Murine Gamma-herpesvirus Immortalization of Fetal Liver-Derived B Cells Requires both the Viral Cyclin D Homolog and Latency-Associated Nuclear Antigen

PLoS Pathogens

Clinton R. Paden¹  Xiaozhen Liang²  Joshy Jacob²  Francine M. Morales²  Ryan P. Powers³  Samuel H. Speck⁴ 

[1] Department of Microbiology & Immunology, Emory University School of Medicine, Atlanta, Georgia, United States of America;Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, United States of America;Immunology and Molecular Pathogenesis Graduate Program, Emory University School of Medicine, Atlanta, Georgia, United States of America;Microbiology and Molecular Genetics Graduate Program, Emory University School of Medicine, Atlanta, Georgia, United States of America

关键词: B cells;    Cell immortalization;    Mouse models;    Lymphomas;    Herpesviruses;    Viral replication;    Polymerase chain reaction;    Kaposi's sarcoma-associated herpesvirus;   

DOI  :  10.1371/journal.ppat.1002220

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Human gammaherpesviruses are associated with the development of lymphoproliferative diseases and B cell lymphomas, particularly in immunosuppressed hosts. Understanding the molecular mechanisms by which human gammaherpesviruses cause disease is hampered by the lack of convenient small animal models to study them. However, infection of laboratory strains of mice with the rodent virus murine gammaherpesvirus 68 (MHV68) has been useful in gaining insights into how gammaherpesviruses contribute to the genesis and progression of lymphoproliferative lesions. In this report we make the novel observation that MHV68 infection of murine day 15 fetal liver cells results in their immortalization and differentiation into B plasmablasts that can be propagated indefinitely in vitro, and can establish metastasizing lymphomas in mice lacking normal immune competence. The phenotype of the MHV68 immortalized B cell lines is similar to that observed in lymphomas caused by KSHV and resembles the favored phenotype observed during MHV68 infection in vivo. All established cell lines maintained the MHV68 genome, with limited viral gene expression and little or no detectable virus production - although virus reactivation could be induced upon crosslinking surface Ig. Notably, transcription of the genes encoding the MHV68 viral cyclin D homolog (v-cyclin) and the homolog of the KSHV latency-associated nuclear antigen (LANA), both of which are conserved among characterized γ2-herpesviruses, could consistently be detected in the established B cell lines. Furthermore, we show that the v-cyclin and LANA homologs are required for MHV68 immortalization of murine B cells. In contrast the M2 gene, which is unique to MHV68 and plays a role in latency and virus reactivation in vivo, was dispensable for B cell immortalization. This new model of gammaherpesvirus-driven B cell immortalization and differentiation in a small animal model establishes an experimental system for detailed investigation of the role of gammaherpesvirus gene products and host responses in the genesis and progression of gammaherpesvirus-associated lymphomas, and presents a convenient system to evaluate therapeutic modalities.

【 授权许可】

CC BY