Multifunctional Nanoprobe for Early Appraisal of Immunotherapeutic Efficacy

点击翻译按钮获取中文摘要

Project Summary Despite advances in imaging technologies, it takes weeks (typically 12-14 weeks) to accurately assess the efficacy of immunotherapy treatment. This time lag is highly undesirable for patients who are ultimately non- responsive or relapse, as they are subject to onerous side effects and are delayed in alternate treatments. To expedite immunotherapy related cancer research and harness the potential of immunotherapy, a technology capable of early assessment of immunotherapy efficacy is critically important. The goal of the proposed effort is to design, synthesize and validate a multifunctional nanoprobe for (i) efficiently administering immunotherapy; and (ii) early detection of the cytotoxic potential of the intra-tumor T cells. With this in mind, the following Specific Aims are proposed: Specific Aim 1: Design and synthesize a multifunctional nanoprobe comprised of an immune checkpoint inhibitor antibody as a targeting immunotherapeutic agent and a fluorophore-substrate complex as a predictive biomarker; and Specific Aim 2: In vivo validation of the multifunctional nanoprobe’s immunotherapeutic potential, and its ability to rapidly monitor the response to immunotherapy. We will utilize gold nanoparticles as a carrier for delivering anti-PD-1 antibody (immunotherapeutic agent) and a specific cleavable substrate for granzyme B with a fluorescent reporter element to T cells. An anti-PD-1 antibody will be chemically conjugated to the nanoparticle using a polyethylene glycol (PEG) linker. The reporter, a fluorescein-tagged specific granzyme B substrate, will also be conjugated to the carrier nanoparticle using another PEG linker. The interaction between activated T cells and cancer cells should lead to localized granzyme B secretion and cleavage of the substrate, releasing fluorescein. Plasmonic-fluor enabled competitive fluoroimmunoassay will be used for the detection of the released reporter (fluorescein) in plasma and subsequently urine. The size of the nanoparticle will be chosen to exploit the enhanced permeation and retention effect for improved infiltration typically seen in tumors. Following ex vivo optimization of the activatable nanoprobe design, we will test the ability to monitor the immuno-theranostic efficacy in vivo. An established melanoma cancer model, developed in C57BL/6 mice using B16-F10 melanoma cells, will be utilized for this purpose although this strategy is cancer agnostic. To investigate the therapeutic efficacy and reporting ability of the nanoprobes, tumor volume and survival will be measured, and the results correlated with those from the serum and urine analysis for fluorescein for validation of the therapeutic efficacy. Clearly, this is a pre-clinical study with translational implications to eventual human studies. The overall goal is to assess the efficacy of immunotherapy treatment in patients at an early time sparing patients the side effects of the therapy and the financial burden (to the insurance industry and/or patient) of continued but non-durable treatment. This strategy is applicable to any therapeutic option employing immunotherapy alone or immunotherapy in combination with conventional chemotherapy