FIG. 1.

(A) Kinetics of NK cell activation during early B. burgdorferi infection. Draining popliteal lymph node cells were harvested from C3H and DBA mice infected with B. burgdorferi 1, 2, or 4 days earlier. (B) Depletion of C3H NK cells by anti-asialo-GM1 antibody treatment abolishes production of IFN-γ on day 1 of infection. Results are shown for two control and two anti-asialo-GM1-treated animals. Cultures were assayed in triplicate. Levels of IFN-γ were measured in 24-h supernatants by ELISA as described in Materials and Methods. Sensitivity of the ELISA was 4 U/ml. Results are representative of one of three separate experiments.