IL-2–mTORC1 signaling coordinates the STAT1/T-bet axis to ensure Th1 cell differentiation and anti-bacterial immune response in fish
Fig 6
IL-2 promotes Th1 cell differentiation of tilapia by activating STAT5 and mTORC1 signaling.
(A) Synteny analysis of tilapia IL-2 and other homology genes by comparative genomics. (B) Spleen leukocytes were stimulated with PHA, and mRNA levels of IL-2 were examined by qPCR, n = 6. (C) SDS-PAGE assay showed the recombination of tilapia IL-2 protein in E.coli. (D, E) Spleen leukocytes were treated with recombinant IL-2, and expression of indicated molecules were examined by qPCR (D, n = 6) or western blot (E) at indicated time points. (F) Tilapia individuals were i.p. injected with recombinant IL-2, the expression of indicated molecules were examined by western blot. (G, H) Spleen leukocytes were stimulated with recombinant IL-2 in the presence of STAT5 inhibitor AC-4-130 for 12 h. The expression levels of indicated molecules were examined by western blot (G) or qPCR (H, n = 4). (I, J) Tilapia was injected with mTORC1 inhibitor rapamycin for 2 days before spleen leukocytes were stimulated with recombinant IL-2 for 12 h. The expression levels of indicated molecules were examined by western blot (I) or qPCR (J, n = 6). These experiments were repeated for at least two independent times. *: p<0.05, **: p<0.01, ***: p<0.001, determined by a two-tailed Student’s t-test.