Cytolethal Distending Toxin From Campylobacter jejuni Requires the Cytoskeleton for Toxic Activity

Abstract

BackgroundCampylobacter jejuni is one of the major causes of infectious diarrhea worldwide. The distending cytolethal toxin (CDT) of Campylobacter spp. interferes with normal cell cycle progression. This toxic effect is considered a result of DNase activity that produces chromosomal DNA damage. To perform this event, the toxin must be endocytosed and translocated to the nucleus.ObjectivesThe aim of this study was to evaluate the role of the cytoskeleton in the translocation of CDT to the nucleus.MethodsCampylobacter jejuni ATCC 33291 and seven isolates donated from Instituto de Biotecnologia were used in this study. The presence of CDT genes in C. jejuni strains was determined by PCR. To evaluate the effect of CDT, HeLa cells were treated with bacterial lysate, and the damage and morphological changes were analyzed by microscopy, immunofluorescence staining, and flow cytometry. To evaluate the role of the cytoskeleton, HeLa cells were treated with either latrunculin A or by nocodazole and analyzed by microscopy, flow cytometry, and immunoquantification (ELISA).ResultsThe results obtained showed that the eight strains of C. jejuni, including the reference strain, had the ability to produce the toxin. Usage of latrunculin A and nocodazole, two cytoskeletal inhibitors, blocked the toxic effect in cells treated with the toxin. This phenomenon was evident in flow cytometry analysis and immunoquantification of Cdc2-phosphorylated.ConclusionsThis work showed that the cytotoxic activity of the C. jejuni CDT is dependent on its endocytosis. The alteration in the microtubules and actin filaments caused a blockage transit of the toxin, preventing it from reaching the nucleus of the cell, as well as preventing DNA fragmentation and alteration of the cell cycle. The CDT toxin appears to be an important element for the pathogenesis of campylobacteriosis, since all clinical isolates showed the presence of cdtA, cdtB and cdtC genes.

Toxins of Locus of Enterocyte Effacement-Negative Shiga Toxin-Producing Escherichia coli

“…Multiple pathways and interaction partners which are affected by the Cdts are known [ 160 , 163 , 164 , 165 , 166 , 167 ]. Nevertheless, there are only few studies that target the regulation of the toxins.…”

Draft Genome Sequence of Ciprofloxacin and Ceftriaxone Resistant Campylobacter jejuni MM26-781 Assigned to Novel ST Isolated From Common Pigeon in Lithuania

“…The CDT is a virulence factor causing damage in the host's DNA chromosome and cell death. [23][24][25] In addition, the sequence analysis identified 6 virulence genes, ciaB, ceuE, cadF, pldA, motB, and bd1A, responsible for invasion, cell adhesion, flagellar motility, and biofilm formation, respectively. The presence of putative virulence factors in C jejuni MM26-781 strain isolated from common pigeon, including invasion with better colonization, may pose a risk for zoonotic transmission to a human host.…”

IN SILICO OLIGONUCLEOTIDE PRIMER DESIGN FOR Campylobacter jejuni cytolethal distending toxin B GENE AMPLIFICATION

“…jejuni, consists of three subunits namely cdtA, cdtB, and cdtC. Specifically, cdtB is a DNase that has ability to induce DNA double-strand breaks (DSB) in the nucleus causing cell cycle arrest at the G2/M phase and apoptosis (6,7). Breakthrough in molecular biology has brought rapid progress in the field of medicine.…”