TLR7 and TLR9 antagonist selectively blocks proinflammatory cytokine production from uninfected rhesus macaque pDC.

(A) Representative gating strategy to define pDC, mDC, monocytes (Mo) and macrophages (Mø) by flow cytometry in rhesus macaque PBMC and lymph node. The lymph node gate to define DC includes autofluorescent cells that encroach on the Lineage+ subset, as previously described [23]. (B) PBMC and lymph node cell suspensions from SIV-naive animals were stimulated with iSIV or influenza virus with and without DV056 and intracellular expression of IFN-α and TNF-α in pDC was determined by flow cytometry. Positive labeling with cytokine-specific antibody as shown by the boxed areas was based on isotype control antibody. Numbers represent the percent positive cells. (C) PBMC, pDC-depleted PBMC and PBMC pretreated with DV056 were stimulated with iSIV, live SIV, influenza virus or CpG-C and supernatants were analyzed for IFN-α by ELISA. Unstimulated PBMC served as a negative control. (D) PBMC and lymph node cell suspensions were stimulated with iSIV or influenza virus and IFN-α and/or TNF-α in mDC, monocytes or macrophages were determined by flow cytometry. SSC = side scatter.