The degree of CTL-induced DNA solubilization is not determined by the human vs mouse origin of the target cell.

CTL-mediated lysis is unique among lytic mechanisms in inducing rapid, prelytic nuclear disintegration. Target cell DNA can be solubilized within minutes as a result of degradation, which can proceed to the nucleosomal level, presumably mediated by endonucleases that are either endogenous or injected by the CTL. Nuclear disintegration has been reported for mouse lymphoid target cells by several groups. However, previous studies in which human target cells were studied saw little or no DNA solubilization. We here report rapid, extensive CTL-induced solubilization of DNA in human lymphoid target cells; on the other hand, we found that three mouse cell lines exhibit little or no nuclear disintegration. We conclude that the degree of nuclear disintegration depends on the nature of the target cell, but is not determined by the species of origin of the target cell.