ABSTRACT
Dendritic cell-based cancer vaccines (DC vaccines) have been proved efficient and safe in immunotherapy of various cancers, including melanoma, ovarian and prostate cancer. However, the clinical responses were not always satisfied. Here we proposed a novel strategy to prepare DC vaccines. In the present study, a fusion protein SNU containing a secretin-penetratin (SecPen) peptide, NY-ESO-1 and ubiquitin was designed and expressed. To establish the DC vaccine (DC-SNU), the mouse bone marrow-derived DCs (BMDCs) were isolated, pulsed with SNU and maturated with cytokine cocktail. Then peripheral blood mononuclear cells (PBMCs) from C57BL/6 mice inoculated intraperitoneally with DC-SNU were separated and cocultured with MC38/MC38
ABSTRACT
T cell immunoglobulin and ITIM domain (TIGIT) is a novel immune checkpoint that has been considered as a target in cancer immunotherapy. Current available bioassays for measuring the biological activity of therapeutic antibodies targeting TIGIT are restricted to mechanistic investigations because donor primary T cells are highly variable. Here, we designed a reporter gene assay comprising two cell lines, namely, CHO-CD112-CD3 scFv, which stably expresses CD112 (PVRL2, nectin-2) and a membrane-bound anti-CD3 single-chain fragment variable (scFv) as the target cell, and Jurkat-NFAT-TIGIT, which stably expresses TIGIT as well as the nuclear factor of activated T-cells (NFAT) response element-controlled luciferase gene, as the effector cell. The anti-CD3 scFv situated on the target cells activates Jurkat-NFAT-TIGIT cells through binding and crosslinking CD3 molecules of the effector cell, whereas interactions between CD112 and TIGIT prevent activation. The presence of anti-TIGIT mAbs disrupts their interaction, which in turn reverses the inactivation and luciferase expression. Optimization and validation studies have demonstrated that this assay is superior in terms of specificity, accuracy, linearity, and precision. In summary, this reliable and effective reporter gene assay may potentially be utilized in lot release control, stability assays, screening, and development of novel TIGIT-targeted therapeutic antibodies.
ABSTRACT
More efficient drug delivery system and formulation with less adverse effects are needed for the clinical application of broad-spectrum antineoplastic agent doxorubicin (DOX). Here we obtained outer-membrane vesicles (OMVs), a nano-sized proteoliposomes naturally released by Gram-negative bacteria, from attenuated and prepared doxorubicin-loaded O0MVs (DOX-OMV). Confocal microscopy and distribution study observed that DOX encapsulated in OMVs was efficiently transported into NSCLC A549 cells. DOX-OMV resulted in intensive cytotoxic effects and cell apoptosis as evident from MTT assay, Western blotting and flow cytometry due to the rapid cellular uptake of DOX. In A549 tumor-bearing BALB/c nude mice, DOX-OMV presented a substantial tumor growth inhibition with favorable tolerability and pharmacokinetic profile, and TUNEL assay and H&E staining displayed extensive apoptotic cells and necrosis in tumor tissues. More importantly, OMVs' appropriate immunogenicity enabled the recruitment of macrophages in tumor microenvironment which might synergize with their cargo DOX . Our results suggest that OMVs can not only function as biological nanocarriers for chemotherapeutic agents but also elicit suitable immune responses, thus having a great potential for the tumor chemoimmunotherapy.