Functional Proteomic Analysis for Regulatory T Cell Surveillance of the HIV-1-Infected Macrophage

Department of Pharmacology, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States.
Journal of Proteome Research (Impact Factor: 5). 10/2010; 9(12):6759-73. DOI: 10.1021/pr1009178
Source: PubMed

ABSTRACT Regulatory T cells (Treg) induce robust neuroprotection in murine models of neuroAIDS, in part, through eliciting anti-inflammatory responses for HIV-1-infected brain mononuclear phagocytes (MP; macrophage and microglia). Herein, using both murine and human primary cell cultures in proteomic and cell biologic tests, we report that Treg promotes such neuroprotection by an even broader range of mechanisms than previously seen including inhibition of virus release, killing infected MP, and inducing phenotypic cell switches. Changes in individual Treg-induced macrophage proteins were quantified by iTRAQ labeling followed by mass spectrometry identifications. Reduction in virus release paralleled the upregulation of interferon-stimulated gene 15, an ubiquitin-like protein involved in interferon-mediated antiviral immunity. Treg killed virus-infected macrophages through caspase-3 and granzyme and perforin pathways. Independently, Treg transformed virus-infected macrophages from an M1 to an M2 phenotype by down- and up- regulation of inducible nitric oxide synthase and arginase 1, respectively. Taken together, Treg affects a range of virus-infected MP functions. The observations made serve to challenge the dogma of solitary Treg immune suppressor functions and provides novel insights into how Treg affects adaptive immunosurveillance for control of end organ diseases, notably neurocognitive disorders associated with advanced viral infection.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Several different types of non-neuronal glial cells with diverse phenotypes are present in the central nervous system (CNS), and all have distinct indispensible functions. Although glial cells primarily provide neurons with metabolic and structural support in the healthy brain, they may switch phenotype from a "resting" to a "reactive" state in response to pathological insults. Furthermore, this reactive gliosis is an invariant feature of the pathogeneses of CNS maladies. The glial proteome serves as a signature of glial phenotype, and not only executes physiological functions, but also acts as a molecular mediator of the reactive glial phenotype. The glial proteome is also involved in intra- and inter-cellular communications as exemplified by glia-glia and neuron-glia interactions. The utilization of authoritative proteomic tools and the bioinformatic analyses have helped to profile the brain glial proteome and explore the molecular mechanisms of diverse glial phenotypes. Furthermore, technologic innovations have equipped the field of "glioproteomics" with refined tools for studies of the expression, interaction, and function of glial proteins in the healthy and in the diseased CNS. Glioproteomics is expected to contribute to the elucidation of the molecular mechanisms of CNS pathophysiology and to the discovery of biomarkers and theragnostic targets in CNS disorders. This article is protected by copyright. All rights reserved.
    Proteomics 03/2014; 14(4-5). DOI:10.1002/pmic.201300236 · 3.97 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Tissue macrophages play important roles in maintaining homeostasis in most organs of the body including the brain where microglia represent the resident phagocytic cells of this compartment. The possibility of one day harnessing macrophage plasticity to treat or ameliorate disorders including obesity, cancer, organ damage, intestinal disorders, neurodegeneration, and cardiovascular disease in which these cells play a role, is a very exciting prospect. Inflammatory signaling is required for regenerative repair, healing, and pathogen clearance functions. However, when the inflammatory response persists in a chronic fashion over an extended period of time, damage to neurons is followed by neuronal injury and dysfunction. Macrophages in the brain are heterogeneous arising from tissues during embryogenesis, and in the adult, from bone marrow derived monocytes that enter through the blood-brain-barrier. While much of our insight regarding macrophage functional subtypes has been garnered through elegant studies in mice, which are amenable to genetic manipulation, far less is known about such cells in human tissues, and particularly in the brain under normal, disease, or injurious conditions. In this regard, non-human primate models for human immunodeficiency virus have been extremely useful for understanding the contribution of bone marrow-derived monocytes in neurological disease and their interaction and impact on the activation state of resident microglia in the brain. This review will focus on what has been learned from the rhesus macaque models about the types of macrophages present in the brains of animals with encephalitis. In vitro studies, which have used human blood monocytes differentiated into macrophages to address the question of macrophage subsets in HIV infection will be highlighted. Recent insights on macrophage phenotype and persistent inflammation in the brain in HIV-associated neurocognitive disorder from immunohistochemical studies on human autopsy tissue will be examined.
    12/2015; 4(1):7. DOI:10.1186/s40169-015-0049-2
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We identified and measured proteins in the cerebral spinal fluid (CSF) involved in HIV-associated neurological disorders. Protein levels were determined by mass spectrometry (MS) in pooled CSF taken from three patient groups (human immunodeficiency virus (HIV)-1-infected patients that developed HIV-associated neurocognitive disorders (HANDs), HIV-1-infected patients without HAND, and healthy controls). Pools were generated from 10 patients each per group. CSF from individual patient groups were digested with trypsin and separately labeled using with isobaric tags for relative and absolute quantitation (iTRAQ). After combining all samples in one, peptides were extensively fractionated by offline two-dimensional separation and identified by tandem MS. One hundred and ninety three proteins were deemed to be interpretable for quantitation based on permutation tests with a 95 % confidence interval with a p value ≤ 0.05. Using a cutoff of 1.5-fold for upregulation and 0.6 for downregulation, 16 proteins were differentially expressed in HIV + HAND (reporter p value ≤0.05) with seven of them previously described as HIV-interacting proteins: endoplasmin, mitochondrial damage mediator-BH3-interacting domanin death agonist, orosomucoid, apolipoprotein E, metalloproteinase inhibitor 2, peroxiredoxin-2, and the nuclear protein, ruvB-like 2. Several previously unidentified proteins with possible neurological implication in HIV patients include forming-binding protein 1, C-reactive protein, leukocyte-associated immunoglobulin receptor 1, renin receptor, mediator of RNA polymerase II transcription subunit 14, multimerin-2, alpha-N-acetylglucosaminidase, caldesmon, and cadherin EGF LAG G-type receptor. Our results suggest that not only a few but possibly a combination of biomarkers that are highly correlated can predict neurocognitive status in HIV-infected patients and might be involved in monocyte or macrophage activation.
    Journal of NeuroVirology 07/2014; 20(5). DOI:10.1007/s13365-014-0263-5 · 3.32 Impact Factor