Despite the introduction of combined antiretroviral therapy (cART) HIV-1 virus persists in the brain in a latent or restricted manner and viral proteins, such as gp120, continue to play a significant disease-inciting role. Gp120 is known to interact with -methyl--aspartate (NMDA) receptors (NMDARs) resulting in neuronal injury. Glutamate is the main excitatory neurotransmitter in the brain and plays an important role in cognitive function and dysregulation of excitatory synaptic transmission impairs neurocognition. It is our hypothesis that gp120 may alter synaptic function via modulating glutamate function from a physiological molecule to a pathophysiological substance. To test this hypothesis, we studied the modulatory effects of gp120 and glutamate on NMDAR-mediated spontaneous excitatory postsynaptic current (sEPSC) and dynamic dendritic spine changes in rat cortical neuronal cultures. Our results revealed that gp120 and glutamate each, at low concentrations, had no significant effects on sEPSC and dendritic spines, but increased sEPSC frequency, decreased numbers of dendritic spines when tested in combination. The observed effects were blocked by either a CXCR4 blocker or an NMDAR antagonist, indicating the involvements of chemokine receptor CXCR4 and NMDARs in gp120 modulation of glutamate effects. These results may imply a potential mechanism for HIV-1-associated neuropathogenesis in the cART era.
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iScience
July 2024
Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA.
The pretriggered conformation of the human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) trimer ((gp120/gp41)) is targeted by virus entry inhibitors and broadly neutralizing antibodies (bNAbs). The lability of pretriggered Env has hindered its characterization. Here, we produce membrane Env variants progressively stabilized in pretriggered conformations, in some cases to a degree beyond that found in natural HIV-1 strains.
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April 2024
Department of Virology, Doris Duke Medical Research Institute, College of Health Sciences, University of KwaZulu-Natala, Durban, South Africa.
Introduction: There is increasing evidence supporting a role for HIV-1 envelope in the development of Protease Inhibitor drug resistance, and a recent report from our group suggested that Env mutations co-evolve with Gag-Protease mutations in the pathway to Lopinavir resistance. In this study, we investigated the effect of co-evolving Env mutations on virus function and structure.
Methods: Co-receptor usage and n-linked glycosylation were investigated using Geno2Pheno as well as tools available at the Los Alamos sequence database.
AIDS
May 2024
Department of Ophthalmology, Huashan Hospital, Fudan University, Shanghai, China.
Objective: This study aims to investigate the functions and mechanistic pathways of Astrocyte Elevated Gene-1 (AEG-1) in the disruption of the blood-retinal barrier (BRB) caused by the HIV-1 envelope glycoprotein gp120.
Design: We utilized ARPE-19 cells challenged with gp120 as our model system.
Methods: Several analytical techniques were employed to decipher the intricate interactions at play.
Brain Behav Immun
May 2024
Division of Biomedical Sciences, School of Medicine, University of California, Riverside, 900 University Ave, Riverside, CA, 92521, USA; Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA. Electronic address:
Human immunodeficiency virus-1 (HIV-1) infects the central nervous system (CNS) and causes HIV-associated neurocognitive disorders (HAND) in about half of the population living with the virus despite combination anti-retroviral therapy (cART). HIV-1 activates the innate immune system, including the production of type 1 interferons (IFNs) α and β. Transgenic mice expressing HIV-1 envelope glycoprotein gp120 (HIVgp120tg) in the CNS develop memory impairment and share key neuropathological features and differential CNS gene expression with HIV patients, including the induction of IFN-stimulated genes (ISG).
View Article and Find Full Text PDFFront Immunol
November 2023
Institute of Clinical and Molecular Virology, University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany.
Background: Fc-fusion proteins have been successfully developed for therapeutic purposes, but are also a promising platform for the fast generation and purification of immunogens capable of inducing strong humoral immune responses in preclinical immunization studies. As the Fc-portion of immunoglobulins fused to an antigen confers functional properties of the parental antibody, such as dimerization, binding to Fc-receptors and complement activation, several studies reported that Fc-fusion proteins elicit stronger antigen-specific antibody responses than the unfused antigen. However, dimerization or half-life extension of an antigen have also been described to enhance immunogenicity.
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