Figure 10.

Responses of CD4⁺ T cells from immunized mice in a microbe-specific manner. (a–d) Proliferation. C57BL/6 mice were immunized with AdMDC-modified DCs pulsed with P. aeruginosa PAO1 strain or E. coli. Three weeks after immunization, splenic CD4⁺ T cells were isolated from immunized or nonimmunized mice using the magnetic beads. In 96-well culture plates, 5 × 10⁵ CD4⁺ T cells were stimulated with 5 × 10⁴ DCs that had been pulsed with heat-killed P. aeruginosa strain PAO1 (a), heat-killed P. aeruginosa strain PA103 (b), heat-killed E. coli (c), or without any microbes (d), and irradiated. In (a–d), controls included DC culture without CD4⁺ T cells. The number of viable cells was determined using the MTS assay, as described in Methods. The data are presented as the mean percentage increase over baseline of duplicate wells. (e) IL-4 secretion. The culture medium was collected 4 days after the initiation of the coculture described above, and the levels of murine IL-4 were assayed by ELISA. The data are presented as means ± SE (n = 3 per data point).