ABSTRACT
Recent clinical studies have shown that mutation of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) gene in cancer cells may be associated with immunosuppressive tumor microenvironment (TME) and poor response to immune checkpoint blockade (ICB) therapy. Therefore, efficiently restoring PTEN gene expression in cancer cells is critical to improving the responding rate to ICB therapy. Here, we screened an adeno-associated virus (AAV) capsid for efficient PTEN gene delivery into B16F10 tumor cells. We demonstrated that intratumorally injected AAV6-PTEN successfully restored the tumor cell PTEN gene expression and effectively inhibited tumor progression by inducing tumor cell immunogenic cell death (ICD) and increasing immune cell infiltration. Moreover, we developed an anti-PD-1 loaded phospholipid-based phase separation gel (PPSG), which formed an in situ depot and sustainably release anti-PD-1 drugs within 42 days in vivo. In order to effectively inhibit the recurrence of melanoma, we further applied a triple therapy based on AAV6-PTEN, PPSG@anti-PD-1 and CpG, and showed that this triple therapy strategy enhanced the synergistic antitumor immune effect and also induced robust immune memory, which completely rejected tumor recurrence. We anticipate that this triple therapy could be used as a new tumor combination therapy with stronger immune activation capacity and tumor inhibition efficacy.
ABSTRACT
Induction of immunogenic cell death promotes antitumor immunity against cancer. However, majority of clinically-approved drugs are unable to elicit sufficient ICD. Here, our study revealed that mitochondria-targeted delivery of doxorubicin (DOX) massively amplified ICD via substantial generation of reactive oxygen species (ROS) after mitochondrial damage. The underlying mechanism behind increased ICD was further demonstrated to be ascribed to two pathways: (1) ROS elevated endoplasmic reticulum (ER) stress, leading to surface exposure of calreticulin; (2) ROS promoted release of various mitochondria-associated damage molecules including mitochondrial transcription factor A. Nevertheless, adaptive upregulation of PD-L1 was found after such ICD-inducing treatment. To overcome such immunosuppressive feedback, we developed a tumor stimuli-responsive nano vehicle to simultaneously exert mitochondrial targeted ICD induction and PD-L1 blockade. The nano vehicle was self-assembled from ICD-inducing copolymer and PD-L1 blocking copolymer, and possessed long-circulating property which contributed to better tumor accumulation and mitochondrial targeting. As a result, the nano vehicle remarkably activated antitumor immune responses and exhibited robust antitumor efficacy in both immunogenic and non-immunogenic tumor mouse models.
ABSTRACT
We report the case of an 84-year-old woman with advanced biliary tract cancer and accompanying colonic invasion and hepatic metastasis, who was successfully treated with single-agent gemcitabine chemotherapy in combination with juzentaihoto (a traditional Japanese herbal medicine). Response to this combination chemo therapy was extremely good, and the patient's tumors disappeared. There have been no reports like our case until today. These findings suggest that combined treatment with juzentaihoto and gemcitabine is effective not only for reducing tumor size, decreasing the side effects of chemotherapy, and maintaining general condition but also for mediating immune antitumor activity.
ABSTRACT
L-10 has been recognized as an irnmune suppressive cytokine which inhibits Ag-specific activation and proliferation of T cells. It also inhibits Ag presenting capacity of monocyte/macrophage and down-regulates monokine production. However it has also shown that IL-10 has stimulatory effect on immune effector cells in recent studies. This report shows that IL-10 has direct stimulatory effect on antitumor cytolytic activity suppressed by TGF-B. To assess the effect of IL-10 on cytolytic activity against tumor, spleen cells prepared from tumor-bearing mice were cultured with mitomycin C-treated MOPC-315 cells in the presence of IL-10. Unexpectedly, IL-10 was able to reverse the cytolytic activity suppressed with TGF-B. The stimulatory effect of IL-10 was dependent on the addition time of IL-10. At day 0, 4, those effects were shown higher than those of the other days. Also, the stimulatory effect of IL-10 showed specificity against MOPC-315 tumor cells. To elucidate the role of endogenous IL-10, TGF-B in MLTC cultures, anti-IL-10 and anti-TGF-B mAb were used. The inhibition of IL-10 release in MLTC cultures by using anti-IL-10 mAb resulted in the suppression of cytolytic activity against MOPC-315 tumor cells. Taken together, although IL- 10 has been recognized as a strong immunosuppressive cytokine derived of tumor cells, IL-10 showed the direct stimulatory effect on the antitumor cytolytic activity of spleen cells.
Subject(s)
Animals , Mice , Interleukin-10 , Mitomycin , Sensitivity and Specificity , Spleen , T-Lymphocytes , Transforming Growth Factor betaABSTRACT
Objective: To study the immune responses of cytotoxic T-lymphocytes against Renal carcinoma cell 786-0(RCC) after activiated by dendritic cells(DCs) loaded with RCC freeze thawing antigen.Methods:DCs were obtained by cultured plastic-adherent monocytes isolated from health human peripheral blood with granulocyte-monocyte colony-stimulating factor(GM-CSF) and interleukin-4(IL-4) and Tumor necrosis factor(TNF) for 9 days.Host lymphocytes were stimulated with freeze thawing antigen of RCC 786-0 under the culture medium containing interleukin-2(IL-2) for 5 day.Killing activity and cytokine release were measured by MTT assay and ELISA.Results:The immune response of CTL activiated by DCs loaded with tumor soluble antigen was demonstrated by the following facts:(1)DCs loaded with tumor antigen could induce the growth of CTL.(2)The cyotoxicity of obtained specific CTL against RCC-7860 was highly enhanced with a significant difference from that of non-specific CTL.(3)The interleukin-12 release/secretion was increased by tumor antigen,which suggest an improved anti-tumor effect.(4)Apoptosis was observed in the RCCs after treated with CTL obtained.Conclution: These findings indicate that specific CTL induced by DCs sensibilized by RCC freeze thawing antigen exerts a remarkable killing activity on RCC 786-0.It is suggestd that DCs antitumor vaccines poses a clinically useful prospect with RCC.
ABSTRACT
Objective:To investigate the role of recombinant E.coli LLO/OVA on regulating the function of murine CD4+ CD25+ Treg cells.Methods:After E.coli LLO/OVA or E.coli OVA vaccination,the murine spleen CD4+ CD25+ Treg,CD4+ CD25- T and CD11c cells were collected respectively by magnetic beads sorting.The concentration of IL-10 in the supernatant of mix cocultured CD4+ CD25+ Treg and CD11c cells,and the suppression role of CD4+ CD25+ Treg cells on the proliferation of CD4+ CD25- T cells were determined.The percentage of OVA specific CD8+ T cells in mouse spleen was analyzed by flow cytometry.The number of metastatic tumor nodules in lungs of the mice transplanted with B16-OVA subcutaneouly was compared before and after dilition of CD4+ CD25+ Treg cells in mice.Results:Compared to E.coli OVA,E.coli LLO/OVA significantly downregulated IL-10 secretion of CD4+CD25+Treg cells and attenuated the suppressive effect of CD4+ CD25+ Treg on the proliferation of CD4+ CD25- T cells(P