Intramuscular immunization of mice with KatA (catalase) generates functional antibodies against Campylobacter jejuni invasion of gut epithelial cells in vitro

Abstract

The high incidence of Campylobacter jejuni-associated diarrhea, increase in the frequency of drug resistance in clinical isolates, and the recent association of C. jejuni infections and Guillain-Barré syndrome has heightened the need to develop effective anti-Campylobacter vaccines. Due to the risk of auto-immunity, vaccination using inactivated whole-cells or attenuated cells cannot be considered. Subunit vaccines however are a viable alternative and have been shown to be effective against similar pathogens. The main goal of this research is to test efficacy of the catalase A (KatA) protein as vaccine candidate against this pathogen. It was determined that KatA co-fractionates with both the soluble and insoluble cell fractions and a balanced IgG1/IgG2a response could be produced against it following immunization in mice. It was demonstrated that these antibodies can mediate complement-specific bactericidal activity and reduced adhesion and invasion of human epithelial (Caco-2) cells by C. jejuni using established in vitro assays.