Publications by authors named "Dale A McPhee"

HIV rapid diagnostic tests (RDTs) are now used widely in non-laboratory settings by non-laboratory-trained operators. Quality assurance programmes are essential in ensuring the quality of HIV RDT outcomes. However, there is no cost-effective means of supplying the many operators of RDTs with suitable quality assurance schemes.

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Article Synopsis
  • - The study explores the link between viral fitness and control of viral load (VL) in early HIV-1 infection using samples from two clinical studies involving patients with varying treatment regimens.
  • - Results showed that viral fitness decreased over time with ART in the PULSE study, while it increased in the absence of ART in the PHAEDRA study; however, there was no correlation between viral fitness and plasma VL.
  • - Notably, the study revealed that the relative fitness of HIV-1 isolates during the acute phase may be higher than previously believed, suggesting that viral fitness should be considered when deciding on the timing of ART initiation.
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Severe immunodeficiency during primary human immunodeficiency virus (HIV) infection is unusual. Here, we characterized viral and immunological parameters in a subject presenting with Pneumocystis jirovecii pneumonia in the setting of prolonged primary HIV illness and delayed seroconversion. HIV antibody was only detected by enzyme-linked immunosorbent assay 12 months after presentation, and Western blot profiles remain indeterminate.

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The development of a rapid and efficient system to identify human immunodeficiency virus type 1 (HIV-1)-infected individuals with broad and potent HIV-1-specific neutralizing antibody responses is an important step toward the discovery of critical neutralization targets for rational AIDS vaccine design. In this study, samples from HIV-1-infected volunteers from diverse epidemiological regions were screened for neutralization responses using pseudovirus panels composed of clades A, B, C, and D and circulating recombinant forms (CRFs). Initially, 463 serum and plasma samples from Australia, Rwanda, Uganda, the United Kingdom, and Zambia were screened to explore neutralization patterns and selection ranking algorithms.

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Background: Elite non-progressors (plasma viral load < 50 copies/ml while antiretroviral naive) constitute a tiny fraction of HIV-infected individuals. After 12 years follow-up of a cohort of 13 long-term non-progressors (LTNP) identified from 135 individuals with transfusion-acquired HIV infection, 5 remained LTNP after 23 to 26 years infection, but only 3 retained elite LTNP status. We examined the mechanisms that differentiated delayed progressors from LTNP in this cohort.

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Rapid antibody tests for the detection of human immunodeficiency virus (HIV) offer an effective means of providing a timely result of HIV serostatus to individuals. The increased use of rapid HIV antibody tests outside the laboratory has highlighted the need for new, cost-effective quality assurance methods to be developed for use in nonlaboratory-based and resource-limited settings. Photographed rapid HIV test results were used in a modified external quality assessment scheme to assess the interpretation proficiency and, therefore, to assess the feasibility of using this method as a basis for a quality assessment program for nonlaboratory-based testing.

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In efforts to develop an effective vaccine, sterilizing immunity to primate lentiviruses has only been achieved by the use of live attenuated viruses carrying major deletions in nef and other accessory genes. Although live attenuated HIV vaccines are unlikely to be developed due to a myriad of safety concerns, opportunities exist to better understand the correlates of immune protection against HIV infection by studying rare cohorts of long-term survivors infected with attenuated, nef-deleted HIV strains such as the Sydney blood bank cohort (SBBC). Here, we review studies of viral evolution, pathogenicity, and immune responses to HIV infection in SBBC members.

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Background: The Sydney blood bank cohort (SBBC) of long-term survivors consists of multiple individuals infected with attenuated, nef-deleted variants of human immunodeficiency virus type 1 (HIV-1) acquired from a single source. Long-term prospective studies have demonstrated that the SBBC now comprises slow progressors (SP) as well as long-term nonprogressors (LTNP). Convergent evolution of nef sequences in SBBC SP and LTNP indicates the in vivo pathogenicity of HIV-1 in SBBC members is dictated by factors other than nef.

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The Sydney Blood Bank Cohort (SBBC) consists of eight blood transfusion recipients infected with nef-attenuated human immunodeficiency virus type 1 (HIV-1) acquired from a single donor. Here, we show that viral phenotypes and antibody responses differ considerably between individual cohort members, despite the single source of infection. Replication of isolated virus varied from barely detectable to similar to that of the wild-type virus, and virus isolated from five SBBC members showed coreceptor usage signatures unique to each individual.

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Long-term survival of human immunodeficiency virus type 1 (HIV-1) infection has been noted in rare cohorts of individuals infected with nef-deleted virus. Enhanced macrophage tropism and cytopathicity contribute to pathogenicity of wild type HIV-1. To better understand the pathogenesis of nef-deleted HIV-1, we analyzed the replication capacity and macrophage cytopathicity of nef-deleted HIV-1 isolated sequentially from a long-term survivor during progression to AIDS (n=6 isolates).

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The authors studied the transcriptional activity of blood-and cerebrospinal fluid (CSF)-derived nef/long-terminal repeat (LTR) sequences isolated from a slow progressor infected with nef-deleted human immunodeficiency virus type 1 (HIV-1) who developed HIV-associated dementia (HIVD). The transcriptional activity of CSF-derived nef/LTR clones isolated during HIVD was up to 4.5-fold higher than blood-derived clones isolated before and during HIVD when tested under basal, phorbol 12-myristate 13-acetate-(PMA-), and Tat-activated conditions, and was associated with the presence of duplicated nuclear factor (NF)-kappaB and specificity factor-1 (Sp-1) binding sites coupled with a truncated nef sequence, increased replication capacity, and high CSF viral load.

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Objectives: To assess the potency, breadth of action, and mechanism of action of the polyclonal goat anti-HIV antibody, PEHRG214.

Design: Typical human antibody responses to HIV-1 infection are unable to neutralize virus efficiently, clear the infection, or prevent disease progression. However, more potent neutralizing antibodies may be capable of playing a pivotal role in controlling HIV replication in vivo.

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We studied the evolution and compartmentalization of nef/long terminal repeat (nef/LTR)-deleted human immunodeficiency virus type 1 (HIV-1) from a long-term survivor who developed HIV-associated dementia (HIVD). Analysis of sequential blood-derived HIV-1 isolated before and during HIVD revealed a persistent R5X4 phenotype and a progressive loss of nef/LTR sequence; in contrast, HIV-1 present in cerebrospinal fluid during HIVD had an R5 phenotype, distinct nef/LTR sequence of unique deletions and additional nuclear factor- kappa B sites and specificity factor-1 sites, and enhanced transcriptional activity, compared with the blood-derived isolates. Thus, nef/LTR-deleted HIV-1 strains may undergo compartmentalized evolution in long-term survivors and cause neurologic disease.

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Disease progression in human immunodeficiency virus type-1 (HIV-1)-infected individuals is frequently accompanied by declining CD4 cell numbers and the acquisition of a T-tropic (X4) or dual tropic (R5X4) phenotype. Understanding the mechanism of CD4 cell loss in HIV-1 infection is essential for the development of effective therapeutic strategies. In this study, donor populations of peripheral blood mononuclear cells (PBMCs) were selected for their ability to support an equivalent acute infection by both R5 and X4 virus phenotypes.

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Purpose: To establish the pharmacokinetics and safety of single-dose polyclonal caprine anti-HIV antibodies ((PE)HRG214)in HIV-1-infected individuals.

Design: A phase 1, open-label, nonrandomized, dose-escalating study.

Method: HIV-1-infected patients with CD4+ T-cell counts of < or =200 cells/microL and plasma HIV viral load (VL)of > or =5,000 copies/mL received a single intravenous dose of HRG.

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The human immunodeficiency virus type 1 (HIV-1) Vpr protein is known to arrest the cell cycle in G(2)/M and induce apoptosis following arrest. The functions of Vpr relative to its location in the cell remain unresolved. We now demonstrate that the location and function of Vpr are dependent on the makeup of fusion proteins and that the functions of G(2)/M arrest and apoptosis are separable.

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HIV-1 has at its disposal numerous proteins encoded by its genome which provide the required arsenal to establish and maintain infection in its host for a considerable number of years. One of the most important and enigmatic of these proteins is Nef. The Nef protein of HIV-1 plays a fundamental role in the virus life cycle.

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Primary HIV-1 infection (PHI) is associated with a period of viremia, the resolution of which generally coincides with the development of both humoral and cellular immune responses. In this study replication-competent quasispecies were derived from virus isolated from an individual before and after seroconversion. Virus was also isolated from the presumed donor.

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The nef gene product of human immunodeficiency virus type 1 (HIV-1) is important for the induction of AIDS, and key to its function is its ability to manipulate T-cell function by targeting cellular signal transduction proteins. We reported that Nef coprecipitates a multiprotein complex from cells which contains tumor suppressor protein p53. We now show that Nef interacts directly with p53.

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