No abstract

BackgroundNeutrophils-linked premetastatic niche plays a key role in tumor metastasis, but not much is known about the heterogeneity and diverse role of neutrophils in niche formation. Our study focuses on the existence and biological function of a rarely delved subset of neutrophils, named as tumor-associated aged neutrophils (Naged, CXCR4+CD62Llow), involved in premetastatic niche formation during breast cancer metastasis.MethodsWe explored the distributions of Naged in 206 patients and mice models (4T1 and MMTV-PyMT) by flow cytometry. The ability of Naged to form neutrophil extracellular traps (NETs) and promote tumor metastasis in patients and mice was determined by polychromatic immunohistochemistry, scanning electron microscopy and real-time video detection. Furthermore, the differences among tumor-associated Naged, Non-Naged and inflammation-associated aged neutrophils were compared by transcriptome, the biological characteristics of Naged were comprehensively analyzed from the perspectives of morphology, the metabolic capacity and mitochondrial function were investigated by Seahorse, co-immunoprecipitation (Co-IP), chromatin immunoprecipitation (ChIP) and transmission electron microscopy (TEM). Finally, 120 patients’ sample were applied to confirm the acceleration of Naged formation through secreted NAMPT, and the importance of blocking this pathway in mice was evaluated.ResultsWe find that Naged accumulate in the lung premetastatic niche at early stage of breast tumorigenesis in multiple mice models and also exist in peripheral blood and metastatic lung of patients with breast cancer. Naged exhibit distinct cell marker and morphological feature of oversegmented nuclei. Further transcriptome reveals that Naged are completely different from those of Non-Aged or inflammation-associated aged neutrophils and illustrates that the key transcription factor SIRT1 in Naged is the core to maintain their lifespan via mitophagy for their function. The responsible mechanism is that SIRT1 can induce the opening of mitochondrial permeability transition pore channels to release mitochondrial DNA and lead to the mitochondria-dependent vital NETs formation, rather than traditional Cit-Histone H3 dependent fatal-NETs. Further mechanically investigation found tumor derived NAMPT could induce Naged formation. Additionally, therapeutic interventions of Naged and its formation-linked pathways could effectively decrease breast cancer lung metastasis.ConclusionsNaged exerts a vital role in breast cancer lung metastasis, and strategies targeting SIRT1-Naged-NETs axis show promise for translational application.

Background:The circular replication-associated protein (Rep)-encoding singlestranded (CRESS) DNA virus emergence in diverse host has been associated with severe disease. Porcine circovirus-like virus (Po-Circo-like [PCL] virus) is a CRESS DNA virus, the prevalence and pathogenicity of which are rarely studied. Methods:We obtained two blood samples, four faecal samples, and two intestinal samples from a pig farm suffered from diarrheal disease in the delivery room in September 2020 and attempted to isolate and identify a causative pathogen. Subsequently, only PCL virus was positive, and qRT-PCR was designed to detect the loading titre of PCL virus. We then initiated a heightened surveillance program on the pathogenicity and epidemiology of PCL virus.Results: Six PCL virus strains, with severe diarrhoea and haemorrhagic enteritis, have been found in six different pig farms in Guangdong province, China. A multiple sequence alignment of these PCL viruses and bovine circovirus-like virus/CH showed a similarity of 92.5-94.8% for the Rep protein, indicating these PCL viruses are highly homologous to Bo-Circo-like virus associated with calf diarrhoea. There were striking similarities between the PCL virus and bovine circovirus-like virus outbreaks in aetiological settings and Genomic sequence. We found that 11.2% (20/178) of diarrhoea samples and 13.3% (6/45) of pig farms were positive for PCL virus, suggesting that PCL virus may have spread widely in Pig farms. Moreover, this article underscores the risk of PCL virus spilling over and adapting to new species.Conclusions: Porcine circovirus-like virus was found to be associated with porcine diarrheal disease in China. INTRODUCTIONThe circular replication-associated protein (Rep)-encoding singlestranded (CRESS) DNA virus possess small genomes, prevalence, and affinity for rolling-circle replication (Zhao et al., 2019). These are widely found in diverse environments, plant samples, dragonflies and damselflies, mosquitoes, rats, bats, duck, cattle, pigs, dogs, human,This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Campylobacter is a zoonotic pathogen that causes foodborne diarrheal illness globally. To better understand health risks in Southeastern China, Campylobacter spp. were surveyed in humans and representative poultry products over 3 years. One hundred and ninety-five representative isolates (n = 148, Campylobacter jejuni; n = 45, Campylobacter coli; n = 2 Campylobacter hyointestinalis) were examined for genetic relatedness and antimicrobial susceptibility. Nearly all Campylobacter isolates (99.0%, 193/195) were resistant to at least one class of antimicrobials, and 45.6% (89/195) of the isolates exhibited multidrug resistance. Genotypic analysis revealed high diversity among tested strains. Multilocus sequence typing (MLST) displayed 120 sequence types (STs) including 42 novel STs being added to the PubMLST international database. Sixty-two STs belonged to 16 previously characterized clonal complexes (CCs), of which CC-21, CC-45, CC-464, CC-574, CC-353, and CC-828 were most frequently identified. In addition, pulsed-field gel electrophoresis (PFGE) fingerprinting resulted in 66 PFGE SmaI patterns among the 125 isolates, with eight patterns shared between human and poultry sources. Subtyping data did not correlate with antimicrobial resistance phenotypes. Taken together, this large-scale surveillance study highlights high antimicrobial resistance and molecular features of Campylobacter isolates in Southeastern China.