Metastasis is one of the main causes of failure in the treatment of triple-negative breast cancer (TNBC). Immunotherapy brings hope and opportunity to solve this challenge, while its clinical applications are greatly inhibited by the tumor immunosuppressive environment. Here, an intelligent biomimetic nanoplatform was designed based on dendritic large-pore mesoporous silica nanoparticles (DLMSNs) for suppressing metastatic TNBC by combining photothermal ablation and immune remodeling. Taking advantage of the ordered large-pore structure and easily chemically modified property of DLMSNs, the copper sulfide (CuS) nanoparticles with high photothermal conversion efficiency were in situ deposited inside the large pores of DLMSNs, and the immune adjuvant resiquimod (R848) was loaded controllably. A homogenous cancer cell membrane was coated on the surfaces of these DLMSNs, followed by conjugation with the anti-PD-1 peptide AUNP-12 through a polyethylene glycol linker with an acid-labile benzoic-imine bond. The thus-obtained AM@DLMSN@CuS/R848 was applied to holistically treat metastatic TNBC in vitro and in vivo. The data showed that AM@DLMSN@CuS/R848 had a high TNBC-targeting ability and induced efficient photothermal ablation on primary TNBC tumors under 980 nm laser irradiation. Tumor antigens thus generated and increasingly released R848 by response to the photothermal effect, combined with AUNP-12 detached from AM@DLMSN@CuS/R848 in the weakly acidic tumor microenvironment, synergistically exerted tumor vaccination, and T lymphocyte activation functions on immune remodeling to prevent TNBC recurrence and metastasis. Taken together, this study provides an intelligent biomimetic nanoplatform to enhance therapeutic outcomes in metastatic TNBC.

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Pseudomonas aeruginosa is a prevalent opportunistic pathogen that causes fatal infections in immunocompromised individuals. Quorum sensing (QS) is a cell-to-cell communication process that controls virulence gene expression and biofilm formation in P. aeruginosa. Here, the QS systems and the relevant virulence traits in clinical P. aeruginosa isolates were characterized. Eleven out of the ninety-four P. aeruginosa isolates exhibited a biofilm-deficient phenotype. Two biofilm-deficient isolates, one from blood and the one from pleural effusion, appeared to carry a same mutation in lasR. These two isolates differed in the ability to produce QS-regulated virulence factors, but contained the same functionally deficient LasR with the truncated C-terminal domains and belonged to the same multilocus sequence type (ST227). Chromosomal lasR complementation in these lasR mutants verified that lasR inactivation was the sole cause of las deficiency. LasR was not absolutely required for rhl signal in these lasR mutants, suggesting the presence of lasR-independent QS systems. We provided evidence that the virulence gene expression are not regulated in the same manner in these isolates. These results support the hypothesis that conventional QS hierarchy can be smashed by naturally occurring lasR mutation in clinical P. aeruginosa isolates and that complex QS hierarchy may play a role in maintaining infection of this opportunistic pathogen.

BackgroundBilirubin-induced neurological dysfunction (BIND), a severe complication of extreme neonatal hyperbilirubinemia, could develop into permanent neurodevelopmental impairments. Several studies have demonstrated that inflammation and nerve cell death play important roles in bilirubin-induced neurotoxicity; however, the underlying mechanism remains unidentified.MethodsThe present study was intended to investigate whether pyroptosis, a highly inflammatory form of programmed cell death, participated in the bilirubin-mediated toxicity on cultured rat cortical astrocytes. Further, VX-765, a potent and selective competitive drug, was used to inhibit the activation of caspase-1. The effects of VX-765 on astrocytes treated with bilirubin, including the cell viability, morphological changes of the cell membrane and nucleus, and the production of pro-inflammation cytokines, were observed.ResultsStimulation of the astrocytes with unconjugated bilirubin (UCB) at the conditions mimicking those of jaundiced newborns significantly increased the activation of caspase-1. Further, caspase-1 activation was inhibited by treatment with VX-765. Compared with UCB-treated astrocytes, the relative cell viability of VX-765-pretreated astrocytes was improved; meanwhile, the formation of plasma membrane pores was prevented, as measured by lactate dehydrogenase release, trypan blue staining, and ethidium bromide (EtBr) uptake. Moreover, DNA fragmentation was partly attenuated and the release of IL-1β and IL-18 was apparently decreased.ConclusionPyroptosis is involved in the process of UCB-induced rat cortical astrocytes’ injury in vitro and may be the missing link of cell death and inflammatory response exacerbating UCB-related neurotoxicity. More importantly, the depression of caspase-1 activation, the core link of pyroptosis, attenuated UCB-induced cellular dysfunction and cytokine release, which might shed light on a new therapeutic approach to BIND.