Fig 1.

Characterization of LAM-CRT and LAM-EGFP. (A) Samples of laminarin, rCRT/39–272, LAM-CRT, a mixture of laminarin and rCRT/39–272, rEGFP, LAM-EGFP, and a mixture of laminarin and rEGFP were run in 12% SDS-PAGE followed by Coomassie blue staining (lanes 1 to 7, respectively). Protein molecular mass markers (lane M) were loaded in the left-hand lane. (B) Freshly fractionated B and T cells from naïve BALB/c mouse splenocytes (3 mice pooled) were stimulated, in triplicate, with rCRT/39–272 or rEGFP (10 μg/ml) or with LAM-CRT, LAM-EGFP, or laminarin (50 μg/ml) for 48 h. A combination of PMA (20 ng/ml) and ionomycin (1 μg/ml) was included as a positive control. [³H]thymidine was added to the cultures (0.2 μCi/well) for the last 8 h of incubation, and then [³H]thymidine incorporation of each well was counted (cpm). The results were calculated using the “cell and medium only” wells as a reference and are expressed as mean stimulation index ± SD of the results determined with triplicate wells. (C) The IgM concentration in the B-cell culture supernatant was quantitated using ELISA, and the results are expressed as mean concentration (ng/ml) ± SD. (D and E) Freshly prepared naïve BALB/c nu/nu mouse splenocytes were used as responder cells in parallel experiments. *, P < 0.05; **, P < 0.01. Data represent results from 3 independent experiments.