A combined Globo H-OCT4-T7 immunotherapy restrains colorectal tumor growth

Background: Malignant tumors express multiple common markers that might constitute targets for tumor immunotherapy. Methods: Here we performed antigen epitope screening and molecular docking to design a new combination vaccine based on covalently linking Globo H and Oct 4 with a TLR7 agonist. We mainly use flow cytometry to analyze the changes in lymphocyte differentiation after the vaccine is applied. Use Elisa technology to detect the antibodies produced by the vaccine and the changes in lymphokines. In order to supplement the immunological data, RNA sequencing was performed on untreated and vaccine-treated tumors to define the interference of the vaccine on the genome-wide gene expression profile. Results: Our results demonstrated that the Globo H-OCT4-T7 conjugate vaccine effectively induced cellular uptake, maturation and antigen presentation of BMDCs. The combination vaccine enhanced cytokine production, CTLs activity elicited high levels of IgG. Importantly, the tumor immune microenvironment was significantly improved in tumor-bearing mice treated by Globo H-OCT4-T7 conjugate vaccine, demonstrated by increased the ratio of M1 to M2 TAMs, reduced number of Tregs in PBMCs and promoted the infiltration of tumor-specific IFN γ-producing CD8+ T cells. Prophylactic vaccination of Globo H-OCT4-T7 significantly reduced tumor growth by >80 % in both CT26 transplanted mice and in a human PDX mouse model when exposing mice to the combined vaccine compared to control. Our novel, combination vaccine is safe and effective at preventing tumor growth in mice. Conclusions: This combination vaccine is more effective than the single vaccine, and thus has the potential to prevent OCT4 and Globo H from expressing cancer.