Figure 5.

Identification of the TH3Z-stimulating H46 ^a antigenic epitope within clone 224–26. (A) Schematic representation of the deletion constructs used to identify the antigenic activity encoded within clone 224–26. ΔN1−3 represent deletions that truncate the NH₂ terminus of the potential polypeptide while ΔC1−3 cause COOH-terminal deletions. The specific nucleotides included in the constructs are shown in parentheses and the region with antigenic activity is indicated by a shaded oval. (B) The TH3Z T cell lacZ response to the N- and COOH-terminal deletion constructs expressed in E. coli that were fed to 129/J BMDC. (C) Overlapping synthetic peptides used for fine mapping the TH3Z T cell epitope. The numbering refers to the predicted protein sequence of clone 224–26 shown in Fig. 4 A. The core sequence required for antigenic activity is boxed. (D) 129/J BMDCs were incubated for 60 min with the indicated concentration of the synthetic peptides shown in C. The TH3Z T cells were added and their lacZ response measured after an overnight culture.