In vitro knockdown of TsDNase II-7 suppresses Trichinella spiralis invasion into the host's intestinal epithelial cells

PLoS Negl Trop Dis. 2023 Jun 8;17(6):e0011323. doi: 10.1371/journal.pntd.0011323. eCollection 2023 Jun.

Abstract

Trichinella spiralis (T. spiralis) adult-specific deoxyribonuclease II-7 (TsDNase II-7), a member of the DNase II-like nuclease family with no DNase II activity, was identified in the excretory-secretory (ES) products of adult worms (AWs). However, its biological functions are still unclear. Our previous study revealed that TsDNase II-7 is located around the infection site in the intestinal tissue, speculating that it was involved in the T. spiralis invasion of host intestinal epithelial cells (IECs). This study aimed to use RNA interference to verify our speculation that TsDNase II-7 in 3-day old adult T. spiralis (Ad3) plays a role in intestinal invasion. TsDNase II-7-specific small interfering RNAs (siRNAs) were delivered into muscle larvae (MLs) to knockdown TsDNase II-7 expression by electroporation. Twenty-four hours later, the MLs transfected with 2 μM siRNA-841 exhibited decreased in TsDNase II-7 transcription and expression as compared to the control MLs. The knockdown of TsDNase II-7 expression did not affect ML viability, and the low expression of TsDNase II-7 still maintained in Ad3 recovered from TsDNase II-7-RNAi-ML infected mice, resulting in a weakened ability of Ad3 to invade intestinal epithelial cells (IECs). These results indicated that knockdown of TsDNase II-7 gene expression via RNA interference (RNAi) suppressed adult worm invasion and confirmed that TsDNase II-7 plays a crucial role during the intestinal phase of T. spiralis infections, which provided new candidate for vaccine development of T. spiralis.

MeSH terms

  • Animals
  • Endodeoxyribonucleases* / genetics
  • Epithelial Cells / metabolism
  • Helminth Proteins* / genetics
  • Intestines
  • Larva / physiology
  • Mice
  • Mice, Inbred BALB C
  • RNA, Double-Stranded
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism
  • Trichinella spiralis* / genetics
  • Trichinellosis* / metabolism
  • Trichinellosis* / parasitology

Substances

  • deoxyribonuclease II
  • Helminth Proteins
  • RNA, Double-Stranded
  • RNA, Small Interfering
  • DNase II-7 protein, Trichinella spiralis
  • Endodeoxyribonucleases

Grants and funding

This study was supported by grants of The National Key Research and Development Program of China No. 2021YFC2600202 (Xiaolei Liu), The National Natural Science Foundation of China No. NSFC32230104 (Mingyuan Liu), and Science and Technology Development Planning Project of Jilin Province No. YDZJ202101ZYTS053, No. 20220101294JC, No. 20220508052RC (Jing Ding). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.