Fig. 3

Therapeutic transfer of activin-A-exposed CD4⁺ T cells decelerates the progression of lung tumor formation. A Experimental protocol utilized. B Representative macroscopic images of lung lobes of LLC-OVA-tumor bearing CD4^−/− mice adoptively transferred with ex vivo activin-A- or PBS-treated CD4⁺ T cells isolated from lung tumors of LLC-OVA-inoculated C57BL/6 mice. C Lung weight and tumor foci measurements. D Representative photomicrographs of H&E-stained lung sections (scale bars: 50 μm). E Cytokine levels in supernatants of lung tumor-infiltrating leukocyte cultures. Data are mean ± SEM of triplicate wells and are representative of 5 independent experiments. F Representative flow cytometry plots (left) and cumulative MFI values of PD-1, CTLA-4 or LAG-3 expression by CD3⁺CD4⁺ T cells infiltrating lung tumors (right). Data are mean ± SEM and are representative of 5 independent experiments. Statistical significance was obtained by unpaired Student’s t-test; *P < 0.05, **P < 0.01 and ***P < 0.001