Immune response in mice and swine to DNA vaccines derived from the Pasteurella multocida toxin gene.

Author(s): Register KB, Sacco RE, Brockmeier SL

Affiliation(s): Respiratory Diseases of Livestock Research Unit, USDA/Agricultural Research, Service/National Animal Disease Center, P.O. Box 70, Ames, IA 50010, United States. kregiste@nadc.ars.usda.gov

Publication date & source: 2007-08-10, Vaccine., 25(32):6118-28. Epub 2007 Jun 8.

Publication type: Randomized Controlled Trial; Research Support, Non-U.S. Gov't

DNA vaccines were constructed with either a 5'-truncated or full-length, genetically detoxified toxin gene from Pasteurella multocida and two different DNA vaccine vectors, distinguished by the presence or absence of a secretion signal sequence. Optimal PMT-specific antibody responses and spleen cell secretion of interferon-gamma following immunization of mice were achieved with pMM4, the construct containing a signal sequence and encoding the entire toxin. Antibody responses were also induced in pigs immunized with pMM4 and levels increased significantly following booster injections and experimental infection with P. multocida. Significantly increased expression of interferon-gamma was detected in only a small subset of pMM4-immunized pigs. This report documents, for the first time, the ability of a DNA vaccine to elicit immune responses to the P. multocida toxin in both mice and swine.