Global transcriptional profiling of Burkholderia pseudomallei under salt stress reveals differential effects on the Bsa type III secretion system

BACKGROUND: Burkholderia pseudomallei is the causative agent of melioidosis where the highest reported incidence world wide is in the Northeast of Thailand, where saline soil and water are prevalent. Moreover, recent reports indicate a potential pathogenic role for B. pseudomallei in cystic fibrosis lung disease, where an increased sodium chloride (NaCl) concentration in airway surface liquid has been proposed. These observations raise the possibility that high salinity may represent a favorable niche for B. pseudomallei. We therefore investigated the global transcriptional response of B. pseudomallei to increased salinity using microarray analysis. RESULTS: Transcriptome analysis of B. pseudomallei under salt stress revealed several genes significantly up-regulated in the presence of 320 mM NaCl including genes associated with the bsa-derived Type III secretion system (T3SS). Microarray data were verified by reverse transcriptase-polymerase chain reactions (RT-PCR). Western blot analysis confirmed the increased expression and secretion of the invasion-associated type III secreted proteins BipD and BopE in B. pseudomallei cultures at 170 and 320 mM NaCl relative to salt-free medium. Furthermore, salt-treated B. pseudomallei exhibited greater invasion efficiency into the lung epithelial cell line A549 in a manner partly dependent on a functional Bsa system. CONCLUSIONS: B. pseudomallei responds to salt stress by modulating the transcription of a relatively small set of genes, among which is the bsa locus associated with invasion and virulence. Expression and secretion of Bsa-secreted proteins was elevated in the presence of exogenous salt and the invasion efficiency was enhanced. Our data indicate that salinity has the potential to influence the virulence of B. pseudomallei

MOESM1 of Increased ETV4 expression correlates with estrogen-enhanced proliferation and invasiveness of cholangiocarcinoma cells

Additional file 1: Table S1. Primer sequences for gene expression analysis of ERs. Figure S1. Relative expression of ERs in CCA cells compared to MCF-7 and MDA-MB-231 breast cancer cells: (A) ER-ι; (B) ER-β. Figure S2. Efficacy of shETV4 plasmid transfection and knockdown: (A) Transfection efficacy determined by expression of GFP and visualized under fluorescence inverted microscope with 40x original magnification, cell type and conditions were labelled in the picture; (B) Knockdown efficacy in transfected cells determined by RT-real time PCR and compared to parental cell mRNA

Transcription profiling of Burkholderia pseudomallei under salt stress and the effect on a type III secretion system

Effect of NaCl of gene expression in Burkholderia pseudomallei at two time points

Potent programmable antiviral against dengue virus in primary human cells by Cas13b RNP with short spacer and delivery by VLP

With sequencing as a standard frontline protocol to identify emerging viruses such Zika virus and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), direct utilization of sequence data to program antivirals against the viruses could accelerate drug development to treat their infections. CRISPR-Cas effectors are promising candidates that could be programmed to inactivate viral genetic material based on sequence data, but several challenges such as delivery and design of effective CRISPR RNA (crRNA) need to be addressed to realize practical use. Here, we showed that virus-like particle (VLP) could deliver PspCas13b-crRNA ribonucleoprotein (RNP) in nanomolar range to efficiently suppress dengue virus infection in primary human target cells. Shortening spacer length could significantly enhance RNA-targeting efficiency of PspCas13b in mammalian cells compared to the natural length of 30 nucleotides without compromising multiplex targeting by a crRNA array. Our results demonstrate the potentials of applying PspCas13b RNP to suppress RNA virus infection, with implications in targeting host RNA as well