Figure 3
T cells from immunized FVB and transgenic VWF-lacZ and TIE2-lacZ mice respond to β-gal in vitro. A. CD4+ and CD8+ lymph node T cells proliferate and express IL-2 receptors (CD25+) in response to β-gal. Representative FACS profiles are shown. Lymph node cells were obtained from mice 7 days after in vivo priming in all the experiments shown. Lymph node cells (2 × 105) were cultured in flat bottom wells and stained for CD4, CD8, and CD25 on day 4. The histograms represent CD25 expression in cultures receiving β-gal (thick line) or not (thin line). B. CD25+ lymphocyte populations expand in cultures of lymph node cells from FVB and transgenic mice. The results of three independent FACS experiments are shown, each represented with a different symbol, and the mean response at each time is indicated with a dash. For the stimulation indices, the background proliferation of cultures receiving no addition or ovalbumin additions were averaged. C. Wild type and transgenic T cells display equivalent avidity for β-gal. Lymph node cells (105) were cultured with irradiated (1500 R) splenocytes (106) in flat bottom wells with the indicated concentrations of β-gal. Results for day 4 are shown. Similar results were obtained in more than 4 independent dose-response proliferation assays. D. FVB and transgenic T cells secrete IFN-γ in response to β-gal. Lymph node cells (2 × 105) were cultured in round bottom wells with β-gal (closed squares) or without (open squares). Culture superantants were recovered at the times indicated, one sample per culture, three cultures per point, and IFN-γ was measured by ELISA.