Authorship note: DK and AL contributed equally to this work. Conflict of interest: DK, SC, WGL, MGP, and SN are co-inventors on a pending US patent (PCT/US2017/068025) covering [ 64 Cu]WL12 and as such are entitled to a portion of any licensing fees and royalties generated by this technology. This arrangement has been reviewed and approved by Johns Hopkins University in accordance with its conflict-of-interest policies. DK, SC, WGL, SN, JTP, CMR, and MGP are inventors on patent applications not related to this work. CMR serves on the Scientific Advisory Board of Harpoon Therapeutics, and has consulted on oncology drug development for AbbVie, Amgen, Ascentage, BMS, Celgene, Daiichi Sankyo, Genentech, Loxo, and Pharmamar. Under a licensing agreement between EMJ, Aduro Biotech Inc., and Johns Hopkins University, the University is entitled to milestone payments and royalties on sales of certain cancer vaccine products. EMJ serves on the Scientific Advisory Board of Genocea, Adaptive Biotech, DragonFly, and CSTONE and received grants from Aduro Biotech, Amgen, BMS, Hertix, and Corvus.

Combination of dietary/herbal spice curcumin (Cur) and COX inhibitors has been tested for improving therapeutic efficacy in pancreatic cancer (PC). The objective of this study was to identify agent with low toxicity and COX-independent mechanism to induce PC cell growth inhibition when used along with Cur. Anti-cancer NSAID, Tolfenamic acid (TA) and Cur combination was evaluated using PC cell lines. L3.6pl and MIA PaCa-2 cells were treated with Cur (5–25 μM) or TA (25–100 μM) or combination of Cur (7.5 μM) and TA (50 μM). Cell viability was measured at 24–72 h post-treatment using CellTiter-Glo kit. While both agents showed a steady/consistent effect, Cur+TA caused higher growth inhibition. Anti-proliferative effect was compared with COX inhibitors, Ibuprofen and Celebrex. Cardiotoxicity was assessed using cordiomyocytes (H9C2). The expression of Sp proteins, survivin, and apoptotic markers (Western blot), caspase 3/7 (caspase-Glo kit), Annexin-V staining (flow cytometry), reactive oxygen species (ROS) and cell cycle phase distribution (flow cytometry) were measured. Cells were treated with TNF-α and NF-kB translocation from cytoplasm to nucleus was evaluated (immunofluorescence). When compared to individual agents, combination of Cur+TA caused significant increase in apoptotic markers, ROS levels and augmented NF-kB translocation to nucleus. TA caused cell cycle arrest in G0/G1 and the combination treatment showed mostly DNA synthesis phase arrest. These results suggest that combination of Cur+TA is less toxic and effectively enhance the therapeutic efficacy in PC cells via COX-independent mechanisms.

Macromolecules such as monoclonal antibodies (mAbs) are likely to experience poor tumor penetration because of their large size, and thus low drug exposure of target cells within a tumor could contribute to suboptimal responses. Given the challenge of inadequate quantitative tools to assess mAb activity within tumors, we hypothesized that measurement of accessible target levels in tumors could elucidate the pharmacologic activity of a mAb and could be used to compare the activity of different mAbs. Using positron emission tomography (PET), we measured the pharmacodynamics of immune checkpoint protein programmed-death ligand 1 (PD-L1) to evaluate pharmacologic effects of mAbs targeting PD-L1 and its receptor programmed cell death protein 1 (PD-1). For PD-L1 quantification, we first developed a small peptide-based fluorine-18–labeled PET imaging agent, [18F]DK222, which provided high-contrast images in preclinical models. We then quantified accessible PD-L1 levels in the tumor bed during treatment with anti–PD-1 and anti–PD-L1 mAbs. Applying mixed-effects models to these data, we found subtle differences in the pharmacodynamic effects of two anti–PD-1 mAbs (nivolumab and pembrolizumab). In contrast, we observed starkly divergent target engagement with anti–PD-L1 mAbs (atezolizumab, avelumab, and durvalumab) that were administered at equivalent doses, correlating with differential effects on tumor growth. Thus, we show that measuring PD-L1 pharmacodynamics informs mechanistic understanding of therapeutic mAbs targeting PD-L1 and PD-1. These findings demonstrate the value of quantifying target pharmacodynamics to elucidate the pharmacologic activity of mAbs, independent of mAb biophysical properties and inclusive of all physiological variables, which are highly heterogeneous within and across tumors and patients.

While the role of Transforming Growth Factor β (TGF-β) as an intrinsic pathway has been well established in driving de novo differentiation of Th17 cells, no study has directly assessed the capacity of TGF-β signaling initiated within dendritic cells (DCs) to regulate Th17 differentiation. The central finding of this study is the demonstration that Th17 cell fate during autoimmune inflammation is shaped by TGF-β extrinsic pathway via DCs. First, we provide evidence that TGF-β limits at the site of inflammation the differentiation of highly mature DCs as a means of restricting Th17 cell differentiation and controlling autoimmunity. Second, we demonstrate that TGF-β controls DC differentiation in the inflammatory site but not in the priming site. Third, we show that TGF-β controls DC numbers at a precursor level but not at a mature stage. While it is undisputable that TGF-β intrinsic pathway drives Th17 differentiation, our data provide the first evidence that TGF-β can restrict Th17 differentiation via DC suppression but such a control occurs in the site of inflammation, not at the site of priming. Such a demarcation of the role of TGF-β in DC lineage is unprecedented and holds serious implications vis-à-vis future DC-based therapeutic targets.