Figure 2.
Tumor secreted Gal-1 facilitates radiation-related T lymphopenia. Four different host/tumor mouse groups, WT/Scr, WT/shGal-1, Gal-1−/−/ Scr and Gal-1−/−/ shGal-1 and two different time points (before radiation (Pre IR) and two weeks after radiation (Post IR)) were used in experiments presented in Figures 3A-D. (A) ELISA quantification of plasma Gal-1 for each host/tumor group before and after RT (N= 5 to 6 mice per group). (B) The percentage of circulating total mature T cells (CD3+), (C) T helper cells (CD3+ CD4+) and (D) cytotoxic T cells (CD3+ CD8+) for each group before and after RT (N= 6 to 7 mice per group). (E) Terminal circulating CD3+, CD4+ and CD8+ T cells in WT/Scr mice with or without tumor irradiation, showing that RT is important in causing a decrease in T lymphocytes (N=5 mice per group). (F) Terminal plasma Gal-1 ELISA from the mice in (E). Inhibition of Gal-1 by Thiodigalactoside (TDG) attenuates radiation-related T lymphopenia. (G) Percentage of CD3+, CD3+CD4+ and CD3+CD8+ circulating T cells in mice treated with intratumoral TDG (120mg/kg) or PBS vehicle injections before and after 20Gy tumor radiation is graphed (N= 5 to 6 mice per group). Data represent the means ± SE, *P<0.05.