Abstract
ABSTRACTAdoptive transfer of tumor-infiltrating lymphocytes (TIL) has shown remarkable results in melanoma, but only modest clinical benefit in other cancers, even after TIL have been genetically modified to improve their tumor homing, cytotoxic potential or overcoming cell exhaustion. The requiredex vivoTIL expansion process may induce changes in the T cell clonal composition, which could likely compromise the tumor reactivity of TIL preparations and ultimately the success of TIL therapy. A promising approach based on the production of bispecific T cell engagers (TCE) by engineered T cells (STAb-T therapy) improves the efficacy of current T cell redirection strategies against tumor-associated antigens in hematological tumors. We studied the TCRβ repertoire in non-small cell lung cancer (NSCLC) tumors and inex vivoexpanded TIL from two unrelated patients. We generated TIL secreting anti-epidermal growth factor receptor (EGFR) x anti-CD3 TCE (TILSTAb) and tested their antitumor efficacyin vitroandin vivousing a NSCLC patient-derived xenograft (PDX) model in which tumor fragments and TIL from the same patient were transplanted intohIL-2NOG mice. We confirmed that the standard TIL expansion protocol promotes the loss of tumor-dominant T cell clones and the overgrowth of virus-reactive TCR clonotypes that were marginally detectable in primary tumors. We demonstrated the antitumor activity of TILSTAbbothin vitroandin vivowhen administered intratumorally and systemically in an autologous immune-humanized PDX EGFR+NSCLC mouse model, where tumor regression was mediated by TCE-redirected CD4+TIL bearing non-tumor dominant clonotypes.SIGNIFICANCEEpithelial tumor-derived TIL can be engineered to secrete TCE capable of redirecting T cells bearing non-tumor-dominant clonotypes regardless of their phenotype, which could have broad applications in immunotherapy for solid tumors.
Publisher
Cold Spring Harbor Laboratory