Localization of T-cell determinants on bovine β-lactoglobulin

T-cell determinants of bovine β-lactoglobulin (β-LG) in BALB/c(H-2 d), C57BL/6(H-2 b) and C3H/He(H-2 k) mice were identified using a set of overlapping synthetic peptides encompassing the entire primary structure of the protein. Lymph node cells from mice immunized with β-LG were subjected to cell proliferation assay in the presence of these peptides and uptake of 3H-labeled thymidine was measured. Determinant regions were indicated to lie in residues 42–56, 62–76 and 139–153 in BALB/c mice, residues 11–26, 72–86, 100–113 and 119–133 in C57BL/6 mice, residues 72–86, 91–104, 129–143 and 139–153 in C3H/He mice. Some of these fragments included the antigenic motifs predicted by hypotheses according to amphipathicity and sequential patterns of peptides. We reported elsewhere that residues 42–56 and 72–86 represent one of the B-cell antigenic determinants in BALB/c and C3H/He, respectively. These peptides serve as good models of colinear T- and B-cell determinants as they contain both of T- and B-cell determinants.