Unlabelled: The establishment of a latent reservoir by human tumor viruses is a vital step in initiating cellular transformation and represents a major shortcoming to current therapeutic strategies and the ability to eradicate virus-infected cells. Human T-cell leukemia virus type 1 (HTLV-1) establishes a lifelong infection and is linked to adult T-cell leukemia lymphoma (ATLL). Here, we demonstrate that HTLV-1 p30 recruits the cellular proteasome activator PA28γ onto the viral tax/rex mRNA to prevent its nuclear export and suppress virus replication. Interaction of p30 with a PA28γ retaining fully functional proteasome activity is required for p30's ability to repress HTLV-1. Consistently, HTLV-1 molecular clones replicate better and produce more virus particles in PA28γ-deficient cells. These results define a unique and novel role for the cellular factor PA28γ in the control of nuclear RNA trafficking and HTLV-1–induced latency. Importantly, knockdown of PA28γ expression in ATLL cells latently infected with HTLV-1 reactivates expression of viral tax/rex RNA and the Tax protein. Because Tax is the most immunogenic viral antigen and triggers strong CTL responses, our results suggest that PA28γ-targeted therapy may reactivate virus expression from latently infected cells and allow their eradication from the host.
Key Points: PA28γ acts as a co-repressor of HTLV-1 p30 to suppress virus replication and is required for the maintenance of viral latency. HTLV-1 has evolved a unique function mediated by its posttranscriptional repressor p30, which is not found in HTLV-2.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3563364 | PMC |
http://dx.doi.org/10.1182/blood-2012-03-420414 | DOI Listing |
Eur J Immunol
January 2025
Division of Hematology and Rheumatology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
The reasons for the low frequency of anti-Ro/SS-A antibody in patients with HTLV-1-associated myelopathy complicated with Sjögren's syndrome (SS) are unclear. In this study, we investigated whether HTLV-1-infected T cells can act directly on B cells and suppress B cells' production of antibodies, including anti-Ro/SS-A antibody. For this purpose, we established an in vitro T-cell-free B-cell antibody production system.
View Article and Find Full Text PDFViruses
December 2024
Laboratory of Virology, National Institute for Infectious Diseases "Lazzaro Spallanzani" (IRCCS), 00149 Rome, Italy.
Persistence is a strategy used by many viruses to evade eradication by the immune system, ensuring their permanence and transmission within the host and optimizing viral fitness. During persistence, viruses can trigger various phenomena, including target organ damage, mainly due to an inflammatory state induced by infection, as well as cell proliferation and/or immortalization. In addition to immune evasion and chronic inflammation, factors contributing to viral persistence include low-level viral replication, the accumulation of viral mutants, and, most importantly, maintenance of the viral genome and reliance on viral oncoprotein production.
View Article and Find Full Text PDFViruses
November 2024
Laboratório Avançado de Saúde Pública, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz (Fiocruz-BA), Salvador 40296-710, Bahia, Brazil.
Human T-cell leukemia virus type 1 (HTLV-1) is associated with an increased risk of tuberculosis (TB). This study aimed to evaluate the performance of the QuantiFERON-TB Gold (QFT) test for the diagnosis of (MTB) infection in HTLV-1-infected individuals. HTLV-1-infected participants were divided into four groups: HTLV-1-infected individuals with a history of tuberculosis (HTLV/TB), individuals with positive HTLV and tuberculin skin tests (HTLV/TST+) or negative TST (HTLV/TST-), and HTLV-1-negative individuals with positive TST results (HN/TST+).
View Article and Find Full Text PDFFront Hum Neurosci
December 2024
Programa de Pós-Graduação em Infectologia e Medicina Tropical, Faculdade de Medicina da Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
Introduction: Galvanic vestibular stimulation (GVS) is a simple, safe, and noninvasive method of neurostimulation that can be used to improve body balance. Several central nervous system diseases cause alterations in body balance, including HTLV-1-associated myelopathy (HAM).
Objective: To test GVS as a balance rehabilitation strategy for HAM.
PLoS Comput Biol
January 2025
Department of Hematology, Rheumatology and Infectious Disease, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan.
Human T-cell leukemia virus type 1 (HTLV-1) causes adult T-cell leukemia (ATL) and HTLV-1-associated myelopathy (HAM) after a long latent period in a fraction of infected individuals. These HTLV-1-infected cells typically have phenotypes similar to that of CD4+T cells, but the cell status is not well understood. To extract the inherent information of HTLV-1-infected CD4+ cells, we integratively analyzed the ATAC-seq and RNA-seq data of the infected cells.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!