T-cell immunotherapy that takes advantage of Epstein-Barr virus (EBV)-

UCAR T cells can overcome antigenic heterogeneity in GBM and lead to improved treatment outcomes.

Cancer-associated fibroblasts (CAFs), the principle component of the tumor-associated stroma, form a highly protumorigenic and immunosuppressive microenvironment that mediates therapeutic resistance. Co-targeting CAFs in addition to cancer cells may therefore augment the antitumor response. Fibroblast activation protein-α (FAP), a type 2 dipeptidyl peptidase, is expressed on CAFs in a majority of solid tumors making it an attractive immunotherapeutic target. To target FAP-positive CAFs in the tumor-associated stroma, we genetically modified T cells to express a FAP-specific chimeric antigen receptor (CAR). The resulting FAP-specific T cells recognized and killed FAP-positive target cells as determined by proinflammatory cytokine release and target cell lysis. In an established A549 lung cancer model, adoptive transfer of FAP-specific T cells significantly reduced FAP-positive stromal cells, with a concomitant decrease in tumor growth. Combining these FAP-specific T cells with T cells that targeted the EphA2 antigen on the A549 cancer cells themselves significantly enhanced overall antitumor activity and conferred a survival advantage compared to either alone. Our study underscores the value of co-targeting both CAFs and cancer cells to increase the benefits of T-cell immunotherapy for solid tumors.

The hedgehog signaling network regulates pattern formation, proliferation, cell fate and stem/progenitor cell self-renewal in many organs. Altered hedgehog signaling is implicated in 20-25% of all cancers, including breast cancer. We demonstrated previously that heterozygous disruption of the gene encoding the patched-1 (PTCH1) hedgehog receptor, a negative regulator of smoothened (Smo) in the absence of ligand, led to mammary ductal dysplasia in virgin mice. We now show that expression of activated human SMO (SmoM2) under the mouse mammary tumor virus (MMTV) promoter in transgenic mice leads to increased proliferation, altered differentiation, and ductal dysplasias distinct from those caused by Ptch1 heterozygosity. SMO activation also increased the mammosphere-forming efficiency of primary mammary epithelial cells. However, limiting-dilution transplantation showed a decrease in the frequency of regenerative stem cells in MMTV-SmoM2 epithelium relative to wild type, suggesting enhanced mammosphere-forming efficiency was due to increased survival or activity of division-competent cell types under anchorageindependent growth conditions, rather than an increase in the proportion of regenerative stem cells per se. In human clinical samples, altered hedgehog signaling occurs early in breast cancer development, with PTCH1 expression reduced in ~50% of ductal carcinoma in situ (DCIS) and invasive breast cancers (IBC). Conversely, SMO is ectopically expressed in 70% of DCIS and 30% of IBC. Surprisingly, in both human tumors and MMTV-SmoM2 mice, SMO rarely colocalized with the Ki67 proliferation marker. Our data suggest that altered hedgehog signaling may contribute to breast cancer development by stimulating proliferation, and by increasing the pool of division-competent cells capable of anchorage-independent growth.