Glutamate release inhibitor and mGluR1 antagonists efficiently blocked KSHV infected cell proliferation.

<p>A) HMVEC-d cells were left uninfected or infected with KSHV for 3 d. The cells were then cultured in the absence or presence of riluzole (10 µM), A841720 (50 µM) or Bay36-7620 (50 µM) for 48 h followed by BrdU pulse labeling for 2 h. BrdU incorporation was detected by staining with a BrdU antibody. Bottom panel shows merged images of BrdU and DAPI. (B and C) BrdU incorporation determined by ELISA in TIVE-LTC (B), and BCBL-1 cells (C) treated in the absence or presence of different concentrations of riluzole, A841720, or Bay36-7620 for 48 h followed by BrdU pulse labeling for 2 h. BrdU incorporation was analyzed by a BrdU cell proliferation ELISA kit. Error bars represent the mean ± SD of three independent experiments. **p<0.001, ***p<0.0001 compared with DMSO treatment. (D and E). MTT assay for cell proliferation. TIVE-LTC (D) and BCBL-1 cells (E) were incubated with riluzole, A841720, or Bay36-7620 for 48 h. At the end of incubation cell growth was measured with Vibrant MTT cell proliferation assay kit as described in <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1004389#s4" target="_blank">materials and methods</a>. Data are mean ± SD. (F and G) mGluR1 shRNA transduction: TIVE-LTC cells transduced with control shRNA lentivirus or with mGluR1 shRNA lentivirus were selected using puromycin hydrochloride. Cell lysates Western blotted with anti mGluR1 antibody showed 80% knockdown of mGluR1 expression in mGluR1 shRNA transduced cells. β-actin was used as a loading control. (G) BrdU incorporation determined by a BrdU cell proliferation ELISA in control and mGluR1 shRNA transduced TIVE-LTC cells. Error bars represent the mean ± SD.