This Article Full Text Full Text (PDF) Other Versions of this Article: IAI.00851-06v1 74/12/6785    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Konjufca, V. Articles by Curtiss, R. Search for Related Content PubMed PubMed Citation Articles by Konjufca, V. Articles by Curtiss, R., III

A Recombinant Attenuated Salmonella enterica Serovar Typhimurium Vaccine Encoding Eimeria acervulina Antigen Offers Protection against E. acervulina Challenge

Department of Biology, Washington University, St. Louis, Missouri 63130,¹ Animal Parasitic Diseases Laboratory, Agricultural Research Service, Building 1040, BARC-EAST, Beltsville, Maryland 20705,² Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, Arizona 85287³

Received 26 May 2006/ Returned for modification 10 July 2006/ Accepted 5 September 2006

Coccidiosis is a ubiquitous disease caused by intestinal protozoan parasites belonging to several distinct species of the genus Eimeria. Cell-mediated immunity (CMI) is critically important for protection against Eimeria; thus, our approach utilizes the bacterial type III secretion system (TTSS) to deliver an antigen directly into the cell cytoplasm of the immunized host and into the major histocompatibility complex class I antigen-processing pathway for induction of CMI and antigen-specific cytotoxic T-lymphocyte responses in particular. To accomplish this goal, Eimeria genes encoding the sporozoite antigen EASZ240 and the merozoite antigen EAMZ250 were fused to the Salmonella enterica serovar Typhimurium effector protein gene sptP in the parental pYA3653 vector, yielding pYA3657 and pYA3658, respectively. SptP protein is secreted by the TTSS of Salmonella and translocated into the cytoplasm of immunized host cells. The host strain chromosomal copy of the sptP gene was deleted and replaced by a reporter gene, xylE. The newly constructed vectors pYA3657 and pYA3658 were introduced into host strain 8879 (phoP233 sptP1033::xylE asdA16). This strain is an attenuated derivative of the highly virulent strain UK-1. When strain 8879(pYA3653) as the vector control and strain 8879 harboring pYA3657 or pYA3658 were used to orally immunize day-of-hatch chicks, colonization of the bursa, spleen, and liver was observed, with peak titers 6 to 9 days postimmunization. In vitro experiments show that the EASZ240 antigen is secreted into the culture supernatant via the TTSS and that it is delivered into the cytoplasm of Int-407 cells by the TTSS. In vivo experiments indicate that both humoral and cell-mediated immune responses are induced in chickens vaccinated with a recombinant attenuated Salmonella serovar Typhimurium vaccine, which leads to significant protection against Eimeria challenge.

Published ahead of print on 18 September 2006.

Editor: W. A. Petri, Jr.

This article has been cited by other articles:

• Lee, Y. H., Kim, J. H., Bang, I. S., Park, Y. K. (2008). The Membrane-Bound Transcriptional Regulator CadC Is Activated by Proteolytic Cleavage in Response to Acid Stress. J. Bacteriol. 190: 5120-5126 [Abstract] [Full Text]  
• Xin, W., Wanda, S.-Y., Li, Y., Wang, S., Mo, H., Curtiss, R. III (2008). Analysis of Type II Secretion of Recombinant Pneumococcal PspA and PspC in a Salmonella enterica Serovar Typhimurium Vaccine with Regulated Delayed Antigen Synthesis. Infect. Immun. 76: 3241-3254 [Abstract] [Full Text]