Mechanisms of recovery from viral infections: destruction of infected cells by neutrophils and complement.

Highly enriched populations of bovine neutrophils (PMN) were able to destroy herpesvirus-infected cells when in the presence of C. This mechanism of cytotoxicity was termed C-dependent neutrophil-mediated cytotoxicity (CDNC). To demonstrate CDNC required viable PMN, an active source of C, and a target cell expressing viral antigens. Noninfected cells were not susceptible to lysis. Several approaches were used to exclude the presence of antibody as an explanation for the cytotoxicity observed. In a comparison of the effectiveness of different cell types at mediating CDNC, PMN were more effective than macrophages, and lymphocytes were without activity. The results was discussed in terms of the possible in vivo significance of the neutrophil as a cell type capable of mediating recovery from infection, since if a mechanism similar to CDNC occurs in vivo, this could play a role in defense before the time when protective levels of antibody and immune cells are generated.