Augmented antitumor immune responses of HER2-targeted pyroptotic induction by long-lasting recombinant immunopyroptotins.

Pyroptosis is a well-documented form of programmed cell death caused by the gasdermin-driven perforation of cell membranes. Selective induction of pyroptosis in tumor cells represents a promising antitumor strategy to enhance the efficacy of immunotherapy. In this study, we established a recombinant protein-based immunopyroptotin strategy that led to the intratumoral induction of pyroptosis for HER2-directed therapy. Long-lasting immunopyroptotins were constructed by sequentially fusing the humanized anti-HER2 single-chain antibody P1h3, albumin-binding peptide (ABD035 or dAb7h8), cathepsin B-cleavable peptide B2, endosome-disruptive peptide E5C3, and active pyroptotic effector gasdermin D-N fragment (GN). After purification, we evaluated the cytotoxicity and antitumor immune responses primarily induced by the immunopyroptotins in HER2-overexpressing breast cancer cells. The resulting ABD035-immunoGN and dAb7h8-immunoGN showed improved in vitro cytotoxicity in HER2-overexpressing cancer cells compared with that in the immunotBid that we previously generated to induce tumor cell apoptosis. The binding of long-lasting immunopyroptotins to albumin increased the half-life by approximately 7-fold in nude mice. The enhanced antitumor efficacy of long-lasting immunopyroptotins was confirmed in both N87 tumor-bearing T cell-deficient mice and 4T1-hHER2 bilateral tumor-bearing immunocompetent mice. Immunopyroptotin treatment elicited systemic antitumor immune responses involving CD8+ T cells and mature dendritic cells and upregulated the expression of proinflammatory cytokines, leading to sustained remission of non-injected distant tumors. This study extends the repertoire of antibody-based therapeutics through the tumor-targeted delivery of a constitutively active pore-forming gasdermin-N fragment, which shows great potential for pyroptosis-based antitumor therapy.

[Current therapy progress on the acute patellar dislocation].

The treatment of acute patellar dislocation remains a topic of debate among orthopedic surgeons. While conservative treatment has traditionally been favored, recent studies have highlighted the high redislocation rate, prompting a reevaluation of treatment strategies. Current approaches recognize the importance of addressing not only the knee joint but also associated factors contributing to instability. Surgical intervention, particularly focusing on restoring patellar stability through medial patella-femoral ligament (MPFL), repair or reconstruction, has gained popularity. MPFL reconstruction can provide long-term stability of the patella, but further research is needed. When acute patellar dislocation is associated with abnormal bony factors, multiple surgical modalities are often required, with the goal of restoring the normal trajectory of the patella, maintaining the stability of the patellofemoral joint, and optimizing knee joint function. This review provides an overview of advances in the treatment of acute patellar dislocation and related problems, so as to provide reference for clinicians.

IFI16 Positively Regulates RIG-I-Mediated Type I Interferon Production in a STING-Independent Manner.

Previous studies have shown that interferon gene-stimulating protein (STING) is essential for IFN-γ-inducible protein 16 (IFI16) as the DNA sensor and RNA sensor to induce transcription of type I interferon (IFN-I) and is essential for IFI16 to synergize with DNA sensor GMP-AMP (cGAMP) synthase (cGAS) in induction of IFN-I transcription. While other and our previous studies have shown that IFI16 enhanced retinoic acid-inducible gene I (RIG-I)-, which was an RNA sensor, and mitochondrial antiviral signaling (MAVS)-, which was the adaptor protein of RIG-I, induced production of IFN-I, so we wonder whether IFI16 regulates the signal pathway of RNA-RIG-I-MAVS-IFN-I in a STING-dependent manner. We used HEK 293T cells, which did not express endogenous STING and were unable to mount an innate immune response upon DNA transfection and found that IFI16 could enhance RIG-I- and MAVS-mediated induction of IFN-I in a STING-independent way. Furthermore, we found that upregulation of the expression of NF-kappa-B essential modulator (NEMO) by IFI16 was not the mechanism that IFI16 regulated the induction of IFN-I. In conclusion, we found that IFI16 regulated the signal pathway of RNA-RIG-I-MAVS-IFN-I in a STING-independent manner.

Modular Hydrogel Vaccine for Programmable and Coordinate Elicitation of Cancer Immunotherapy.

Immunotherapy holds great promise for the treatment of malignant cancer. However, the lack of sufficient tumor neoantigens and incomplete dendritic cell (DC) maturation compromise the efficacy of immunotherapy. Here, a modular hydrogel-based vaccine capable of eliciting a powerful and sustained immune response is developed. Briefly, CCL21a and ExoGM-CSF+Ce6 (tumor cell-derived exosomes with granulocyte-macrophage colony-stimulating factor (GM-CSF) mRNA encapsulated inside and sonosensitizer chlorin e6 (Ce6) incorporated in the surface) are mixed with nanoclay and gelatin methacryloyl, forming the hydrogel designated as CCL21a/ExoGM-CSF+Ce6 @nanoGel. The engineered hydrogel releases CCL21a and GM-CSF with a time gap. The earlier released CCL21a diverts the tumor-draining lymph node (TdLN) metastatic tumor cells to the hydrogel. Consequently, the trapped tumor cells in the hydrogel, in turn, engulf the Ce6-containing exosomes and thus are eradicated by sonodynamic therapy (SDT), serving as the antigen source. Later, together with the remnant CCL21a, GM-CSF produced by cells engulfing ExoGM-CSF+Ce6 continuously recruits and provokes DCs. With the two programmed modules, the engineered modular hydrogel vaccine efficiently inhibits tumor growth and metastasis via diverting TdLN metastatic cancer to hydrogel, killing the trapped tumor cells, and eliciting prolonged and powerful immunotherapy in an orchestrated manner. The strategy would open an avenue for cancer immunotherapy.

Efficient Delivery of GSDMD-N mRNA by Engineered Extracellular Vesicles Induces Pyroptosis for Enhanced Immunotherapy.

Pyroptosis is a newly discovered inflammatory form of programmed cell death, which promotes systemic immune response in cancer immunotherapy. GSDMD is one of the key molecules executing pyroptosis, while therapeutical delivery of GSDMD to tumor cells is of great challenge. In this study, an extracellular vesicles-based GSDMD-N mRNA delivery system (namely EVTx ) is developed for enhanced cancer immunotherapy, with GSDMD-N mRNA encapsulated inside, Ce6 (Chlorin e6 (Ce6), a hydrophilic sensitizer) incorporated into extracellular vesicular membrane, and HER2 antibody displayed onto the surface. Briefly, GSDMD-N mRNA is translationally repressed in donor cells by optimized puromycin, ensuring the cell viability and facilitating the mRNA encapsulation into extracellular vesicles. When targeted and delivered into HER2+ breast cancer cells by the engineered extracellular vesicles, the translational repression is unleashed in the recipient cells as the puromycin is diluted and additionally inactivated by sonodynamic treatment as the extracellular vesicles are armed with Ce6, allowing GSDMD-N translation and pyroptosis induction. In addition, sonodynamic treatment also induces cell death in the recipient cells. In the SKBR3- and HER2 transfected 4T1- inoculated breast tumor mouse models, the engineered EVTx efficiently induces a powerful tumor immune response and suppressed tumor growth, providing a nanoplatform for cancer immunotherapy.

A Novel Polyphenol Oxidoreductase OhLac from Ochrobactrum sp. J10 for Lignin Degradation.

Identifying the enzymes involved in lignin degradation by bacteria is important in studying lignin valorization to produce renewable chemical products. In this paper, the catalytic oxidation of lignin by a novel multi-copper polyphenol oxidoreductase (OhLac) from the lignin degrader Ochrobactrum sp. J10 was explored. Following its expression, reconstitution, and purification, a recombinant enzyme OhLac was obtained. The OhLac enzyme was characterized kinetically against a range of substrates, including ABTS, guaiacol, and 2,6-DMP. Moreover, the effects of pH, temperature, and Cu2+ on OhLac activity and stability were determined. Gas chromatography-mass spectrometer (GC-MS) results indicated that the ß-aryl ether lignin model compound guaiacylglycerol-ß-guaiacyl ether (GGE) was oxidized by OhLac to generate guaiacol and vanillic acid. Molecular docking analysis of GGE and OhLac was then used to examine the significant amino residues and hydrogen bonding sites in the substrate-enzyme interaction. Altogether, we were able to investigate the mechanisms involved in lignin degradation. The breakdown of the lignocellulose materials wheat straw, corn stalk, and switchgrass by the recombinant OhLac was observed over 3 days, and the degradation results revealed that OhLac plays a key role in lignin degradation.