A cysteine protease inhibitor rescues mice from a lethal Cryptosporidium parvum infection

Authors

Momar Ndao, National Reference Centre for Parasitology, Research Institute of the McGill University Health CenterFollow
Milli Nath-Chowdhury, National Reference Centre for Parasitology, Research Institute of the McGill University Health Center
Mohammed Sajid, University of California, San Francisco, Leiden University Medical Center, Leiden, Netherlands
Victoria Marcus, McGill University Health Centre, Montreal General Hospital, Montreal, Canada
Susan T. Mashiyama, University of California, San Francisco
Judy Sakanari, University of California, San Francisco
Erik Chow, University of California, San Francisco
Zachary Mackey, University of California, San Francisco
Kirkwood M. Land, University of the Pacific, University of California, San FranciscoFollow
Matthew P. Jacobson, University of California, San Francisco
Chakrapani Kalyanaraman, University of California, San Francisco
James H. McKerrow, University of California, San Francisco
Michael J. Arrowwood, Centers for Disease Control and Prevention, Atlanta, Georgia
Conor R. Caffrey, University of California, San Francisco

ORCID

Kirkwood M. Land: 0000-0001-5951-9630

Document Type

Article

Publication Title

Antimicrobial Agents and Chemotherapy

Department

Biological Sciences

ISSN

Print: 0066-4804, Electronic: 1098-6596

Volume

57

Issue

12

DOI

10.1128/AAC.00734-13

First Page

6063

Last Page

6073

Publication Date

12-1-2013

Abstract

Cryptosporidiosis, caused by the protozoan parasite Cryptosporidium parvum, can stunt infant growth and can be lethal in immunocompromised individuals. The most widely used drugs for treating cryptosporidiosis are nitazoxanide and paromomycin, although both exhibit limited efficacy. To investigate an alternative approach to therapy, we demonstrate that the clan CA cysteine protease inhibitor N-methyl piperazine-Phe-homoPhe-vinylsulfone phenyl (K11777) inhibits C. parvum growth in mammalian cell lines in a concentration-dependent manner. Further, using the C57BL/6 gamma interferon receptor knockout (IFN-γR-KO) mouse model, which is highly susceptible to C. parvum, oral or intraperitoneal treatment with K11777 for 10 days rescued mice from otherwise lethal infections. Histologic examination of untreated mice showed intestinal inflammation, villous blunting, and abundant intracellular parasite stages. In contrast, K11777-treated mice (210 mg/kg of body weight/day) showed only minimal inflammation and no epithelial changes. Three putative protease targets (termed cryptopains 1 to 3, or CpaCATL-1, -2, and -3) were identified in the C. parvum genome, but only two are transcribed in infected mammals. A homology model predicted that K11777 would bind to cryptopain 1. Recombinant enzymatically active cryptopain 1 was successfully targeted by K11777 in a competition assay with a labeled active-site-directed probe. K11777 exhibited no toxicity in vitro and in vivo, and surviving animals remained free of parasites 3 weeks after treatment. The discovery that a cysteine protease inhibitor provides potent anticryptosporidial activity in an animal model of infection encourages the investigation and development of this biocide class as a new, and urgently needed, chemotherapy for cryptosporidiosis.

Recommended Citation

Ndao, M., Nath-Chowdhury, M., Sajid, M., Marcus, V., Mashiyama, S. T., Sakanari, J., Chow, E., Mackey, Z., Land, K. M., Jacobson, M. P., Kalyanaraman, C., McKerrow, J. H., Arrowwood, M. J., & Caffrey, C. R. (2013). A cysteine protease inhibitor rescues mice from a lethal Cryptosporidium parvum infection. Antimicrobial Agents and Chemotherapy, 57(12), 6063–6073. DOI: 10.1128/AAC.00734-13
https://scholarlycommons.pacific.edu/cop-facarticles/797