Lysis of Human Arterial Smooth Muscle Cells Infected with Herpesviridae by Peripheral Blood Mononuclear Cells: Implications for Atherosclerosis

ABSTRACT The cytotoxicity of peripheral blood mononuclear cells (PBMC) to human arterial smooth muscle cells (SMC) infected with cytomegalovirus (CMV) or herpes simplex virus-1 (HSV) was investigated. PBMC were isolated from heparinized blood of healthy donors by Ficoll–Hypaque centrifugation and were tested for cytotoxicity against human SMC or human fibroblast-like (MRC-5) cells infected with CMV or HSV, using the chromium-51 (5lCr) release cytotoxicity assay. Both SMC and MRC-5 cells infected with either CMV (SMCCMV), (MRC-5-CMV), or HSV (SMC-HSV), (MRC-5-HSV) were lysed by PBMC above background lysis of uninfected SMC cells. Treatment of PBMC with NK-specific monoclonal CD16 antibody and rabbit complement reduced greatly the lysis of SMC, SMC-CMV, and K562 cells, suggesting that lysis of different types of target cell by PBMC was mediated mainly by natural killer (NK) cells. The pattern of natural cytotoxicity against SMC-CMV was different from that against SMC-HSV. Maximum lysis of SMC-CMV was observ...