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bioRxiv · 10.1101/2025.07.30.667708

Enabling CAR-T Cell Immunotherapy in Glioblastoma by Modifying Tumor Microenvironment via Oncolytic Adenovirus Encoding Bispecific T Cell Engager

Choi, M. J.·So, E. Y.·Akosman, B.·Lee, Y. E.·Raufi, A. G.·Bertone, P.·Reginato, A. M.·Chen, C. C.·Lawler, S. E.·Wong, E. T.·Liang, O. D.
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Abstract

Recent clinical trials show that CAR-T cell therapies can initially blunt tumor growth in glioblastoma (GBM) patients. However, the tumor microenvironment activates mechanisms that inhibit tumor-killing potential of the CAR-T cells and limit their therapeutic efficacy. To counteract this, we have utilized oncolytic adenovirus (OV) Ad5-{Delta}24-RGD as a platform to overexpress a bispecific T cell engager (BiTE) targeting both T cell marker CD3 and GBM specific tumor associated antigen IL-13R2. We first demonstrated that OV-BiTE could enhance recruitment of T cells to GBM in vitro and in vivo. We then showed that intratumoral injection of OV-BiTE followed by infusion of combined EGFR- and EGFRvIII-CAR-T cells was more effective than OV-BiTE supplemented with either CAR-T therapy alone, and led to significant tumor eradication in a GBM xenograft mouse model. In conclusion, our multimodal OV-BiTE & CAR-T cell immunotherapy is capable of overcoming immunosuppressive tumor microenvironment and GBM resistance to treatment. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=160 SRC="FIGDIR/small/667708v1_ufig1.gif" ALT="Figure 1"> View larger version (47K): org.highwire.dtl.DTLVardef@c55b15org.highwire.dtl.DTLVardef@deffb2org.highwire.dtl.DTLVardef@64ff90org.highwire.dtl.DTLVardef@c65fc2_HPS_FORMAT_FIGEXP M_FIG C_FIG HIGHLIGHTSO_LIOncolytic adenovirus encoding bispecific T cell engager (OV-BiTE) combines two immunotherapeutic agents into one. C_LIO_LIOV-BiTE strategy modifies tumor microenvironment and enhances recruitment of T cells to glioblastoma (GBM) in vitro and in vivo. C_LIO_LIMultimodal OV-BiTE & CAR-T cell immunotherapy effectively reduced tumor mass in a GBM xenograft mouse model and is superior to either immunotherapy alone. C_LI

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Choi, M. J., So, E. Y., Akosman, B., Lee, Y. E., Raufi, A. G., Bertone, P., Reginato, A. M., Chen, C. C., Lawler, S. E., Wong, E. T., Liang, O. D.. 2025-08-02. Enabling CAR-T Cell Immunotherapy in Glioblastoma by Modifying Tumor Microenvironment via Oncolytic Adenovirus Encoding Bispecific T Cell Engager. https://doi.org/10.1101/2025.07.30.667708

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