Cryptosporidium parvum Subtilisin-Like serine protease (SUB1) is crucial for parasite egress from host cells

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


Despite the severity and global burden of Cryptosporidium infection, treatments are less than optimal, and there is no effective vaccine. Egress from host cells is a key process for the completion of the life cycle of apicomplexan parasites. For Plasmodium species, subtilisin-like serine protease (SUB1) is a key mediator of egress. For Toxoplasma species, calcium-dependent protein kinases (CDPKs) are critical. In this study, we characterized Cryptosporidium SUB1 expression and evaluated its effect using an infection model. We found increased expression between 12 and 20 h after in vitro infection, prior to egress. We induced silencing of SUB1 (ΔSUB1) mRNA using SUB1 single-stranded antisense RNA coupled with human Argonaute 2. Silencing of SUB1 mRNA expression did not affect parasite viability, excystation, or invasion of target cells. However, knockdown led to a 95% decrease in the proportion of released merozoites in vitro (P 0.0001). In contrast, silencing of CDPK5 had no effect on egress. Overall, our results indicate that SUB1 is a key mediator of Cryptosporidium egress and suggest that interruption of the life cycle at this stage may effectively inhibit the propagation of infection.

Original languageEnglish (US)
Article numbere00784-18
JournalInfection and immunity
Issue number5
StatePublished - May 1 2019


  • Calcium-dependent protein kinase
  • Cryptosporidiosis
  • Cryptosporidium parvum
  • Egress
  • Subtilisin

ASJC Scopus subject areas

  • Parasitology
  • Microbiology
  • Immunology
  • Infectious Diseases


Dive into the research topics of 'Cryptosporidium parvum Subtilisin-Like serine protease (SUB1) is crucial for parasite egress from host cells'. Together they form a unique fingerprint.

Cite this