Fig. 9.

Quantitation of naive CD4+ T cell proliferation on contact with resting (a) or flagellin-activated (b) Muc1^+/+ and Muc1^−/− BM-DC. Resting or flagellin-activated DC were reciprocally titrated (1 to 5 dilution series) against a constant number of naive alloreactive murine CD4+ CD62L+ T cells. T cell proliferation was enumerated by pulsing co-cultures with bromodeoxyuridine (BrdU) for the final 18 h of culture of a 4-day co-culture. In addition, stimulation of naive CD4+ CD62L+ T cells by Muc1^+/+ and Muc1^−/− primary lung DC (c, d) as well as primary splenic DC (e, f) is also shown for comparison. We used a colorimetric immunoassay for the quantitation of cell proliferation, based on the measurement of BrdU incorporation during DNA synthesis according to the manufacturer's instructions (Roche Molecular Biochemicals, Mannheim, Germany; see Materials and Methods). Data are expressed as mean Δ OD (at an absorbance wavelength of 450 nm and a reference wavelength of 690 nm) ± 1 standard deviation about the mean (product of 5 independent proliferation experiments for BM-DC and 3 independent experiments for lung and spleen DC).