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1.
J Virol ; 85(11): 5504-12, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21411526

RESUMO

Development of a microbicide that prevents rectal transmission of human immunodeficiency virus (HIV) is a vital component in reducing HIV spread. We recently demonstrated that a formulation of the nonnucleoside reverse transcriptase inhibitor (NNRTI) MIV-150 in carrageenan reduced vaginal infection of macaques with simian immunodeficiency virus SIVmac239 with HIV-1(HxB2) reverse transcriptase (SHIV-RT). Herein, we performed the first testing of MIV-150-carrageenan against rectal infection. Rhesus macaques were treated rectally with MIV-150-carrageenan or methyl cellulose (MC) placebo gel up to 4 h prior to rectal challenge with 10³ or 10(4) 50% tissue culture infective doses (TCID50) of SHIV-RT. Infection was assessed by measuring plasma virus RNA as well as T and B cell responses. MIV-150-carrageenan protected all animals challenged with 10³ TCID(50 when gel was applied either 30 min or 4 h prior to challenge, while 100% of the MC-treated animals became infected (n = 4 each; P < 0.03). Partial protection (2 of 4 animals) by MIV-150-carrageenan was observed for rectal challenge with 10-fold more virus applied 4 h after the gel. Sequencing of the RT gene from plasma virus RNA isolated at peak viremia confirmed that both of these animals (like infected MC controls) were infected with wild-type virus. Infection correlated with the development of SIV-specific T and B cell responses. MIV-150 was detected in the rectal fluids and tissues 4 h after gel application but was not detected in the blood at any time (0.5 to 24 h). These data are promising for the development of NNRTI-containing gels to prevent rectal HIV transmission.


Assuntos
Anti-Infecciosos Locais/administração & dosagem , Carragenina/administração & dosagem , Géis/administração & dosagem , Piridinas/administração & dosagem , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Vírus da Imunodeficiência Símia/efeitos dos fármacos , Ureia/análogos & derivados , Administração Retal , Animais , Anti-Infecciosos Locais/farmacologia , Linfócitos B/imunologia , Carragenina/farmacologia , Géis/farmacologia , Macaca mulatta , Placebos/administração & dosagem , Plasma/virologia , Piridinas/farmacologia , RNA Viral/sangue , Síndrome de Imunodeficiência Adquirida dos Símios/transmissão , Linfócitos T/imunologia , Ureia/administração & dosagem , Ureia/farmacologia
2.
J Virol ; 82(11): 5329-39, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18367527

RESUMO

Dendritic cells (DCs) play a key role in innate immune responses, and their interactions with T cells are critical for the induction of adaptive immunity. However, immunodeficiency viruses are efficiently captured by DCs and can be transmitted to and amplified in CD4(+) T cells, with potentially deleterious effects on the induction of immune responses. In DC-T-cell cocultures, contact with CD4(+), not CD8(+), T cells preferentially facilitated virus movement to and release at immature and mature DC-T-cell contact sites. This occurred within 5 min of DC-T-cell contact. While the fusion inhibitor T-1249 did not prevent virus capture by DCs or the release of viruses at the DC-T-cell contact points, it readily blocked virus transfer to and amplification in CD4(+) T cells. Higher doses of T-1249 were needed to block the more robust replication driven by mature DCs. Virus accumulated in DCs within T-1249-treated cocultures but these DCs were actually less infectious than DCs isolated from untreated cocultures. Importantly, T-1249 did not interfere with the stimulation of virus-specific CD4(+) and CD8(+) T-cell responses when present during virus-loading of DCs or for the time of the DC-T-cell coculture. These results provide clues to identifying strategies to prevent DC-driven virus amplification in CD4(+) T cells while maintaining virus-specific immunity, an objective critical in the development of microbicides and therapeutic vaccines.


Assuntos
Antivirais/farmacologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , HIV/fisiologia , Vírus da Imunodeficiência Símia/fisiologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Animais , Células Cultivadas , Técnicas de Cocultura , Células Dendríticas/ultraestrutura , Células Dendríticas/virologia , Feminino , Proteína gp41 do Envelope de HIV/farmacologia , Humanos , Macaca mulatta , Masculino , Microscopia Eletrônica de Transmissão , Fragmentos de Peptídeos/farmacologia , Linfócitos T/ultraestrutura , Fatores de Tempo
3.
J Leukoc Biol ; 79(2): 257-67, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16443827

RESUMO

Cytosine-phosphate-guanine class C (CpG-C) immunostimulatory sequence oligodeoxynucleotides (ISS-ODNs) activate human B cells and dendritic cells (DCs), properties that suggest potential use as a novel adjuvant to enhance vaccine efficacy. After demonstrating that the CpG-C ISS-ODN C274 activates macaque DCs, we examined in vitro activation of macaque B cells by C274 as a prelude to evaluation of this molecule as an adjuvant in the testing of candidate human immunodeficiency virus vaccines in the rhesus macaque-simian immunodeficiency virus (SIV) model. C274 induced macaque CD20(+) B cells to proliferate more strongly than CD40 ligand or CpG-B ISS-ODN. C274 enhanced B cell survival; increased viability was most evident after 3-7 days of culture. Increased expression of CD40, CD80, and CD86 by B cells was apparent within 24 h of exposure to C274 and persisted for up to 1 week. C274-stimulated, B cell-enriched and peripheral blood mononuclear cell suspensions from naïve and immunodeficiency virus-infected monkeys secreted several cytokines [e.g., interleukin (IL)-3, IL-6, IL-12, interferon-alpha] and chemokines [e.g., monocyte chemoattractant protein-1/CC chemokine ligand 2 (CCL2), macrophage-inflammatory protein-1alpha/CCL3, IL-8/CXC chemokine ligand 8]. In comparison, exposure of macaque B cells to SIV had minimal impact on surface phenotype, despite inducing cytokine and chemokine production in cells from infected and uninfected animals. These observations emphasize the need to identify strategies to optimally boost immune function, as immunodeficiency viruses themselves only partially activate B cells and DCs. The ability of C274 to stimulate B cells and DCs in healthy and infected monkeys suggests its possible use as a broad-acting adjuvant to be applied in the rhesus macaque model for the development of preventative and therapeutic vaccines.


Assuntos
Vacinas contra a AIDS/farmacologia , Linfócitos B/efeitos dos fármacos , Infecções por HIV/imunologia , Oligodesoxirribonucleotídeos/farmacologia , Oligonucleotídeos/farmacologia , Vírus da Imunodeficiência Símia/imunologia , Animais , Linfócitos B/imunologia , Ligante de CD40/farmacologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Quimiocinas/imunologia , Doença Crônica , Citocinas/imunologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Modelos Animais de Doenças , Feminino , Técnicas In Vitro , Macaca mulatta , Masculino , Vírus da Imunodeficiência Símia/efeitos dos fármacos
4.
J Med Primatol ; 32(4-5): 211-7, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-14498981

RESUMO

In vivo passage of non-pathogenic, CCR5-tropic simian/human immunodeficiency virus (SHIV) - SHIVsf162 resulted in a pathogenic isolate, SHIVsf162p3. In an attempt to characterize envelope (Env)-mediated properties that may contribute to its pathogenicity, major (P3 major) and minor (P3 minor) Env gp120 variants were cloned from the plasma of a SHIVsf162p3-infected animal, and expressed in the context of luciferase reporter viruses. Entry mediated by these envelopes and susceptibility to neutralization by CD4 induced-site (CD4i) antibodies (MAbs) was analyzed in comparison to parental SF162. Sequence analysis revealed that the P3 major and minor variant Envs contained 14 and 17 amino acid changes, respectively, compared with SF162. The rank order of entry mediated by the three envelopes was P3 major > SF162 > P3 minor, whereas the reverse order was observed for susceptibility to neutralization by CD4i MAbs. Since CD4i epitopes overlap the coreceptor (CoR) binding site, these findings suggest that the amino acid changes accumulated upon in vivo passage of SHIVsf162 result in Env gp120 structural rearrangements that modulate the exposure and/or conformation of the CoR binding site. This, in turn, led to increased entry and infectivity of the P3 major variant and may be responsible, in part, for the enhanced pathogenicity of SHIVsf162p3.


Assuntos
Antígenos CD4/genética , Proteína gp120 do Envelope de HIV/genética , HIV/imunologia , Receptores CCR5/imunologia , Vírus da Imunodeficiência Símia/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais , Variação Antigênica , Western Blotting , Ensaio de Imunoadsorção Enzimática , HIV/genética , Humanos , Luciferases , Dados de Sequência Molecular , Vírus da Imunodeficiência Símia/genética
5.
J Med Primatol ; 31(4-5): 164-70, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12390538

RESUMO

Infection of rhesus macaques with chimeric simian-human immunodeficiency viruses (SHIV) is an established model to study acquired immunodeficiency syndrome (AIDS) pathogenesis. Such a controlled system allows for detailed analysis of the molecular determinants of viral pathogenesis in addition to studying host-specific immune responses that modulate disease progression. Furthermore, the use of a pathogenic molecular clone affords the opportunity to study both viral evolution within a host and to examine the generation of tissue specific variants. In this report we describe viral diversification within tissues of two rhesus macaques infected intravenously with the CXCR4-specific molecular clone SHIVSF33A2. Heteroduplex tracking analysis (HTA) was used to determine the complexity of viral DNA within distinct lymphoid tissues. Not surprising, heterogeneity of the proviral quasispecies in tissues obtained during the acute infection was limited. However, tissues obtained at necropsy harbored a more diverse and often different population of env variants. As the inoculating virus is a molecular clone, the variants generated are likely due to the presence of tissue specific selective forces rather than a founder's effect.


Assuntos
Variação Genética/genética , HIV/genética , HIV/fisiologia , Tecido Linfoide/virologia , Macaca mulatta/virologia , Vírus da Imunodeficiência Símia/genética , Vírus da Imunodeficiência Símia/fisiologia , Animais , DNA Recombinante/genética , DNA Viral/análise , DNA Viral/genética , Modelos Animais de Doenças , Evolução Molecular , Infecções por HIV/virologia , Análise Heteroduplex , Mutação/genética , Especificidade de Órgãos , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Fatores de Tempo , Viremia/virologia
6.
Immunol Lett ; 79(1-2): 47-55, 2001 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-11595289

RESUMO

Rhesus macaques immunized with the HIV-1 SF162DeltaV2 gp140 envelope using the DNA-prime plus protein-boost vaccination methodology, developed HIV envelope-specific T-cell lymphoproliferative responses and potent neutralizing antibodies. To evaluate the protective potential of these antibodies during acute infection, the animals were depleted of their CD8+ T lymphocytes using specific monoclonal antibodies and subsequently challenged intravenously with the pathogenic SHIV(SF162P4) isolate. As compared to non-vaccinated animals (one of which died from AIDS 16 weeks post-exposure) the vaccinated macaques had lower levels of peak viremia, rapidly cleared virus from the periphery and developed delayed seroconversion to SIV core antigens.


Assuntos
Vacinas contra a AIDS/farmacologia , Produtos do Gene env/imunologia , Anticorpos Anti-HIV/biossíntese , HIV-1/imunologia , Macaca mulatta/imunologia , Vacinas de DNA/farmacologia , Animais , Linfócitos T CD8-Positivos/imunologia , Produtos do Gene env/genética , HIV-1/genética , HIV-1/isolamento & purificação , Ativação Linfocitária , Depleção Linfocítica , Testes de Neutralização , Vacinas contra a SAIDS/farmacologia , Deleção de Sequência , Vírus da Imunodeficiência Símia/imunologia , Linfócitos T/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana
7.
J Acquir Immune Defic Syndr ; 27(3): 222-8, 2001 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-11464140

RESUMO

Infection of rhesus macaques with chimeric simian-human immunodeficiency viruses (SHIV) is an established method to study AIDS pathogenesis and is increasingly used to assess the efficacy of vaccine and antiviral candidates. For these reasons, a detailed understanding of those molecular determinants, which confer pathogenic potential to SHIV viruses, should assist in both rational experimental design and interpretation of results. In this report, we describe the development and in vivo characterization of a pathogenic molecular clone, SHIVSF33A2, which contains an envelope sequence derived from the CXCR4-dependent isolate, HIV-1SF33. Proviral DNA, amplified from a rhesus macaque infected with the pathogenic isolate SHIVSF33A, was substituted into the corresponding region of the parental, nonpathogenic SHIVSF33 genome creating the molecular clone SHIVSF33A2. Coreceptor specificity of SHIVSF33A2 was determined to be CXCR4 specific. Naive rhesus macaques were productively infected after a single exposure to cell-free SHIVSF33A2 by either the intravenous (IV) or intravaginal (IVAG) routes. Animals infected with SHIVSF33A2 suffered a severe loss of peripheral CD4+ T cells and high acute plasma viremia with development of simian AIDS 9 months after inoculation. Sequence analysis identified 25 discreet amino acid changes within the V1-V5 regions of the envelope protein when compared with the nonpathogenic parental virus. These data indicate that domains within the HIV-1 envelope protein are sufficient to define pathogenic potential in the context of the SIVmac239 genome.


Assuntos
Proteína gp120 do Envelope de HIV/química , HIV-1/patogenicidade , Receptores CXCR4/metabolismo , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/patogenicidade , Sequência de Aminoácidos , Animais , Quimera , Clonagem Molecular , DNA Viral , Modelos Animais de Doenças , Feminino , Proteína gp120 do Envelope de HIV/genética , Proteína gp120 do Envelope de HIV/fisiologia , HIV-1/fisiologia , Macaca mulatta , Dados de Sequência Molecular , Síndrome de Imunodeficiência Adquirida dos Símios/genética , Vírus da Imunodeficiência Símia/genética , Vagina
8.
J Virol ; 75(12): 5526-40, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11356960

RESUMO

Partial deletion of the second hypervariable region from the envelope of the primary-like SF162 virus increases the exposure of certain neutralization epitopes and renders the virus, SF162DeltaV2, highly susceptible to neutralization by clade B and non-clade B human immunodeficiency virus (HIV-positive) sera (L. Stamatatos and C. Cheng-Mayer, J. Virol. 78:7840-7845, 1998). This observation led us to propose that the modified, SF162DeltaV2-derived envelope may elicit higher titers of cross-reactive neutralizing antibodies than the unmodified SF162-derived envelope. To test this hypothesis, we immunized rabbits and rhesus macaques with the gp140 form of these two envelopes. In rabbits, both immunogens elicited similar titers of binding antibodies but the modified immunogen was more effective in eliciting neutralizing antibodies, not only against the SF162DeltaV2 and SF162 viruses but also against several heterologous primary HIV type 1 (HIV-1) isolates. In rhesus macaques both immunogens elicited potent binding antibodies, but again the modified immunogen was more effective in eliciting the generation of neutralizing antibodies against the SF162DeltaV2 and SF162 viruses. Antibodies capable of neutralizing several, but not all, heterologous primary HIV-1 isolates tested were elicited only in macaques immunized with the modified immunogen. The efficiency of neutralization of these heterologous isolates was lower than that recorded against the SF162 isolate. Our results strongly suggest that although soluble oligomeric envelope subunit vaccines may elicit neutralizing antibody responses against heterologous primary HIV-1 isolates, these responses will not be broad and potent unless specific modifications are introduced to increase the exposure of conserved neutralization epitopes.


Assuntos
Vacinas contra a AIDS , Regiões Determinantes de Complementaridade/genética , Deleção de Genes , Produtos do Gene env/imunologia , HIV-1/imunologia , Vacinas contra a AIDS/genética , Vacinas contra a AIDS/imunologia , Animais , Anticorpos Antivirais/sangue , Antígenos Virais/imunologia , Reações Cruzadas/imunologia , Produtos do Gene env/química , Produtos do Gene env/genética , Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/imunologia , Infecções por HIV/prevenção & controle , Humanos , Imunização , Imunização Secundária , Macaca mulatta , Testes de Neutralização , Fragmentos de Peptídeos/imunologia , Coelhos , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Vacinas de DNA/imunologia
9.
J Virol ; 75(4): 1990-5, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11160699

RESUMO

Nonhuman primate models are increasingly used in the screening of candidate AIDS vaccine and immunization strategies for advancement to large-scale human trials. The predictive value of such macaque studies is largely dependent upon the fidelity of the model system in mimicking human immunodeficiency virus (HIV) type 1 infection in terms of viral transmission, replication, and pathogenesis. Herein, we describe the efficient mucosal transmission of a CCR5-specific chimeric simian/human immunodeficiency virus, SHIV(SF162P3). Female rhesus macaques were infected with SHIV(SF162P3) after a single atraumatic application to the cervicovaginal mucosa. The disease course of SHIV(SF162P3)-infected monkeys is similar and as varied as natural HIV infection in terms of viral replication, gradual loss of CD4(+) peripheral blood mononuclear cells, and the development of simian AIDS-defining opportunistic infections. The SHIV(SF162P3)/macaque model should facilitate direct preclinical assessment of HIV vaccine strategies in addition to antiviral compounds directed towards envelope target cell interactions. Furthermore, this controlled model provides the setting to investigate immunologic responses and putative host-specific susceptibility factors that alter viral transmission and subsequent disease progression.


Assuntos
HIV-1/patogenicidade , Receptores CCR5/metabolismo , Síndrome de Imunodeficiência Adquirida dos Símios/transmissão , Vírus da Imunodeficiência Símia/patogenicidade , Animais , Colo do Útero/virologia , Feminino , HIV-1/genética , Humanos , Macaca mulatta , Mucosa/virologia , Síndrome de Imunodeficiência Adquirida dos Símios/patologia , Síndrome de Imunodeficiência Adquirida dos Símios/fisiopatologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/genética , Vírus da Imunodeficiência Símia/fisiologia , Vagina/virologia
10.
J Virol ; 75(3): 1547-50, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11152527

RESUMO

DNA immunization of macaques with the SF162DeltaV2 envelope elicited lymphoproliferative responses and potent neutralizing antibodies. The animals were depleted of their CD8(+) T lymphocytes and then challenged intravenously with SHIV162P4. Compared to unvaccinated animals, the vaccinated macaques had lower peak viremia levels, rapidly cleared plasma virus, and showed delayed seroconversion.


Assuntos
Vacinas contra a AIDS/imunologia , Síndrome da Imunodeficiência Adquirida/prevenção & controle , Linfócitos T CD8-Positivos/fisiologia , HIV-1/imunologia , Depleção Linfocítica , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Vacinas de DNA/imunologia , Proteínas do Envelope Viral/imunologia , Animais , Anticorpos Anti-HIV/sangue , Macaca mulatta , Vacinação
11.
J Med Primatol ; 29(3-4): 158-65, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11085578

RESUMO

Sooty mangabeys (Cercocebus atys) showed age-dependent changes in T cell regeneration. Younger animals had a high percentage of CD4+ CD45RA + T cells and a high concentration of T cell receptor excisional circles (TRECs) in peripheral blood, which indicated active thymopoiesis. In contrast, older animals had an increased T cell turnover, which suggested that most T cell production occurred in the periphery. In addition, the number of peripheral CD4+ T cells naturally decreased with age. Non-pathogenic SIVsm infection did not significantly change the T cell proliferation rate or the TREC concentration, though it did cause a moderate loss of peripheral CD4 + T cells. The viral load correlated negatively with age, which could be accounted for by the reduced availability of CD4 + target cells in older mangabeys. Thus, the number of susceptible target cells may be a limiting factor in natural SIV infection.


Assuntos
Envelhecimento/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vírus da Imunodeficiência Símia/fisiologia , Subpopulações de Linfócitos T/imunologia , Linfócitos T/imunologia , Animais , Contagem de Linfócito CD4 , Linfócitos T CD4-Positivos/imunologia , Cercocebus atys , Homeostase , RNA Viral/sangue , Análise de Regressão , Síndrome de Imunodeficiência Adquirida dos Símios/sangue , Síndrome de Imunodeficiência Adquirida dos Símios/fisiopatologia , Vírus da Imunodeficiência Símia/isolamento & purificação , Carga Viral
12.
AIDS Res Hum Retroviruses ; 16(11): 1055-9, 2000 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-10933620

RESUMO

Dendritic cells (DCs) have been shown to be important in the replication of human and simian immunodeficiency viruses (HIV and SIV, respectively) in vivo and in vitro. DCs express CD4 and several chemokine receptors, such as CCR5 and CXCR4, which are important for viral entry. In vivo, DCs are abundant at body surfaces, where they might be one of the first cells that encounter naturally transmitted virus. Furthermore, DCs pulsed with HIV or SIV in vitro can efficiently transmit virus to T cells, thereby propagating vigorous viral replication. Reports have implicated Bonzo/STRL33/TYMSTR to be an additional alternative coreceptor for HIV and especially SIV infection. However, at present there are no reports regarding the expression of Bonzo/STRL33/TYMSTR by human or macaque DCs. Here we demonstrate the presence of Bonzo/STRL33/TYMSTR transcripts in rhesus macaque and human skin-derived DCs, in immature and mature blood monocyte-derived DCs, and in T cells from both skin and blood. Therefore, Bonzo/STRL33/TYMSTR is expressed in DCs and T cells that can play a role in the transmission of immunodeficiency viruses.


Assuntos
Células Dendríticas/metabolismo , Monócitos/citologia , Receptores de Citocinas/metabolismo , Receptores Acoplados a Proteínas G , Receptores Virais/metabolismo , Pele/citologia , Animais , Células Cultivadas , Humanos , Macaca mulatta , Monócitos/metabolismo , RNA Mensageiro/metabolismo , Receptores CCR5/metabolismo , Receptores CXCR6 , Receptores de Quimiocinas , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Pele/metabolismo , Linfócitos T/metabolismo
13.
J Virol ; 74(15): 6893-910, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10888629

RESUMO

We have used coreceptor-targeted inhibitors to investigate which coreceptors are used by human immunodeficiency virus type 1 (HIV-1), simian immunodeficiency viruses (SIV), and human immunodeficiency virus type 2 (HIV-2) to enter peripheral blood mononuclear cells (PBMC). The inhibitors are TAK-779, which is specific for CCR5 and CCR2, aminooxypentane-RANTES, which blocks entry via CCR5 and CCR3, and AMD3100, which targets CXCR4. We found that for all the HIV-1 isolates and all but one of the HIV-2 isolates tested, the only relevant coreceptors were CCR5 and CXCR4. However, one HIV-2 isolate replicated in human PBMC even in the presence of TAK-779 and AMD3100, suggesting that it might use an undefined, alternative coreceptor that is expressed in the cells of some individuals. SIV(mac)239 and SIV(mac)251 (from macaques) were also able to use an alternative coreceptor to enter PBMC from some, but not all, human and macaque donors. The replication in human PBMC of SIV(rcm) (from a red-capped mangabey), a virus which uses CCR2 but not CCR5 for entry, was blocked by TAK-779, suggesting that CCR2 is indeed the paramount coreceptor for this virus in primary cells.


Assuntos
Fármacos Anti-HIV/farmacologia , HIV-1/fisiologia , HIV-2/fisiologia , Receptores de HIV/metabolismo , Receptores Virais/metabolismo , Vírus da Imunodeficiência Símia/fisiologia , Amidas/farmacologia , Animais , Benzilaminas , Antígenos CD4/metabolismo , Linhagem Celular , Quimiocina CCL5/análogos & derivados , Quimiocina CCL5/farmacologia , Ciclamos , HIV-1/efeitos dos fármacos , HIV-1/patogenicidade , HIV-2/efeitos dos fármacos , HIV-2/patogenicidade , Compostos Heterocíclicos/farmacologia , Humanos , Leucócitos Mononucleares/virologia , Linfócitos , Macaca , Compostos de Amônio Quaternário/farmacologia , Receptores CCR2 , Receptores CCR3 , Receptores CCR5/metabolismo , Receptores de Quimiocinas/metabolismo , Receptores de HIV/antagonistas & inibidores , Receptores Virais/antagonistas & inibidores , Vírus da Imunodeficiência Símia/efeitos dos fármacos , Vírus da Imunodeficiência Símia/patogenicidade , Transfecção , Células Tumorais Cultivadas , Replicação Viral/efeitos dos fármacos
14.
J Virol ; 74(14): 6501-10, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10864663

RESUMO

The increasing prevalence of human immunodeficiency virus type 1 (HIV-1) subtype C infection worldwide calls for efforts to develop a relevant animal model for evaluating strategies against the transmission of the virus. A chimeric simian/human immunodeficiency virus (SHIV), SHIV(CHN19), was generated with a primary, non-syncytium-inducing HIV-1 subtype C envelope from a Chinese strain in the background of SHIV(33). Unlike R5-tropic SHIV(162), SHIV(CHN19) was not found to replicate in rhesus CD4(+) T lymphocytes. SHIV(CHN19) does, however, replicate in CD4(+) T lymphocytes of pig-tailed macaques (Macaca nemestrina). The observed replication competence of SHIV(CHN19) requires the full tat/rev genes and partial gp41 region derived from SHIV(33). To evaluate in vivo infectivity, SHIV(CHN19) was intravenously inoculated, at first, into two pig-tailed and two rhesus macaques. Although all four animals became infected, the virus replicated preferentially in pig-tailed macaques with an earlier plasma viral peak and a faster seroconversion. To determine whether in vivo adaptation would enhance the infectivity of SHIV(CHN19), passages were carried out serially in three groups of two pig-tailed macaques each, via intravenous blood-bone marrow transfusion. The passages greatly enhanced the infectivity of the virus as shown by the increasingly elevated viral loads during acute infection in animals with each passage. Moreover, the doubling time of plasma virus during acute infection became much shorter in passage 4 (P4) animals (0.2 day) in comparison to P1 animals (1 to 2 days). P2 to P4 animals all became seropositive around 2 to 3 weeks postinoculation and had a decline in CD4/CD8 T-cell ratio during the early phase of infection. In P4 animals, a profound depletion of CD4 T cells in the lamina propria of the jejunum was observed. Persistent plasma viremia has been found in most of the infected animals with sustained viral loads ranging from 10(3) to 10(5) per ml up to 6 months postinfection. Serial passages did not change the viral phenotype as confirmed by the persistence of the R5 tropism of SHIV(CHN19) isolated from P4 animals. In addition, the infectivity of SHIV(CHN19) in rhesus peripheral blood mononuclear cells was also increased after in vivo passages. Our data indicate that SHIV(CHN19) has adapted well to grow in macaque cells. This established R5-tropic SHIV(CHN19)/macaque model would be very useful for HIV-1 subtype C vaccine and pathogenesis studies.


Assuntos
Produtos do Gene env/genética , HIV-1/patogenicidade , Vírus da Imunodeficiência Símia/patogenicidade , Animais , Contagem de Linfócito CD4 , Modelos Animais de Doenças , Produtos do Gene env/metabolismo , HIV-1/genética , HIV-1/metabolismo , Injeções Intravenosas , Macaca nemestrina , Fenótipo , Reação em Cadeia da Polimerase , Vírus da Imunodeficiência Símia/genética , Vírus da Imunodeficiência Símia/metabolismo , Carga Viral , Viremia/sangue , Replicação Viral
15.
J Exp Med ; 191(11): 1921-31, 2000 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-10839807

RESUMO

The role of CD8(+) T lymphocytes in controlling replication of live, attenuated simian immunodeficiency virus (SIV) was investigated as part of a vaccine study to examine the correlates of protection in the SIV/rhesus macaque model. Rhesus macaques immunized for >2 yr with nef-deleted SIV (SIVmac239Deltanef) and protected from challenge with pathogenic SIVmac251 were treated with anti-CD8 antibody (OKT8F) to deplete CD8(+) T cells in vivo. The effects of CD8 depletion on viral load were measured using a novel quantitative assay based on real-time polymerase chain reaction using molecular beacons. This assay allows simultaneous detection of both the vaccine strain and the challenge virus in the same sample, enabling direct quantification of changes in each viral population. Our results show that CD8(+) T cells were depleted within 1 h after administration of OKT8F, and were reduced by as much as 99% in the peripheral blood. CD8(+) T cell depletion was associated with a 1-2 log increase in SIVmac239Deltanef plasma viremia. Control of SIVmac239Deltanef replication was temporally associated with the recovery of CD8(+) T cells between days 8 and 10. The challenge virus, SIVmac251, was not detectable in either the plasma or lymph nodes after depletion of CD8(+) T cells. Overall, our results indicate that CD8(+) T cells play an important role in controlling replication of live, attenuated SIV in vivo.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Vírus da Imunodeficiência Símia/imunologia , Vacinas Virais/imunologia , Replicação Viral/imunologia , Animais , Antígenos CD20/imunologia , DNA Viral/sangue , Linfonodos/patologia , Linfonodos/virologia , Depleção Linfocítica , Macaca mulatta , RNA Viral/sangue , Receptores de IgG/imunologia , Vírus da Imunodeficiência Símia/genética , Vírus da Imunodeficiência Símia/fisiologia , Vacinação , Vacinas Atenuadas , Carga Viral
16.
Virology ; 270(1): 237-49, 2000 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-10772996

RESUMO

Antibody responses are often considered to play only a limited role in controlling viremia during chronic infections with human or simian immunodeficiency virus (SIV). We investigated this by determining the effect of passively infused antibody on plasma viremia in infected rhesus macaques. The emphasis of the study was to understand the mechanism(s) underlying any observed effects. We infused serum immunoglobulins (SIVIG) purified from SIV(mac)251-infected macaques into other SIV(mac)251-infected macaques. The rapid progressor recipients had high viral loads but negligible titers of antibodies to SIV. Thus, we could significantly increase antibody titers with exogenous SIVIG. Despite restoring anti-SIV titers to levels typical of macaques with a normal disease course, SIVIG had only a modest effect on plasma SIV RNA and cell-associated viral load; the maximum, transient, reduction was threefold. The decrease in plasma RNA commenced within 1-2 h of SIVIG infusion, the nadir was at 12 h, and then a rebound occurred. A two- to threefold drop in cell-associated viral RNA was simultaneous with the decrease in plasma RNA. The kinetics of the viremia changes are inconsistent with neutralization of new cycles of infection. More likely, perhaps unexpectedly, is that infused antibodies killed SIV-infected cells, via an effector mechanism such as antibody-dependent cellular cytotoxicity.


Assuntos
Anticorpos Antivirais/imunologia , Imunização Passiva , Macaca mulatta/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vírus da Imunodeficiência Símia/imunologia , Vírus da Imunodeficiência Símia/fisiologia , Viremia/imunologia , Animais , Anticorpos Antivirais/administração & dosagem , Anticorpos Antivirais/sangue , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Progressão da Doença , Soros Imunes/administração & dosagem , Soros Imunes/sangue , Soros Imunes/imunologia , Imunoglobulina G/administração & dosagem , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Cinética , Contagem de Linfócitos , Macaca mulatta/virologia , Testes de Neutralização , RNA Viral/sangue , Síndrome de Imunodeficiência Adquirida dos Símios/patologia , Síndrome de Imunodeficiência Adquirida dos Símios/terapia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/genética , Vírus da Imunodeficiência Símia/isolamento & purificação , Carga Viral , Viremia/patologia , Viremia/terapia , Viremia/virologia
17.
J Virol ; 74(3): 1209-23, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10627531

RESUMO

Sooty mangabeys naturally infected with simian immunodeficiency virus (SIV) remain healthy though they harbor viral loads comparable to those in rhesus macaques that progress to AIDS. To assess the immunologic basis of disease resistance in mangabeys, we compared the effect of SIV infection on T-cell regeneration in both monkey species. Measurement of the proliferation marker Ki-67 by flow cytometry showed that mangabeys harbored proliferating T cells at a level of 3 to 4% in peripheral blood irrespective of their infection status. In contrast, rhesus macaques demonstrated a naturally high fraction of proliferating T cells (7%) that increased two- to threefold following SIV infection. Ki-67(+) T cells were predominantly CD45RA(-), indicating increased proliferation of memory cells in macaques. Quantitation of an episomal DNA product of T-cell receptor alpha rearrangement (termed alpha1 circle) showed that the concentration of recent thymic emigrants in blood decreased with age over a 2-log unit range in both monkey species, consistent with age-related thymic involution. SIV infection caused a limited decrease of alpha1 circle numbers in mangabeys as well as in macaques. Dilution of alpha1 circles by T-cell proliferation likely contributed to this decrease, since alpha1 circle numbers and Ki-67(+) fractions correlated negatively. These findings are compatible with immune exhaustion mediated by abnormal T-cell proliferation, rather than with early thymic failure, in SIV-infected macaques. Normal T-cell turnover in SIV-infected mangabeys provides an explanation for the long-term maintenance of a functional immune system in these hosts.


Assuntos
Cercocebus , Ativação Linfocitária , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vírus da Imunodeficiência Símia/imunologia , Subpopulações de Linfócitos T/imunologia , Envelhecimento , Animais , Contagem de Linfócito CD4 , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Rearranjo Gênico da Cadeia alfa dos Receptores de Antígenos dos Linfócitos T , Imunidade Inata , Memória Imunológica , Antígeno Ki-67/análise , Macaca mulatta , Dados de Sequência Molecular , RNA Viral/sangue , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/patogenicidade
18.
Contemp Top Lab Anim Sci ; 39(6): 24-6, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11487248

RESUMO

To support an infectious disease study, we developed a surgical procedure to collect serial thymic biopsies in rhesus monkeys (Macaca mulatta). In many instances in which thymic tissue is required from living animals, open surgical approaches (thoracotomies) are used, which result in greater postoperative pain and longer recovery periods than those associated with thoracoscopic procedures. Our intent was to develop a surgical procedure that allowed serial biopsy of the thymus with minimal surgical morbidity. We modified a previously published experimental method of thoracoscopic total thymectomy in the dog to collect thymic biopsies in M. mulatta. Of the 15 animals evaluated, 8 underwent two biopsy procedures separated by a 5- to 6-week interoperative interval. The other seven animals underwent a single biopsy procedure. Thymic tissue was collected successfully during all procedures, with an average surgical time of 15 min. No significant intra- or postoperative complications were noted, and the animals recoveries from the surgical procedures were uneventful. Minimally invasive thoracoscopic surgical techniques can be used successfully to collect thymic tissue from adult and juvenile rhesus monkeys with minimal surgical morbidity.


Assuntos
Cirurgia Torácica Vídeoassistida/veterinária , Timo/patologia , Animais , Biópsia/métodos , Biópsia/veterinária , Feminino , Macaca mulatta , Masculino , Morbidade , Dor Pós-Operatória/prevenção & controle , Dor Pós-Operatória/veterinária , Cirurgia Torácica Vídeoassistida/métodos
19.
Virology ; 266(1): 203-10, 2000 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-10612675

RESUMO

In this study, we examined the role of simian immunodeficiency virus (SIV)-specific cytotoxic T lymphocytes (CTLs) in macaques immunized with an attenuated strain of simian immunodeficiency virus (SIVmac239Deltanef) in protection against pathogenic challenge with SIVmac251. Our results indicate that attenuated SIVmac239Deltanef can elicit specific CTL precursor cells (CTLp), but no correlation was observed between breadth or strength of CTLp response to structural proteins SIV-Env, -Gamg or -Pol (as measured by limiting dilution assay) and protection against infection. In one animal, we longitudinally followed the SIV-Gag-specific response to an MHC class I Mamu-A*01-restricted epitope p11C, C-M using a tetrameric MHC/peptide complex reagent. A low frequency of SIV p11C, C-M peptide-specific tetramer-reactive cells was present at the time of challenge but could be expanded in vitro. Surprisingly, the low level of Mamu-A*01/p11C, C-M-specific CTLs induced through attenuated SIVmac239Deltanef vaccination increased in the absence of detectable SIVmac251 or SIVmac239Deltanef proviral DNA. Overall, our results suggest that protection against infection in this model can be achieved through more than one mechanism, with SIV-specific CTLs being important in controlling SIVmac239Deltanef viral replication postchallenge.


Assuntos
Vacinas contra a SAIDS/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Vírus da Imunodeficiência Símia/imunologia , Linfócitos T Citotóxicos/imunologia , Animais , Feminino , Macaca mulatta , RNA Viral/sangue , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vacinação , Vacinas Atenuadas/imunologia
20.
J Med Primatol ; 28(4-5): 164-8, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10593481

RESUMO

The chemokine receptor CCR5 is known to be a critical determinant of human immunodeficiency virus (HIV) transmission and pathogenesis in the human host. Towards the development of a macaque model to evaluate the efficacy of vaccines and therapeutics against infection with CCR5-specific viruses, and to delineate the pathogenic properties of such viruses, we constructed a chimeric simian human immunodeficiency virus, SHIV(SF162), containing the env, tat, rev, and vpu genes from HIV-1(SF162) (R5, MT/NSI) in the context of the molecular clone simian immunodeficiency virus, SIV(mac239). Virus generated from this molecular clone was used to intravenously infect two juvenile macaques, followed by three consecutive serial blood/bone marrow transfusions. Animals infected with parental SHIV(SF162) (P1) had detectable levels of viral replication (as determined by p27(gag) production) within days of infection; however, viral set-points fell below detection by Week 3. Late passage animals (P3 and P4) had a two-log increase in the level of plasma p27(gag) antigen. These results demonstrate that in vivo serial passage of the R5-specific SHIV(SF162) enhanced its replicative capacity.


Assuntos
Receptores CCR5/genética , Receptores de Quimiocinas/imunologia , Vírus da Imunodeficiência Símia/imunologia , Proteínas do Envelope Viral/genética , Vacinas contra a AIDS , Animais , Antígenos Virais/análise , Contagem de Linfócito CD4 , Relação CD4-CD8 , Quimera , Modelos Animais de Doenças , Humanos , Macaca mulatta/imunologia , Receptores CCR5/metabolismo , Receptores de Quimiocinas/genética , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/fisiopatologia , Vírus da Imunodeficiência Símia/genética
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