Search results for "Simian Acquired Immunodeficiency Syndrome"

Gut germinal center regeneration and enhanced antiviral immunity by mesenchymal stem/stromal cells in SIV infection.

2021

Although antiretroviral therapy suppresses HIV replication, it does not eliminate viral reservoirs or restore damaged lymphoid tissue, posing obstacles to HIV eradication. Using the SIV model of AIDS, we investigated the effect of mesenchymal stem/stromal cell (MSC) infusions on gut mucosal recovery, antiviral immunity, and viral suppression and determined associated molecular/metabolic signatures. MSC administration to SIV-infected macaques resulted in viral reduction and heightened virus-specific responses. Marked clearance of SIV-positive cells from gut mucosal effector sites was correlated with robust regeneration of germinal centers, restoration of follicular B cells and T follicular h…

AIDS and the Central Nervous System: Examining Pathobiology and Testing Therapeutic Strategies in the SIV-Infected Rhesus Monkey

1993

Cortical astrocytosis in juvenile rhesus monkeys infected with simian immunodeficiency virus

1993

The pattern of expression of GFAP immunoreactivity in astrocytes of the juvenile rhesus monkey cortex was examined following infection with simian immunodeficiency virus (SIV). Blocks of cerebral cortex plus subjacent white matter from saline- and formalin-perfused brain were examined by peroxidase-linked immunochemical and immunofluorescence staining of deparaffinized sections. Strong GFAP immunoreactivity was found in astrocytic cells in both uninfected and SIV-infected juvenile macaque in the subpial cerebral cortex and in subcortical white matter, where GFAP-positive cells were abundant. GFAP staining of cortical layers 2-6 on the other hand was weak or absent in three uninfected contro…

Flow cytometric investigation of neutrophil oxidative burst and apoptosis in physiological and pathological situations

2009

Flow cytometric analysis provides a rapid screen for abnormalities of polymorphonuclear neutrophils (PMN) function and reflect their behavior in vivo more accurately. This review summarizes the major fluorescent probes used to study PMN oxidative burst and apoptosis using flow cytometry (FCM). We also provide examples of FCM studies in physiological and pathological situations, illustrating the advantages of FCM for assessment of PMN oxidative burst and PMN apoptosis. These data point to the role of FCM in detecting primary immunodeficiencies such as IRAK4 deficiency and support the use of the assessment of the PMN oxidative burst for routine testing in patients with bacterial infections. W…

Cytopathologic and neurochemical correlates of progression to motor/cognitive impairment in SIV-infected rhesus monkeys.

1994

Neurochemical, pathologic, virologic, and histochemical correlates of simian immunodeficiency virus (SIV)-associated central nervous system (CNS) dysfunction were assessed serially or at necropsy in rhesus monkeys that exhibited motor and cognitive deficits after SIV infection. Some infected monkeys presented with signs of acquired immunodeficiency disease (AIDS) at the time of sacrifice. Seven of eight animals exhibited motor skill impairment which was associated with elevated quinolinic acid in cerebrospinal fluid (CSF). Examination of the brains revealed diffuse increases in glial fibrillary acidic protein immunoreacti vity in cerebral cortex in all animals, regardless of evidence of imm…

Evolutionary plasticity of SH3 domain binding by Nef proteins of the HIV-1/SIVcpz lentiviral lineage

2021

The accessory protein Nef of human and simian immunodeficiency viruses (HIV and SIV) is an important pathogenicity factor known to interact with cellular protein kinases and other signaling proteins. A canonical SH3 domain binding motif in Nef is required for most of these interactions. For example, HIV-1 Nef activates the tyrosine kinase Hck by tightly binding to its SH3 domain. An archetypal contact between a negatively charged SH3 residue and a highly conserved arginine in Nef (Arg77) plays a key role here. Combining structural analyses with functional assays, we here show that Nef proteins have also developed a distinct structural strategy—termed the "R-clamp”—that favors the formation …