Figure 3.

5′-ValCAC activates TLR7 in human macrophages

(A) Secondary structure of mature tRNA^ValCAC, 5′-ValCAC, and 3′-ValCAC (predicted by mFold⁴⁶).

(B) After DOTAP-mediated endosomal delivery of the indicated RNAs into macrophages, culture medium was subjected to the measurement of concentration of the indicated cytokines. The error bars denote the SD of three independent experiments. ∗∗∗p < 0.001.

(C) The DOTAP experiments were performed by using two different TLR7 KO THP-1 cell clones (#1 and #2), followed by quantification of cytokine mRNAs by RT-qPCR. Two independent experiments were performed, which are shown as separated bars, while the error bars indicate the SD of qPCR replicates.

(D and E) After DOTAP-mediated endosomal delivery of the indicated RNAs, macrophages were subjected to bacterial infection and invasion assay. Representative pictures of the plates with E. coli colonies (D) and bar graphs of the counted numbers of colonies (E) are shown. The error bars indicate the SD of three independent experiments. ∗∗∗p < 0.001.