Polyphosphate (polyP), synthesized by polyP kinase (PPK) using the terminal phosphate of ATP as substrate, performs important functions in every living cell. The present work reports on the relationship between polyP metabolism and bioinsecticide production in Bacillus thuringiensis subsp. israelensis (Bti). The ppk gene of Bti was cloned into vector pHT315 and the effect of its overexpression on endotoxin production was determined. Endotoxin production by the recombinant strain was found to be consistently higher than that by the wild type strain and the strain that carried the empty plasmid. The toxicity of the recombinant mutant strain (LC50 5.8±0.6ngml(-1)) against late 2nd instar Culex quinquefasciatus was about 7.7 times higher than that of Bti (LC50 44.9±7ngml(-1)). To our knowledge this is the first reported study which relates polyP metabolism with bioinsecticide biosynthesis.

No abstract

No abstract

DEK locates in the nucleus of the cells or the cytoplasmic granules of neutrophils and plays different roles in cellular processes including NETosis, a suicide mechanism of neutrophils. Here we showed that the interaction of rDEK with CXCR2 leads to NETosis, which could be reduced by the CXCR1/CXCR2 inhibitor reparixin. We found that IL-8, IL-6, IL1-β, MPO, and CitH3 were increased whereas DEK was decreased in the serum of COVID-19 patients. Interestingly, reparixin or anti-DEK antibody reduced the NETosis induced by the serums of patients , suggesting that initial cytokine stimulation may further induce the release of DEK. Our results support the use of reparixin as a potential therapeutic strategy in COVID-19 and suggest that DEK-CXCR2 interaction plays a role in NETosis.

DEK locates in the nucleus of the cells or the cytoplasmic granules of neutrophils and plays different roles in cellular processes including NETosis, a suicide mechanism of neutrophils. Here we showed that the interaction of rDEK with CXCR2 leads to NETosis, which could be reduced by the CXCR1/CXCR2 inhibitor reparixin. We found that IL-8, IL-6, IL1-β, MPO, and CitH3 were increased whereas DEK was decreased in the serum of COVID-19 patients. Interestingly, reparixin or anti-DEK antibody reduced the NETosis induced by the patients’ serum, suggesting that initial cytokine stimulation may further induce the release of DEK. Our results support the use of reparixin as a potential therapeutic strategy in COVID-19 and suggest that DEK-CXCR2 interaction plays a role in NETosis.