Project description:FOXO3 is an evolutionally conserved transcription factor that has been linked to longevity. Here we asked whether human stem cells could be functionally enhanced by engineering them to express an activated form of FOXO3. This was accomplished via HDAdV-mediated gene editing of human embryonic stem cells. These cells were then differentiated into a range of vascular cell types, as FOXO3 has been shown to play a protective role in the cardiovascular system. FOXO3-enhanced vascular cells exhibited delayed senescence and increased resistance to oxidative injuries, compared with wild type cells. When tested in a therapeutic context, FOXO3-enhanced human mesenchymal stem cells promoted vasculature regeneration in a mouse model of ischemic injury, and were resistant to tumorigenic transformation, both in vitro and in vivo. Mechanistically, constitutively active FOXO3 conferred cytoprotection by transcriptionally downregulating CSRP1. Taken together, our findings provide mechanistic insights into FOXO3-mediated vascular protection, and indicate that FOXO3 activation may provide a means for generating more effective and safe biomaterials for cell replacement therapies.
Project description:Adoptively transferred T cells and agents designed to block the CD47/SIRPalpha axis are promising cancer therapeutics that activate distinct arms of the immune system. We administered anti-CD47 with adoptively transferred T cells with the goal of enhancing antitumor efficacy but observed rapid macrophage-mediated clearance of T cells expressing chimeric antigen receptors (CARs) or engineered T cell receptors, which abrogated therapeutic benefit. anti-CD47 mediated CAR T clearance was potent and rapid enough to serve as an effective safety switch. To overcome this challenge, we engineered a CD47 variant (47E) that engaged SIRPalpha and provided a “don’t-eat-me” signal that was not blocked by anti-CD47 antibodies. TCR or CAR T cells expressing 47E were resistant to clearance by macrophages following anti-CD47, and mediated significant, sustained macrophage recruitment into the TME. Although many of the recruited macrophages manifested an M2-like profile, the combined therapy synergistically enhanced antitumor efficacy. This work identifies macrophages as major regulators of T cell persistence and illustrates the fundamental challenge of combining T cell directed therapeutics with those designed to activate macrophages. It further delivers a therapeutic approach capable of simultaneously harnessing the antitumor effects of T cells and macrophages that manifests enhanced potency against solid tumors.
Project description:Regulatable CAR platforms could circumvent toxicities associated with CAR-T therapy, but existing systems have shortcomings including leakiness and attenuated activity. Here, we present SNIP-CARs, a novel protease-based platform for regulating CAR activity using an FDA-approved small molecule. Design iterations yielded CAR-T cells that manifest full functional capacity with drug and no leaky activity in the absence of drug. In numerous models, SNIP CAR-T cells were more potent than constitutive CAR-T cells and showed diminished T cell exhaustion and greater stemness. In a ROR1-based CAR lethality model, drug cessation following toxicity onset reversed toxicity, thereby credentialling the platform as a safety switch. In the same model, reduced drug dosing opened a therapeutic window that resulted in tumor eradication in the absence of toxicity. SNIP-CARs enable remote tuning of CAR activity, which provides solutions to safety and efficacy barriers currently limiting progress in using CAR T cells to treat solid tumors.
Project description:UNIFI was a randomized placebo-controlled phase 3 clinical trial evaluating the efficacy and safety of ustekinumab (ClinicalTrials.gov Identifier: NCT02407236). Gene expression profiling by microarrays was carried out at baseline on biopsies from the sigmoid colon (15-20cm from anal verge) of patients (n=550) with moderate-to-severe ulcerative colitis and of healthy subjects (n=18). Ulcerative colitis patients received placebo (n=186) or ustekinumab (n=364). The effects of two different dosages were investigated: 130mg (n=180) and 6mg/kg (n=184).
Project description:This clinical trial (NCT02252640) assesses the safety and immune responses to vaccination with experimental malaria vaccine candidates RTS,S/AS01, ChAd63 ME-TRAP and MVA ME-TRAP in different combinations. All healthy volunteers were recruited in England and administered the experimental malaria vaccines. Furthermore, volunteers were infected with malaria by mosquito bites, 12 weeks after the first vaccination to assess vaccine efficacy.