| Abstract: | T-cell recognition sites, i.e. T-cell determinants, of bovine β-lactoglobulin, a major allergen in milk, were analyzed in
detail. For this purpose, we prepared primary cultures of lymph node cells from three strains of mice, C57BL/6 (H-2b), C3H/HeN (H-2k), and BALB/c (H-2d), and examined the proliferative response of these cells to a complete set of overlapping 15-mer peptides which covered the
entire sequence of β-lactoglobulin by shifting in single amino acid steps. We were able to determine the putative core sequence
of each T-cell determinant and estimate its relative importance. In the case of C57BL/6 mice, dominant, subdominant, and minor
determinants were identified as residues 122–130, 16–26, and 108–122, respectively, as represented by their core sequences.
Each determinant peptide induced the production of interferon-γ, the amount of which showed a correlation with the intensity
of the proliferative response induced by each determinant. In the case of C3H/HeN mice, a dominant determinant comprised of
residues 140–148 was identified together with three subdominant and two minor determinants. Dominant T-cell determinants recognized
in BALB/c mice were identified as residues 67–75, 71–79, and 80–88, and six other regions were identified as subdominant determinants.
Comparisons between our results and the determinants predicted from relevant MHC-binding motifs reported to date revealed
the inadequacy of the motifs in predicting even the dominant determinants. The information obtained by complete mapping of
T-cell determinants as done in this study is expected to be helpful in establishment and evaluation of new prediction methods
and also may contribute to the development of a new approach to control immune responses by manipulation of the T-cell determinants
of allergens.
This revised version was published online in June 2006 with corrections to the Cover Date. |
