51
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Miller CJ. Does viral tropism play a role in heterosexual transmission of HIV? Findings in the SIV-rhesus macaque model. AIDS Res Hum Retroviruses 1998; 14 Suppl 1:S79-82. [PMID: 9581889 PMCID: PMC3401011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Substantial effort is being directed toward generating vaccines that can prevent the heterosexual transmission of HIV-1. If "selection" for specific variants during sexual intercourse occurs, then vaccines should be designed to prevent transmission of these specific viruses. Using the SIV-rhesus macaque model to test the hypothesis that specific HIV genotypes are more efficient at producing infection by sexual transmission, it was possible to demonstrate that the genotypic determinants that permit SIV or SHIV to produce systemic infection differ depending on the route of virus inoculation. This finding supports the conclusion that there is selection for viral genotypes during sexual transmission of HIV. However, the ability of a virus to grow in rhesus macaque monocyte-derived macrophages in vitro does not predict the outcome of intravaginal inoculation with that virus. We did find that after intravenous inoculation all the vaginally transmitting viruses produced plasma antigenemia and high levels of plasma viral RNA. In contrast, although the nontransmitting viruses infect rhesus macaques after intravenous inoculation, the infection that occurs after intravenous inoculation is characterized by a lack of viral antigen in plasma and low levels of plasma viral RNA. On the basis of these results, it is clear that viruses which are adapted to replicate to high levels in vivo are transmitted by vaginal inoculation. This principle may also apply to the transmission of HIV in humans.
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Affiliation(s)
- C J Miller
- California Regional Primate Research Center, and Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California-Davis, 95616, USA
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52
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Cook RF, Leroux C, Cook SJ, Berger SL, Lichtenstein DL, Ghabrial NN, Montelaro RC, Issel CJ. Development and characterization of an in vivo pathogenic molecular clone of equine infectious anemia virus. J Virol 1998; 72:1383-93. [PMID: 9445039 PMCID: PMC124617 DOI: 10.1128/jvi.72.2.1383-1393.1998] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/1997] [Accepted: 10/16/1997] [Indexed: 02/05/2023] Open
Abstract
An infectious nonpathogenic molecular clone (19-2-6A) of equine infectious anemia virus (EIAV) was modified by substitution of a 3.3-kbp fragment amplified by PCR techniques from a pathogenic variant (EIAV(PV)) of the cell culture-adapted strain of EIAV (EIAV(PR)). This substitution consisted of coding sequences for 77 amino acids at the carboxyl terminus of the integrase, the S1 (encoding the second exon of tat), S2, and S3 (encoding the second exon of rev) open reading frames, the complete env gene (including the first exon of rev), and the 3' long terminal repeat (LTR). Modified 19-2-6A molecular clones were designated EIAV(PV3.3), and infection of a single pony (678) with viruses derived from a mixture of five of these molecular clones induced clinical signs of acute equine infectious anemia (EIA) at 23 days postinfection (dpi). As a consequence of this initial study, a single molecular clone, EIAV(PV3.3#3) (redesignated EIAV(UK)), was selected for further study and inoculated into two ponies (613 and 614) and two horses (700 and 764). Pony 614 and the two horses developed febrile responses by 12 dpi, which was accompanied by a 48 to 64% reduction in platelet number, whereas pony 613 did not develop fever (40.6 degrees C) until 76 dpi. EIAV could be isolated from the plasma of these animals by 5 to 7 dpi, and all became seropositive for antibodies to this virus by 21 dpi. Analysis of the complete nucleotide sequence demonstrated that the 3.3-kbp 3' fragment of EIAV(UK) differed from the consensus sequence of EIAV(PV) by just a single amino acid residue in the second exon of the rev gene. Complete homology with the EIAV(PV) consensus sequence was observed in the hypervariable region of the LTR. However, EIAV(UK) was found to contain an unusual 68-bp nucleotide insertion/duplication in a normally conserved region of the LTR sequence. These results demonstrate that substitution of a 3.3-kbp fragment from the EIAV(PV) strain into the infectious nonpathogenic molecular clone 19-2-6A leads to the production of progeny virus particles with the ability to induce clinical signs of EIA. Therefore, EIAV(UK), which is the first pathogenic, cell culture-adapted molecular clone of EIAV to be described, should be of value in identifying viral determinants of pathogenicity.
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Affiliation(s)
- R F Cook
- Department of Veterinary Science, Gluck Equine Research Center, University of Kentucky, Lexington 40546, USA.
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53
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Rudensey LM, Kimata JT, Long EM, Chackerian B, Overbaugh J. Changes in the extracellular envelope glycoprotein of variants that evolve during the course of simian immunodeficiency virus SIVMne infection affect neutralizing antibody recognition, syncytium formation, and macrophage tropism but not replication, cytopathicity, or CCR-5 coreceptor recognition. J Virol 1998; 72:209-17. [PMID: 9420217 PMCID: PMC109366 DOI: 10.1128/jvi.72.1.209-217.1998] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/1997] [Accepted: 09/24/1997] [Indexed: 02/05/2023] Open
Abstract
Simian immunodeficiency virus SIVMne, like human immunodeficiency virus, evolves from a macrophage-tropic, non-syncytium-inducing virus at early times in infection to a T-cell-tropic, syncytium-inducing, cytopathic virus population over the course of progression to AIDS. Because the viruses isolated late in SIVMne infection of macaques include a complex mixture of variants, the viral determinants of such phenotypic changes have not been defined. To identify genetic changes that are important to virus evolution in the host, we constructed chimeric viruses by introducing variant envelope genes representative of proviruses throughout the course of infection and disease into the SIVMne parental clone (SIVMneCL8) that infected the macaque. The chimeric viruses expressed sequences encoding the surface unit of the envelope glycoprotein (Env-SU) of variants cloned between 35 and 170 weeks postinfection. The chimera with Env-SU from 35 weeks postinfection encoded only four changes in V1 compared to SIVMneCL8, whereas the chimeras encoding Env-SU from variants isolated later in infection encoded progressively more mutations both in V1 and elsewhere. Like SIVMneCL8, the chimeras were infectious for CEMx174 cells and macaque peripheral blood mononuclear cells. However, in contrast to SIVMneCL8, the chimeric viruses did not infect macaque macrophages, although each retained the ability to recognize the CCR-5 coreceptor. Thus, these data provide direct evidence that changes which evolve in Env-SU during the course of SIVMne infection do not alter CCR-5 interactions. Viruses encoding Env-SU from the latest times in infection (121 to 170 weeks postinfection), after disease was apparent, were syncytium inducing. However, these viruses were not highly cytopathic, suggesting that additional viral determinants may be required for the rapidly replicating, cytopathic phenotype of the uncloned mixed variant population. Changes in Env-SU did allow the virus to escape serum neutralizing antibodies that recognized the SIVMneCL8 parent. Moreover, the chimera encoding the Env-SU of a virus from 35 weeks postinfection, which differed from SIVMneCL8 only in V1, was not sensitive to neutralization by infected macaque sera, suggesting that V1 may define a portion of the principal neutralizing determinant for SIVMne. Together, these data suggest that SIV variants with changes in the Env-SU may be selected primarily by virtue of their ability to escape neutralizing antibody recognition.
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Affiliation(s)
- L M Rudensey
- Department of Microbiology, University of Washington, Seattle 98195, USA
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54
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Lü X, Kiyono H, Lu D, Kawabata S, Torten J, Srinivasan S, Dailey PJ, McGhee JR, Lehner T, Miller CJ. Targeted lymph-node immunization with whole inactivated simian immunodeficiency virus (SIV) or envelope and core subunit antigen vaccines does not reliably protect rhesus macaques from vaginal challenge with SIVmac251. AIDS 1998; 12:1-10. [PMID: 9456249 PMCID: PMC3401021 DOI: 10.1097/00002030-199801000-00001] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Sexual transmission of HIV is the most common route of HIV transmission throughout the world. To prevent sexually transmitted HIV infection, a vaccine is urgently needed. A previous report demonstrated the targeted immunization of the iliac lymph nodes with simian immunodeficiency virus (SIV) subunits protects rhesus macaques from rectal challenge with SIV. We sought to determine whether this immunization strategy could protect rhesus macaques from vaginal challenge with SIV. DESIGN Macaques were immunized with either whole-killed SIV or envelope and core subunit antigen vaccines. Using three independent groups, with three macaques in each group, macaques were immunized by the targeted iliac lymph-node (TILN) route, injecting the vaccine close to the iliac lymph nodes that drain the genital tract. RESULTS The TILN immunization procedure induced high-titer SIV-specific immunoglobulin (Ig) G antibodies in serum in all animals and anti-SIV IgG and IgA antibodies in the cervicovaginal secretions of most animals. After a series of three or four TILN immunizations, the animals were intravaginally challenged with SIVmac251. All animals became virus isolation-positive, except one animal immunized with SIV p27 and gp120. This animal was virus isolation-negative but SIV DNA proviral sequences were detected in peripheral blood mononuclear cells. CONCLUSIONS In this series of studies, reliable protection from vaginal transmission of SIV was not achieved by the TILN immunization procedure.
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MESH Headings
- Animals
- Antibodies, Viral/analysis
- Antibodies, Viral/blood
- Antibodies, Viral/immunology
- Cells, Cultured
- Cervix Uteri/immunology
- DNA, Viral/analysis
- DNA, Viral/genetics
- DNA, Viral/immunology
- Disease Transmission, Infectious
- Female
- Gene Products, gag/genetics
- Gene Products, gag/immunology
- HIV Envelope Protein gp120/immunology
- Ilium
- Immunoglobulin A/analysis
- Immunoglobulin A/immunology
- Immunoglobulin G/analysis
- Immunoglobulin G/immunology
- Immunoglobulin M/analysis
- Immunoglobulin M/immunology
- Leukocytes, Mononuclear/virology
- Lymph Nodes/immunology
- Macaca
- Membrane Glycoproteins
- Polymerase Chain Reaction
- RNA, Viral/analysis
- RNA, Viral/genetics
- SAIDS Vaccines/administration & dosage
- SAIDS Vaccines/immunology
- Simian Acquired Immunodeficiency Syndrome/immunology
- Simian Acquired Immunodeficiency Syndrome/prevention & control
- Simian Acquired Immunodeficiency Syndrome/transmission
- Simian Immunodeficiency Virus/genetics
- Simian Immunodeficiency Virus/immunology
- Simian Immunodeficiency Virus/isolation & purification
- Vaccines, Inactivated/administration & dosage
- Vaccines, Inactivated/immunology
- Vaccines, Synthetic/administration & dosage
- Vaccines, Synthetic/immunology
- Vagina/immunology
- Vagina/virology
- Viral Envelope Proteins
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Affiliation(s)
- X Lü
- California Regional Primate Research Center, School of Veterinary Medicine, University of California Davis, USA
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55
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Fuller FJ. Genes controlling retroviral virulence. ADVANCES IN VETERINARY MEDICINE 1997; 40:135-55. [PMID: 9395732 DOI: 10.1016/s0065-3519(97)80007-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- F J Fuller
- Department of Microbiology, Pathology, and Parasitology, North Carolina State University, College of Veterinary Medicine, Raleigh 27606, USA
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56
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Kimata JT, Overbaugh J. The cytopathicity of a simian immunodeficiency virus Mne variant is determined by mutations in Gag and Env. J Virol 1997; 71:7629-39. [PMID: 9311845 PMCID: PMC192112 DOI: 10.1128/jvi.71.10.7629-7639.1997] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Previous studies suggested that the rapidly replicating, highly cytopathic, syncytium-inducing (rapid-high/SI) phenotype of simian immunodeficiency virus Mne variants that evolved in macaques inoculated with a slowly replicating, minimally cytopathic, non-syncytium-inducing (slow-low/NSI) molecular clone was not solely the result of changes in the envelope surface protein (Env SU). To define the viral determinants responsible for the change in phenotype, we molecularly cloned a rapid-high/SI variant (designated SIVMne170) derived from the peripheral blood mononuclear cells (PBMCs) of a pig-tailed macaque that was inoculated with a slow-low/NSI molecular clone, SIVMneCL8. SIVMne170 was SI and replicated with faster kinetics and was more cytopathic than the parent SIVMneCL8 in CEMx174 cells. Additionally, SIVMne170 was more cytopathic for the CD4+ T-cell population than SIVMneCL8 in macaque PBMCs. An analysis of chimeric viruses constructed between the variant SIVMne170 and the parent virus SIVMneCL8 demonstrated that there are determinants encoded within both the 5' and 3' halves of SIVMne170 that independently contribute to its rapid-high/SI phenotype. As we previously observed with other SIVMne variants, the Env SU of SIVMne170 was important for syncytium induction but was not a key determinant of cytopathicity. By contrast, the intracellular domain of the envelope transmembrane protein (Env TM) contributed to both the SI and cytopathic properties of SIVMne170. We also found that the minimal determinant within the 5' half of SIVMne170 that conferred its rapid replication kinetics and cytopathicity mapped to the capsid- and nucleocapsid-encoding regions of gag. Together, these data demonstrate that mutations selected in Gag and Env TM intracytoplasmic tail influence the replication and cytopathicity of SIVMne variants that evolve in the host.
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MESH Headings
- Amino Acid Sequence
- Animals
- CD4-Positive T-Lymphocytes/virology
- Cell Line
- Cells, Cultured
- Chimera
- Cloning, Molecular
- DNA Primers
- Gene Products, env/biosynthesis
- Gene Products, env/chemistry
- Gene Products, gag/biosynthesis
- Gene Products, gag/chemistry
- Genes, env
- Genes, gag
- Genetic Variation
- Giant Cells
- Humans
- Jurkat Cells
- Kinetics
- Lymphocytes/virology
- Macaca nemestrina
- Macrophages/virology
- Molecular Sequence Data
- Monocytes/virology
- Mutagenesis, Site-Directed
- Polymerase Chain Reaction
- Recombination, Genetic
- Simian Immunodeficiency Virus/genetics
- Simian Immunodeficiency Virus/pathogenicity
- Simian Immunodeficiency Virus/physiology
- Tumor Cells, Cultured
- Virus Replication
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Affiliation(s)
- J T Kimata
- Department of Microbiology, University of Washington, Seattle 98195, USA
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57
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Stephens EB, Joag SV, Atkinson B, Sahni M, Li Z, Foresman L, Adany I, Narayan O. Infected macaques that controlled replication of SIVmac or nonpathogenic SHIV developed sterilizing resistance against pathogenic SHIV(KU-1). Virology 1997; 234:328-39. [PMID: 9268165 DOI: 10.1006/viro.1997.8662] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Twenty macaques were used to evaluate the ability of nonpathogenic SIV(mac) or nonpathogenic chimeric SIV-HIV (SHIV) to induce protection in macaques against superinfection with a pathogenic variant of SHIV (SHIV(KU-1)) originally containing the tat, rev, vpu, and env of HIV-1 (strain HXB2) in a genetic background of SIV(mac)239. Specifically, three macaques inoculated with molecularly cloned, macrophage-tropic SIV(mac)LG1 developed an early systemic infection but recovered with only traces of SIV(mac) DNA in visceral lymphoid tissues. These animals were then inoculated parenterally with pathogenic SHIV(KU-1). All three animals resisted infection with SHIV(KU-1), as indicated by lack of virus recovery and absence of SHIV-specific env and vpu sequences in the visceral lymphoid tissues and multiple regions in the CNS. We also examined the ability of five macaques that had been inoculated with nonpathogenic SHIV (NP-SHIV) to withstand challenge with the pathogenic SHIV(KU-1). Like the SIV(mac)LG1-inoculated macaques, these animals also resisted SHIV(KU-1) challenge as judged by the inability to recover infectious virus, normal CD4+ T cell counts, and the absence of SHIV(KU-1) signature sequences in the lymph node tissue. Thus, eight of eight animals that developed control over primary lentivirus infections had also developed resistance to infection with pathogenic SHIV(KU-1). Three groups of macaques were used as controls for this study. The first group consisted of six macaques inoculated with SHIV(KU-1) alone. All animals developed viremia, showed severe loss of CD4+ T cells within 4 weeks, and succumbed to AIDS within 6 months. The second group of three macaques was inoculated first with SHIV(KU-1) and inoculated later with uncloned, neurovirulent SIV(mac)7F-Lu. A third group of three macaques was inoculated with SIV(mac)7F-Lu followed by inoculation with SHIV(KU-1). PCR analyses using oligonucleotide primers specific for the SIV or HIV env revealed that macaques from the last two groups had widespread infection with both SHIV(KU-1) and SIV(mac), indicating that animals that failed to control productive replication of either SHIV(KU-1) or SIV(mac)7F-Lu could not resist superinfection with the other virus. These data indicate that sterilizing immunity against the virulent SHIV could be induced in animals that had experienced an immunizing infection. Moreover, the divergence of the envelope glycoprotein of the protective avirulent and virulent challenge virus suggests that a single vaccine could protect against infection with a virus containing a different envelope glycoprotein.
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Affiliation(s)
- E B Stephens
- Department of Microbiology, Molecular Genetics, and Immunology, University of Kansas Medical Center, Kansas City 66160-7240, USA.
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58
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Pessler F, Pendergrast PS, Hernandez N. Purification and characterization of FBI-1, a cellular factor that binds to the human immunodeficiency virus type 1 inducer of short transcripts. Mol Cell Biol 1997; 17:3786-98. [PMID: 9199312 PMCID: PMC232230 DOI: 10.1128/mcb.17.7.3786] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The human immunodeficiency virus (HIV-1) promoter directs the synthesis of two classes of RNA molecules, short transcripts and full-length transcripts. The synthesis of short transcripts depends on a bipartite DNA element, the inducer of short transcripts (IST), located in large part downstream of the HIV-1 start site of transcription. IST does not require any viral product for function and is thought to direct the assembly of transcription complexes that are incapable of efficient elongation. Nothing is known, however, about the biochemical mechanisms that mediate IST function. Here, we report the identification and purification of a factor that binds specifically to the IST. This factor, FBI-1, recognizes a large bipartite binding site that coincides with the bipartite IST element. It is constituted at least in part by an 86-kDa polypeptide that can be specifically cross-linked to IST. FBI-1 also binds to promoter and attenuation regions of a number of cellular and viral transcription units that are regulated by a transcription elongation block. This observation, together with the observation that the binding of FBI-1 to IST mutants correlates with the ability of these mutants to direct IST function, suggests that FBI-1 may be involved in the establishment of abortive transcription complexes.
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Affiliation(s)
- F Pessler
- Cold Spring Harbor Laboratory, New York 11724, USA
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59
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Sinclair E, Barbosa P, Feinberg MB. The nef gene products of both simian and human immunodeficiency viruses enhance virus infectivity and are functionally interchangeable. J Virol 1997; 71:3641-51. [PMID: 9094638 PMCID: PMC191513 DOI: 10.1128/jvi.71.5.3641-3651.1997] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Adult rhesus macaques infected with nef-defective simian immunodeficiency virus (SIV) exhibit extremely low levels of steady-state virus replication, do not succumb to immunodeficiency disease, and are protected from experimental challenge with pathogenic isolates of SIV. Similarly, rare humans found to be infected with nef-defective human immunodeficiency virus type 1 (HIV-1) variants display exceptionally low viral burdens and do not show evidence of disease progression after many years of infection. HIV-1 Nef induces the rapid endocytosis and lysosomal degradation of cell surface CD4 and enhances virus infectivity in primary human T cells and macrophages. Although expression of SIV Nef also leads to down-modulation of cell surface CD4 levels, no evidence for SIV Nef-induced enhancement of virus infectivity was observed in earlier studies. Thus, it remains unclear whether fundamental differences exist between the activities of HIV-1 and SIV Nef. To establish more clearly whether the SIV and HIV-1 nef gene products are functionally analogous, we compared the replication kinetics and infectivity of variants of SIVmac239 that either do (SIVnef+) or do not (SIV delta nef) encode intact nef gene products. SIVnef+ replicates more rapidly than nef-defective viruses in both human and rhesus peripheral blood mononuclear cells (PBMCs). As previously described for HIV-1 Nef, SIV Nef also enhances virus infectivity within each cycle of virus replication. As a strategy for evaluating the in vivo contribution of HIV-1 nef alleles and long terminal repeat regulatory sequences to the pathogenesis of immunodeficiency disease, we constructed SIV-HIV chimeras in which the nef coding and U3 regulatory regions of SIVmac239 were replaced by the corresponding regions from HIV-1/R73 (SIVR7nef+). SIVR7nef+ displays enhanced infectivity and accelerated replication kinetics in primary human and rhesus PBMC infections compared to its nef-defective counterpart. Converse chimeras, containing SIV Nef in an HIV-1 background (R7SIVnef+) also exhibit greater infectivity than matched nef-defective viruses (R7SIV delta nef). These data indicate that SIV Nef, like that of HIV-1, does enhance virus replication in primary cells in tissue culture and that HIV-1 and SIV Nef are functionally interchangeable in the context of both HIV-1 and SIV.
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Affiliation(s)
- E Sinclair
- Gladstone Institute of Virology and Immunology, San Francisco, California 94141-100, USA
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60
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Chen Z, Zhou P, Ho DD, Landau NR, Marx PA. Genetically divergent strains of simian immunodeficiency virus use CCR5 as a coreceptor for entry. J Virol 1997; 71:2705-14. [PMID: 9060623 PMCID: PMC191392 DOI: 10.1128/jvi.71.4.2705-2714.1997] [Citation(s) in RCA: 254] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Entry of human immunodeficiency virus type 1 (HIV-1) requires CD4 and one of a family of related seven-transmembrane-domain coreceptors. Macrophage-tropic HIV-1 isolates are generally specific for CCR5, a receptor for the CC chemokines RANTES, MIP-1alpha, and MIP-1beta, while T-cell line-tropic viruses tend to use CXCR4 (also known as fusin, LESTR, or HUMSTR). Like HIV-1, simian immunodeficiency virus (SIV) requires CD4 on the target cell surface; however, whether it also requires a coreceptor is not known. We report here that several genetically divergent SIV isolates, including SIVmac, SIVsmSL92a, SIVsmLib-1, and SIVcpzGAB, can use human and rhesus CCR5 for entry. CXCR4 did not facilitate entry of any of the simian viruses tested, nor did any of the other known chemokine receptors. Moreover, SIVmac251 that had been extensively passaged in a human transformed T-cell line retained its use of CCR5. Rhesus and human CCR5 differed at only eight amino acid residues, four of which were in regions of the receptor that could be exposed, two in the amino-terminal extracellular region and two in the second extracellular loop. The human coreceptor was as active as the simian for SIV entry. In addition, HIV-1 was able to use the rhesus homologs of the human coreceptors, CCR5 and CXCR4. The SIV strains tested were specific for CCR5 regardless of whether they were able to replicate in transformed T-cell lines or macrophages and whether they were phenotypically syncytium inducing or noninducing in MT-2 cells. However, SIV replication was not restricted to cells expressing CCR5. SIV strains replicated efficiently in the human transformed lymphoid cell line CEMx174, which does not express detectable amounts of transcripts of CCR5. SIV also replicated in human peripheral blood mononuclear cells that were genetically deficient in CCR5. These findings indicated that, in addition to CCR5, SIV can use one or more unknown coreceptors that are expressed on human PBMCs and CEMx174 cells.
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Affiliation(s)
- Z Chen
- Aaron Diamond AIDS Research Center, The Rockefeller University, New York, New York 10016, USA
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61
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Miller CJ, McChesney MB, Lü X, Dailey PJ, Chutkowski C, Lu D, Brosio P, Roberts B, Lu Y. Rhesus macaques previously infected with simian/human immunodeficiency virus are protected from vaginal challenge with pathogenic SIVmac239. J Virol 1997; 71:1911-21. [PMID: 9032322 PMCID: PMC191267 DOI: 10.1128/jvi.71.3.1911-1921.1997] [Citation(s) in RCA: 116] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Nontraumatic vaginal inoculation of rhesus macaques with a simian/human immunodeficiency virus (SIV/HIV) chimera containing the envelope gene from HIV-1 89.6 (SHIV 89.6) results in systemic infection (Y. Lu, B. Brosio, M. Lafaile, J. Li, R. G. Collman, J. Sodroski, and C. J. Miller, J. Virol. 70:3045-3050, 1996). A total of five rhesus macaques have each been infected by exposure to at least three intravaginal inoculations of SHIV 89.6. The SHIV 89.6 infection is characterized by a transient viremia that evokes humoral and cellular immune responses to HIV and SIV antigens, but disease does not develop in animals infected with SHIV 89.6. To determine if a previous infection with SHIV 89.6 by vaginal inoculation could protect animals from vaginal challenge with pathogenic SIV, all five animals were intravaginally inoculated twice with pathogenic SIV-mac239. After challenge, all of the SHIV-immunized animals had low or undetectable viral RNA levels in plasma compared to control animals. Three of the five of the SHIV-immunized animals remained virus isolation negative for more than 8 months, while two became virus isolation positive. The presence of SIV Gag-specific cytotoxic T lymphocytes in peripheral blood mononuclear cells and SIV-specific antibodies in cervicovaginal secretions at the time of challenge was associated with resistance to pathogenic SIV infection after vaginal challenge. These results suggest that protection from sexual transmission of HIV may be possible by effectively stimulating both humoral and cellular antiviral immunity in the systemic and genital mucosal immune compartments.
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Affiliation(s)
- C J Miller
- California Regional Primate Research Center, Department of Pathology, School of Veterinary Medicine, University of California Davis, 95616, USA.
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62
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Zou W, Lackner AA, Simon M, Durand-Gasselin I, Galanaud P, Desrosiers RC, Emilie D. Early cytokine and chemokine gene expression in lymph nodes of macaques infected with simian immunodeficiency virus is predictive of disease outcome and vaccine efficacy. J Virol 1997; 71:1227-36. [PMID: 8995646 PMCID: PMC191177 DOI: 10.1128/jvi.71.2.1227-1236.1997] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Competitive PCR was used to evaluate the expression of cytokine, granzyme B, and chemokine genes in lymph nodes of macaques recently infected with the simian immunodeficiency virus (SIV) pathogenic molecular clone SIVmac239 (n = 16), the nonpathogenic vaccine strain SIVmac239 delta nef (n = 8), and the nonpathogenic molecular clone SIVmac1A11 (n = 8). For both SIVmac239 and its nef-deleted derivative, strong expression was observed as early as 7 days postinfection for interleukin 1beta (IL-1beta), IL-6, tumor necrosis factor alpha, gamma interferon, and IL-13. The levels of gene induction were equally intense for both viruses despite a lower viral load for SIVmac239 deltanef compared with that for SIVmac239. However, the nature of the cytokine network activation varied with the viral inocula. Primary infection with SIVmac239 was characterized by a higher level of IL-4, IL-10, MIP-1alpha, MIP-1beta, MCP-1, and RANTES gene expression and a lower level of IL-12 and granzyme B gene expression compared with infection with SIVmac239 delta nef. Thus, infection with nef-deleted SIV was associated with a preferential Th1 versus Th2 pattern of cytokine production. Infection with SIVmac1A11 was characterized by a delayed immune response for all markers tested. The unique patterns of cytokine and chemokine gene expression in lymph nodes correlated nicely with the pathogenic potential of the SIV strains used as well as with differences in their ability to serve as protective vaccines.
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Affiliation(s)
- W Zou
- Institut Paris-Sud sur les Cytokines, INSERM U131, Clamart, France
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63
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Sawai ET, Khan IH, Montbriand PM, Peterlin BM, Cheng-Mayer C, Luciw PA. Activation of PAK by HIV and SIV Nef: importance for AIDS in rhesus macaques. Curr Biol 1996; 6:1519-27. [PMID: 8939608 DOI: 10.1016/s0960-9822(96)00757-9] [Citation(s) in RCA: 130] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND The primate lentiviruses, human immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2) and simian immunodeficiency virus (SIV), encode a conserved accessory gene product, Nef. In vivo, Nef is important for the maintenance of high virus loads and progression to AIDS in SIV-infected adult rhesus macaques. In tissue culture cells expressing Nef, this viral protein interacts with a cellular serine kinase, designated Nef-associated kinase. RESULTS This study identifies the Nef-associated kinase as a member of the p21-activated kinase (PAK) family of kinases and investigates the role of this Nef-associated kinase in vivo. Mutants of Nef that do not associate with the cellular kinase are unable to activate the PAK-related kinase in infected cells. To determine the role of cellular kinase association in viral pathogenesis, macaques were infected with SIV containing point-mutations in Nef that block PAK activation. Virus recovered at early time points after inoculation with mutant virus was found to have reverted to prototype Nef function and sequence. Reversion of the kinase-negative mutant to a kinase-positive genotype in macaques infected with the mutant virus preceded the induction of high virus loads and disease progression. CONCLUSIONS Nef associates with and activates a PAK-related kinase in lymphocytes infected in vitro. Moreover, the Nef-mediated activation of a PAK-related kinase correlates with the induction of high virus loads and the development of AIDS in the infected host. These findings reveal that there is a strong selective pressure in vivo for the interaction between Nef and the PAK-related kinase.
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Affiliation(s)
- E T Sawai
- Department of Medical Pathology, University of California, Davis 95616, USA.
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64
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Lichtenstein DL, Issel CJ, Montelaro RC. Genomic quasispecies associated with the initiation of infection and disease in ponies experimentally infected with equine infectious anemia virus. J Virol 1996; 70:3346-54. [PMID: 8648664 PMCID: PMC190205 DOI: 10.1128/jvi.70.6.3346-3354.1996] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Equine infectious anemia virus (EIAV) provides a uniquely dynamic system in which to study the mechanism and role of genomic variation in lentiviral persistence and pathogenesis. We have used a Shetland pony model of infection to investigate the association of specific long terminal repeat (LTR) and env gene genomic sequences with the initiation of infection and the onset of disease. We analyzed viral RNA isolated from a pathogenic stock of virus (EIAV PV) and from plasma taken during the first disease episode from two ponies infected with EIAV PV. Overall sequence variation within gp90 was low in EIAV PV and only slightly higher in plasma virus samples isolated from ponies during the first disease episode. However, a high proportion of mutations were localized to the principal neutralizing domain in EIAV PV and to the principal neutralizing domain and the gp90 hypervariable region in the two pony-derived samples. The rate of fixation of mutations was analyzed and determined to be approximately 4 x 10(-2) mutations per site per year. Sequence diversity within the U3 region of the LTR was extremely low, which suggested that the previously reported hypervariability of this region may be a consequence of selection for replication of EIAV in different host cells. The predominant EIAV PV env and LTR sequences were used to construct chimeric viruses so that the contribution of these sequences to viral pathogenicity could be examined. The chimeras replicated in cultured equine monocytes to the same extent as the parental nonpathogenic virus and did not cause disease in Shetland ponies by 120 days postinfection, suggesting that the EIAV genomic determinants of pathogenesis are complex.
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Affiliation(s)
- D L Lichtenstein
- Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pennsylvania 15261, USA
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65
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Abstract
Research on human immunodeficiency virus (HIV) infection is compromised by the obvious limitation in having for study only virus-infected individuals or those exposed to the virus. Steps involved in transmission or pathogenesis require planned experimentation. The identification of animal models of acquired immunodeficiency syndrome (AIDS) has therefore been helpful for evaluating phases of HIV pathogenesis. Of the seven subgenera of lentiviruses now recognized, two share the characteristics with HIV of a T cell tropism and the associated loss of CD4+ cells in the host associated with disease: the feline immunodeficiency virus (FIV) and the simian immunodeficiency virus (SIV) (Table 1). The other animal lentiviruses grow best in macrophages and their infection generally reflects clinical sequellae of infection of this cell type. This review addresses those features of SIV, HIV, and SHIV infections of non-human primates that illustrate the importance of the animal models of AIDS.
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Affiliation(s)
- J A Levy
- Department of Medicine, University of California, School of Medicine, San Francisco 94143-1270, USA
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66
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Lu S, Arthos J, Montefiori DC, Yasutomi Y, Manson K, Mustafa F, Johnson E, Santoro JC, Wissink J, Mullins JI, Haynes JR, Letvin NL, Wyand M, Robinson HL. Simian immunodeficiency virus DNA vaccine trial in macaques. J Virol 1996; 70:3978-91. [PMID: 8648735 PMCID: PMC190276 DOI: 10.1128/jvi.70.6.3978-3991.1996] [Citation(s) in RCA: 187] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
An experimental vaccine consisting of five DNA plasmids expressing different combinations and forms of simian immunodeficiency virus-macaque (SIVmac) proteins has been evaluated for the ability to protect against a highly pathogenic uncloned SIVmac251 challenge. One vaccine plasmid encoded nonreplicating SIVmac239 virus particles. The other four plasmids encoded secreted forms of the envelope glycoproteins of two T-cell-tropic relatives (SIVmac239 and SIVmac251) and one monocyte/macrophage-tropic relative (SIVmac316) of the uncloned challenge virus. Rhesus macaques were inoculated with DNA at 1 and 3, 11 and 13, and 21 and 23 weeks. Four macaques were inoculated intravenously, intramuscularly, and by gene gun inoculations. Three received only gene gun inoculations. Two control monkeys were inoculated with control plasmids by all three routes of inoculation. Neutralizing antibody titers of 1:216 to 1:768 were present in all of the vaccinated monkeys after the second cluster of inoculations. These titers were transient, were not boosted by the third cluster of inoculations, and had fallen to 1:24 to 1:72 by the time of challenge. Cytotoxic T-cell activity for Env was also raised in all of the vaccinated animals. The temporal appearance of cytotoxic T cells was similar to that of antibody. However, while antibody responses fell with time, cytotoxic T-cell responses persisted. The SIVmac251 challenge was administered intravenously at 2 weeks following the last immunization. The DNA immunizations did not prevent infection or protect against CD4+ cell loss. Long-term chronic levels of infection were similar in the vaccinated and control animals, with 1 in 10,000 to 1 in 100,000 peripheral blood cells carrying infectious virus. However, viral loads were reduced to the chronic level over a shorter period of time in the vaccinated groups (6 weeks) than in the control group (12 weeks). Thus, the DNA vaccine raised both neutralizing antibody and cytotoxic T-lymphocyte responses and provided some attenuation of the acute phase of infection, but it did not prevent the loss of CD4+ cells.
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Affiliation(s)
- S Lu
- Department of Pathology, University of Massachusetts Medical Center, Worcester 01655, USA
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67
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Lu Y, Brosio P, Lafaile M, Li J, Collman RG, Sodroski J, Miller CJ. Vaginal transmission of chimeric simian/human immunodeficiency viruses in rhesus macaques. J Virol 1996; 70:3045-50. [PMID: 8627782 PMCID: PMC190165 DOI: 10.1128/jvi.70.5.3045-3050.1996] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Chimeric simian/human immunodeficiency viruses (SHIVs) that express the env genes derived from distinct HIV type 1 (HIV-1) isolates were tested for the ability to infect rhesus macaques following intravaginal inoculation. SHIVs containing either the HIV-1 HXBc2 or the HIV-1 89.6 envelope glycoproteins were capable of replicating in intravenously inoculated rhesus macaques. However, intravaginal inoculation of animals with these two SHIVs resulted in infection only with the SHIV containing the HIV-1 89.6 glycoprotein. Thus, properties conferred by the envelope glycoproteins in the chimeric virus affect the ability of particular SHIVs to initiate a systemic infection following vaginal inoculation. These results provide indirect support for the hypothesis that the selection of specific viral variants occurs in the genital tracts of individuals exposed to HIV by sexual contact.
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Affiliation(s)
- Y Lu
- Virus Research Institute, Cambridge, Massachusetts 02138, USA
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68
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Gardner MB, Luciw PA, Sawai ET, Marthas ML, Miller CJ, McChesney MB, Lerche NW, Pedersen NC. Simian retrovirus vaccines: simian retrovirus and simian immunodeficiency lentivirus. AIDS Res Hum Retroviruses 1996; 12:399-401. [PMID: 8882318 DOI: 10.1089/aid.1996.12.399] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- M B Gardner
- Department of Medical Pathology, University of California at Davis 95616, USA
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69
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Clements JE, Zink MC. Molecular biology and pathogenesis of animal lentivirus infections. Clin Microbiol Rev 1996; 9:100-17. [PMID: 8665473 PMCID: PMC172884 DOI: 10.1128/cmr.9.1.100] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Lentiviruses are a subfamily of retroviruses that are characterized by long incubation periods between infection of the host and the manifestation of clinical disease. Human immunodeficiency virus type 1, the causative agent of AIDS, is the most widely studied lentivirus. However, the lentiviruses that infect sheep, goats, and horses were identified and studied prior to the emergence of human immunodeficiency virus type 1. These and other animal lentiviruses provide important systems in which to investigate the molecular pathogenesis of this family of viruses. This review will focus on two animal lentivirus models: the ovine lentivirus visna virus; and the simian lentivirus, simian immunodeficiency virus. These animal lentiviruses have been used to examine, in particular, the pathogenesis of lentivirus-induced central nervous system disease as models for humans with AIDS as well as other chronic diseases.
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Affiliation(s)
- J E Clements
- Division of Comparative Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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70
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Sakuragi S, Sakuragi J, Adachi A. Both SU and TM env proteins are responsible for monkey cell tropism of simian immunodeficiency virus SIV mac. Arch Virol 1995; 140:2255-60. [PMID: 8572945 DOI: 10.1007/bf01323244] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
While simian immunodeficiency virus (SIV) derived from an infectious molecular clone pMA239 is tropic and pathogenic for monkeys, the virus derived from another infectious clone pMA142 does not replicate in monkey cells. To determine genetic sequences responsible for this tropism, a series of recombinant clones were constructed from pMA142 and pMA239. The determinant in pMA239 was mapped within regions encompassing the env gene. Viruses, which carry the 239 env gene encoding surface and/or transmembrane proteins, were tropic for monkey cells.
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Affiliation(s)
- S Sakuragi
- Institute for Virus Research, Kyoto University, Japan
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71
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Hoch J, Lang SM, Weeger M, Stahl-Hennig C, Coulibaly C, Dittmer U, Hunsmann G, Fuchs D, Müller J, Sopper S. vpr deletion mutant of simian immunodeficiency virus induces AIDS in rhesus monkeys. J Virol 1995; 69:4807-13. [PMID: 7609047 PMCID: PMC189293 DOI: 10.1128/jvi.69.8.4807-4813.1995] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
In previous experiments, animals infected with SIVmac239 containing a point mutation in the vpr and nef genes developed AIDS-like symptoms after early reversion of the vpr and nef genes. Here we show that two animals in which the nef gene but not the vpr gene had reverted in the first few months did not develop disease during a 3-year observation period even after reversion to a functional vpr gene 70 weeks postinfection. To study the influence of a stable vpr mutation on virus load and pathogenesis, a 43-bp deletion was introduced into the vpr gene of SIVmac239on, a nef-open mutant of SIVmac239. Four rhesus monkeys were inoculated with the vpr deletion mutant (SIV delta vpr), and two control animals were infected with SIVmac239on. Both control animals had persistent antigenemia, high cell-associated virus loads, and elevated neopterin levels. They had to be euthanized 20 and 30 weeks postinfection because of AIDS-related symptoms. However, all four rhesus monkeys inoculated with SIV delta vpr showed only transiently detectable antigenemia. The cell-associated virus loads were high in three of the four animals. Two animals with AIDS-like symptoms had to be euthanized 71 and 73 weeks postinfection. The two remaining monkeys infected with SIV delta vpr were still alive 105 weeks postinfection. In contrast to the SIVmac239on-infected animals, SIV delta vpr-infected animals had strong humoral immune responses and intermittent cellular immune responses to SIV antigens. Our data show that a functional vpr gene is not necessary for pathogenesis. However, vpr-deficient SIVmac239 variants might be slightly attenuated, allowing some animals to resist progression to disease for an extended period of time.
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Affiliation(s)
- J Hoch
- Institut für Klinische und Molekulare Virologie, Universität Erlangen-Nürnberg, Germany
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72
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Luciw PA, Pratt-Lowe E, Shaw KE, Levy JA, Cheng-Mayer C. Persistent infection of rhesus macaques with T-cell-line-tropic and macrophage-tropic clones of simian/human immunodeficiency viruses (SHIV). Proc Natl Acad Sci U S A 1995; 92:7490-4. [PMID: 7638218 PMCID: PMC41365 DOI: 10.1073/pnas.92.16.7490] [Citation(s) in RCA: 181] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
To elucidate the functions of human immunodeficiency virus type 1 (HIV-1) genes in a nonhuman primate model, we have constructed infectious recombinant viruses (chimeras) between the pathogenic molecular clone of simian immunodeficiency virus (SIV) SIVmac239 and molecular clones of HIV-1 that differ in phenotypic properties controlled by the env gene. HIV-1SF33 is a T-cell-line-tropic virus which induces syncytia, and HIV-1SF162 is a macrophage-tropic virus that does not induce syncytia. A DNA fragment encoding tat, rev, and env (gp160) of SIVmac239 has been replaced with the counterpart genetic region of HIV-1SF33 and HIV-1SF162 to derive chimeric recombinant simian/human immunodeficiency virus (SHIV) strains SHIVSF33 and SHIVSF162, respectively. In the acute infection stage, macaques inoculated with SHIVSF33 had levels of viremia similar to macaques infected with SIVmac239, whereas virus loads were 1/10th to 1/100th those in macaques infected with SHIVSF162. Of note is the relatively small amount of virus detected in lymph nodes of SHIVSF162-infected macaques. In the chronic infection stage, macaques infected with SHIVSF33 also showed higher virus loads than macaques infected with SHIVSF162. Virus persists for over 1 year, as demonstrated by PCR for amplification of viral DNA in all animals and by virus isolation in some animals. Antiviral antibodies, including antibodies to the HIV-1 env glycoprotein (gp160), were detected; titers of antiviral antibodies were higher in macaques infected with SHIVSF33 than in macaques infected with SHIVSF162. Although virus has persisted for over 1 year after inoculation, these animals have remained healthy with no signs of immunodeficiency. These findings demonstrate the utility of the SHIV/macaque model for analyzing HIV-1 env gene functions and for evaluating vaccines based on HIV-1 env antigens.
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Affiliation(s)
- P A Luciw
- Department of Medical Pathology, University of California, Davis 95616, USA
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73
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Marthas ML, van Rompay KK, Otsyula M, Miller CJ, Canfield DR, Pedersen NC, McChesney MB. Viral factors determine progression to AIDS in simian immunodeficiency virus-infected newborn rhesus macaques. J Virol 1995; 69:4198-205. [PMID: 7769679 PMCID: PMC189157 DOI: 10.1128/jvi.69.7.4198-4205.1995] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
To evaluate how viral variants may affect disease progression in human pediatric AIDS, we studied the potential of three simian immunodeficiency virus (SIV) isolates to induce simian AIDS in newborn rhesus macaques. The three virus isolates were previously shown to range from pathogenic (SIVmac251 and SIVmac239) to nonpathogenic (SIVmac1A11) when inoculated intravenously into juvenile and adult rhesus macaques. Six newborn macaques inoculated with pathogenic, uncloned SIVmac251 developed persistent, high levels of cell-associated and cell-free viremia, had no detectable antiviral antibodies, and had poor weight gain; these animals all exhibited severe clinical disease and pathologic lesions diagnostic for simian AIDS and were euthanatized 10 to 26 weeks after inoculation. Two newborns inoculated with pathogenic, molecularly cloned SIVmac239 developed persistent high virus load in peripheral blood, but both animals had normal weight gain and developed antiviral antibodies. One of the SIVmac239-infected neonates exhibited pathologic lesions diagnostic for SAIDS and was euthanatized at 34 weeks after inoculation; the other SIVmac239-infected neonate remained alive and exhibited no significant clinical disease for more than 1 year after inoculation. In contrast, three newborn rhesus macaques inoculated with the nonpathogenic molecular clone, SIVmac1A11, had transient, low-level viremia, seroconverted by 10 weeks after inoculation, had normal weight gain, and remained healthy for over 1 year. These results indicate that (i) newborn rhesus macaques infected with an uncloned, virulent SIVmac isolate have a more rapid, fulminant disease course than do adults inoculated with the same virus, (ii) the most rapid disease progression is associated with lack of a detectable humoral immune response in SIV-infected infant macaques, (iii) a molecularly cloned, attenuated SIV isolate is nonpathogenic in neonatal macaques, and (iv) SIV-infected neonatal macaques exhibit patterns of infection, virus load, and disease progression similar to those observed in human immunodeficiency virus-infected children. This SIV/neonatal rhesus model of pediatric AIDS provides a rapid, sensitive model with which to compare the virulence of SIV isolates and to study the mechanisms underlying the differences in disease progression in human immunodeficiency virus-infected infants.
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Affiliation(s)
- M L Marthas
- California Regional Primate Research Center, University of California, Davis 95616, USA
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74
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Endres CL, Bergquam E, Axthelm MK, Wong SW. Assessing genetic-based therapies for AIDS using the simian immunodeficiency virus. J Med Primatol 1995; 24:141-4. [PMID: 8751053 DOI: 10.1111/j.1600-0684.1995.tb00159.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A plasmid encoding the full-length infectious molecular proviral clone of SIVmac239 was generated. Virus derived from cells transfected with this clone replicated to high levels and was cytopathic for some transformed human CD4+ cell lines and primary rhesus macaque peripheral blood mononuclear cells. Since replication of SIV requires the functional expression of the viral encoded rev protein, transient co-transfection studies were initiated with the infectious proviral clone and a well-characterized trans-dominant negative HIV-1 rev mutant.
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Affiliation(s)
- C L Endres
- Division of Pathobiology and Immunology, Oregon Regional Primate Research Center, Beaverton, USA
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75
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Stone JD, Heise CC, Canfield DR, Elices MJ, Dandekar S. Differences in viral distribution and cell adhesion molecule expression in the intestinal tract of rhesus macaques infected with pathogenic and nonpathogenic SIV. J Med Primatol 1995; 24:132-40. [PMID: 8751052 DOI: 10.1111/j.1600-0684.1995.tb00158.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We investigated SIV infection and expression of adhesion molecules in the small intestine of rhesus macaques infected with pathogenic SIV (SIVmac) or nonpathogenic clone (SIV1A11). There was a wider dissemination and marked difference in tissue localization of SIVmac relative to SIV1A11. Our results also indicate that viral pathogenicity is associated with increased migration of inflammatory cells expressing VLA-alpha 4, LFA-1 alpha, Mac-1 alpha, ICAM-1, and beta 2 integrin into the intestinal mucosa.
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Affiliation(s)
- J D Stone
- Department of Internal Medicine, University of California, Davis, USA
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76
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Sasseville VG, Lane JH, Walsh D, Ringler DJ, Lackner AA. VCAM-1 expression and leukocyte trafficking to the CNS occur early in infection with pathogenic isolates of SIV. J Med Primatol 1995; 24:123-31. [PMID: 8751051 DOI: 10.1111/j.1600-0684.1995.tb00157.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
This study reports on the endothelial expression of vascular cell adhesion molecule-1 (VCAM-1) in the central nervous system (CNS) early after experimental infection of rhesus monkeys (Macaca mulatta) with pathogenic and nonpathogenic simian immunodeficiency virus (SIV). Diffuse endothelial expression of VCAM-1 was observed in the CNS in all animals receiving pathogenic SIV. These findings demonstrate the rapidity with which pathogenic SIV is able to enter the CNS and induce endothelial cell activation.
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Affiliation(s)
- V G Sasseville
- Division of Comparative Pathology, New England Regional Primate Research Center, Harvard Medical School, Southborough, MA, 01772-9102, USA
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77
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Baskin GB, Martin LN, Murphey-Corb M, Hu FS, Kuebler D, Davison B. Distribution of SIV in lymph nodes of serially sacrificed rhesus monkeys. AIDS Res Hum Retroviruses 1995; 11:273-85. [PMID: 7742041 DOI: 10.1089/aid.1995.11.273] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Rhesus monkeys were inoculated with SIVDeltaB670 and sacrificed 2, 4, 8, and 24 weeks after inoculation or when moribund. Two monkeys predicted to have a rapid disease course and two predicted to have a slower disease course were sacrificed at each time point. Lymph nodes were studied by histopathology, immunohistochemistry, in situ hybridization, electron microscopy, flow cytometry for lymphocyte subsets, and mitogen responsiveness. A greater selective decrease in peripheral CD4+CD29+ (helper-inducer/memory) T cells occurred in monkeys with high antigenemia. Although the percentage of CD8+ lymphocytes was increased and the CD4+/CD8+ ratio decreased in all infected groups, there were no consistent differences between monkeys with high or low antigenemia in lymph node lymphocyte subsets. Blastogenic responses of lymph node lymphocytes to PHA, ConA, or PWM were not significantly altered in infected monkeys. A reticular pattern typical of antigen deposition within germinal center follicular dendritic cells was seen in three monkeys with atrophic lymph nodes, high serum antigenemia, and a low percentage of circulating CD4+/CD29+ cells. More individually stained cells were in monkeys with high serum antigen and in moribund animals. By in situ hybridization, most monkeys had signal in a reticular pattern of germinal centers. Animals with higher levels of serum antigenemia tended to have more infected cells and a more intense signal. Extracellular virions were found between the FDC foot processes in the germinal centers of lymph nodes. Disease course was already established 2 weeks after inoculation.
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Affiliation(s)
- G B Baskin
- Department of Pathology, Tulane Regional Primate Research Center, Tulane University, Covington, Louisiana 70433, USA
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78
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Lohman BL, McChesney MB, Miller CJ, McGowan E, Joye SM, Van Rompay KK, Reay E, Antipa L, Pedersen NC, Marthas ML. A partially attenuated simian immunodeficiency virus induces host immunity that correlates with resistance to pathogenic virus challenge. J Virol 1994; 68:7021-9. [PMID: 7933084 PMCID: PMC237139 DOI: 10.1128/jvi.68.11.7021-7029.1994] [Citation(s) in RCA: 125] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Three infectious, attenuated molecular clones of simian immunodeficiency virus (SIVmac) were tested for viral and host determinants of protective immunity. The viruses differed in degree of virulence from highly attenuated to moderately attenuated to partially attenuated. Levels of immune stimulation and antiviral immunity were measured in rhesus macaques inoculated 2 years previously with these viruses. Monkeys infected with the highly attenuated or moderately attenuated viruses had minimal lymphoid hyperplasia, normal CD4/CD8 ratios, low levels of SIV-specific antibodies, and cytotoxic T-lymphocyte activity against p55gag (Gag) or gp160env (Env). Monkeys infected with the partially attenuated virus had moderate to marked lymphoid hyperplasia, normal CD4/CD8 ratios, high levels of SIV-specific antibodies, and cytotoxic T-lymphocyte activity against both Gag and Env. After pathogenic virus challenge, monkeys immunized with the partially attenuated virus had 100- to 1,000-fold-lower viral load in peripheral blood mononuclear cells and lymph node mononuclear cells than naive control animals. One of four monkeys immunized with the highly attenuated virus and two of four monkeys immunized with the moderately attenuated virus developed similarly low viral loads after challenge. These three attenuated strains of SIV induced a spectrum of antiviral immunity that was inversely associated with their degree of attenuation. Only the least attenuated virus induced resistance to challenge infection in all immunized monkeys.
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Affiliation(s)
- B L Lohman
- Department of Medicine, University of California--Davis 95616
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Miller CJ, Marthas M, Torten J, Alexander NJ, Moore JP, Doncel GF, Hendrickx AG. Intravaginal inoculation of rhesus macaques with cell-free simian immunodeficiency virus results in persistent or transient viremia. J Virol 1994; 68:6391-400. [PMID: 8083977 PMCID: PMC237059 DOI: 10.1128/jvi.68.10.6391-6400.1994] [Citation(s) in RCA: 148] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The simian immunodeficiency virus (SIV)-rhesus macaque model of heterosexual human immunodeficiency virus transmission consists of atraumatic application of cell-free SIVmac onto the intact vaginal mucosa of mature female rhesus macaques. This procedure results in systemic infection, and eventually infected animals develop the clinical signs and pathologic changes of simian AIDS. To achieve 100% transmission with the virus stocks used to date, multiple intravaginal inoculations are required. The current titration study utilized two stocks of SIVmac and demonstrated that a single intravaginal dose of cell-free SIV can reliably produce infection in rhesus macaques. This study also demonstrated that some animals intravaginally inoculated with cell-free SIVmac develop transient viremia characterized by a limited ability to isolate virus from peripheral blood mononuclear cells and lymph node mononuclear cells and no seroconversion to SIV antigen. SIV could be isolated from the peripheral lymph nodes of transiently viremic animals only during periods of viremia and not at times when SIV was not detected in circulating mononuclear cells. Thus, peripheral lymphoid tissues were not reservoirs of infection in the transiently viremic animals. Taken together, these results suggest either that the SIV infection was cleared in the transiently viremic animals or that SIV infection is limited to a compartment of the genital mucosal immune system that cannot be assessed by monitoring SIV infection in peripheral blood mononuclear cells and peripheral lymphoid tissue.
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Affiliation(s)
- C J Miller
- California Regional Primate Research Center, School of Veterinary Medicine, University of California, Davis 95616
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80
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Lackner AA, Vogel P, Ramos RA, Kluge JD, Marthas M. Early events in tissues during infection with pathogenic (SIVmac239) and nonpathogenic (SIVmac1A11) molecular clones of simian immunodeficiency virus. THE AMERICAN JOURNAL OF PATHOLOGY 1994; 145:428-39. [PMID: 8053500 PMCID: PMC1887396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The extent of virus replication, tissue distribution, localization of virus within tissues, and the presence of pathological lesions was examined early after experimental infection of rhesus monkeys with simian immunodeficiency virus (SIV). Three strains of SIV were used: molecularly cloned pathogenic SIVmac239; molecularly cloned nonpathogenic SIVmac1A11; and uncloned pathogenic SIVmac. The major targets of infection in all animals at 2 weeks postinoculation were the thymus and spleen. The distribution of virus within lymphoid organs varied with the viral inoculum: nonpathogenic SIVmac1A11 was present primarily within lymphoid follicles and in the thymic cortex; SIVmac239 was present primarily within periarteriolar lymphoid sheaths in the spleen, the paracortex of lymph nodes, and the medulla of the thymus; uncloned SIVmac was present in all these areas but tended to parallel the distribution of SIVmac239. Animals inoculated with nonpathogenic SIVmac1A11 had fewer SIV-positive cells by in situ hybridization and after 13 weeks postinoculation, virus was undetectable in any tissue from these animals. No significant pathological abnormalities were recognized in animals inoculated with this nonpathogenic virus. In contrast, nearly half of the animals inoculated with either SIVmac or SIVmac239 developed significant pathological lesions, including opportunistic infections by 13 weeks postinoculation, highlighting the virulence of these viruses. Our results indicate marked differences in tissue distribution between pathogenic and nonpathogenic molecular clones of SIV during the acute phase of infection. The most striking differences were the absence of SIVmac1A11 from the central nervous system and thymic medulla. The prominent early involvement of the thymus suggests that infection of this organ is a key event in the induction of immune suppression by SIV.
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Affiliation(s)
- A A Lackner
- New England Regional Primate Research Center, Harvard Medical School, Southborough, MA 01772
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81
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Ahmad S, Lohman B, Marthas M, Giavedoni L, el-Amad Z, Haigwood NL, Scandella CJ, Gardner MB, Luciw PA, Yilma T. Reduced virus load in rhesus macaques immunized with recombinant gp160 and challenged with simian immunodeficiency virus. AIDS Res Hum Retroviruses 1994; 10:195-204. [PMID: 8198872 DOI: 10.1089/aid.1994.10.195] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
As a safe alternative to inactivated and live-attenuated whole-virus SIV vaccines, we have evaluated the potential of SIVmac239 gp160 expressed by recombinant vaccinia virus (vSIVgp160) and baculovirus (bSIVgp160) to protectively immunize rhesus macaques against intravenous (i.v.) infection with pathogenic SIVmac isolates. Macaques were immunized with live vSIVgp160 and/or bSIVgp160 protein partially purified from insect cells. The challenge viruses, propagated in rhesus peripheral blood mononuclear cells, consisted of the molecular clone SIVmac239 and another genetically similar, uncloned isolate, SIVmac251. Although antibodies that bind gp130 were induced in all animals following immunization with SIVgp160, neutralizing antibodies were undetectable 1 week prior to virus challenge. These results differ from those for macaques vaccinated with inactivated, whole SIV. All animals became infected after i.v. inoculation with 1-10 AID50 of either challenge virus. For animals challenged with SIVmac251, but not those challenged with SIVmac239, the cell-free infectious virus load in plasma of vSIVgp160-primed, bSIVgp160-boosted macaques was significantly lower than in unimmunized controls at 2 weeks postchallenge. Virus virulence, immunization regimen, and challenge with homologous or heterologous virus are factors critical to the outcome of the study. Immunization with surface glycoprotein may not necessarily provide protective immunity against infection but may reduce virus load. The relationship between reduction in virus load by vaccination and delay in onset of disease remains to be determined.
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Affiliation(s)
- S Ahmad
- Department of Pathology, Microbiology, and Immunology, University of California at Davis 95616
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