Pore-forming alpha-hemolysin efficiently improves the immunogenicity and protective efficacy of protein antigens.

Highly immunogenic exotoxins are used as carrier proteins because they efficiently improve the immunogenicity of polysaccharides. However, their efficiency with protein antigens remains unclear. In the current study, the candidate antigen PA0833 from Pseudomonas aeruginosa was fused to the α-hemolysin mutant HlaH35A from Staphylococcus aureus to form a HlaH35A-PA0833 fusion protein (HPF). Immunization with HPF resulted in increased PA0833-specific antibody titers, higher protective efficacy, and decreased bacterial burden and pro-inflammatory cytokine secretion compared with PA0833 immunization alone. Using fluorescently labeled antigens to track antigen uptake and delivery, we found that HlaH35A fusion significantly improved antigen uptake in injected muscles and antigen delivery to draining lymph nodes. Both in vivo and in vitro studies demonstrated that the increased antigen uptake after immunization with HPF was mainly due to monocyte- and macrophage-dependent macropinocytosis, which was probably the result of HPF binding to ADAM10, the Hla host receptor. Furthermore, a transcriptome analysis showed that several immune signaling pathways were activated by HPF, shedding light on the mechanism whereby HlaH35A fusion improves immunogenicity. Finally, the improvement in immunogenicity by HlaH35A fusion was also confirmed with two other antigens, GlnH from Klebsiella pneumoniae and the model antigen OVA, indicating that HlaH35A could serve as a universal carrier protein to improve the immunogenicity of protein antigens.

Co-delivery of cisplatin and oleanolic acid by silica nanoparticles-enhanced apoptosis and reverse multidrug resistance in lung cancer.

Multidrug resistance (MDR) of chemotherapy is one of the significant concerns in cancer therapy. Here in our study, cisplatin (DDP) and oleanolic acid (OA) were co-loaded in mesoporous silica nanoparticles (Nsi) to construct DDP/OA-Nsi and solve the DDP-resistance in lung cancer therapy. The cytotoxicity and apoptosis assays demonstrated that in DDP-resistant A549/DDP cells, the cytotoxicity of DDP/OA-Nsi was significantly higher than that of free DDP or DDP single delivery system (DDP-Nsi). The intracellular drug accumulation study revealed that the intracellular DDP concentration in the DDP/OA-Nsi group was also higher than that in free DDP and DDP-Nsi groups. In the A549/DDP xenograft tumor model, DDP/OA-Nsi showed the best anticancer effect. In summary, DDP/OA-Nsi was a promising drug delivery system to solve MDR in lung cancer therapy.

[Study on the HPLC fingerprint of toad skin from different regions].

OBJECTIVE: To study the HPLC fingerprint of toad skin and provide a reliable method for quality control and identification. METHODS: It used HPLC for detection and computer aided similarity evaluation system for processing and analysing HPLC fingerprint. RESULTS: The common pattern of HPLC fingerprint of toad skin was astablished, 29 peaks were identified as the characteristic fingerprints, in which 9 peaks corresponded to 9 bufogenins. (2) Each samples' similarity of relative retention time was all above 0.99, but the similarity of relative peak areas was low. CONCLUSION: (1) The method is accurate and with good reproducibility. The fingerprints can be used for the identification and quality control of toad skin. (2) The toad skin from different regions are stable in composition, but the contents of the components are different.

Burn-induced apoptosis of cardiomyocytes is survivin dependent and regulated by PI3K/Akt, p38 MAPK and ERK pathways.

Survivin belongs to the family of genes known as inhibitors of apoptosis, and although it has been implicated in the prevention of cancer, its potential role in burn-induced cardiac injury is unknown. In this study, we investigated the effects of survivin blockade on burn-induced cardiac apoptosis. Using a standardized Sprague-Dawley rat model of third-degree burn injury over 40% of total body surface area, apoptosis was measured in vivo followed by in vitro assessment of burn serum-stimulated cardiomyocytes. Based on the Western blot analyses, real-time PCR, ELISA, and TUNEL, apoptosis and caspase activation both in vivo and in vitro were significantly increased after severe burn injury, while survivin expression was increased (up to 2.90-fold) during the early stage of burn injury and was almost completely abolished 8 h after the burn. Survivin-deficient cardiomyocytes, as well as hearts from rats treated with the survivin inhibitor YM155, exhibited increased caspase-3 protein and mRNA expression and apoptosis ratio at different times after the burn. Furthermore, inhibition of ERK, phosphoinositol 3-kinase contributed the burn serum-induced increase in apoptosis and caspase-3 protein expression, and decreased survivin expression, whereas burn serum-induced increase in apoptosis was attenuated by P38 mitogen-activated protein kinase inhibition. These data identify survivin as a critical anti-apoptotic regulator of cardiomyocytes after burn injury. ERK, P38 MAPK and PI3K were found to be upstream regulators of survivin.