In a previous study we showed that vaccination of cattle with recombinant MAP Hsp70 significantly reduced bacterial shedding [9]. This reduction coincided unexpectedly with a clear Hsp70 antibody response and a limited cell mediated response. This suggests that induction of Hsp70 antibodies could contribute to effective immune responses against Map in vivo. Similar to the smaller 16 kD α-crystallin heat shock protein with respect to MTb [15], Hsp70 appears to be present in the intact cell wall of MAP, as evidenced by a recent study identifying cell wall proteins using a proteomics approach [24]. Furthermore it has been shown that

local application of specific monoclonal antibodies to the 16 kD α-crystallin confers protection to early stage tuberculous infection in a murine PI3K inhibitor model of tuberculosis [15]. Thus, likewise, antibodies specific for Hsp70 may contribute to protective immunity in mycobacterial infections, which other studies have also indicated (reviewed in [14]). We characterized MAP Hsp70 B cell epitopes recognized by murine monoclonal antibodies as well as sera from Hsp70 vaccinated goat and cattle. Our synthetic peptide approach resulted in definition of two linear epitopes. One of them (recognized by KoKo.B03) is located in the conserved N-terminus of the native protein, while the other (recognized by KoKo.B01 and KoKo.B02) is located

in the less evolutionary conserved C-terminal region of the protein. Five more monoclonal antibodies most likely recognized conformational selleck screening library epitopes, of which four are located in the N-terminus of MAP Hsp70. Although we were not able to fine-map these epitopes, this first finding shows that Hsp70 contains multiple targets for antibody interactions. Immunization of mice with whole-cell extracts of MAP also led to the generation of monoclonal antibodies specific for Hsp70 (MAP3840), indicating that this protein is immunogenic

and abundantly present in MAP [25]. The intact protein, as well as the dominant linear epitopes were recognized by antibodies of cattle vaccinated with recombinant Hsp70 protein. Whether or not these calves were experimentally infected with MAP did not alter the antibody response to these epitopes. Similar results were obtained with goat kids. Both in goats and calves, the experimental exposure to MAP concurrent with vaccination did not substantially influence the major B cell responses to vaccination with Hsp70. In the C-terminus of MAP Hsp70 other linear epitopes were also recognized, indicating that in vaccinated calves and goats multiple targets are recognized. For diagnostic purposes the combined use of antibodies specific for the C-terminal and N-terminal epitopes of Hsp70 offers possibilities as an alternative to Ziehl–Neelsen staining, increasing specificity for detection of mycobacteria in diagnostic specimen. The known specificity of the monoclonal antibodies KoKo.