMC7473056 DOI: 10.1080/22221751.2020.1773323] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Lentiviruses harbour high genetic variability for efficient evasion from host immunity.
An attenuated equine infectious anaemia (EIA) vaccine was developed decades ago in China
and presented remarkably robust protection against EIA. The vaccine was recently proven to
have high genomic diversity, particular in env. However, how
and to what extent the high env diversity relates to immune
protection remains unclear. In this study, we compared immune protections and responses of
three groups of horses stimulated by the high-diversity vaccine EIAV_HD, a single
molecular clone of the vaccine EIAV_LD with low env
diversity, as well as a constructed vaccine strain EIAV_MD with moderate env diversity. The disparity of virus-host interactions between
three env diversity-varied groups (5 horses in each group)
was evaluated using clinical manifestation, pathological scores, and env-specific antibody. We found the highest titres of env antibodies (Abs) or neutralizing Abs (nAbs) in the EIAV_HD group, followed
by the EIAV_MD group, and the lowest titres in the EIAV_LD group (P<0.05). The occurrence of disease/death was different between EIAV_HD
group (1/0), EIAV_MD (2/2), and EIAV_LD group (4/2). A similar env diversity-related linear relationship was observed in the clinical
manifestations and pathological changes. This diversity-dependent disparity in changes
between the three groups was more distinct after immunosuppression, suggesting that
env diversity plays an important role in protection under
low host immunocompetence. In summary, inoculation with vaccines with higher genetic
diversity could present broader and more efficient protection. Our findings strongly
suggest that an abundance of Env antigens are required for efficient protection against
lentiviruses.
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Affiliation(s)
- Yuezhi Lin
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Xue-Feng Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China.,Shanghai Key Laboratory of Veterinary Biotechnology, Shanghai, People's Republic of China
| | - Yuhong Wang
- Department of Geriatrics and Gerontology, First Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - Cheng Du
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Huiling Ren
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Cong Liu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Dantong Zhu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Jie Chen
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Lei Na
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Diqiu Liu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Zhibiao Yang
- Shanghai Key Laboratory of Veterinary Biotechnology, Shanghai, People's Republic of China
| | - Xiaojun Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
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Goh GKM, Uversky VN. Shell disorder and the HIV vaccine mystery: lessons from the legendary Oswald Avery. J Biomol Struct Dyn 2021; 40:5702-5711. [PMID: 33410379 DOI: 10.1080/07391102.2020.1870562] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The search for a human immunodeficiency virus (HIV) vaccine has spanned nearly four decades without much success. A much needed paradigm shift can be found in the abnormally high levels of intrinsic disorder in the outer shells of HIVs, the hepatitis C virus (HCV), and herpes simplex viruses (HSVs), for which successful vaccines have not been established. On the other hand, this feature (high levels of intrinsic disorder in the outer shells) is completely absent in classic viruses for which effective vaccines are found, such as the rabies virus. The motions arising from the disordered outer shell result in the inability of antibodies to bind tightly to the polysaccharides on the viral surface proteins, and, therefore, induce inadequate immune response. Experiments conducted by the legendary Avery Oswald in the 1920s form the theoretical underpinning of this new model. Failures of the vaccines based on the HIV glycoprotein Gp120 and other vaccines can be traced back to the lack of understanding of the important roles of shell disorder in a "Trojan-horse" immune evasion mechanism utilized by the virus.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
| | - Vladimir N Uversky
- Department of Molecular Medicine, USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, USA.,Laboratory of New Methods in Biology, Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Pushchino, Russia Institute for Biological Instrumentation, Russian Academy of Sciences, Pushchino, Russia
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6
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Goh GKM, Dunker AK, Foster JA, Uversky VN. HIV Vaccine Mystery and Viral Shell Disorder. Biomolecules 2019; 9:biom9050178. [PMID: 31072073 PMCID: PMC6572542 DOI: 10.3390/biom9050178] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 04/25/2019] [Accepted: 04/30/2019] [Indexed: 12/14/2022] Open
Abstract
Hundreds of billions of dollars have been spent for over three decades in the search for an effective human immunodeficiency virus (HIV) vaccine with no success. There are also at least two other sexually transmitted viruses, for which no vaccine is available, the herpes simplex virus (HSV) and the hepatitis C virus (HCV). Traditional textbook explanatory paradigm of rapid mutation of retroviruses cannot adequately address the unavailability of vaccine for many sexually transmissible viruses, since HSV and HCV are DNA and non-retroviral RNA viruses, respectively, whereas effective vaccine for the horsefly-transmitted retroviral cousin of HIV, equine infectious anemia virus (EIAV), was found in 1973. We reported earlier the highly disordered nature of proteins in outer shells of the HIV, HCV, and HSV. Such levels of disorder are completely absent among the classical viruses, such as smallpox, rabies, yellow fever, and polio viruses, for which efficient vaccines were discovered. This review analyzes the physiology and shell disorder of the various related and non-related viruses to argue that EIAV and the classical viruses need harder shells to survive during harsher conditions of non-sexual transmissions, thus making them vulnerable to antibody detection and neutralization. In contrast, the outer shell of the HIV-1 (with its preferential sexual transmission) is highly disordered, thereby allowing large scale motions of its surface glycoproteins and making it difficult for antibodies to bind to them. The theoretical underpinning of this concept is retrospectively traced to a classical 1920s experiment by the legendary scientist, Oswald Avery. This concept of viral shapeshifting has implications for improved treatment of cancer and infections via immune evasion.
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Affiliation(s)
| | - A Keith Dunker
- Center for Computational Biology, Indiana and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
| | - James A Foster
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA.
- Institute for Bioinformatics and Evolutionary Studies, University of Idaho, Moscow, ID 83844, USA.
| | - Vladimir N Uversky
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA.
- Institute for Biological Instrumentation, Russian Academy of Sciences, Moscow Region, Pushchino 142290, Russia.
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Pathogenic Correlates of Simian Immunodeficiency Virus-Associated B Cell Dysfunction. J Virol 2017; 91:JVI.01051-17. [PMID: 28931679 DOI: 10.1128/jvi.01051-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 09/12/2017] [Indexed: 01/08/2023] Open
Abstract
We compared and contrasted pathogenic (in pig-tailed macaques [PTMs]) and nonpathogenic (in African green monkeys [AGMs]) SIVsab infections to assess the significance of the B cell dysfunction observed in simian (SIV) and human immunodeficiency virus (HIV) infections. We report that the loss of B cells is specifically associated with the pathogenic SIV infection, while in the natural hosts, in which SIV is nonpathogenic, B cells rapidly increase in both lymph nodes (LNs) and intestine. SIV-associated B cell dysfunction associated with the pathogenic SIV infection is characterized by loss of naive B cells, loss of resting memory B cells due to their redistribution to the gut, increases of the activated B cells and circulating tissue-like memory B cells, and expansion of the B regulatory cells (Bregs). While circulating B cells are virtually restored to preinfection levels during the chronic pathogenic SIV infection, restoration is mainly due to an expansion of the "exhausted," virus-specific B cells, i.e., activated memory cells and tissue-like memory B cells. Despite of the B cell dysfunction, SIV-specific antibody (Ab) production was higher in the PTMs than in AGMs, with the caveat that rapid disease progression in PTMs was strongly associated with lack of anti-SIV Ab. Neutralization titers and the avidity and maturation of immune responses did not differ between pathogenic and nonpathogenic infections, with the exception of the conformational epitope recognition, which evolved from low to high conformations in the natural host. The patterns of humoral immune responses in the natural host are therefore more similar to those observed in HIV-infected subjects, suggesting that natural hosts may be more appropriate for modeling the immunization strategies aimed at preventing HIV disease progression. The numerous differences between the pathogenic and nonpathogenic infections with regard to dynamics of the memory B cell subsets point to their role in the pathogenesis of HIV/SIV infections and suggest that monitoring B cells may be a reliable approach for assessing disease progression.IMPORTANCE We report here that the HIV/SIV-associated B cell dysfunction (defined by loss of total and memory B cells, increased B regulatory cell [Breg] counts, and B cell activation and apoptosis) is specifically associated with pathogenic SIV infection and absent during the course of nonpathogenic SIV infection in natural nonhuman primate hosts. Alterations of the B cell population are not correlated with production of neutralizing antibodies, the levels of which are similar in the two species. Rapid progressive infections are associated with a severe impairment in SIV-specific antibody production. While we did not find major differences in avidity and maturation between the pathogenic and nonpathogenic SIV infections, we identified a major difference in conformational epitope recognition, with the nonpathogenic infection being characterized by an evolution from low to high conformations. B cell dysfunction should be considered in designing immunization strategies aimed at preventing HIV disease progression.
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8
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Goh GKM, Dunker AK, Uversky VN. Shell disorder, immune evasion and transmission behaviors among human and animal retroviruses. MOLECULAR BIOSYSTEMS 2016; 11:2312-23. [PMID: 26080321 DOI: 10.1039/c5mb00277j] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
This study involves measurements of percentages of intrinsic disorder (PIDs) in the GAG protein shells of various retroviruses. Unique patterns of shell protein disorder can be seen especially when GAG proteins (matrix M, capsid C, and nucleocapsid N) of primate and non-primate retroviruses are compared. HIV-1 presents the most unique pattern of disorder distribution with generally high levels of disorder in all three proteins, while EIAV (PIDs:: 26, 29, 13) is diametrically different from HIV-1 (N C M PIDs: 39.5 ± 3.0, 44.5 ± 2.6, 56.5 ± 10.8). The HTLV viruses (CPID: 32.8 ± 3.4) resemble HIV-2 (C PID: 26.6 ± 2.9) with a moderately disordered capsid. Totally distinct patterns, however, are seen for the non-primate retroviruses. They generally have highly disordered nucleocapsids (PID > 65%) and more ordered outer shells especially the matrix. These characteristics might be attributed to the differences in the way the retroviruses are transmitted, with non-primate viruses having greater non-sexual transmission components such as oral-fecal transmission. These differences are also evolutionarily related to the ways the viruses evade the host immune systems, and thus, have implications for oncolytic virotherapy and animal models in vaccine research. The importance of protein shell disorder in immune evasion, as related to the case of HIV-1, and the difficult search for its vaccines are highlighted.
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9
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Wang XF, Lin YZ, Li Q, Liu Q, Zhao WW, Du C, Chen J, Wang X, Zhou JH. Genetic Evolution during the development of an attenuated EIAV vaccine. Retrovirology 2016; 13:9. [PMID: 26842878 PMCID: PMC4738788 DOI: 10.1186/s12977-016-0240-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 01/18/2016] [Indexed: 08/30/2023] Open
Abstract
Background The equine infectious anemia virus (EIAV) vaccine is the only attenuated lentiviral vaccine applied on a large scale that has been shown to be effective in controlling the prevalence of EIA in China. This vaccine was developed by successive passaging of a field-isolated virulent strain in different hosts and cultivated cells. To explore the molecular basis for the phenotype alteration of this vaccine strain, we systematically analyzed its genomic evolution during vaccine development. Results Sequence analysis revealed that the genetic distance between the wild-type strain and six representative strains isolated from key development stages gradually increased with the number of passages. Env gene, but not gag and pol, showed a clear evolutionary flow similar to that of the whole genomes of different generations during the attenuation. Stable mutations were identified in multiple regions of multiple genes along with virus passaging. The adaption of the virus to the growth environment of cultured cells with accumulated genomic and genetic variations was positively correlated with the reduction in pathogenicity and rise of immunogenicity. Statistical analyses revealed significant differences in the frequency of the most stable mutations between in vivo and ex vivo-adapted strains and between virulent and attenuated strains. Conclusions These data indicate that EIAV evolution during vaccine development generated an accumulation of mutations under the selective drive force, which helps to better understand the molecular basis of lentivirus pathogenicity and immunogenicity. Electronic supplementary material The online version of this article (doi:10.1186/s12977-016-0240-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xue-Feng Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China. .,Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, Harbin, China.
| | - Yue-Zhi Lin
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China.
| | - Qiang Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China. .,Harbin Weike Biotechnology Development Company, Harbin, China.
| | - Qiang Liu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China.
| | - Wei-Wei Zhao
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China.
| | - Cheng Du
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China.
| | - Jie Chen
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China.
| | - Xiaojun Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China.
| | - Jian-Hua Zhou
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China. .,Harbin Pharmaceutical Group Biovaccine Co., Harbin, 150069, China.
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10
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Craigo JK, Ezzelarab C, Cook SJ, Liu C, Horohov D, Issel CJ, Montelaro RC. Protective efficacy of centralized and polyvalent envelope immunogens in an attenuated equine lentivirus vaccine. PLoS Pathog 2015; 11:e1004610. [PMID: 25569288 PMCID: PMC4287611 DOI: 10.1371/journal.ppat.1004610] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 12/07/2014] [Indexed: 11/18/2022] Open
Abstract
Lentiviral Envelope (Env) antigenic variation and related immune evasion present major hurdles to effective vaccine development. Centralized Env immunogens that minimize the genetic distance between vaccine proteins and circulating viral isolates are an area of increasing study in HIV vaccinology. To date, the efficacy of centralized immunogens has not been evaluated in the context of an animal model that could provide both immunogenicity and protective efficacy data. We previously reported on a live-attenuated (attenuated) equine infectious anemia (EIAV) virus vaccine, which provides 100% protection from disease after virulent, homologous, virus challenge. Further, protective efficacy demonstrated a significant, inverse, linear relationship between EIAV Env divergence and protection from disease when vaccinates were challenged with viral strains of increasing Env divergence from the vaccine strain Env. Here, we sought to comprehensively examine the protective efficacy of centralized immunogens in our attenuated vaccine platform. We developed, constructed, and extensively tested a consensus Env, which in a virulent proviral backbone generated a fully replication-competent pathogenic virus, and compared this consensus Env to an ancestral Env in our attenuated proviral backbone. A polyvalent attenuated vaccine was established for comparison to the centralized vaccines. Additionally, an engineered quasispecies challenge model was created for rigorous assessment of protective efficacy. Twenty-four EIAV-naïve animals were vaccinated and challenged along with six-control animals six months post-second inoculation. Pre-challenge data indicated the consensus Env was more broadly immunogenic than the Env of the other attenuated vaccines. However, challenge data demonstrated a significant increase in protective efficacy of the polyvalent vaccine. These findings reveal, for the first time, a consensus Env immunogen that generated a fully-functional, replication-competent lentivirus, which when experimentally evaluated, demonstrated broader immunogenicity that does not equate to higher protective efficacy.
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Affiliation(s)
- Jodi K. Craigo
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
| | - Corin Ezzelarab
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Sheila J. Cook
- Department of Veterinary Science, Gluck Equine Research Center, University of Kentucky, Lexington, Kentucky, United States of America
| | - Chong Liu
- Department of Veterinary Science, Gluck Equine Research Center, University of Kentucky, Lexington, Kentucky, United States of America
| | - David Horohov
- Department of Veterinary Science, Gluck Equine Research Center, University of Kentucky, Lexington, Kentucky, United States of America
| | - Charles J. Issel
- Department of Veterinary Science, Gluck Equine Research Center, University of Kentucky, Lexington, Kentucky, United States of America
| | - Ronald C. Montelaro
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
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11
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Liu C, Cook SJ, Craigo JK, Cook FR, Issel CJ, Montelaro RC, Horohov DW. Epitope shifting of gp90-specific cellular immune responses in EIAV-infected ponies. Vet Immunol Immunopathol 2014; 161:161-9. [PMID: 25176006 DOI: 10.1016/j.vetimm.2014.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 07/02/2014] [Accepted: 08/04/2014] [Indexed: 11/16/2022]
Abstract
Unlike other lentiviruses, EIAV replication can be controlled in most infected horses leading to an inapparent carrier state free of overt clinical signs which lasts for many years. While the resolution of the initial infection is correlated with the appearance of virus specific cellular immune responses, the precise immune mechanisms responsible for control of the infection are not yet identified. Since the virus undergoes rapid mutation following infection, the immune response must also adapt to meet this challenge. We hypothesize that this adaptation involves peptide-specific recognition shifting from immunodominant variable determinants to conserved immunorecessive determinants following EIAV infection. Forty-four peptides, spanning the entire surface unit protein (gp90) of EIAV, were used to monitor peptide-specific T cell responses in vivo over a six-month period following infection. Peptides were injected intradermally and punch biopsies were collected for real-time PCR analysis to monitor the cellular peptide-specific immune responses in vivo. Similar to the CMI response to HIV infection, peptide-specific T cell recognition patterns changed over time. Early post infection (1 month), immune responses were directed to the peptides in the carboxyl-terminus variable region. By six months post infection, the peptide recognition spanned the entire gp90 sequence. These results indicate that peptide recognition broadens during EIAV infection.
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Affiliation(s)
- Chong Liu
- Department of Veterinary Science, University of Kentucky, Lexington, KY, USA
| | - Sheila J Cook
- Department of Veterinary Science, University of Kentucky, Lexington, KY, USA
| | - Jodi K Craigo
- Center for Vaccine Research and Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Frank R Cook
- Department of Veterinary Science, University of Kentucky, Lexington, KY, USA
| | - Charles J Issel
- Department of Veterinary Science, University of Kentucky, Lexington, KY, USA
| | - Ronald C Montelaro
- Center for Vaccine Research and Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA
| | - David W Horohov
- Department of Veterinary Science, University of Kentucky, Lexington, KY, USA.
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12
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Craigo JK, Montelaro RC. Lessons in AIDS vaccine development learned from studies of equine infectious, anemia virus infection and immunity. Viruses 2013; 5:2963-76. [PMID: 24316675 PMCID: PMC3967156 DOI: 10.3390/v5122963] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 11/20/2013] [Accepted: 11/25/2013] [Indexed: 11/16/2022] Open
Abstract
Equine infectious anemia (EIA), identified in 1843 [1] as an infectious disease of horses and as a viral infection in 1904, remains a concern in veterinary medicine today. Equine infectious anemia virus (EIAV) has served as an animal model of HIV-1/AIDS research since the original identification of HIV. Similar to other lentiviruses, EIAV has a high propensity for genomic sequence and antigenic variation, principally in its envelope (Env) proteins. However, EIAV possesses a unique and dynamic disease presentation that has facilitated comprehensive analyses of the interactions between the evolving virus population, progressive host immune responses, and the definition of viral and host correlates of immune control and vaccine efficacy. Summarized here are key findings in EIAV that have provided important lessons toward understanding long term immune control of lentivirus infections and the parameters for development of an enduring broadly protective AIDS vaccine.
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Affiliation(s)
- Jodi K Craigo
- Center for Vaccine Research, Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA 15261, USA.
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Immunization against small ruminant lentiviruses. Viruses 2013; 5:1948-63. [PMID: 23917352 PMCID: PMC3761235 DOI: 10.3390/v5081948] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 07/24/2013] [Accepted: 07/25/2013] [Indexed: 11/16/2022] Open
Abstract
Multisystemic disease caused by Small Ruminant Lentiviruses (SRLV) in sheep and goats leads to production losses, to the detriment of animal health and welfare. This, together with the lack of treatments, has triggered interest in exploring different strategies of immunization to control the widely spread SRLV infection and, also, to provide a useful model for HIV vaccines. These strategies involve inactivated whole virus, subunit vaccines, DNA encoding viral proteins in the presence or absence of plasmids encoding immunological adjuvants and naturally or artificially attenuated viruses. In this review, we revisit, comprehensively, the immunization strategies against SRLV and analyze this double edged tool individually, as it may contribute to either controlling or enhancing virus replication and/or disease.
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Craigo JK, Ezzelarab C, Cook SJ, Chong L, Horohov D, Issel CJ, Montelaro RC. Envelope determinants of equine lentiviral vaccine protection. PLoS One 2013; 8:e66093. [PMID: 23785473 PMCID: PMC3682429 DOI: 10.1371/journal.pone.0066093] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 05/02/2013] [Indexed: 11/18/2022] Open
Abstract
Lentiviral envelope (Env) antigenic variation and associated immune evasion present major obstacles to vaccine development. The concept that Env is a critical determinant for vaccine efficacy is well accepted, however defined correlates of protection associated with Env variation have yet to be determined. We reported an attenuated equine infectious anemia virus (EIAV) vaccine study that directly examined the effect of lentiviral Env sequence variation on vaccine efficacy. The study identified a significant, inverse, linear correlation between vaccine efficacy and increasing divergence of the challenge virus Env gp90 protein compared to the vaccine virus gp90. The report demonstrated approximately 100% protection of immunized ponies from disease after challenge by virus with a homologous gp90 (EV0), and roughly 40% protection against challenge by virus (EV13) with a gp90 13% divergent from the vaccine strain. In the current study we examine whether the protection observed when challenging with the EV0 strain could be conferred to animals via chimeric challenge viruses between the EV0 and EV13 strains, allowing for mapping of protection to specific Env sequences. Viruses containing the EV13 proviral backbone and selected domains of the EV0 gp90 were constructed and in vitro and in vivo infectivity examined. Vaccine efficacy studies indicated that homology between the vaccine strain gp90 and the N-terminus of the challenge strain gp90 was capable of inducing immunity that resulted in significantly lower levels of post-challenge virus and significantly delayed the onset of disease. However, a homologous N-terminal region alone inserted in the EV13 backbone could not impart the 100% protection observed with the EV0 strain. Data presented here denote the complicated and potentially contradictory relationship between in vitro virulence and in vivo pathogenicity. The study highlights the importance of structural conformation for immunogens and emphasizes the need for antibody binding, not neutralizing, assays that correlate with vaccine protection.
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Affiliation(s)
- Jodi K Craigo
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.
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Meng Q, Lin Y, Ma J, Ma Y, Zhao L, Li S, Yang K, Zhou J, Shen R, Zhang X, Shao Y. A pilot study comparing the development of EIAV Env-specific antibodies induced by DNA/recombinant vaccinia-vectored vaccines and an attenuated Chinese EIAV vaccine. Viral Immunol 2012; 25:477-84. [PMID: 23171359 DOI: 10.1089/vim.2012.0014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Data from successful attenuated lentiviral vaccine studies indicate that fully mature Env-specific antibodies characterized by high titer, high avidity, and the predominant recognition of conformational epitopes are associated with protective efficacy. Although vaccination with a DNA prime/recombinant vaccinia-vectored vaccine boost strategy has been found to be effective in some trials with non-human primate/simian/human immunodeficiency virus (SHIV) models, it remains unclear whether this vaccination strategy could elicit mature equine infectious anemia virus (EIAV) Env-specific antibodies, thus protecting vaccinated horses against EIAV infection. Therefore, in this pilot study we vaccinated horses using a strategy based on DNA prime/recombinant Tiantan vaccinia (rTTV)-vectored vaccines encoding EIAV env and gag genes, and observed the development of Env-specific antibodies, neutralizing antibodies, and p26-specific antibodies. Vaccination with DNA induced low titer, low avidity, and the predominant recognition of linear epitopes by Env-specific antibodies, which was enhanced by boosting vaccinations with rTTV vaccines. However, the maturation levels of Env-specific antibodies induced by the DNA/rTTV vaccines were significantly lower than those induced by the attenuated vaccine EIAV(FDDV). Additionally, DNA/rTTV vaccines did not elicit broadly neutralizing antibodies. After challenge with a virulent EIAV strain, all of the vaccinees and control horses died from EIAV disease. These data indicate that the regimen of DNA prime/rTTV vaccine boost did not induce mature Env-specific antibodies, which might have contributed to immune protection failure.
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Affiliation(s)
- Qinglai Meng
- State Key Laboratory for Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
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The determination of in vivo envelope-specific cell-mediated immune responses in equine infectious anemia virus-infected ponies. Vet Immunol Immunopathol 2012; 148:302-10. [PMID: 22795699 DOI: 10.1016/j.vetimm.2012.06.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 06/15/2012] [Accepted: 06/18/2012] [Indexed: 11/24/2022]
Abstract
Distinct from human lentivirus infection, equine infectious anemia virus (EIAV)-infected horses will eventually enter an inapparent carrier state in which virus replication is apparently controlled by adaptive immune responses. Although recrudescence of disease can occur after immune suppression, the actual immune correlate associated with protection has yet to be determined. Therefore, EIAV provides a model for investigating immune-mediated protective mechanisms against lentivirus infection. Here, we have developed a method to monitor EIAV-envelope specific cellular immunity in vivo. An EIA carrier horse with no clinical signs infected 7 years ago and 4 related experimental ponies infected 6 months previously were used in this study. Forty-four 20-mer peptides, representing the entire surface unit protein (gp90) of EIAV, were combined into 14 peptide pools and intradermally injected into the neck of EIAV-infected horses. An identical volume of saline alone was injected into a fifteenth site as a negative control. After 48 h, those sites with palpable infiltrations were measured prior to the collection of 2mm and 4mm punch biopsies. Total RNA was extracted from each 2mm biopsy for determination of CD3 and interferon-γ (IFN-γ) mRNA expression by real-time PCR. The 4mm skin biopsies were formalin-fixed and paraffin-embedded for immunohistochemistry (IHC) staining for CD3, CD20, CD25 and MAC387 (macrophage marker). Peripheral blood mononuclear cells (PBMC) were obtained prior to the injection and tested for in vitro reactivity against the same peptides. Histological examination showed that some of the envelope peptides elicited a lymphocytic cellular infiltration at the injection site, as evidenced by positive staining for CD3. Gp90 peptide-specific increases in CD3 and IFN-γ gene expression were also detected in the injection sites. Furthermore, differences were found between in vivo and in vitro responses to gp90 specific peptides. These results demonstrate a novel method for detecting in vivo cell-mediated immune responses to EIAV-specific peptides that is readily applicable to other host/pathogen systems.
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Lin YZ, Shen RX, Zhu ZY, Deng XL, Cao XZ, Wang XF, Ma J, Jiang CG, Zhao LP, Lv XL, Shao YM, Zhou JH. An attenuated EIAV vaccine strain induces significantly different immune responses from its pathogenic parental strain although with similar in vivo replication pattern. Antiviral Res 2011; 92:292-304. [PMID: 21893100 DOI: 10.1016/j.antiviral.2011.08.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Revised: 07/25/2011] [Accepted: 08/18/2011] [Indexed: 01/06/2023]
Abstract
The EIAV (equine infectious anemia virus) multi-species attenuated vaccine EIAV(DLV121) successfully prevented the spread of equine infectious anemia (EIA) in China in the 1970s and provided an excellent model for the study of protective immunity to lentiviruses. In this study, we compared immune responses induced by EIAV(DLV121) to immunity elicited by the virulent EIAV(LN40) strain and correlated immune responses to protection from infection. Horses were randomly grouped and inoculated with either EIAV(DLV121) (Vaccinees, Vac) or a sublethal dose of EIAV(LN40) (asymptomatic carriers, Car). Car horses became EIAV(LN40) carriers without disease symptoms. Two of the four Vac horses were protected against infection and the other two had delayed onset or reduced severity of EIA with a lethal EIAV(LN40) challenge 5.5 months post initial inoculation. In contrast, all three Car animals developed acute EIA and two succumbed to death. Specific humoral and cellular immune responses in both Vac and Car groups were evaluated for potential correlations with protection. These analyses revealed that although plasma viral loads remained between 10(3) and 10(5)copies/ml for both groups before EIAV(LN40) challenge, Vac-treated animals developed significantly higher levels of conformational dependent, Env-specific antibody, neutralizing antibody as well as significantly elevated CD4(+) T cell proliferation and IFN-γ-secreting CD8(+) T cells than those observed in EIAV(LN40) asymptomatic carriers. Further analysis of protected and unprotected cases in vaccinated horses identified that cellular response parameters and the reciprocal anti-p26-specific antibody titers closely correlated with protection against infection with the pathogenic EIAV(LN40). These data provide a better understanding of protective immunity to lentiviruses.
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Affiliation(s)
- Yue-Zhi Lin
- State Key Laboratory of Veterinary Biotechnology, Division of Livestock Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, China
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Meng Q, Lin Y, Ma J, Ma Y, Zhao L, Li S, Liang H, Zhou J, Shen R, Zhang X, Shao Y. A pilot study on an attenuated Chinese EIAV vaccine inducing broadly neutralizing antibodies. Arch Virol 2011; 156:1455-62. [DOI: 10.1007/s00705-011-0992-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Accepted: 03/28/2011] [Indexed: 10/18/2022]
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Wang X, Wang S, Lin Y, Jiang C, Ma J, Zhao L, Lv X, Wang F, Shen R, Zhou J. Unique evolution characteristics of the envelope protein of EIAV(LN₄₀), a virulent strain of equine infectious anemia virus. Virus Genes 2011; 42:220-8. [PMID: 21369830 DOI: 10.1007/s11262-010-0563-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Accepted: 12/20/2010] [Indexed: 11/30/2022]
Abstract
The Chinese equine infectious anemia virus (EIAV) virulent strain EIAV(LN40) is derived from a naturally occurring virus by continuously passing in horses for 16 generations. Its genome sequence is 23% different from that of the American strains or the Japanese strains, and the variation of envelope gp90 surface unit (SU) is as high as 41%. In this study, evolutions of the EIAV(LN40) gp90 gene in four infected horses were analyzed. Results showed that new quasispecies arose in the early stage of infection in all EIAV(LN40)-infected horses. These quasispecies belonged to branches different from EIAV(LN40) in a phylogenetic tree. In contrast, the gp90 sequences of viruses isolated after disease onset remained in the same phylogenetic branch as EIAV(LN40), with some having exactly the same sequences. The glycosylation sites 191NSSN and 237NNTW in the V3 and V4 region present or absent simultaneously in most of the predicted amino acid sequences. Changes in the glycosylation sites within V3, V4, and V5 regions are usually associated with the disease status. Glycosylation sites (191NSSN, 237NNTW, and 280NDTS) within these three regions were present in EIAV(LN40) and most of the quasispecies isolated after, but not before disease onset. These unique evolutionary characteristics of SU have not been reported for EIAV and other lentiviruses. Our results provide a reference for a further understanding of the mechanism underlying the persistent infection and escape from immune surveillance of EIAV.
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Affiliation(s)
- Xuefeng Wang
- Division of Large Animal Infectious Diseases, Stated key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, China
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Craigo JK, Barnes S, Cook SJ, Issel CJ, Montelaro RC. Divergence, not diversity of an attenuated equine lentivirus vaccine strain correlates with protection from disease. Vaccine 2010; 28:8095-104. [PMID: 20955830 DOI: 10.1016/j.vaccine.2010.10.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 08/17/2010] [Accepted: 10/01/2010] [Indexed: 10/18/2022]
Abstract
We recently reported an attenuated EIAV vaccine study that directly examined the effect of lentiviral envelope sequence variation on vaccine efficacy. The study [1] demonstrated for the first time the failure of an ancestral vaccine to protect and revealed a significant, inverse, linear relationship between envelope divergence and protection from disease. In the current study we examine in detail the evolution of the attenuated vaccine strain utilized in this previous study. We demonstrate here that the attenuated strain progressively evolved during the six-month pre-challenge period and that the observed protection from disease was significantly associated with divergence from the original vaccine strain.
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Affiliation(s)
- Jodi K Craigo
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA 15261, USA
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Liu L, Wan Y, Wu L, Sun J, Li H, Li H, Ma L, Shao Y. Broader HIV-1 neutralizing antibody responses induced by envelope glycoprotein mutants based on the EIAV attenuated vaccine. Retrovirology 2010; 7:71. [PMID: 20807451 PMCID: PMC2940887 DOI: 10.1186/1742-4690-7-71] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Accepted: 09/01/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In order to induce a potent and cross-reactive neutralizing antibody (nAb), an effective envelope immunogen is crucial for many viral vaccines, including the vaccine for the human immunodeficiency virus (HIV). The Chinese equine infectious anemia virus (EIAV) attenuated vaccine has controlled the epidemic of this virus after its vaccination in over 70 million equine animals during the last 3 decades in China. Data from our past studies demonstrate that the Env protein of this vaccine plays a pivotal role in protecting horses from both homologous and heterogeneous EIAV challenges. Therefore, the amino acid sequence information from the Chinese EIAV attenuated vaccine, in comparison with the parental wild-type EIAV strains, was applied to modify the corresponding region of the envelope glycoprotein of HIV-1 CN54. The direction of the mutations was made towards the amino acids conserved in the two EIAV vaccine strains, distinguishing them from the two wild-type strains. The purpose of the modification was to enhance the immunogenicity of the HIV Env. RESULTS The induced nAb by the modified HIV Env neutralized HIV-1 B and B'/C viruses at the highest titer of 1:270. Further studies showed that a single amino acid change in the C1 region accounts for the substantial enhancement in induction of anti-HIV-1 neutralizing antibodies. CONCLUSIONS This study shows that an HIV envelope modified by the information of another lentivirus vaccine induces effective broadly neutralizing antibodies. A single amino acid mutation was found to increase the immunogenicity of the HIV Env.
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Affiliation(s)
- Lianxing Liu
- State Key Laboratory for Infectious Diseases Prevention and Control, National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China
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Multiplex immunoassays of equine virus based on fluorescent encoded magnetic composite nanoparticles. Anal Bioanal Chem 2010; 398:805-13. [DOI: 10.1007/s00216-010-4001-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Revised: 06/30/2010] [Accepted: 07/01/2010] [Indexed: 11/25/2022]
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Qi X, Wang X, Wang S, Lin Y, Jiang C, Ma J, Zhao L, Lv X, Shen R, Wang F, Kong X, Su Z, Zhou J. Genomic analysis of an effective lentiviral vaccine-attenuated equine infectious anemia virus vaccine EIAV FDDV13. Virus Genes 2010; 41:86-98. [PMID: 20526660 DOI: 10.1007/s11262-010-0491-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Accepted: 05/03/2010] [Indexed: 11/26/2022]
Abstract
Chinese equine infectious anemia virus (EIAV) attenuated vaccine is the first lentiviral vaccine with a successful application. In order to understand the correlation of viral genomic mutations with viral attenuation and with induced immunoprotective properties, we analyzed the proviral genome sequences of the EIAV-attenuated vaccine strain EIAV(FDDV13) (EIAV fetal donkey dermal cell-adapted vaccine) and its highly virulent parental strain EIAV(LN40). The sequences of these strains were compared with those of the major foreign EIAV strains. The results indicated a large genetic distance between the Chinese EIAV strain and the major EIAV strains in America and Japan. The Chinese strains belong to an independent phylogenetic branch. The divergence between the entire genome of the Chinese strains and that of other major EIAV strains is approximately 23%. The divergence rate in LTR is over 14%, whereas that in each open reading frame is over 20%. The gp90 exhibited a divergence of 35% in its nucleotide sequence and 40% in its amino acid sequence. The present study found that after long-term passage in vitro, EIAV(FDDV13) has accumulated many stable substitution mutations in each gene. These mutations at multiple sites in multiple genes of the vaccine strain, especially the conserved mutations, provide important references for further understanding the attenuation mechanism of Chinese EIAV-attenuated vaccine and the immunoprotection mechanism of lentiviral vaccines.
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Affiliation(s)
- Xu Qi
- Department of Neurology, First Affiliated Hospital of Harbin Medical University, Harbin, 150001, China
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JIANG CG, MA J, GAO X, LIN YZ, ZHAO LP, HUA YP, LIU D, ZHOU JH. Effects on In vitro Replication of Equine Infectious Anemia Virus Attenuated Vaccine Strain With Truncated Mutation in The Transmembrane Protein*. PROG BIOCHEM BIOPHYS 2010. [DOI: 10.3724/sp.j.1206.2009.00595] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Craigo JK, Barnes S, Zhang B, Cook SJ, Howe L, Issel CJ, Montelaro RC. An EIAV field isolate reveals much higher levels of subtype variability than currently reported for the equine lentivirus family. Retrovirology 2009; 6:95. [PMID: 19843328 PMCID: PMC2770520 DOI: 10.1186/1742-4690-6-95] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Accepted: 10/20/2009] [Indexed: 11/16/2022] Open
Abstract
Background Equine infectious anemia virus (EIAV), a lentivirus that infects horses, has been utilized as an animal model for the study of HIV. Furthermore, the disease associated with the equine lentivirus poses a significant challenge to veterinary medicine around the world. As with all lentiviruses, EIAV has been shown to have a high propensity for genomic sequence and antigenic variation, especially in its envelope (Env) proteins. Recent studies have demonstrated Env variation to be a major determinant of vaccine efficacy, emphasizing the importance of defining natural variation among field isolates of EIAV. To date, however, published EIAV sequences have been reported only for cell-adapted strains of virus, predominantly derived from a single primary virus isolate, EIAVWyoming (EIAVWY). Results We present here the first characterization of the Env protein of a natural primary isolate from Pennsylvania (EIAVPA) since the widely utilized and referenced EIAVWY strain. The data demonstrated that the level of EIAVPA Env amino acid sequence variation, approximately 40% as compared to EIAVWY, is much greater than current perceptions or published reports of natural EIAV variation between field isolates. This variation did not appear to give rise to changes in the predicted secondary structure of the proteins. While the EIAVPA Env was serologically cross reactive with the Env proteins of the cell-adapted reference strain, EIAVPV (derivative of EIAVWY), the two variant Envs were shown to lack any cross neutralization by immune serum from horses infected with the respective virus strains. Conclusion Taking into account the significance of serum neutralization to universal vaccine efficacy, these findings are crucial considerations towards successful EIAV vaccine development and the potential inclusion of field isolate Envs in vaccine candidates.
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Affiliation(s)
- Jodi K Craigo
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA 15261, USA.
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