Paclitaxel Induces Immunogenic Cell Death in Ovarian Cancer via TLR4/IKK2/SNARE-Dependent Exocytosis

Emerging evidence shows that the efficacy of chemotherapeutic drugs is reliant on their capability to induce immunogenic cell death (ICD), thus transforming dying tumor cells into antitumor vaccines. We wanted to uncover potential therapeutic strategies that target ovarian cancer by having a better understanding of the standard-of-care chemotherapy treatment. Here, we showed in ovarian cancer that paclitaxel induced ICD-associated damage-associated molecular patterns (DAMP, such as CALR exposure, ATP secretion, and HMGB1 release) in vitro and elicited significant antitumor responses in tumor vaccination assays in vivo Paclitaxel-induced TLR4 signaling was essential to the release of DAMPs, which led to the activation of NF-κB-mediated CCL2 transcription and IkappaB kinase 2-mediated SNARE-dependent vesicle exocytosis, thus exposing CALR on the cell surface. Paclitaxel induced endoplasmic reticulum stress, which triggered protein kinase R-like ER kinase activation and eukaryotic translation initiation factor 2α phosphorylation independent of TLR4. Paclitaxel chemotherapy induced T-cell infiltration in ovarian tumors of the responsive patients; CALR expression in primary ovarian tumors also correlated with patients' survival and patient response to chemotherapy. These findings suggest that the effectiveness of paclitaxel relied upon the activation of antitumor immunity through ICD via TLR4 and highlighted the importance of CALR expression in cancer cells as an indicator of response to paclitaxel chemotherapy in ovarian cancer.

Anti-TSNARE1 IgG plasma levels differ by sex in patients with schizophrenia in a Chinese population

It was recently reported that levels of plasma IgG antibodies against peptide antigens derived from proteins encoded by schizophrenia-associated genes are altered in individuals with schizophrenia treated with antipsychotics. This study aimed to replicate the initial finding in antipsychotic-naïve patients with first-episode schizophrenia and to explore the possible mechanism by which immune tolerance of B cells may be altered in this disease. A total of 408 case-control plasma samples were collected for analysis of circulating IgG antibodies against fragments derived from TCF4, TSNARE1, ZNF804A, TRANK1, ERCC4, DPYD and CD25 using an in-house ELISA. The Mann-Whitney U-test revealed that patients with schizophrenia had a significant change in plasma anti-TSNARE1 and anti-CD25 IgG levels; male patients mainly contributed to the increased levels of anti-TSNARE1 IgG and anti-CD25 IgG. Receiver operating characteristic (ROC) curve analysis revealed that the anti-TSNARE1 IgG assay had an area under the ROC curve of 0.625 with a sensitivity of 15.7% and a specificity of 95.2%. Work on a B-cell model revealed that TRANK1-derived antigen treatments could enhance the proportions of CD83+ cells and apoptotic B cells when compared with TSNARE1-derived antigen and vehicle treatment. We conclude that there is a gender difference in autoimmune responses in schizophrenia and suggest that anti-TSNARE1 IgG may be indicative of schizophrenia in a subgroup of male patients.

[Preparation, characterization and application of rice Qb-SNARE protein OsNPSN11 polyclonal antibody]

Membrane fusion in vesicle trafficking in the cells of eukaryotic organisms is mediated by soluble-N-ethyl- maleimide-sensitive fusion protein attachment protein receptor (SNARE) proteins. OsNPSN11 is a member of Qb-SNARE gene family isolate from rice. The cDNA of OsNPSN11 was subcloned into pET-30a and fusion to the 6 × His tag. Induced by 0.5 mmol/L IPTG for four hours, the recombinant protein was highly expressed in Escherichia coli, which was purified by Ni2+ -NTA His-bind resin affinity chromatography column to be used as an antigen to raise the antibody in New Zealand rabbits. Western blotting analysis showed that the antibody can specifically recognize the expressed antigen and the OsNPSN11 in plasma membrane protein from various rice tissues. This indicated that the antibody can be used for expres-sion analysis in transgenic rice.