A comparison of efficacy and specificity of three NK depleting antibodies

This study compares in vivo efficacy and specificity of the three NK cell depleting antibodies anti-asialo GM(1), anti-NK 1.1 and the recently described TM beta 1, which is directed against the interleukin-2 receptor beta chain. All three antibodies are equally efficacious as assessed by abolishing NK mediated cytolytic activity induced by a high dose virus infection or Poly IC against YAC-1 targets. Similarly, the generation of virus-specific cytotoxic T cells (CTL) was unimpaired after NK a depletion in two different virus infections. However, if mice are treated with the antibodies several days after virus infection, when 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 CTL activity. Only after treatment with anti-NK 1.1 antibody, CTL activity was not significantly impaired. We conclude, that of the NK depleting antibodies currently available, anti-NK 1.1 allows the best differentiation of activated CTL and NK cells in vivo.