NSCLC patient-derived xenografts perpetuating tumor-associated, tumor-reactive T cells that respond to immunotherapy but do not cause GVHD in host mice

Abstract Non-small cell lung cancer (NSCLC) is the leading cause of malignancy-related deaths worldwide. We wished to overcome a current major limitation of PDX modeling, by providing autologous human T cells suitable for immunotherapy responses, but notably, without graft versus host disease (GVHD). We have developed PDXs from NSCLC by implanting surgically resected patient tumors subcutaneously in NOD scid gamma (NSG) mice. We used a metastatic PDX model to test potential therapeutic efficacy of a novel T cell molecule, anti-human-CD3ɛ monovalent Fab fragment (Mono-OKT3-Fab) and compared tumor growth results with anti-human PD-L1 therapy. Overall engraftment rate of unique, primary patient tumors was 52%. Over multiple passages in vivo, PDX tumors retained expression of primary tumor-matched NSCLC-diagnostic pathological markers. Moreover, primary-tumor-associated T cells were present and passaged in mice in vivo, without producing any signs of GVHD. Immunotherapy showed significant response from a PDL-1+ tumor, consistent with functional tumor-specific T cell passaging in our system. In contrast, control experiments using patient-matched human PBMCs showed vigorous GVHD in the presence or absence of co-transplanted PDX tumor; this demonstrated that non-tumor-associated lymphocytes from these patients were capable of xenoreaction, even though tumor-associated T cells were not. We observed that PDX-NSG mice treated with either modality showed significantly reduced tumor burden and increased survival over control-Ig-treated mice. Overall, our study shows that PDXs implanted in NSG mice from surgically resected-NSCLC retain T cells sufficient for preclinical evaluation of novel T cell-targeting immunotherapies. NIH, National Cancer Institute, IOTN(U01 CA244314) NIH, NIAID, R01 AI097187 Mizzou Start-up funds