ABSTRACT
@#[Abstract] Objective: To explore the anti-tumor activity of oncolytic adenovirus co-expressing lymphocyte activation gene 3 (LAG-3) antibody (aLAG) against glioblastoma. Methods: aLAG sequence was inserted into the skeleton of oncolytic adenovirus Ad3 to obtain recombinant oncolytic adenovirus (Ad3-aLAG). The expression of aLAG in infected gliblastoma GL261 cells was detected by WB. The cytotoxicity of recombinant oncolytic adenovirus against glioblastoma was detected by MTT method. The tumor inhibitory activity of recombinant oncolytic adenovirus against glioblastoma in vivo was evaluated with mice subcutaneous xenograft model. Tumor infiltrating T cells were detected by immunohistochemical staining, and the levels of cytokines TNF-α and IFN-γ secreted by tumor infiltrating T cells were detected by Flow cytometry. Results: The recombinant oncolytic adenovirus was successfully constructed, which could effectively express aLAG and kill GL261 cells in vitro (all P<0.01). Experimental results of mice subcutaneous xenograft model showed that the tumor inhibition ability of recombinant oncolytic adenovirus Ad3-aLAG was stronger than that of Ad3 oncolytic adenovirus (P<0.01), and Ad3-aLAG could effectively enhance the infiltration of CD3+ T cells in tumor tissue (P<0.01) and enhance the IFN-γ secretion ability of infiltrating T cells (P<0.01). Conclusion: Ad3-aLAG recombinant oncolytic adenovirus can significantly inhibit the growth of glioblastoma cells in vivo and in vitro, and enhance the anti-tumor immune response in vivo, which is promising to provide a new scheme for the treatment of glioblastoma.