Modifications of an immunodominant peptide antigen induce different anti-polyoma tumor responses in two separate mouse strains
✍ Scribed by Git Reinholdsson-Ljunggren; Tina Dalianis
- Publisher
- John Wiley and Sons
- Year
- 1992
- Tongue
- French
- Weight
- 535 KB
- Volume
- 51
- Category
- Article
- ISSN
- 0020-7136
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✦ Synopsis
An immunodominant polyoma peptide antigen MTI 62-I76 was modified with regard to amino acid (aa) composition in an attempt to analyze its immunogenicity in detail. Twelve modifications of peptide MTI 62-176, 3 overlapping peptides and 9 peptides with point mutations, were synthesized and used for immunizations of (A.CA X C57BL/6)Fl and CBA mice against the syngeneic polyoma tumors SECA and SEBA. All 3 overlapping peptides MT 162-176, M T I 65-I74 and MTI 70-176, were immunogenic in (A.CA X C57BL/6)FI mice against SECA, indicating that possibly more than one immunogenic epitope may be recognized within the MT162-176 sequence. In CBA mice, the 2 peptides covering the C-terminal half were immunogenic against SEBA, while the N-terminal peptide was possibly somewhat less efficient. The peptides with aa point mutations induced different anti-tumor responses in the 2 mouse strains.
In CBA mice, only one mutant, MT162-176.28, was immunogenic. For (A.CA X C57BI)Fl 3 different mutants, MTI62-176.29, MT 162-176.35 and MT 162-176.36 were immunogenic against SECA, while the remaining 6 had lost their activity. These results suggest that a different emphasis of recognition of peptide MT162-176 exists with regard to the 2 mouse strains examined. Furthermore, different immunization procedures were tested. We found that repeated immunizations with peptide without Freund's adjuvant was the most efficient.