Interleukin-37 promotes DMBA/TPA skin cancer through SIGIRR-mediated inhibition of glycolysis in CD103+DC cells.

Interleukin 37 (IL-37), a member of the IL-1 family, is considered a suppressor of innate and adaptive immunity and, hence is a regulator of tumor immunity. However, the specific molecular mechanism and role of IL-37 in skin cancer remain unclear. Here, we report that IL-37b-transgenic mice (IL-37tg) treated with the carcinogenic 7,12-dimethylbenzoanthracene (DMBA)/12-o-tetradecylphorbol-13-acetate (TPA) exhibited enhanced skin cancer and increased tumor burden in the skin by inhibiting the function of CD103+ dendritic cells (DCs). Notably, IL-37 induced rapid phosphorylation of adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK), and via single immunoglobulin IL-1-related receptor (SIGIRR), inhibited the long-term Akt activation. Specifically, by affecting the SIGIRR-AMPK-Akt signaling axis, which is related to the regulation of glycolysis in CD103+DCs, IL-37 inhibited their anti-tumor function. Our results show that a marked correlation between the CD103+DC signature (IRF8, FMS-like tyrosine kinase 3 ligand, CLEC9A, CLNK, XCR1, BATF3, and ZBTB46) and chemokines C-X-C motif chemokine ligand 9, CXCL10, and CD8A in a mouse model with DMBA/TPA-induced skin cancer. In a word, our results highlight that IL-37 as an inhibitor of tumor immune surveillance through modulating CD103+DCs and establishing an important link between metabolism and immunity as a therapeutic target for skin cancer.

Interleukin-37 promotes colitis-associated carcinogenesis via SIGIRR-mediated cytotoxic T cells dysfunction.

Interleukin-37b (hereafter called IL-37) was identified as fundamental inhibitor of natural and acquired immunity. The molecular mechanism and function of IL-37 in colorectal cancer (CRC) has been elusive. Here, we found that IL-37 transgenic (IL-37tg) mice were highly susceptible to colitis-associated colorectal cancer (CAC) and suffered from dramatically increased tumor burdens in colon. Nevertheless, IL-37 is dispensable for intestinal mutagenesis, and CRC cell proliferation, apoptosis, and migration. Notably, IL-37 dampened protective cytotoxic T cell-mediated immunity in CAC and B16-OVA models. CD8+ T cell dysfunction is defined by reduced retention and activation as well as failure to proliferate and produce cytotoxic cytokines in IL-37tg mice, enabling tumor evasion of immune surveillance. The dysfunction led by IL-37 antagonizes IL-18-induced proliferation and effector function of CD8+ T cells, which was dependent on SIGIRR (single immunoglobulin interleukin-1 receptor-related protein). Finally, we observed that IL-37 levels were significantly increased in CRC patients, and positively correlated with serum CRC biomarker CEA levels, but negatively correlated with the CD8+ T cell infiltration in CRC patients. Our findings highlight the role of IL-37 in harnessing antitumor immunity by inactivation of cytotoxic T cells and establish a new defined inhibitory factor IL-37/SIGIRR in cancer-immunity cycle as therapeutic targets in CRC.

[The construction of anti-EGFR single chain variable fragment fused with gelonin toxin prokaryotic expressing plasmid and the study of its anti-tumor effects].

OBJECTIVE: To construct a prokaryotic expressing plasmid for recombinant immunotoxin which fused anti-EGFR scFv together with gelonin toxin, express and verify its function. METHODS: The gene fragments coding anti-EGFR single chain fragment were amplified with PCR and cloned into pET32a vector which contains gelonin toxin. The new plasmid was transformed into BL21 (DE3) cells. The induced inclusion bodies were denatured, refolded and purified through SP Sepharose Fast Flow Column. The purified immunotoxin rEG was identified by western blot analysis, and the bioactivity was identified using cell immnuohistochemistry and MTT assay. RESULTS: The expressing vector pET32a-rEG has been constructed correctly, confirmed by restriction endonuclease digestion and sequencing. The recombinant immunotoxin rEG was purified after denaturing the inclusion bodies, refolding and cationic exchange chromatograph. The purified protein rEG had the right immunology specificity, rEG could efficiently target to EGFR positive cells identified by cell immnuohistochemistry. And the result of MTT assay showed rEG could specifically kill EGFR positive cells. CONCLUSION: The recombinant immunotoxin rEG with high purity and biologic activity was prepared in this study, which would become the basic for the further study of the biologic function of rEG.