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1.
MMWR Morb Mortal Wkly Rep ; 70(35): 1195-1200, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34473687

RESUMO

To prevent transmission of SARS-CoV-2, the virus that causes COVID-19, colleges and universities have implemented multiple strategies including testing, isolation, quarantine, contact tracing, masking, and vaccination. In April 2021, the Chicago Department of Public Health (CDPH) was notified of a large cluster of students with COVID-19 at an urban university after spring break. A total of 158 cases of COVID-19 were diagnosed among undergraduate students during March 15-May 3, 2021; the majority (114; 72.2%) lived in on-campus dormitories. CDPH evaluated the role of travel and social connections, as well as the potential impact of SARS-CoV-2 variants, on transmission. Among 140 infected students who were interviewed, 89 (63.6%) reported recent travel outside Chicago during spring break, and 57 (40.7%) reported indoor social exposures. At the time of the outbreak, undergraduate-aged persons were largely ineligible for vaccination in Chicago; only three of the students with COVID-19 (1.9%) were fully vaccinated. Whole genome sequencing (WGS) of 104 specimens revealed multiple distinct SARS-CoV-2 lineages, suggesting several nearly simultaneous introductions. Most specimens (66; 63.5%) were B.1.1.222, a lineage not widely detected in Chicago before or after this outbreak. These results demonstrate the potential for COVID-19 outbreaks on university campuses after widespread student travel during breaks, at the beginning of new school terms, and when students participate in indoor social gatherings. To prevent SARS-CoV-2 transmission, colleges and universities should encourage COVID-19 vaccination; discourage unvaccinated students from travel, including during university breaks; implement serial COVID-19 screening among unvaccinated persons after university breaks; encourage masking; and implement universal serial testing for students based on community transmission levels.


Assuntos
COVID-19/epidemiologia , COVID-19/virologia , Surtos de Doenças , SARS-CoV-2/isolamento & purificação , Estudantes/estatística & dados numéricos , Universidades , COVID-19/prevenção & controle , COVID-19/transmissão , Teste para COVID-19 , Vacinas contra COVID-19/administração & dosagem , Chicago/epidemiologia , Feminino , Humanos , Masculino , Interação Social , Doença Relacionada a Viagens , Adulto Jovem
2.
MMWR Morb Mortal Wkly Rep ; 69(43): 1591-1594, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-34463672

RESUMO

Data on transmission of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), among college athletes are limited. In August 2020, the Chicago Department of Public Health (CDPH) was notified of a cluster of COVID-19 cases among a university's men's and women's soccer teams. CDPH initiated an investigation, interviewed members of both teams, and collated laboratory data to understand transmission of SARS-CoV-2 within the teams. Numerous social gatherings with limited mask use or social distancing preceded the outbreak. Transmission resulted in 17 laboratory-confirmed COVID-19 cases across both teams (n = 45), likely from a single source introduction of SARS-CoV-2 (based on whole genome sequencing) and subsequent transmission during multiple gatherings. Colleges and universities are at risk for COVID-19 outbreaks because of shared housing and social gatherings where recommended prevention guidance is not followed. Improved strategies to promote mask use and social distancing among college-aged adults need to be implemented, as well as periodic repeat testing to identify asymptomatic infections and prevent outbreaks among groups at increased risk for infection because of frequent exposure to close contacts in congregate settings on and off campus.


Assuntos
Atletas/estatística & dados numéricos , COVID-19/epidemiologia , Surtos de Doenças , Futebol , Estudantes/estatística & dados numéricos , Universidades , Adolescente , COVID-19/prevenção & controle , COVID-19/transmissão , Teste para COVID-19 , Chicago/epidemiologia , Busca de Comunicante , Surtos de Doenças/prevenção & controle , Feminino , Humanos , Masculino , Máscaras/estatística & dados numéricos , Distanciamento Físico , Quarentena , SARS-CoV-2/isolamento & purificação , Adulto Jovem
3.
Microbiol Resour Announc ; 8(19)2019 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-31072893

RESUMO

We report the 9.7-Mb genome sequence of Streptomyces sp. strain F001, isolated from a marine sediment sample from Raja Ampat, Indonesia. F001 produces diazaquinomycins, which exhibit potent and selective antituberculosis activity. In addition, it is also known to produce akashin A, a blue pigment that has shown cytotoxic activity.

4.
J Nat Prod ; 81(9): 2057-2068, 2018 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-30110167

RESUMO

Actinomycete bacteria isolated from freshwater environments are an unexplored source of natural products. Here we report the complete genome of the Great Lakes-derived Micromonospora sp. strain B006, revealing its potential for natural product biosynthesis. The 7-megabase pair chromosome of strain B006 was sequenced using Illumina and Oxford Nanopore technologies followed by Sanger sequencing to close remaining gaps. All identified biosynthetic gene clusters (BGCs) were manually curated. Five known BGCs were identified encoding desferrioxamine, alkyl- O-dihydrogeranylmethoxyhydroquinone, a spore pigment, sioxanthin, and diazepinomicin, which is currently in phase II clinical trials to treat Phelan-McDermid syndrome and co-morbid epilepsy. We report here that strain B006 is indeed a producer of diazepinomicin and at yields higher than previously reported. Moreover, 11 of the 16 identified BGCs are orphan, eight of which were transcriptionally active under the culture condition tested. Orphan BGCs include an enediyne polyketide synthase and an uncharacteristically large, 36-module polyketide synthase-nonribosomal peptide synthetase BGC. We developed a genetics system for Micromonospora sp. B006 that will contribute to deorphaning BGCs in the future. This study is one of the few attempts to report the biosynthetic capacity of a freshwater-derived actinomycete and highlights this resource as a potential reservoir for new natural products.


Assuntos
Genoma Bacteriano , Lagos/microbiologia , Micromonospora/genética , Michigan , Micromonospora/metabolismo , Família Multigênica , Transcrição Gênica
6.
PLoS One ; 6(12): e28047, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22164225

RESUMO

Maraviroc (MVC) gels are effective at protecting rhesus macaques from vaginal SHIV transmission, but breakthrough infections can occur. To determine the effects of a vaginal MVC gel on infecting SHIV populations in a macaque model, we analyzed plasma samples from three rhesus macaques that received a MVC vaginal gel (day 0) but became infected after high-dose SHIV-162P3 vaginal challenge. Two infected macaques that received a placebo gel served as controls. The infecting SHIV-162P3 stock had an overall mean genetic distance of 0.294±0.027%; limited entropy changes were noted across the envelope (gp160). No envelope mutations were observed consistently in viruses isolated from infected macaques at days 14-21, the time of first detectable viremia, nor selected at later time points, days 42-70. No statistically significant differences in MVC susceptibilities were observed between the SHIV inoculum (50% inhibitory concentration [IC(50)] 1.87 nM) and virus isolated from the three MVC-treated macaques (MVC IC(50) 1.18 nM, 1.69 nM, and 1.53 nM, respectively). Highlighter plot analyses suggested that infection was established in each MVC-treated animal by one founder virus genotype. The expected Poisson distribution of pairwise Hamming Distance frequency counts was observed and a phylogenetic analysis did not identify infections with distinct lineages from the challenge stock. These data suggest that breakthrough infections most likely result from incomplete viral inhibition and not the selection of MVC-resistant variants.


Assuntos
Cicloexanos/química , Farmacorresistência Viral , Vírus da Imunodeficiência Símia/genética , Vírus da Imunodeficiência Símia/metabolismo , Triazóis/química , Administração Intravaginal , Animais , Linhagem Celular , Entropia , Feminino , Genoma Viral , Humanos , Macaca mulatta , Maraviroc , Glicoproteínas de Membrana , Modelos Genéticos , Dados de Sequência Molecular , Mutação , Reprodutibilidade dos Testes , Cremes, Espumas e Géis Vaginais/metabolismo , Proteínas do Envelope Viral/genética , Carga Viral , Proteínas Virais/química
7.
BMC Immunol ; 12: 39, 2011 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-21762519

RESUMO

BACKGROUND: MHC class I proteins are partly responsible for shaping the magnitude and focus of the adaptive cellular immune response. In humans, conventional wisdom suggests that the HLA-A, -B, and -C alleles are equally expressed on the majority of cell types. While we currently have a thorough understanding of how total MHC class I expression varies in different tissues, it has been difficult to examine expression of single MHC class I alleles due to the homogeneity of MHC class I sequences. It is unclear how cDNA species are expressed in distinct cell subsets in humans and particularly in macaques which transcribe upwards of 20 distinct MHC class I alleles at variable levels. RESULTS: We examined MHC gene expression in human and macaque leukocyte subsets. In humans, while we detected overall differences in locus transcription, we found that transcription of MHC class I genes was consistent across the leukocyte subsets we studied with only small differences detected. In contrast, transcription of certain MHC cDNA species in macaques varied dramatically by up to 45% between different subsets. Although the Mafa-B134:02 RNA is virtually undetectable in CD4+ T cells, it represents over 45% of class I transcripts in CD14+ monocytes. We observed parallel MHC transcription differences in rhesus macaques. Finally, we analyzed expression of select MHC proteins at the cell surface using fluorescent peptides. This technique confirmed results from the transcriptional analysis and demonstrated that other MHC proteins, known to restrict SIV-specific responses, are also differentially expressed among distinct leukocyte subsets. CONCLUSIONS: We assessed MHC class I transcription and expression in human and macaque leukocyte subsets. Until now, it has been difficult to examine MHC class I allele expression due to the similarity of MHC class I sequences. Using two novel techniques we showed that expression varies among distinct leukocyte subsets of macaques but does not vary dramatically in the human cell subsets we examined. These findings suggest pathogen tropism may have a profound impact on the shape and focus of the MHC class I restricted CD8+ T cell response in macaques.


Assuntos
Antígenos de Histocompatibilidade Classe I/metabolismo , Leucócitos/imunologia , Alelos , Animais , Linfócitos T CD8-Positivos/imunologia , Regulação da Expressão Gênica , Haplótipos , Antígenos de Histocompatibilidade Classe I/genética , Humanos , Leucócitos/metabolismo , Macaca , Transcrição Gênica
8.
AIDS ; 24(11): 1784-5, 2010 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-20597166

RESUMO

Xenotropic murine leukemia virus-related virus has been detected in blood cells of patients with chronic fatigue syndrome and in 3.7% of healthy controls from the same geographic region. We evaluated 996 men who were participants in the Multicenter AIDS Cohort Study for xenotropic murine leukemia virus-related virus sequences in blood cells by means of a real-time quantitative PCR assay. Xenotropic murine leukemia virus-related virus was detected in none of the men on the basis of the absence of xenotropic murine leukemia virus-related virus DNA, suggesting that infection may be population-specific.


Assuntos
Infecções por HIV/complicações , Vírus da Leucemia Murina/isolamento & purificação , Infecções por Retroviridae/complicações , Infecções Tumorais por Vírus/complicações , DNA Viral/sangue , Infecções por HIV/transmissão , Infecções por HIV/virologia , Homossexualidade Masculina , Humanos , Masculino , Infecções por Retroviridae/virologia , Infecções Tumorais por Vírus/virologia
10.
J Virol ; 83(18): 9474-85, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19587057

RESUMO

Human APOBEC3 enzymes are cellular DNA cytidine deaminases that inhibit and/or mutate a variety of retroviruses, retrotransposons, and DNA viruses. Here, we report a detailed examination of human APOBEC3 gene expression, focusing on APOBEC3G (A3G) and APOBEC3F (A3F), which are potent inhibitors of human immunodeficiency virus type 1 (HIV-1) infection but are suppressed by HIV-1 Vif. A3G and A3F are expressed widely in hematopoietic cell populations, including T cells, B cells, and myeloid cells, as well as in tissues where mRNA levels broadly correlate with the lymphoid cell content (gonadal tissues are exceptions). By measuring mRNA copy numbers, we find that A3G mRNA is approximately 10-fold more abundant than A3F mRNA, implying that A3G is the more significant anti-HIV-1 factor in vivo. A3G and A3F levels also vary between donors, and these differences are sustained over 12 months. Responses to T-cell activation or cytokines reveal that A3G and A3F mRNA levels are induced approximately 10-fold in macrophages and dendritic cells (DCs) by alpha interferon (IFN-alpha) and approximately 4-fold in naïve CD4(+) T cells. However, immunoblotting revealed that A3G protein levels are induced by IFN-alpha in macrophages and DCs but not in T cells. In contrast, T-cell activation and IFN-gamma had a minimal impact on A3G or A3F expression. Finally, we noted that A3A mRNA expression and protein expression are exquisitely sensitive to IFN-alpha induction in CD4(+) T cells, macrophages, and DCs but not to T-cell activation or other cytokines. Given that A3A does not affect HIV-1 infection, these observations imply that this protein may participate in early antiviral innate immune responses.


Assuntos
Citidina Desaminase/genética , Citosina Desaminase/genética , Células-Tronco Hematopoéticas/citologia , Imunidade Inata , Desaminase APOBEC-3G , Infecções por HIV/imunologia , Sistema Hematopoético/química , Sistema Hematopoético/citologia , Humanos , Sistema Imunitário/química , Sistema Imunitário/citologia , Interferon-alfa/farmacologia , RNA Mensageiro/análise , Distribuição Tecidual , Ativação Transcricional/efeitos dos fármacos
11.
PLoS One ; 3(6): e2516, 2008 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-18575590

RESUMO

Elevated plasma lipopolysaccharide (LPS), an indicator of microbial translocation from the gut, is a likely cause of systemic immune activation in chronic HIV infection. LPS induces monocyte activation and trafficking into brain, which are key mechanisms in the pathogenesis of HIV-associated dementia (HAD). To determine whether high LPS levels are associated with increased monocyte activation and HAD, we obtained peripheral blood samples from AIDS patients and examined plasma LPS by Limulus amebocyte lysate (LAL) assay, peripheral blood monocytes by FACS, and soluble markers of monocyte activation by ELISA. Purified monocytes were isolated by FACS sorting, and HIV DNA and RNA levels were quantified by real time PCR. Circulating monocytes expressed high levels of the activation markers CD69 and HLA-DR, and harbored low levels of HIV compared to CD4(+) T-cells. High plasma LPS levels were associated with increased plasma sCD14 and LPS-binding protein (LBP) levels, and low endotoxin core antibody levels. LPS levels were higher in HAD patients compared to control groups, and were associated with HAD independently of plasma viral load and CD4 counts. LPS levels were higher in AIDS patients using intravenous heroin and/or ethanol, or with Hepatitis C virus (HCV) co-infection, compared to control groups. These results suggest a role for elevated LPS levels in driving monocyte activation in AIDS, thereby contributing to the pathogenesis of HAD, and provide evidence that cofactors linked to substance abuse and HCV co-infection influence these processes.


Assuntos
Complexo AIDS Demência/imunologia , Síndrome da Imunodeficiência Adquirida/metabolismo , Ativação Linfocitária , Monócitos/imunologia , Síndrome da Imunodeficiência Adquirida/complicações , Síndrome da Imunodeficiência Adquirida/imunologia , Linfócitos T CD4-Positivos/virologia , Separação Celular , DNA Viral/sangue , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , HIV/genética , HIV/isolamento & purificação , HIV/fisiologia , Humanos , Lipopolissacarídeos/sangue , Reação em Cadeia da Polimerase , RNA Viral/sangue , Replicação Viral
12.
Nucleic Acids Res ; 34(7): e54, 2006 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-16617142

RESUMO

Here we report a real-time PCR-based method for determining the surface coverage of dithiol-capped oligonucleotides bound onto gold nanoparticles alone and in tandem with antibody. The detection of gold nanoparticle-bound DNA is accomplished by targeting the oligonucleotide with primer and probe binding sites, amplification of the oligonucleotide by PCR, and real-time measurement of the fluorescence emitted during the reaction. This method offers a wide dynamic range and is not dependant on the dissociation of the oligonucleotide strands from the gold nanoparticle surface; the fluorophore is not highly quenched by the gold nanoparticles in solution during fluorescence measurements. We show that this method and a fluorescence-based method give equivalent results for determining the surface coverage of oligonucleotides bound onto 13 or 30 nm gold nanoparticles alone and in tandem with antibody. Quantifying the surface coverage of immobilized oligonucleotides on metallic nanoparticle surfaces is important for optimizing the sensitivity of gold nanoparticle-based detection methods and for better understanding the interactions between thiol-functionalized oligonucleotides and gold nanoparticles.


Assuntos
DNA/análise , Ouro/química , Nanoestruturas/química , Sondas de Oligonucleotídeos/química , Reação em Cadeia da Polimerase/métodos , Tionucleotídeos/química , Corantes Fluorescentes/química , Temperatura , Fatores de Tempo
13.
Virology ; 344(2): 267-76, 2006 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-16305804

RESUMO

The CD16+ subset of monocytes is dramatically expanded in peripheral blood during progression to AIDS, but its contribution to HIV pathogenesis is unknown. Here, we demonstrate that CD16+ but not CD16- monocytes promote high levels of HIV replication upon differentiation into macrophages and interaction with T cells. Conjugates formed between CD16+ monocyte-derived macrophages and T cells are major sites of viral replication. Furthermore, similar monocyte-T cell conjugates detected in peripheral blood of HIV-infected patients harbor HIV DNA. Thus, expansion of CD16+ monocytes during HIV infection and their subsequent recruitment into tissues such as lymph nodes, brain, and intestine may contribute to HIV dissemination and establishment of productive infection in T cells.


Assuntos
Diferenciação Celular/fisiologia , HIV-1/fisiologia , Macrófagos/citologia , Monócitos/citologia , Monócitos/virologia , Receptores de IgG/metabolismo , Linfócitos T/citologia , Replicação Viral/fisiologia , Antígenos CD4/metabolismo , Humanos , Macrófagos/virologia , Ligação Proteica , Linfócitos T/imunologia
14.
J Infect Dis ; 192(6): 1078-87, 2005 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-16107963

RESUMO

In hepatitis C virus (HCV) infection, race is a determinant of treatment response and interferon (IFN) effectiveness. Here, we investigated whether there were differences in the pretreatment viral strains between African American patients and white patients and whether these differences correlated with viral kinetics. IFN effectiveness was calculated using a viral kinetic model. The HCV NS5A region from 21 treated patients with HCV genotype 1a was sequenced and analyzed. White patients displayed more mutations in the V3 region (mean+/-SD, 4.5+/-1.4 vs. 2.9+/-1.6; P=.016), and treatment responders tended to have more mutations in this region than did nonresponders. There was a significant positive correlation between IFN effectiveness and the number of mutations in the V3 region (P=.03). There was no clustering of strains by race, treatment response, or IFN effectiveness in phylogenetic analyses. The results of this study, in conjunction with those of a previous study illustrating the impaired IFN effectiveness in African Americans, suggest a role for host-related factors.


Assuntos
Negro ou Afro-Americano , Hepacivirus/efeitos dos fármacos , Hepacivirus/genética , Hepatite C/virologia , Proteínas não Estruturais Virais/genética , População Branca , Substituição de Aminoácidos , Antivirais/farmacologia , Variação Genética , Hepacivirus/classificação , Hepacivirus/isolamento & purificação , Hepatite C/tratamento farmacológico , Humanos , Interferons/farmacologia , Cinética , Dados de Sequência Molecular , Mutação , Filogenia , Análise de Sequência de DNA
15.
Nat Immunol ; 6(3): 247-52, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15685174

RESUMO

Viral escape from cytotoxic T lymphocytes (CTLs) can undermine immune control of human immunodeficiency virus 1. It is therefore important to assess the stability of viral mutations in CTL epitopes after transmission to naive hosts. Here we demonstrate the persistence of mutations in a dominant CTL epitope after transmission of simian immunodeficiency virus variants to major histocompatibility complex-matched rhesus monkeys. Transient reversions to wild-type sequences occurred and elicited CTLs specific for the wild-type epitope, resulting in immunological pressure that rapidly reselected the mutant viruses. These data suggest that mutations in dominant human immunodeficiency virus 1 CTL epitopes may accumulate in human populations with limited major histocompatibility complex heterogeneity by a mechanism involving dynamic CTL control of transiently reverted wild-type virus.


Assuntos
Epitopos de Linfócito T/imunologia , Mutação , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/genética , Vírus da Imunodeficiência Símia/imunologia , Linfócitos T Citotóxicos/imunologia , Animais , Epitopos de Linfócito T/genética , Humanos , Epitopos Imunodominantes/genética , Macaca mulatta , Complexo Principal de Histocompatibilidade/imunologia , Vírus da Imunodeficiência Símia/patogenicidade
16.
Virology ; 328(1): 19-29, 2004 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-15380354

RESUMO

Human immunodeficiency virus type 1 (HIV-1) fusion with its target cells is initiated by sequential interactions between its envelope glycoprotein, CD4, and a co-receptor, usually CCR5 or CXCR4. Small molecules that bind to CCR5 and prevent its use by R5 HIV-1 strains are now being developed clinically as antiviral drugs. To test whether a block to CCR5 promotes the replication of viruses that enter cells via CXCR4 and are associated with accelerated disease progression, we administered a small molecule CCR5 inhibitor, CMPD 167, to three macaques dual-infected with both R5 (SIVmac251) and X4 (SHIV-89.6P) viruses. CMPD 167 caused a rapid and substantial (on average, 50-fold) suppression of R5 virus replication in each animal. In two of the animals, but not in the third, a rapid, transient, 8- to 15-fold increase in the amount of plasma X4 virus occurred. In neither animal was the increase in X4 viral load sustained throughout therapy, however. These observations may have relevance for the development of CCR5 inhibitors for treatment of HIV-1 infection of humans.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Antagonistas dos Receptores CCR5 , Infecções por HIV/tratamento farmacológico , HIV-1 , Pirazóis/uso terapêutico , Vírus Reordenados , Síndrome de Imunodeficiência Adquirida dos Símios/tratamento farmacológico , Vírus da Imunodeficiência Símia , Valina/uso terapêutico , Animais , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Infecções por HIV/virologia , HIV-1/fisiologia , Macaca mulatta , Vírus Reordenados/fisiologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/genética , Vírus da Imunodeficiência Símia/patogenicidade , Valina/análogos & derivados , Carga Viral , Replicação Viral/efeitos dos fármacos
17.
J Virol ; 78(6): 2790-807, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14990699

RESUMO

We have described previously the generation of an escape variant of human immunodeficiency virus type 1 (HIV-1), under the selection pressure of AD101, a small molecule inhibitor that binds the CCR5 coreceptor (A. Trkola, S. E. Kuhmann, J. M. Strizki, E. Maxwell, T. Ketas, T. Morgan, P. Pugach, S. X. L. Wojcik, J. Tagat, A. Palani, S. Shapiro, J. W. Clader, S. McCombie, G. R. Reyes, B. M. Baroudy, and J. P. Moore, Proc. Natl. Acad. Sci. USA 99:395-400, 2002). The escape mutant, CC101.19, continued to use CCR5 for entry, but it was at least 20,000-fold more resistant to AD101 than the parental virus, CC1/85. We have now cloned the env genes from the the parental and escape mutant isolates and made chimeric infectious molecular clones that fully recapitulate the phenotypes of the corresponding isolates. Sequence analysis of the evolution of the escape mutants suggested that the most relevant changes were likely to be in the V3 loop of the gp120 glycoprotein. We therefore made a series of mutant viruses and found that full AD101 resistance was conferred by four amino acid changes in V3. Each change individually caused partial resistance when they were introduced into the V3 loop of a CC1/85 clone, but their impact was dependent on the gp120 context in which they were made. We assume that these amino acid changes alter how the HIV-1 Env complex interacts with CCR5. Perhaps unexpectedly, given the complete dependence of the escape mutant on CCR5 for entry, monomeric gp120 proteins expressed from clones of the fully resistant isolate failed to bind to CCR5 on the surface of L1.2-CCR5 cells under conditions where gp120 proteins from the parental virus and a partially AD101-resistant virus bound strongly. Hence, the full impact of the V3 substitutions may only be apparent at the level of the native Env complex.


Assuntos
Fármacos Anti-HIV/farmacologia , Antagonistas dos Receptores CCR5 , Farmacorresistência Viral , HIV-1/efeitos dos fármacos , HIV-1/genética , Sequência de Aminoácidos , Genótipo , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/genética , Proteína gp160 do Envelope de HIV/química , Proteína gp160 do Envelope de HIV/genética , Infecções por HIV/virologia , HIV-1/classificação , HIV-1/metabolismo , Humanos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , Fenótipo , Receptores CCR5/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Alinhamento de Sequência
18.
J Virol ; 77(24): 13348-60, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14645590

RESUMO

Given the current difficulties generating vaccine-induced neutralizing antibodies to human immunodeficiency virus (HIV), the focus of the vaccine community has shifted toward creating cytotoxic-T-lymphocyte (CTL)-based vaccines. Recent reports of CTL-based vaccine trials in macaques challenged with simian/human immunodeficiency virus SHIV-89.6P have supported the notion that such vaccines can ameliorate the course of disease. However, almost all of these studies included Env as an immunogen and since SHIV-89.6P is sensitive to neutralizing antibodies it is difficult to determine the mechanism(s) of protection. Consequently, SHIV-89.6P challenge of macaques may be a poor model for determining vaccine efficacy in humans. To ascertain the effect of vaccine-induced multispecific mucosal CTL, in the absence of Env-specific antibody, on the control of an immunodeficiency virus challenge, we vaccinated Mamu-A*01(+) macaques with constructs encoding a combination of CTL epitopes and full-length proteins (Tat, Rev, and Nef) by using a DNA prime/recombinant modified vaccinia virus Ankara (rMVA) boost regimen. The vaccination induced virus-specific CTL and CD4(+) helper T lymphocytes with CTL frequencies as high as 20,000/million peripheral blood mononuclear cells. The final rMVA vaccination, delivered intravenously, engendered long-lived mucosal CTL. At 16 weeks after the final rMVA vaccination, the vaccinees and naive, Mamu-A*01(+) controls were challenged intrarectally with SIVmac239. Massive early anamnestic cellular immune responses controlled acute-phase viral replication; however, the three vaccinees were unable to control virus replication in the chronic phase. The present study suggests that multispecific mucosal CTL, in the absence of neutralizing antibodies, can achieve a modicum of control over early viral replication but are unable to control chronic-phase viral replication after a high-dose mucosal challenge with a pathogenic simian immunodeficiency virus.


Assuntos
Imunidade nas Mucosas , Vacinas contra a SAIDS/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Vírus da Imunodeficiência Símia/imunologia , Linfócitos T Citotóxicos/imunologia , Replicação Viral/imunologia , Doença Aguda , Animais , Antígenos de Histocompatibilidade Classe I/metabolismo , Imunização Secundária , Macaca mulatta , Vacinas contra a SAIDS/administração & dosagem , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vacinação , Vacinas de DNA , Vaccinia virus/genética , Vaccinia virus/imunologia
19.
J Virol ; 77(23): 12572-8, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14610180

RESUMO

Virus-specific cytotoxic T lymphocytes (CTL) exert intense selection pressure on replicating simian immunodeficiency virus (SIV) and human immunodeficiency virus type 1 (HIV-1) in infected individuals. The immunodominant Mamu-A(*)01-restricted Gag p11C, C-M epitope is highly conserved among all sequenced isolates of SIV and therefore likely is structurally constrained. The strategies used by virus isolates to mutate away from an immunodominant epitope-specific CTL response are not well defined. Here we demonstrate that the emergence of a position 2 p11C, C-M epitope substitution (T47I) in a simian-human immunodeficiency virus (SHIV) strain 89.6P-infected Mamu-A(*)01(+) monkey is temporally correlated with the emergence of a flanking isoleucine-to-valine substitution at position 71 (I71V) of the capsid protein. An analysis of the SIV and HIV-2 sequences from the Los Alamos HIV Sequence Database revealed a significant association between any position 2 p11C, C-M epitope mutation and the I71V mutation. The T47I mutation alone is associated with significant decreases in viral protein expression, infectivity, and replication, and these deficiencies are restored to wild-type levels with the introduction of the flanking I71V mutation. Together, these data suggest that a compensatory mutation is selected for in SHIV strain 89.6P to facilitate the escape of that virus from CTL recognition of the dominant p11C, C-M epitope.


Assuntos
Epitopos/imunologia , HIV/fisiologia , Vírus da Imunodeficiência Símia/fisiologia , Linfócitos T Citotóxicos/imunologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Linhagem Celular , Primers do DNA , Epitopos/química , Produtos do Gene gag/química , Genes gag , HIV/genética , HIV/imunologia , Haplorrinos , Humanos , Dados de Sequência Molecular , Mutação Puntual , Estudos Prospectivos , Conformação Proteica , Homologia de Sequência de Aminoácidos , Vírus da Imunodeficiência Símia/genética , Vírus da Imunodeficiência Símia/imunologia
20.
J Virol ; 77(22): 12310-8, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14581567

RESUMO

A chemokine receptor from the seven-transmembrane-domain G-protein-coupled receptor superfamily is an essential coreceptor for the cellular entry of human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV) strains. To investigate nonhuman primate CC-chemokine receptor 5 (CCR5) homologue structure and function, we amplified CCR5 DNA sequences from peripheral blood cells obtained from 24 representative species and subspecies of the primate suborders Prosimii (family Lemuridae) and Anthropoidea (families Cebidae, Callitrichidae, Cercopithecidae, Hylobatidae, and Pongidae) by PCR with primers flanking the coding region of the gene. Full-length CCR5 was inserted into pCDNA3.1, and multiple clones were sequenced to permit discrimination of both alleles. Compared to the human CCR5 sequence, the CCR5 sequences of the Lemuridae, Cebidae, and Cercopithecidae shared 87, 91 to 92, and 96 to 99% amino acid sequence homology, respectively. Amino acid substitutions tended to cluster in the amino and carboxy termini, the first transmembrane domain, and the second extracellular loop, with a pattern of species-specific changes that characterized CCR5 homologues from primates within a given family. At variance with humans, all primate species examined from the suborder Anthropoidea had amino acid substitutions at positions 13 (N to D) and 129 (V to I); the former change is critical for CD4-independent binding of SIV to CCR5. Within the Cebidae, Cercopithecidae, and Pongidae (including humans), CCR5 nucleotide similarities were 95.2 to 97.4, 98.0 to 99.5, and 98.3 to 99.3%, respectively. Despite this low genetic diversity, the phylogeny of the selected primate CCR5 homologue sequences agrees with present primate systematics, apart from some intermingling of species of the Cebidae and Cercopithecidae. Constructed HOS.CD4 cell lines expressing the entire CCR5 homologue protein from each of the Anthropoidea species and subspecies were tested for their ability to support HIV-1 and SIV entry and membrane fusion. Other than that of Cercopithecus pygerythrus, all CCR5 homologues tested were able to support both SIV and HIV-1 entry. Our results suggest that the shared structure and function of primate CCR5 homologue proteins would not impede the movement of primate immunodeficiency viruses between species.


Assuntos
HIV-1/fisiologia , Haplorrinos/virologia , Receptores CCR5/química , Vírus da Imunodeficiência Símia/fisiologia , Strepsirhini/virologia , Sequência de Aminoácidos , Animais , Haplorrinos/classificação , Humanos , Fusão de Membrana , Dados de Sequência Molecular , Filogenia , Receptores CCR5/fisiologia , Homologia de Sequência , Strepsirhini/classificação
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