Tumor Suppressor Interferon-Regulatory Factor 1 Counteracts the Germinal Center Reaction Driven by a Cancer-Associated Gammaherpesvirus. J Virol 2015 Dec 30;90(6):2818-29
Date
01/01/2016Pubmed ID
26719266Pubmed Central ID
PMC4810652DOI
10.1128/JVI.02774-15Scopus ID
2-s2.0-84961115924 (requires institutional sign-in at Scopus site) 18 CitationsAbstract
UNLABELLED: Gammaherpesviruses are ubiquitous pathogens that are associated with the development of B cell lymphomas. Gammaherpesviruses employ multiple mechanisms to transiently stimulate a broad, polyclonal germinal center reaction, an inherently mutagenic stage of B cell differentiation that is thought to be the primary target of malignant transformation in virus-driven lymphomagenesis. We found that this gammaherpesvirus-driven germinal center expansion was exaggerated and lost its transient nature in the absence of interferon-regulatory factor 1 (IRF-1), a transcription factor with antiviral and tumor suppressor functions. Uncontrolled and persistent expansion of germinal center B cells led to pathological changes in the spleens of chronically infected IRF-1-deficient animals. Additionally, we found decreased IRF-1 expression in cases of human posttransplant lymphoproliferative disorder, a malignant condition associated with gammaherpesvirus infection. The results of our study define an unappreciated role for IRF-1 in B cell biology and provide insight into the potential mechanism of gammaherpesvirus-driven lymphomagenesis.
IMPORTANCE: Gammaherpesviruses establish lifelong infection in most adults and are associated with B cell lymphomas. While the infection is asymptomatic in many hosts, it is critical to identify individuals who may be at an increased risk of virus-induced cancer. Such identification is currently impossible, as the host risk factors that predispose individuals toward viral lymphomagenesis are poorly understood. The current study identifies interferon-regulatory factor 1 (IRF-1) to be one of such candidate host factors. Specifically, we found that IRF-1 enforces long-term suppression of an inherently mutagenic stage of B cell differentiation that gammaherpesviruses are thought to target for transformation. Correspondingly, in the absence of IRF-1, chronic gammaherpesvirus infection induced pathological changes in the spleens of infected animals. Further, we found decreased IRF-1 expression in human gammaherpesvirus-induced B cell malignancies.
Author List
Mboko WP, Olteanu H, Ray A, Xin G, Darrah EJ, Kumar SN, Kulinski JM, Cui W, Dittel BN, Gauld SB, Tarakanova VLAuthors
Suresh Kumar PhD Associate Professor in the Pathology department at Medical College of WisconsinVera Tarakanova PhD Professor in the Microbiology and Immunology department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AnimalsB-Lymphocytes
Cell Transformation, Viral
Gammaherpesvirinae
Germinal Center
Host-Pathogen Interactions
Humans
Interferon Regulatory Factor-1
Mice, Inbred C57BL
Mice, Knockout
Neoplasms
Spleen