Peptides of Tetraspanin Oncoprotein CD151 Trigger Active Immunity Against Primary Tumor and Experimental Lung Metastasis

Abstract

Background: Active immunotherapy is an effective, long-lasting, cheap and safe way to suppress the progression of cancer, however, the key issue is to find the appropriate vaccines. Oncoproteins are up-regulated under various stresses, such as radiation, chemodrugs, targeted drugs, hypoxia, malnutrition and so on to promote the cell growth, suppress apoptosis and alter the micro-environment for survival locally and remotely. Oncoproteins and their immunogenic domain could well serve as vaccines to prime the host active anti-tumor immunity, which might enhance the immune (such as anti-PD-1) modulators given exogenously on effective stage. Methods: Proteomics and bio-information analysis were performed to identify potential associated antigens (TAAs) induced by 8 Gy irradiation (IR). Then, peptides derived from CD151 were designed and synthesized according to MHC I binding and immunogenicity. Cell killing assay, flow cytometer, immunohistochemistry staining, and in vivo bioluminescence imaging were applied to assessed active anti-tumor immunity triggered by CD151 peptides in H22 hepatoma primary and experimental 4T1 breast cancer lung metastasis model. Results: We utilized 8 Gy irradiation as therapeutic stress to up-regulate a panel of oncoproteins, and identified CD151 as a TAA according to proteomics and bio-information analysis. Two CD151 peptides were synthesized as tumor vaccine to immunize the mice, which triggered active anti-cancer immunity against both the primary growth of H22 hepatoma and the lung metastasis of 4T1 breast cancer in two mouse model via activation of CD8+IFNγ+ lymphocytes and their targeted cytotoxicity as well as reduction of negative regulator of MDSC cells. The survival of mice with lung metastases in CD151 peptide immunized group was also prolonged. Conclusions: The stress-upregulated oncoproteins defined by proteomics and bio-information on 8 Gy irradiated cells are the good candidates for designing immunogenic peptides as vaccines. Anti-tumor active immunity primed by peptides from tetraspanin oncoprotein CD151 could exert effective, long-lasting, cheap and safe way to suppress the progression of cancer. Funding: The project was funded in part by the grants of Fujian Province Natural Science Foundation (2017J01260); the Key Clinical Specialty Discipline Construction Program of Fujian; the National Clinical Key Specialty Construction Program; Fujian Engineering Research Center of Cancer precision Diagnosis and Immunotherapy; Science&Technology Program of Fujian Province, China (#2018Y2003). Declaration of Interest: The authors declare that they have no competing interests. Ethical Approval: Animal experiments were approved by Fujian Medical University Institutional Animal Ethical Committee (FJMU IACUC #2018-075). The applicable institutional guidelines for the care and use of animals were followed.