Animal experiments were approved by the Ethical committee of Utrecht University, and performed according to its regulations. The following antigens were used for vaccination and determination of specificity of monoclonal antibodies (mAb):

recombinant MAP Hsp 65 kD (rMAP Hsp60) and Hsp 70 kD (rMAP Hsp70). These antigens were produced as described earlier [6] and [17]. A recombinant C-terminal deletion mutant protein of the Hsp70 molecule was constructed, comprising the receptor binding part. It consisted of N-terminal amino acids 1–359 of wildtype Hsp70, had a molecular weight of approximately 45 kD and was designated RBS70. RBS70 was constructed by restriction endonuclease digestion of the original MAPK inhibitor recombinant MAP Hsp70 pTrcHis expression vector with AflII (NE Biolabs, USA) and HindIII (Gibco-Invitrogen, the Netherlands) using 5 units of each enzyme CX 5461 per μg DNA. The digested fragment was separated from the vector DNA by agarose gel (1%) electroforesis and isolated from the gel using a QIAEXII

kit (Promega, the Netherlands). The vector DNA was blunted by using T4 DNA polymerase (Fermentas, Germany) subsequently purified using a DNA cleaning kit (Zymo Research, USA), religated using T4 DNA ligase (Quick Ligation kit, NE Biolabs, USA) and purified using the DNA cleaning kit. Finally, chemically competent Top10 bacteria (Invitrogen, the Netherlands) were transformed with the vector DNA using a heat shock protocol provided by the manufacturer. Transformed bacteria were selected and protein expression and purification was performed similar to the procedure described for recombinant MAP Hsp70 [6]. In addition, the following antigens were used: recombinant M. tuberculosis Hsp70 (MTb), recombinant Escherichia coli (E. coli) Hsp70 and bovine Hsc70 purified from bovine brain (generous gifts from Stressgen, Canada). Purified

protein derivatives (PPDs) were produced at CVI (Lelystad, the Netherlands) as previously described [18], from MAP strain 3+5/C (PPDP), M. bovis (MB) strain AN5 (PPDB), and M. avium ssp. avium (MAA) strain D4 (PPDA). MAP strain and 316F was grown at the CVI (generous gifts from D. Bakker). To define peptides for the screening of monoclonal antibodies and sera from cattle and goats the following HSP70 Genbank-derived sequences were used: Q00488 (MAP Hsp70); A0QLZ6 (MAA Hsp70); P0A5C0 (MB Hsp70); P0A5B9 (MTb Hsp70); P04475 (E. coli Hsp70); NP776975 (Bos taurus Hsp70-1A). A first set of 124 synthetic 14-mer peptides, with an aminoterminal cysteine, a 5 amino acids (aa) shift and an overlap of 9 aa, covering the MAP Hsp70 molecule, was synthesized using the simultaneous multiple peptide synthesis (SMPS) technique described previously [19]. To enable di-sulphate binding of peptides to the solid phase ELISA plate, an amino-terminal cysteine residue was coupled to each peptide during synthesis. For primary screening peptides were pooled in 11 groups of sequential peptides.