Figure 4: Lymphoma DCs mediate the suppression of T-cell responses.

(a) Wt mice (B6, n=13) or C/EBPβ^−/− mice (n=6) were transplanted with 2 × 10⁵ Eμ-Myc lymphoma B cells (n=2–3 independent experiments per genotype). Between days 7 and 9, eFluor 670-labelled naive CD4⁺ OT-II T cells (6–8 × 10⁵) were adoptively transferred into tumour-bearing mice or tumour-naive mice (n=9). Mice were immunized by s.c. injection of 100 μg OVA protein and 25 μg CpGs. Control Wt and C/EBPβ^−/− animals received T cells but no OVA protein. Proliferation of transferred T cells in draining lymph nodes was analysed with flow cytometry on day 3. Representative FACS plots of gated CD4⁺ cells from draining lymph nodes are shown; numbers indicate the percentage of proliferated OVA-specific CD4⁺/OT-II⁺/eFluor670⁺ T cells in recipient mice within the gate. (b) Quantification of the proliferation rate. Bars represent means±s.e.m.; a Student’s t-test was used. *P<0.05.