The wild boar (sus scrofa) lymphocyte function-associated antigen-I (CDIIa/CDI8) receptor: cDNA sequencing, structure analysis and comparison With homologues

Abstract

Background: The most predominant beta2-integrin lymphocyte function-associated antigen-I (LFA-I, CDIIa/CDI8, alphaLbeta2), expressed on all leukocytes, is essential for many adhesive functions of the immune system. Interestingly, RTX toxin-producing bacteria specifically target this leukocyte beta2-integrin which exacerbates lesions and disease development. Results: This study reports the sequencing of the wild boar beta2-integrin CDIIa and CDI8 cDNAs. Predicted CDIIa and CDI8 subunits share all the main structural characteristics of their mammalian homologues, with a larger interspecies conservation for the CDI8 than the CDIIa. Besides these strong overall similarities, wild boar and domestic pig LFA-I differ by 2 (CDI8) and I or 3 (CDIIa) substitutions, of which one is located in the crucial I-domain (CDIIa, EI68D). Conclusion: As most wild boars are seropositive to the RTX toxin-producing bacterium Actinobacillus pleuropneumoniae and because they have sustained continuous natural selection, future studies addressing the functional impact of these polymorphisms could bring interesting new information on the physiopathology of Actinobacillus pleuropneumoniae-associated pneumonia in domestic pigs. © 2007 Bergh et al.; licensee BioMed Central Ltd.