RNA-Based Therapy for Cryptosporidium parvum Infection: Proof-of-Concept Studies

Infect Immun. 2022 Jul 21;90(7):e0019622. doi: 10.1128/iai.00196-22. Epub 2022 Jun 1.

Abstract

Cryptosporidium is a leading cause of moderate-to-severe diarrhea in children, which is one of the major causes of death in children under 5 years old. Nitazoxanide is the only FDA-approved treatment for cryptosporidiosis. However, it has limited efficacy in immunosuppressed patients and malnourished children. Therefore, it is urgent to develop novel therapies against this parasite. RNA interference-mediated therapies are emerging as novel approaches for the treatment of infectious diseases. We have developed a novel method to silence essential genes in Cryptosporidium using single-stranded RNA (ssRNA)/Argonaute (Ago) complexes. In this work we conducted proof-of-concept studies to test the anticryptosporidial activity of these complexes by silencing Cryptosporidium parvum nucleoside diphosphate kinase (NDK) using in vitro and in vivo models. We demonstrated that a 3-day treatment with anti-sense NDK ssRNA/Ago decreased parasite burden by ~98% on infected cells. In vivo studies showed that ssRNA/Ago complexes encapsulated in lipid nanoparticles can be delivered onto intestinal epithelial cells of mice treated orally. In addition a cryptosporidiosis-mouse model showed that treatment with NDK ssRNA/Ago complexes reduced oocyst shedding in 4/5 SCID/beige mice during the acute phase of the infection. Our findings highlight the potential use of antisense RNA-based therapy as an alternative approach to cryptosporidiosis treatment.

Keywords: Argonaute; Cryptosporidium; NDK; cryptosporidiosis; gene silencing; siRNA.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cryptosporidiosis* / drug therapy
  • Cryptosporidiosis* / parasitology
  • Cryptosporidium parvum* / genetics
  • Cryptosporidium* / genetics
  • Liposomes
  • Mice
  • Mice, SCID
  • Nanoparticles
  • RNA

Substances

  • Lipid Nanoparticles
  • Liposomes
  • RNA