Characterization Of T Cell Hybridomas Raised Against A Glycopeptide Containing The Tumor-Associated T Antigen, (Beta Gal (1-3) Alpha Galnac-O/Ser)

T cell hybridomas were raised against the glycopeptide S-72 (Core-1) containing the tumor-associated disaccharide betaGal (1-3) alphaGalNAc (Core-1) O-linked to serine at position 72 in the mouse hemoglobin derived decapeptide Hb(67-76). All hybridomas recognized the glycopeptide S-72 (Core-1). Two of the selected hybridomas responded, however, much better to the S-72 (Tn) glycopeptide containing the monosaccharide aGalNAc O-linked to serine. In addition, one hybridoma cross-responded to the glycopeptide T-72 (Core-1) having a threonine at position 72 instead of a serine. No cross-responses were found to other glycopeptides consisting of the same hemoglobin peptide with different glycans attached or to the unglycosylated peptides. The T cell receptor Valpha and Vbeta usage was clearly diverse. The CDR3alpha regions demonstrated moreover a predominance of small polar amino acid side chains, and three hybridomas contained a common sequence motif. All the sequenced CDR3beta regions contained furthermore a conserved proline-glycine motif. In conclusion, immunization with the disaccharide containing glycopeptides S-72 (Core-1) created a heterogeneous population of glycopeptide specific T cells with the ability of cross-responding toward related glycopeptides.