A recombinant chimera composed of repeat region RR1 of Mycoplasma hyopneumoniae adhesin with Pseudomonas exotoxin: in vivo evaluation of specific IgGresponse in mice and pigs

Using the binding and translocation domain of Pseudomonas exotoxin A [domai n III deleted PE termed PE(Delta III)] as a vehicle, this study characteriz ed and evaluated a novel application of PE toxin in Mycoplasma hyopneumonia e adhesin used as an immunogen. PCR and sequence analysis revealed that 16 copies of AAKPV(E) in tandem repeat region 1 (RR1) of M. hyopneumoniae 97 k Da adhesion were successfully fused to the downstream of PE(Delta III) to c reate a subunit vaccine, i.e. PE(Delta III)-RR1. This chimeric protein, ove r-expressed in inclusion bodies of E. coli BL21(DES)pLysS, was characterize d by a monoclonal antibody (MAb) F2G5 prepared against RR1 of the 97 kDa ad hesin and was readily purified. The data indicated that the epitope recogni zed by MAb F2G5 was located in the structure of PE(Delta III)-RR1. Using EL ISA and Western blot analyses, the specific IgG immune response against RR1 and whole adhesin in mice immunized with PE(Delta III)-RR1 was found more marked than that in mice immunized with the M. hyopneumoniae whole cells. S imilarly, PE(Delta III)-RR1 also stimulated a remarkable IgG response again st RR1 in pigs compared to that in pigs immunized with the conventional M. hyopneumoniae vaccine. The PE(Delta III)-RR1 would be potentially useful fo r the future development of a M. hyopneumoniae adhesin vaccine. (C) 2001 El sevier Science B.V. All rights reserved.