Molecular localization of the full profile of the continuous regions recognized by myoglobin-primed T-cells using synthetic overlapping peptides encompassing the entire molecule

Abstract

The molecular localization of the full antigenic profile for T-cell recognition of a complex multi-determinant protein antigen has not to date been accomplished. Previously, this laboratory has introduced a comprehensive strategy for the systematic localization of all continuous antigenic sites within a protein. This strategy depends on the synthesis of a series of overlapping peptides that together account for the entire structure of a protein. Such a strategy has been applied, in this report, to the delineation of the continuous sites of T-cell recognition of sperm whale myoglobin. Thirteen peptides, accounting for the entire protein chain, were synthesized and subsequently examined in vitro for their ability to stimulate lymph node cells from myoglobin primed DBA/2 (H-2d) mice, a known high responder. This strategy has enabled for the first time the localization of the full profile of the protein regions which contain the sites of T-cell recognition. Three regions gave a high response (one being immunodominant and coinciding with antigenic, i.e. antibody binding, site 4 of myoglobin). At least three regions appear to coincide with previously known antigenic (antibody binding) sites. Noteworthy is the finding of regions that are recognized by T-cells but to which no detectable antibody response is directed.