Long-term immunovirologic control following antiretroviral therapy interruption in patients treated at the time of primary HIV-1 infection
ABSTRACT Five out of 32 patients who received very early and prolonged antiretroviral therapy displayed an unusual, sustained immunovirological control after treatment discontinuation (mean duration: 77 months). These 'post-treatment controllers' did not have the genetic characteristics of spontaneous 'elite' controllers, although they shared very low and stable level of viral reservoir. Treatment may have dramatically decreased this reservoir and preserved potent HIV-specific immunologic responses, inducing a new balance between the virus and the host's immune system in these patients.
SourceAvailable from: Yahia Chebloune[Show abstract] [Hide abstract]
ABSTRACT: Novel HIV vaccine vectors and strategies are needed to control HIV/AIDS epidemic in humans and eradicate the infection. DNA vaccines alone failed to induce immune responses robust enough to control HIV-1. Development of lentivirus-based DNA vaccines deficient for integration and with a limited replication capacity is an innovative and promising approach. This type of vaccine mimics the early stages of virus infection/replication like the live-attenuated viruses but lacks the inconvenient integration and persistence associated with disease. We developed a novel lentivector DNA vaccine "CAL-SHIV-IN(-)" that undergoes a single round of replication in the absence of integration resulting in augmented expression of vaccine antigens in vivo. Vaccine gene expression is under control of the LTRs of a naturally attenuated lentivirus, Caprine arthritis encephalitis virus (CAEV) the natural goat lentivirus. The safety of this vaccine prototype was increased by the removal of the integrase coding sequences from the pol gene. We examined the functional properties of this lentivector DNA in cell culture and the immunogenicity in mouse models. Viral proteins were expressed in transfected cells, assembled into viral particles that were able to transduce once target permissive cells. Unlike the parental replication-competent SHIV-KU2 that was detected in DNA samples from any of the serial passage infected cells, CAL-SHIV-IN(-) DNA was detected only in target cells of the first round of infection, hence demonstrating the single cycle replication of the vaccine. A single dose DNA immunization of humanized NOD/SCID/β2 mice showed a substantial increase of IFN-γ-ELISPOT in splenocytes compared to the former replication and integration defective Δ4SHIV-KU2 DNA vaccine. Copyright © 2015. Published by Elsevier Ltd.Vaccine 03/2015; DOI:10.1016/j.vaccine.2015.03.021 · 3.49 Impact Factor
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ABSTRACT: This randomised, open label, phase I, immunotherapeutic study investigated the effects of interleukin (IL)-2, granulocyte-macrophage colony-stimulating factor (GM-CSF), recombinant human growth hormone (rhGH), and therapeutic immunisation (a Clade B DNA vaccine) on combination antiretroviral therapy (cART)-treated HIV-1-infected individuals, with the objective to reverse residual T-cell dysfunction.Methods Twelve HIV-1+ patients on suppressive cART with baseline CD4 T-cell counts >400 cells/mm3 blood were randomised into one of three groups: (1) vaccine, IL-2, GM-CSF and rhGH (n = 3); (2) vaccine alone (n = 4); or (3) IL-2, GM-CSF and rhGH (n = 5). Samples were collected at weeks 0, 1, 2, 4, 6, 8, 12, 16, 24 and 48. Interferon (IFN)-γ, IL-2, IL-4 and perforin ELISpot assays performed at each time point quantified functional responses to Gag p17/p24, Nef, Rev, and Tat peptides; and detailed T-cell immunophenotyping was undertaken by flow cytometry. Proviral DNA was also measured.ResultsMedian baseline CD4 T-cell count was 757 cells/mm3 (interquartile range [IQR] 567–886 cells/mm3), median age 48 years (IQR 42–51 years), and plasma HIV-1-RNA <50 copies/ml for all subjects. Patients who received vaccine plus IL-2, GM-CSF and rhGH (group 1) showed the most marked changes. Assessing mean changes from baseline to week 48 revealed significantly elevated numbers of CD4 T cells (p = 0.0083) and improved CD4/CD8 T-cell ratios (p = 0.0033). This was accompanied by a significant reduction in expression of CD38 on CD4 T cells (p = 0.0194), significantly increased IFN-γ and IL-2 production in response to Gag (p = 0.0122) and elevated IFN-γ production in response to Tat (p = 0.041) at week 48 compared to baseline. Subjects in all treatment groups showed significantly reduced PD-1 expression at week 48 compared to baseline, with some reductions in proviral DNA.Conclusions Multifarious immunotherapeutic approaches in the context of fully suppressive cART further reduce immune activation, and improve both CD4 T-lymphocyte counts and HIV-1-specific T-cell responses (NCT01130376).Vaccine 10/2014; DOI:10.1016/j.vaccine.2014.09.072 · 3.49 Impact Factor
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ABSTRACT: Raltegravir (Isentress ™) is a potent integrase inhibitor of gammaretroviruses in vitro.•In this study, the effect of Raltegravir was evaluated in vivo for safety (3 cats) and efficacy in 7 cats persistently viremic with FeLV.•While Raltegravir treatment was well tolerated up to.•80 mg b.i.d., it resulted in a significant decrease in plasma FeLV loads (5x). However, after treatment termination, plasma FeLV loads increased to default levels.•It was concluded that Raltegravir treatment efficiently reduces FeLV loads but that this reduction was not sufficient for the immune system to subdue viremia.•In combiantion with other antiretroviral procedures, Raltegravir may be efficacious to control FeLV viremia and to cure cats from its consequences.Veterinary Microbiology 11/2014; 175(2-4). DOI:10.1016/j.vetmic.2014.10.031 · 2.73 Impact Factor