Different herpesviral immunoevasins inhibit MHC class I expression on hMSCs to a different extent.

<p>(A) Flow cytometric analysis of culture-expanded (Ctrl) hMSCs and of hMSCs transduced with RVs coding for eGFP alone or for eGFP and either the BHV-1 UL49.5, EBV BNLF2A, HCMV US2 or HCMV US11 protein. The data are from cells analyzed 30 days after transduction. Analysis of the hMSCs at 5 and 90 days post-transduction yielded very similar results (data not shown). MFIs of the HLA-ABC signal of eGFP^- (untransduced [UT]) and eGFP⁺ (transduced [T]) cell populations in each sample and their ratio are given below the dot plots (B). (C) Western blot analysis of lysates from untransduced hMSCs (−) and of hMSCs transduced with RV-BLF2A-eGFP, RV-UL49.5-eGFP, RV-US2-eGFP or RV-US11-eGFP (+). The specificity of the antibodies used is indicated at the left. Numbers at the right represent molecular weights in kilodalton (kDa). The 26-kDa and 19.4-kDa protein species recognized by the US2-specific antibodies correspond to N-glycosylated and non-glycosylated forms of the US2 protein, respectively.