Modifications of an immunodominant peptide antigen induce different anti-polyoma tumor responses in two separate mouse strains.
An immunodominant polyoma peptide antigen MT162-176 was modified with regard to amino acid (aa) composition in an attempt to analyze its immunogenicity in detail. Twelve modifications of peptide MT162-176, 3 overlapping peptides and 9 peptides with point mutations, were synthesized and used for immunizations of (A.CA x C57BL/6)F1 and CBA mice against the syngeneic polyoma tumors SECA and SEBA. All 3 overlapping peptides MT162-176, MT165-174 and MT170-176, were immunogenic in (A.CA x C57BL/6)F1 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)F1 3 different mutants, MT162-176.29, MT162-176.35 and MT162-176.36 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.
Reinholdsson-Ljunggren
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G
Department of Virology, Stockholm City Council, Central Microbiological Laboratory, Sweden.
Dalianis
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T
D000595:Amino Acid Sequence; D000818:Animals; D000952:Antigens, Polyomavirus Transforming; D000956:Antigens, Viral / Q000627:therapeutic use*; D006084:Graft Rejection; D007114:Immunization; D051379:Mice; D008808:Mice, Inbred CBA; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D009368:Neoplasm Transplantation; D010455:Peptides / Q000138:chemical synthesis / Q000276:immunology / Q000627:therapeutic use*; D011120:Polyomavirus / Q000276:immunology*; D013329:Structure-Activity Relationship; D014412:Tumor Virus Infections / Q000276:immunology* / Q000628:therapy
D000952:Antigens, Polyomavirus Transforming; D000956:Antigens, Viral; D010455:Peptides; C075879:polyoma peptide antigen MT162-176