Fine specificity of the murine immune response to SV40 large tumour antigen utilizing synthetic peptides that define selected epitopes.
Baculovirus-derived recombinant simian virus 40 large tumour antigen (SV40 T-ag) was used to immunize BALB/c, C57Bl/6 and CB6/F1 mice and their anti-SV40 T-ag antibody responses were examined for the ability to bind synthetic peptides representing six predicted B cell epitopes on SV40 T-ag. In C57Bl/6 mice, anti-SV40 T-ag antibodies failed to bind any of the six SV40 T-ag peptides. However, the antibody responses induced in both BALB/c and CB6/F1 mice recognized synthetic peptides corresponding to two distinct epitopes (amino acids 690-708 and 660-679, respectively) associated with the carboxyl-terminal half of SV40 T-ag. In addition, murine MoAbs (BALB/c) generated to native SV40 T-ag, and previously characterized as recognizing the carboxyl-terminus of SV40 T-ag by deletion mutant analysis, also bound the synthetic peptide (residues 690-708) defining the carboxyl-terminus of SV40 T-ag. These data indicate that the antibody responses induced in BALB/c and CB6/F1 mice by immunization with baculovirus-derived recombinant SV40 T-ag are capable of recognizing sequential carboxyl-terminal epitopes on SV40 T-ag defined by peptides 690-708 and 660-679, respectively. No statistically significant differences in anti-SV40 T-ag antibody titres were observed between the three inbred mouse strains. These data suggested that the fine specificities of the anti-SV40 T-ag responses as assessed by synthetic peptide binding were different in the three inbred strains of mice examined. Finally, in vivo tumour challenge studies comparing recombinant SV40 T-ag with the two carboxyl-terminus peptide epitopes indicated that some tumour immunity was induced in BALB/c, but not CB6/F1 mice, by immunization with peptide 690-708 conjugated to a carrier protein. These studies suggest that the carboxyl-terminal region of SV40 T-ag represents a continuous sequential epitope involved in both the antibody response to SV40 T-ag and tumour immunity in BALB/c mice.
Bright
R K
RK
Department of Virology and Immunology, Southwest Foundation for Biomedical Research, San Antonio, TX.
Shearer
M H
MH
Kennedy
R C
RC
D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis; D000918:Antibody Specificity; D000957:Antigens, Viral, Tumor / Q000235:genetics / Q000276:immunology*; D016367:Baculoviridae / Q000235:genetics; D000939:Epitopes / Q000235:genetics / Q000276:immunology*; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000235:genetics / Q000276:immunology*; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D013539:Simian virus 40 / Q000235:genetics / Q000276:immunology*; D013045:Species Specificity
D000914:Antibodies, Viral; D000957:Antigens, Viral, Tumor; D000939:Epitopes; D010455:Peptides; D011994:Recombinant Proteins