Survivin mRNA lipid nanoparticles and CTLA-4 inhibitor co-delivery activates anti-tumor cytotoxic T-lymphocytes for oral cancer immunotherapy.
Oral carcinoma is the sixth most prevalent cancer type with a poor 5-year survival rate. mRNA-lipid nanoparticle-based immunotherapy can overcome the challenges associated with conventional treatment options. Here, we investigated the immunogenicity and antitumor efficacy of survivin antigen encoded mRNA lipid nanoparticles (LNPs) in combination with anti-CTLA-4 immune checkpoint inhibitor. Survivin mRNA was synthesized by in vitro transcription technique after cloning the antigenic target sequence into an expression vector. The mRNA-LNPs were prepared with lipids, ALC-0315, DOPE, and cholesterol using a droplet-based microfluidic device. The average particle size, polydispersity index and encapsulation efficiency of mRNA-LNPs was found to be 305 ± 68 nm, 0.11, and 65 ± 3.9%, respectively. Survivin mRNA-LNPs incubated with mouse-derived bone marrow dendritic cells showed activation of tumor-associated antigen specific T-cells. The co-culture of splenocytes, and cheek cells derived from C57BL/6 mouse administered with survivin mRNA-LNPs and CTLA-4 inhibitor with MOC-1 oral carcinoma cells showed significant (P < 0.05) reduction in the cancer cell viability compared with control group. The oral cancer cytotoxicity is attributed to the upregulation of MHCI and MHCII, CD8 + and CD4 + T-lymphocytes and reduction in the T-regulatory cells. Taken together, this study provides preliminary evidence for further development of survivin mRNA-LNPs and CTLA-4 inhibitor combination for oral cancer immunotherapy.