ORLL-NIH001 inhibited the expansion of human Th17 cells.

<p>(A) CD4⁺ T cells isolated from PBMC of healthy human subjects were labeled with CFSE and then stimulated with anti-CD3/CD28 for 4 days in medium containing vehicle alone or different doses of ORLL-NIH001. Numbers in the quadrants indicate percent of proliferating or non-proliferating T cells expressing IL-17 or IFN-γ. (B) Human PBMC were activated with anti-CD3/CD28 abs for 4 days, stimulated with IL-6 in serum-free medium containing vehicle or ORLL-NIH001. The cells were then analyzed for the expression of STAT3, pSTAT1 or β-actin by Western blotting. Activated human (C) or mouse (D–H) CD4 T cells were stimulated with IL-2 or IL-6 and expression of pSTAT1, pSTAT3 and pSTAT5 was detected by Western blotting (C, D, E) or flow cytometry (F, G, H). (E) Western blots (B, C, D) were analyzed using NIH Image Quant program and each band was normalized to corresponding β-actin band and expressed in arbitrary relative protein expression units. Results are representative of 3 independent experiments.