作者: Wadsworth, Angela ; Marubayashi, Sachie ; Wustrow, David ; Jackson, Jeffrey J ; Cutler, Gene ; Marshall, Lisa A ; Pookot, Deepa ; Robles, Omar ; Sanchez, Jerick ; Wong, Brian ; Brovarney, Martin ; Talay, Oezcan ; Brockstedt, Dirk G ; Kassner, Paul D ; Jacobson, Scott ; Jorapur, Aparna ; Zibinsky, Mikhail ; Hu, Dennis Xiaozhou ; Chian, David

BackgroundCheckpoint inhibitors (CPIs) such as anti-PD(L)-1 and anti-CTLA-4 antibodies have resulted in unprecedented rates of antitumor responses and extension of survival of patients with a variety of cancers. But some patients fail to respond or initially respond but later relapse as they develop resistance to immune therapy. One of the tumor-extrinsic mechanisms for resistance to immune therapy is the accumulation of regulatory T cells (Treg) in tumors. In preclinical and clinical studies, it has been suggested that tumor trafficking of Tregis mediated by CC chemokine receptor 4 (CCR4). Over 90% of human Tregexpress CCR4 and migrate toward CCL17 and CCL22, two major CCR4 ligands that are either high at baseline or upregulated in tumors on CPI treatment. Hence, CCR4 antagonism has the potential to be an effective antitumor treatment by reducing the accumulation of Treginto the tumor microenvironment (TME).MethodsWe developed in vitro and in vivo models to assess Tregmigration and antitumor efficacy using a potent and selective CCR4 antagonist, CCR4-351. We used two separate tumor models, Pan02 and CT26 mouse tumors, that have high and low CCR4 ligand expression, respectively. Tumor growth inhibition as well as the frequency of tumor-infiltrating Tregand effector T cells was assessed following the treatment with CCR4 antagonist alone or in combination with CPI.ResultsUsing a selective and highly potent, novel small molecule inhibitor of CCR4, we demonstrate that migration of CCR4+Treginto the tumor drives tumor progression and resistance to CPI treatment. In tumor models with high baseline levels of CCR4 ligands, blockade of CCR4 reduced the number of Tregand enhanced antitumor immune activity. Notably, in tumor models with low baseline level of CCR4 ligands, treatment with immune CPIs resulted in significant increases of CCR4 ligands and Tregnumbers. Inhibition of CCR4 reduced Tregfrequency and potentiated the antitumor effects of CPIs.ConclusionTaken together, we demonstrate that CCR4-dependent Tregrecruitment into the tumor is an important tumor-extrinsic mechanism for immune resistance. Blockade of CCR4 led to reduced frequency of Tregand resulted in increased antitumor activity, supporting the clinical development of CCR4 inhibitors in combination with CPI for the treatment of cancer.Statement of significanceCPI upregulates CCL17 and CCL22 expression in tumors and increases Tregmigration into the TME. Pharmacological antagonism of the CCR4 receptor effectively inhibits Tregrecruitment and results in enhanced antitumor efficacy either as single agent in CCR4 ligandhightumors or in combination with CPIs in CCR4 ligandlowtumors.

2011-04-20·Investigative Opthalmology & Visual Science2区 · 医学

High-Resolution, Noninvasive, Two-Photon Fluorescence Measurement of Molecular Concentrations in Corneal Tissue

2区 · 医学

ArticleOA

作者: MacRae, Scott ; Huxlin, Krystel R. ; Knox, Wayne H. ; Xu, Lisen ; Cui, Liping

PURPOSETo perform high-resolution, noninvasive, calibrated measurements of the concentrations and diffusion profiles of fluorescent molecules in the live cornea after topical application to the ocular surface.METHODSAn 800-nm femtosecond laser was used to perform two-photon fluorescence (TPF) axial scanning measurements. Calibration solutions consisting of sodium fluorescein (Na-Fl; concentration range, 0.01%-2.5%) and riboflavin (concentration range, 0.0125%-0.1%) were tested in well slides, and TPF signals were assessed. Excised feline eyeballs preserved in corneal storage medium and with either intact or removed corneal epithelia were then treated with Na-Fl, riboflavin, or fluorescein dextran (Fl-d) of different molecular weight (MW) for 30 minutes. Calibrated TPF was then used immediately to measure the concentration of these molecules across the central corneal depth.RESULTSThe axial resolution of our TPF system was 6 μm, and a linear relationship was observed between TPF signal and low concentrations of most fluorophores. Intact corneas treated with Na-Fl or riboflavin exhibited a detectable penetration depth of only approximately 20 μm, compared with approximately 400 to 600 μm when the epithelium was removed before fluorophore application. Peak concentrations for intact corneas were half those attained with epithelial removal. Debrided corneas treated with 2,000,000 MW Fl-d showed a half-maximum penetration depth of 156.7 μm compared with 384 μm for the 3,000 MW dextran. The peak concentration of the high MW dextran was one quarter that of the lower MW dextran.CONCLUSIONSTPF is an effective, high-resolution, noninvasive method of quantifying the diffusion and concentration of fluorescent molecules across the cornea.

2010-06-01·Astrobiology2区 · 物理与天体物理

High-Density 16S Microarray and Clone Library–Based Microbial Community Composition of the Phoenix Spacecraft Assembly Clean Room

2区 · 物理与天体物理

Article

作者: Venkateswaran, Kasthuri ; Andersen, Gary ; Osman, Shariff ; Vaishampayan, Parag

The bacterial diversity and comparative community structure of a clean room used for assembling the Phoenix spacecraft was characterized throughout the spacecraft assembly process by using 16S rRNA gene cloning/sequencing and DNA microarray (PhyloChip) technologies. Samples were collected from several locations of the clean room at three time points: before Phoenix's arrival (PHX-B), during hardware assembly (PHX-D), and after the spacecraft was removed for launch (PHX-A). Bacterial diversity comprised of all major bacterial phyla of PHX-B was found to be statistically different from PHX-D and PHX-A samples. Due to stringent cleaning and decontamination protocols during assembly, PHX-D bacterial diversity was dramatically reduced when compared to PHX-B and PHX-A samples. Comparative community analysis based on PhyloChip results revealed similar overall trends as were seen in clone libraries, but the high-density phylogenetic microarray detected larger diversity in all sampling events. The decrease in community complexity in PHX-D compared to PHX-B, and the subsequent recurrence of these organisms in PHX-A, speaks to the effectiveness of NASA cleaning protocols. However, the persistence of a subset of bacterial signatures throughout all spacecraft assembly phases underscores the need for continued refinement of sterilization technologies and the implementation of safeguards that monitor and inventory microbial contaminants.

100 项与 CCR4-351 相关的药物交易

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