科研论文

返回至主页
  • Infection with multidrug resistant, dual-tropic HIV-1 and rapid progression to AIDS: A case report

    • 摘要:

      Background: Rapid progression to AIDS after acute HIV-1 infection, though uncommon, has been noted, as has the transmission of multidrug resistant viruses. Here, we describe a patient in whom these two factors arose concomitantly and assess the effects. Methods: We did a case study of a patient with HIV-1 seroconversion. We genotyped the virus and host genetic markers by PCR and nucleotide sequencing. To ascertain the drug susceptibility of our patient's HIV-1 we did phenotypic studies with the PhenoSense assay. We assessed viral coreceptor use via syncytium formation in vitro and with a modified PhenoSense assay. Findings: Our patient seems to have been recently infected by a viral variant of HIV-1 resistant to multiple classes of antiretroviral drugs. Furthermore, his virus population is dual tropic for cells that express CCR5 or CXCR4 coreceptor. The infection has resulted in progression to symptomatic AIDS in 4-20 months. Interpretation: The intersection of multidrug resistance and rapid development of AIDS in this patient is of concern, especially in view of his case history, which includes high-risk sexual contacts and use of metamfetamine. The public health ramifications of such a case are great.

    • 作者:

      Markowitz Martin    Mohri Hiroshi    Mehandru    Shet Anita    Berry Leslie    Kalyanaraman Roopa    Kim Alexandria J.    Chung Christopher W.    Jean-Pierre Patrick    Horowitz Amir    La Mar Melissa    Wrin Terri    Parkin Neil    Poles Michael    Petropoulos Christos J.    Mullen Michael P.    Boden Daniel    何大一    

    • 刊名:

      Lancet

    • 在线出版时间:

      2005

  • In vivo replication kinetics of a nef-deleted strain of HIV-1 [2]

    • 摘要:

    • 作者:

      Suzanne Crowe    何大一     Marriott Deborah    Bruce james Brew    Gorry Paul R.    John stephen Sullivan    Learmont Jenny    Mills John   

    • 刊名:

      AIDS

    • 在线出版时间:

      2005

  • Identification of microRNAs of the herpesvirus family

    • 摘要:

      Epstein-Barr virus (EBV or HHV4), a member of the human herpesvirus (HHV) family, has recently been shown to encode microRNAs (miRNAs). In contrast to most eukaryotic miRNAs, these viral miRNAs do not have close homologs in other viral genomes or in the genome of the human host. To identify other miRNA genes in pathogenic viruses, we combined a new miRNA gene prediction method with small-RNA cloning from several virus-infected cell types. We cloned ten miRNAs in the Kaposi sarcoma-associated virus (KSHV or HHV8), nine miRNAs in the mouse gammaherpesvirus 68 (MHV68) and nine miRNAs in the human cytomegalovirus (HCMV or HHV5). These miRNA genes are expressed individually or in clusters from either polymerase (pol) II or pol III promoters, and share no substantial sequence homology with one another or with the known human miRNAs. Generally, we predicted miRNAs in several large DNA viruses, and we could neither predict nor experimentally identify miRNAs in the genomes of small RNA viruses or retroviruses.

    • 作者:

      Pfeffer Sébastien    Alain Sewer    Lagos-Quintana Mariana    Robert Sheridan    Chris Sander    Grässer Friedrich A.    Van Dyk Linda Faye    Ho C. Kiong    Stewart Shuman    Minchen Chien    James Russo    Ju Jingyue    Glenn Randall    Brett Lindenbach    Charles Rice    Simon Viviana    何大一     Mihaela Zǎvolan    Thomas Tuschl   

    • 刊名:

      Nature Methods

    • 在线出版时间:

      2005

  • SARS coronavirus spike polypeptide DNA vaccine priming with recombinant spike polypeptide from Escherichia coli as booster induces high titer of neutralizing antibody against SARS coronavirus

    • 摘要:

      Different forms of SARS coronavirus (SARS-CoV) spike protein-based vaccines for generation of neutralizing antibody response against SARS-CoV were compared using a mouse model. High IgG levels were detected in mice immunized with intraperitoneal (i.p.) recombinant spike polypeptide generated by Escherichia coli (S-peptide), mice primed with intramuscular (i.m.) tPA-optimize800 DNA vaccine (tPA-S-DNA) and boosted with i.p. S-peptide, mice primed with i.m. CTLA4HingeSARS800 DNA vaccine (CTLA4-S-DNA) and boosted with i.p. S-peptide, mice primed with oral live-attenuated Salmonella typhimurium (Salmonella-S-DNA-control) and boosted with i.p. S-peptide, mice primed with oral live-attenuated S. typhimurium that contained tPA-optimize800 DNA vaccine (Salmonella-tPA-S-DNA) and boosted with i.p. S-peptide, and mice primed with oral live-attenuated S. typhimurium that contained CTLA4HingeSARS800 DNA vaccine (Salmonella-tPA-S-DNA) and boosted with i.p. S-peptide. No statistical significant difference was observed among the Th1/Th2 index among these six groups of mice with high IgG levels. Sera of all six mice immunized with i.p. S-peptide, i.m. DNA vaccine control and oral Salmonella-S-DNA-control showed no neutralizing antibody against SARS-CoV. Sera of the mice immunized with i.m. tPA-S-DNA, i.m. CTLA4-S-DNA, oral Salmonella-S-DNA-control boosted with i.p. S-peptide, oral Salmonella-tPA-S-DNA, oral Salmonella-tPA-S-DNA boosted with i.p S-peptide, oral Salmonella-CTLA4-S-DNA and oral Salmonella-CTLA4-S-DNA boosted with i.p. S-peptide showed neutralizing antibody titers of <1:20-1:160. Sera of all the mice immunized with i.m. tPA-S-DNA boosted with i.p. S-peptide and i.m. CTLA4-S-DNA boosted with i.p. S-peptide showed neutralizing antibody titers of ≥1:1280. The present observation may have major practical value, such as immunization of civet cats, since production of recombinant proteins from E. coli is far less expensive than production of recombinant proteins using eukaryotic systems. © 2005 Elsevier Ltd. All rights reserved.

    • 作者:

      Patrick Woo    Susanna Lau    Hoi wah Tsoi    Zhiwei Chen    Beatrice Wong    Zhang Linqi    Chan Jim K.H.    Leipo Wong    He Wei    Ma Chi    Chan Kwok-Hung    何大一     袁国勇   

    • 刊名:

      Vaccine

    • 在线出版时间:

      2005

  • Single amino acid substitutions in the severe acute respiratory syndrome coronavirus spike glycoprotein determine viral entry and immunogenicity of a major neutralizing domain

    • 摘要:

      Neutralizing antibodies (NAbs) against severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV) spike (S) glycoprotein confer protection to animals experimentally infected with the pathogenic virus. We and others previously demonstrated that a major mechanism for neutralizing SARS-CoV was through blocking the interaction between the S glycoprotein and the cellular receptor angiotensin-converting enzyme 2 (ACE2). In this study, we used in vivo electroporation DNA immunization and a pseudovirus-based assay to functionally evaluate immunogenicity and viral entry. We characterized the neutralization and viral entry determinants within the ACE2-binding domain of the S glycoprotein. The deletion of a positively charged region SΔ(422-463) abolished the capacity of the S glycoprotein to induce NAbs in mice vaccinated by in vivo DNA electroporation. Moreover, the SΔ(422-463) pseadovirus was unable to infect HEK293T-ACE2 cells. To determine the specific residues that contribute to related phenotypes, we replaced eight basic amino acids with alanine. We found that a single amino acid substitution (R441A) in the full-length S DNA vaccine failed to induce NAbs and abolished viral entry when pseudoviruses were generated. However, another substitution (R453A) abolished viral entry while retaining the capacity for inducing NAbs. The difference between R441A and R453A suggests that the determinants for immunogenicity and viral entry may not be identical. Our findings provide direct evidence that these basic residues are essential for immunogenicity of the major neutralizing domain and for viral entry. Our data have implications for the rational design of vaccine and antiviral agents as well as for understanding viral tropism. Copyright © 2005, American Society for Microbiology. All Rights Reserved.

    • 作者:

      Yi Christopher E.    Ba Lei    Zhang Linqi    何大一     Zhiwei Chen   

    • 刊名:

      Journal of Virology

    • 在线出版时间:

      2005

  • A shot in the arm for AIDS vaccine research

    • 摘要:

    • 作者:

      何大一    

    • 刊名:

      PLoS Medicine

    • 在线出版时间:

      2005

  • Natural variation in vif: differential impact on APOBEC3G/3F and a potential role in HIV-1 diversification

    • 摘要:

      The HIV-1 Vif protein counteracts the antiviral activity exhibited by the host cytidine deaminases APOBEC3G and APOBEC3F. Here, we show that defective vif alleles can readily be found in HIV-1 isolates and infected patients. Single residue changes in the Vif protein sequence are sufficient to cause the loss of Vif-induced APOBEC3 neutralization. Interestingly, not all the detected defects lead to a complete inactivation of Vif function since some mutants retained selective neutralizing activity against APOBEC3F but not APOBEC3G or vice versa. Concordantly, independently hypermutated proviruses with distinguishable patterns of G-to-A substitution attributable to cytidine deamination induced by APOBEC3G, APOBEC3F, or both enzymes were present in individuals carrying proviruses with completely or partly defective Vif variants. Natural variation in Vif function may result in selective and partial neutralization of cytidine deaminases and thereby promote viral sequence diversification within HIV-1 infected individuals. © 2005 Simon et al.

    • 作者:

      Simon Viviana    Zennou Veronique    Murray Deya    Huang Yaoxing    何大一     Paul Bieniasz   

    • 刊名:

      PLoS Pathogens

    • 在线出版时间:

      2005

  • Modeling the long-term control of viremia in HIV-1 infected patients treated with antiretroviral therapy

    • 摘要:

      Highly active antiretroviral therapy (HAART), administered to a HAART-naïve patient, perturbs the steady state of chronic infection. This perturbation provides an opportunity to investigate the existence and dynamics of different sources of viral production. Models of HIV dynamics can be used to make a comparative analysis of the efficacies of different drug regimens. When HAART is administered for long periods of time, most patients achieve 'undetectable' viral loads (VLs), i.e., below 50 copies/ml. Use of an ultrasensitive VL assay demonstrates that some of these patients obtain a low steady state VL in the range 5-50 copies/ml, while others continue to exhibit VL declines to below 5 copies/ml. Interestingly, when patients exhibit continued declines below 50 copies/ml the virus has a half-life of ~6 months, consistent with some estimates of the rate of latent cell decline. Some patients, despite having sustained undetectable VLs, show periods of transient viremia (blips). We present a statistical characterization of the blips observed in a set of 123 patients, suggesting that patients have different tendencies to show blips during the period of VL suppression, that intermittent episodes of viremia have common amplitude profiles, and that VL decay from the peak of a blip may have two phases.

    • 作者:

      Di Mascio Michele    Ruy Ribeiro    Markowitz Martin    何大一     Alan Perelson   

    • 刊名:

      Mathematical Biosciences

    • 在线出版时间:

      2004

  • Molecular characterization of human immunodeficiency virus type 1 and hepatitis C virus in paid blood donors and injection drug users in China

    • 摘要:

      China is facing a rapid upsurge in cases of human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) infection due to large numbers of paid blood donors (PBD), injection drug users (IDU), and sexual partners of infected individuals. In this report, a total of 236 HIV-1-positive blood samples were collected from PBD, IDU, and their sexual partners in the most severely affected provinces, such as Henan, Yunnan, Guangxi, and Xinjiang. PCR was used to amplify the p17 region of gag and the C2-V3 region of env of HIV-1 and the 5′ noncoding region and a region of E1/E2 of HCV. Genetic characterization of viral sequences indicated that there are two major epidemics of HIV-1 and multiple HCV epidemics in China. The PBD and transfusion recipients in Henan harbored HIV-1 subtype B', which is similar to the virus found in Thailand, and HCV genotypes 1b and 2a, whereas the IDU in Yunnan, Guangxi, and Xinjiang carried HIV-1 circulating recombinant forms 07 and 08, which resemble those in India, and HCV genotypes 1b, 3a, and 3b. Our findings show that the epidemics of HIV-1 and HCV infection in China are the consequences of multiple introductions. The distinct distribution patterns of both the HIV-1 and HCV genotypes in the different high-risk groups are tightly linked to the mode of transmission rather than geographic proximity. These findings provide information relevant to antiviral therapy and vaccine development in China and should assist public health workers in implementing measures to reduce the further dissemination of these viruses in the world's most populous nation.

    • 作者:

      Zhang Linqi    Zhiwei Chen    Yunzhen Cao    Yu Jian    Li Guanghan    Wenjie Yu    Yin Ning    Mei Shan    Li Li    Peter Balfe    He T.    Ba Lei    Zhang Fengwen    Lin Hsi-Hsun    Yuen Man-Fung    Ching lung Lai    何大一    

    • 刊名:

      Journal of Virology

    • 在线出版时间:

      2004

  • Retraction of an interpretation.

    • 摘要:

    • 作者:

      Zhang Linqi    Lopez    He Tian    Wenjie Yu    何大一    

    • 刊名:

      Science

    • 在线出版时间:

      2004

共11页 转到