Previous studies have demonstrated that the genetic determinants of simian immunodeficiency virus (SIV) neurovirulence map to the env and nef genes. Recent studies from our laboratory demonstrated that SIV replication in primary rhesus macaque astrocyte cultures is dependent upon the nef gene. Here, we demonstrate that macrophage tropism is not sufficient for replication in astrocytes and that specific amino acids in the transmembrane (TM) portion of Env are also important for optimal SIV replication in astrocytes. Specifically, a Gly at amino acid position 751 and truncation of the cytoplasmic tail of TM are required for efficient replication in these cells. Studies using soluble CD4 demonstrated that these changes within the TM protein regulate CD4-independent, CCR5-dependent entry of virus into astrocytes. In addition, we observed that two distinct CD4-independent, neuroinvasive strains of SIV/DeltaB670 also replicated efficiently in astrocytes, further supporting the role of CD4 independence as an important determinant of SIV infection of astrocytes in vitro and in vivo.
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http://dx.doi.org/10.1128/JVI.79.8.4944-4951.2005 | DOI Listing |
Cell Rep Med
January 2025
IrsiCaixa Immunopathology Research Institute, Badalona, Spain; Germans Trias i Pujol Research Institute, Badalona, Spain; CIBERINFEC, Institute of Health Carlos III, Madrid, Spain. Electronic address:
High-efficacy antiretroviral treatment (ART) has been a game-changer for HIV/AIDS pandemic, but incomplete CD4 T cell recovery and persistent chronic immune activation still affect HIV-suppressed people. Exceptional cases of HIV infection that naturally exhibit delayed disease progression provide invaluable insights into protective biological mechanisms with potential clinical application. Viremic non-progressors (VNPs) represent an extremely rare population of individuals with HIV, characterized by preservation of the CD4 T cell compartment despite persistent high levels of viral load (>10,000 copies/mL).
View Article and Find Full Text PDFCommun Biol
January 2025
Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, NE, USA.
The primary immune constituents in the brain, microglia and macrophages, are the target for HIV in people and simian immunodeficiency virus (SIV) in nonhuman primates. This infection can lead to neurological dysfunction, known as HIV-associated neurocognitive disorder (HAND). Given the gaps in our knowledge on how these cells respond in vivo to CNS infection, we perform single-cell multiomic sequencing, including gene expression and ATAC-seq, on myeloid cells from the brains of rhesus macaques with SIV-induced encephalitis (SIVE) as well as uninfected controls.
View Article and Find Full Text PDFSci Signal
January 2025
Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education), Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310000, China.
Activation of the stimulator of interferon genes (STING) pathway by cytosolic DNA leads to the activation of the transcription factors interferon regulatory factor 3 (IRF3) and nuclear factor κB (NF-κB). Although many viruses produce proteins that inhibit IRF3-dependent antiviral responses, some viruses produce proteins that inhibit STING-induced NF-κB activation without blocking IRF3 activation. Here, we found that STING-activated, NF-κB-dependent, and IRF3-independent innate immunity inhibited the replication of the DNA virus herpes simplex virus type 1 (HSV-1), the RNA virus coxsackievirus A16 (CV-A16), and the retrovirus HIV-1.
View Article and Find Full Text PDFTransl Med Commun
January 2024
Department of Anatomy, Physiology, & Cell Biology, School of Veterinary Medicine, and California National Primate Research Center, University of California, Davis, County Road 98 & Hutchison Drive, Davis, CA, USA.
Background: Late-stage human immunodeficiency virus (HIV) infection is typically characterized by low CD4 + T-cell count. We previously showed that profound changes in the monocyte turnover (MTO) rate in rhesus macaques infected by the simian immunodeficiency virus (SIV) outperforms declining CD4 + T-cell counts in predicting rapid health decline associated with progression to terminal disease. High MTO is associated with increased tissue macrophage death.
View Article and Find Full Text PDFPLoS Pathog
January 2025
Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, United States of America.
The latent viral reservoir remains the major barrier to HIV cure, placing the burden of strict adherence to antiretroviral therapy (ART) on people living with HIV to prevent recrudescence of viremia. For infants with perinatally acquired HIV, adherence is anticipated to be a lifelong need. In this study, we tested the hypothesis that administration of ART and viral Envelope-specific rhesus-derived IgG1 monoclonal antibodies (RhmAbs) with or without the IL-15 superagonist N-803 early in infection would limit viral reservoir establishment in SIV-infected infant rhesus macaques.
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