title: Glutamate secretion and metabotropic glutamate receptor 1 expression during Kaposi's sarcoma-associated herpesvirus infection promotes cell proliferation.
abstract: Kaposi's sarcoma associated herpesvirus (KSHV) is etiologically associated with endothelial Kaposi's sarcoma (KS) and B-cell proliferative primary effusion lymphoma (PEL), common malignancies seen in immunocompromised HIV-1 infected patients. The progression of these cancers occurs by the proliferation of cells latently infected with KSHV, which is highly dependent on autocrine and paracrine factors secreted from the infected cells. Glutamate and glutamate receptors have emerged as key regulators of intracellular signaling pathways and cell proliferation. However, whether they play any role in the pathological changes associated with virus induced oncogenesis is not known. Here, we report the first systematic study of the role of glutamate and its metabotropic glutamate receptor 1 (mGluR1) in KSHV infected cell proliferation. Our studies show increased glutamate secretion and glutaminase expression during de novo KSHV infection of endothelial cells as well as in KSHV latently infected endothelial and B-cells. Increased mGluR1 expression was detected in KSHV infected KS and PEL tissue sections. Increased c-Myc and glutaminase expression in the infected cells was mediated by KSHV latency associated nuclear antigen 1 (LANA-1). In addition, mGluR1 expression regulating host RE-1 silencing transcription factor/neuron restrictive silencer factor (REST/NRSF) was retained in the cytoplasm of infected cells. KSHV latent protein Kaposin A was also involved in the over expression of mGluR1 by interacting with REST in the cytoplasm of infected cells and by regulating the phosphorylation of REST and interaction with β-TRCP for ubiquitination. Colocalization of Kaposin A with REST was also observed in KS and PEL tissue samples. KSHV infected cell proliferation was significantly inhibited by glutamate release inhibitor and mGluR1 antagonists. These studies demonstrated that elevated glutamate secretion and mGluR1 expression play a role in KSHV induced cell proliferation and suggest that targeting glutamate and mGluR1 is an attractive therapeutic strategy to effectively control the KSHV associated malignancies.
authors.affiliation: H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America.
authors.forename: Mohanan
authors.initials: M
authors.lastname: Valiya Veettil
authors.affiliation: H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America.
authors.forename: Dipanjan
authors.initials: D
authors.lastname: Dutta
authors.affiliation: H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America.
authors.forename: Virginie
authors.initials: V
authors.lastname: Bottero
authors.affiliation: H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America.
authors.forename: Chirosree
authors.initials: C
authors.lastname: Bandyopadhyay
authors.affiliation: H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America.
authors.forename: Olsi
authors.initials: O
authors.lastname: Gjyshi
authors.affiliation: H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America.
authors.forename: Neelam
authors.initials: N
authors.lastname: Sharma-Walia
authors.affiliation: H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America.
authors.forename: Sujoy
authors.initials: S
authors.lastname: Dutta
authors.affiliation: H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America.
authors.forename: Bala
authors.initials: B
authors.lastname: Chandran
mesh_terms: D001402:B-Lymphocytes / Q000821:virology; D002460:Cell Line; D049109:Cell Proliferation / Q000502:physiology; D042783:Endothelial Cells / Q000378:metabolism; D005971:Glutamates / Q000378:metabolism*; D006566:Herpesviridae Infections / Q000821:virology; D006801:Humans; D018094:Receptors, Metabotropic Glutamate / Q000276:immunology / Q000378:metabolism*; D012514:Sarcoma, Kaposi / Q000378:metabolism / Q000821:virology*; D017735:Virus Latency / Q000276:immunology
chemical_list: D005971:Glutamates; D018094:Receptors, Metabotropic Glutamate; C104077:metabotropic glutamate receptor type 1