Immunization against <it>Clostridium perfringens </it>cells elicits protection against <it>Clostridium tetani </it>in mouse model: identification of cross-reactive proteins using proteomic methodologies

• Main Authors: Singh Lokendra, Bansod Sunita, Alam Syed
• Format: Article
• Language: English
• Published: BMC 2008-11-01
• Series: BMC Microbiology
• Online Access: http://www.biomedcentral.com/1471-2180/8/194

<p>Abstract</p> <p>Background</p> <p><it>Clostridium tetani </it>and <it>Clostridium perfringens </it>are among the medically important clostridial pathogens causing diseases in man and animals. Several homologous open reading frames (ORFs) have been identified in the genomes of the two pathogens by comparative genomic analysis. We tested a likelihood of extensive sharing of common epitopes between homologous proteins of these two medically important pathogens and the possibility of cross-protection using active immunization.</p> <p>Results</p> <p>Eight predominant cross-reactive spots were identified by mass spectrometry and had hits in the <it>C. tetani </it>E88 proteome with significant MOWSE scores. Most of the cross-reactive proteins of <it>C. tetani </it>shared 65–78% sequence similarity with their closest homologues in <it>C. perfringens </it>ATCC13124. Electron transfer flavoprotein beta-subunit (CT3) was the most abundant protein (43.3%), followed by methylaspartate ammonia-lyase (36.8%) and 2-phosphoglycerate dehydratase (35.6%). All the proteins were predicted to be cytoplasmic by PSORT protein localization algorithm. Active immunization with <it>C. perfringens </it>whole cells elicited cross-protective immunity against <it>C. tetani </it>infection in a mouse model.</p> <p>Conclusion</p> <p>Most of the dominant cross-reactive proteins of <it>C. tetani </it>belonged to the cluster of orthologous group (COG) functional category, either of posttranslational modification, protein turnover, and chaperones (O) or energy production and conversion (C). The homologs of the identified proteins have been shown to play role in pathogenesis in other Gram-positive pathogenic bacteria. Our findings provide basis for the search of potential vaccine candidates with broader coverage, encompassing more than one pathogenic clostridial species.</p>