Objective: To prepare the fusion protein mGM-CSF-GnRH3 (mGGn) of mouse granulocyte-macrophage colony stimulating factor (mGM-CSF) combining with gonadotropin releasing hormone (GnRH) and the fusion protein mGM-CSF-GRP6 (mG6) of mGM-CSF combining with gastrin-releasing peptide (GRP), and to investigate the inhibitory effect of the above two fusion proteins on B16F10 melanoma in vitro as well as to preliminarily predict their isoelectric point, relative molecular weight, hydrophobicity, stability, subcellular localization, signal peptide, spatial structure and potential epitopes. Methods:After the successful preparation of mGGn and mG6, the effects of different concentrations of fusion proteins on tumor cell morphology, migration, proliferation and cell cycle were detected by microscopic observation, scratch test, CCK-8 method and flow cytometry, respectively. The protein online analysis systems EXPASY, GOR4, SWISS MODEL were used to predict the basic properties and secondary/tertiary structure of recombinant fusion proteins. The B cell epitopes were predicted by IEDB and ABCpred software, the CTL epitopes were comprehensively predicted by SYFPEITHI, BlMAS and NetCTL software, and the Th epitopes were predicted by NetMHCIIpan 3.1 Server and IEDB software. Results:Both mGGn and mG6 inhibited the migration and proliferation of tumor cells. mGGn could block B16F10 cell cycle at G1 phase while mG6 could block B16F10 cell cycle at S phase, all of which prevented cells entering into G2 phase to inhibit tumor cell growth. The mGGn and mG6 fusion proteins got diverse structures and had multiple potential B epitopes, CTL epitopes and Th epitopes. Conclusion: mGGn and mG6 have inhibitory effect on B16F10 melanoma in vitro, and bioinformatics predictions have laid a foundation for further study of the biological functions and immunological activities of these fusion proteins.

Rheumatoid arthritis (RA) is an autoimmune disease characterized by severe synovial inflammation and cartilage damage. Despite great progress in RA therapy, there still lacks the drugs to completely cure RA patients. Herein, we propose a reprogrammed neutrophil cytopharmaceuticals loading with TNFα-targeting-siRNA (siTNFα) as an alternative anti-inflammatory approach for RA treatment. The loaded siTNFα act as not only the gene therapeutics to inhibit TNFα production by macrophages in inflamed synovium, but also the editors to reprogram neutrophils to anti-inflammatory phenotypes. Leveraging the active tendency of neutrophils to inflammation, the reprogrammed siTNFα/neutrophil cytopharmaceuticals (siTNFα/TP/NEs) can rapidly migrate to the inflamed synovium, transfer the loaded siTNFα to macrophages followed by the significant reduction of TNFα expression, and circumvent the pro-inflammatory activity of neutrophils, thus leading to the alleviated synovial inflammation and improved cartilage protection. Our work provides a promising cytopharmaceutical for RA treatment, and puts forward a living neutrophil-based gene delivery platform.