Evaluation of DNA encoding acidic ribosomal protein P2 of Cryptosporidium parvum as a potential vaccine candidate for cryptosporidiosis

• Type of Material: Article
• Authors: Alvaro Benitez, Emory University; Jeffrey W. Priest, Centers for Disease Control & Prevention; Humphrey N. Ehigiator, Veterans Affairs Medical Center, Atlanta, GA; Nina McNair, Emory University; Jan R Mead, Emory University
• Language: English
• Date: 2011-11-15
• Publisher: Elsevier: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2011 Elsevier Inc. All rights reserved.
• License: Creative Commons Attribution-NonCommerical-NoDerivs 3.0 Unported
• Final Published Version (URL): http://dx.doi.org/10.1016%2Fj.vaccine.2011.09.094
• Title of Journal or Parent Work: Vaccine
• ISSN: 0264-410X
• Volume: 29
• Issue: 49
• Start Page: 9239
• End Page: 9245
• Grant/Funding Information: This work was supported, in part, by Grant RO1-AI-36680 from the National Institutes of Health, and Medical Research Service, U.S. Department of Veterans Affairs.
• Keywords: acidic ribosomal proteins; Cryptosporidium; P2; DNA vaccine; antigen
• Research Categories: Health Sciences, Immunology

Abstract

The Cryptosporidium parvum acidic ribosomal protein P2 (CpP2) is an important immunodominant marker in C. parvum infection. In this study, the CpP2 antigen was evaluated as a vaccine candidate using a DNA vaccine model in adult C57BL/6 IL-12 knockout (KO) mice, which are susceptible to C. parvum infection. Our data show that subcutaneous immunization in the ear with DNA encoding CpP2 (CpP2-DNA) cloned into the pUMVC4b vector induced a significant anti-CpP2 IgG antibody response that was predominantly of the IgG1 isotype. Compared to control KO mice immunized with plasmid alone, CpP2-immunized mice demonstrated specific in vitro spleen cell proliferation as well as enhanced IFN-γ production to recombinant CpP2. Further, parasite loads in CpP2 DNA-immunized mice were compared to control mice challenged with C. parvum oocysts. Although a trend in reduction of infection was observed in the CpP2 DNA-immunized mice, differences between groups were not statistically significant. These results suggest that a DNA vaccine encoding the C. parvum P2 antigen is able to provide an effective means of eliciting humoral and cellular responses and has the potential to generate protective immunity against C. parvum infection but may require using alternative vectors or adjuvant to generate a more potent and balanced response.