Fig. 5.

³[H]-Thymidine-proliferation assay and T helper type 2 (Th2) cytokine enzyme-linked immunosorbent assay (ELISA) of in vitro restimulated lymphocytes isolated from wild-type (WT) and CD137^−/− mice. Mice were immunized with ovalbumin (OVA) according to the protocols described in Fig. 1. Lymphocytes isolated from pooled spleen derived from WT and CD137^−/− mice were restimulated with 200 µg/ml OVA in 96-well tissue-culture plates for 48 h, pulsed with 1 µCi tritiated thymidine per well for 14 h, and thereafter the incorporated activity was measured in a betaplate scintillation counter (a). Supernatants were analysed by ELISA with regard to the production of the Th2 cytokines Interleukin (IL)-5 and IL-13 (b). Data are presented as median ± interquartile range. One representative of three independent experiments is shown; n ≥ 5 animals per group; **P ≤ 0·01, *P ≤ 0·05, not significant (n.s.) P > 0·05; Mann–Whitney U-test.