A COMPARISON OF EFFICACY AND SPECIFICITY OF 3 NK DEPLETING ANTIBODIES

This study compares in vivo efficacy and specificity of the three NK c ell depleting antibodies anti-asialo GM(1), anti-NK 1.1 and the recent ly described TM beta 1, which is directed against the interleukin-2 re ceptor beta chain. All three antibodies are equally efficacious as ass essed by abolishing NK mediated cytolytic activity induced by a high d ose virus infection or Poly IC against YAC-1 targets. Similarly, the g eneration of virus-specific cytotoxic T cells (CTL) was unimpaired aft er NK a depletion in two different virus infections. However, if mice are treated with the antibodies several days after virus infection, wh en strong CTL responses have already been generated, anti-asialo GM(1) and-to a lesser extent-also TM beta 1 have a significant effect on CT L activity. Only after treatment with anti-NK 1.1 antibody, CTL activi ty was not significantly impaired. We conclude, that of the NK depleti ng antibodies currently available, anti-NK 1.1 allows the best differe ntiation of activated CTL and NK cells in vivo.