Inhibition of interferon response by cystatin B: implication in HIV replication of macrophage reservoirs.
Enviado por Loyda Milagros Melendez, Ph.D. el
Título | Inhibition of interferon response by cystatin B: implication in HIV replication of macrophage reservoirs. |
Publication Type | Journal Article |
Year of Publication | 2012 |
Autores | Rivera-Rivera, L, Perez-Laspiur, J, Colon, K, Meléndez, LM |
Journal | J Neurovirol |
Volume | 18 |
Issue | 1 |
Pagination | 20-9 |
Date Published | 2012 Feb |
ISSN | 1538-2443 |
Palabras clave | Animals, Cells, Cultured, Cercopithecus aethiops, Cystatin B, Gene Expression, Genes, Reporter, HIV Infections, HIV-1, Humans, Immunoprecipitation, Interleukin-6, Luciferases, Firefly, Macrophages, Phosphorylation, Protein Binding, Pyruvate Kinase, STAT1 Transcription Factor, Transfection, Vault Ribonucleoprotein Particles, Vero Cells, Virus Replication |
Abstract | Cystatin B and signal transducer and activator of transcription-1 (STAT-1) phosphorylation have recently been shown to increase human immunodeficiency virus-1 (HIV-1) replication in monocyte-derived macrophages (MDM), but the molecular pathways by which they do are unknown. We hypothesized that cystatin B inhibits the interferon (IFN) response and regulates STAT-1 phosphorylation by interacting with additional proteins. To test if cystatin B inhibits the IFN-β response, we performed luciferase reporter gene assays in Vero cells, which are IFN deficient. Interferon-stimulated response element (ISRE)-driven expression of firefly luciferase was significantly inhibited in Vero cells transfected with a cystatin B expression vector compared to cells transfected with an empty vector. To determine whether cystatin B interacts with other key players regulating STAT-1 phosphorylation and HIV-1 replication, cystatin B was immunoprecipitated from HIV-1-infected MDM. The protein complex was analyzed by liquid chromatography tandem mass spectrometry. Protein interactions with cystatin B were verified by Western blots and immunofluorescence with confocal imaging. Our findings confirmed that cystatin B interacts with pyruvate kinase M2 isoform, a protein previously associated cocaine enhancement of HIV-1 replication, and major vault protein (MVP), an IFN-responsive protein that interferes with JAK/STAT signals. Western blot studies confirmed the interaction with pyruvate kinase M2 isoform and MVP. Immunofluorescence studies of HIV-1-infected MDM showed that upregulated MVP colocalized with STAT-1. To our knowledge, the current study is the first to demonstrate the coexpression of cystatin B, STAT-1, MVP, and pyruvate kinase M2 isoform with HIV-1 replication in MDM and thus suggests novel targets for HIV-1 restriction in macrophages, the principal reservoirs for HIV-1 in the central nervous system. |
DOI | 10.1007/s13365-011-0061-2 |
Alternate Journal | J. Neurovirol. |
PubMed ID | 22147503 |
PubMed Central ID | PMC3309143 |
Grant List | G12 RR-03051 / RR / NCRR NIH HHS / United States R01 MH083516-01 / MH / NIMH NIH HHS / United States |