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Identification of overlapping epitopes in mutant ras oncogene peptides that activate CD4+ and CD8+ T cell responses.
Eur J Immunol 1996; 26(2):435-43EJ

Abstract

Mutant ras p21 proteins contain sequences which distinguish them from normal endogenous ras and, thus, may represent unique epitopes for T cell recognition of antigen bearing tumor cells. Here, we examined the capacity of a mutant K-ras 9-mer peptide to induce in vivo CD8+ cytotoxic T lymphocytes (CTL). The peptide chosen reflected positions 4-12 of the point-mutated sequence of the K-ras oncogene encoding the Gly to Val substitution at codon 12. The overall rationale for selecting this particular 9-mer sequence was threefold: the mutant peptide contained a putative major histocompatibility complex (MHC) class I consensus anchor motif for murine H-2Kd; specific binding to MHC class I may then create an immunogenic complex for the induction of anti-ras CD8+ CTL; and finally, the mutant sequence overlapped with a newly characterized anti-ras CD4+ T helper type 1 epitope, which may have implications for the coordination and activation of both anti-ras immune mechanisms against the same target cell antigenic determinant. A functional interaction with H-2Kd was demonstrated with the mutant ras4-12(V12) peptide, but not the normal ras4-12(G12) peptide, which specifically inhibited an H-2Kd-restricted, anti-nucleoprotein NP147-155 CTL response in a dose-dependent fashion. An anti-ras CD8+ T cell line was then established from immune splenocytes of BALB/c (H-2d) mice injected with ras4-12 (V12) in adjuvant, which mediated peptide-specific lysis of syngeneic P815 tumor targets. Cytotoxicity was restricted by H-2Kd and strongly specific for the mutant ras peptide. Importantly, these anti-ras CTL specifically lysed a syngeneic tumor line (i.e. A20 lymphoma) transduced with the corresponding point-mutated ras oncogene, suggesting T cell receptor recognition of endogenously derived antigen. Overall, these data demonstrated that mutant ras p21 at codon 12(Gly-->Val) contained a peptide sequence which exhibited specific functional binding to a murine MHC class I molecule; the ability of the mutant, but not the normal sequence to bind selectively to murine MHC class I likely reflected the generation of a C-terminal anchor residue; and the ras4-12(V12) peptide was immunogenic for the production of antigen-specific CD8+ CTL, which lysed in vitro a syngeneic tumor cell line harboring the mutant K-ras oncogene.

Authors+Show Affiliations

Laboratory of Tumor Immunology and Biology, National Cancer Institute, Bethesda, MD 20892-1750, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

8617315

Citation

Abrams, S I., et al. "Identification of Overlapping Epitopes in Mutant Ras Oncogene Peptides That Activate CD4+ and CD8+ T Cell Responses." European Journal of Immunology, vol. 26, no. 2, 1996, pp. 435-43.
Abrams SI, Stanziale SF, Lunin SD, et al. Identification of overlapping epitopes in mutant ras oncogene peptides that activate CD4+ and CD8+ T cell responses. Eur J Immunol. 1996;26(2):435-43.
Abrams, S. I., Stanziale, S. F., Lunin, S. D., Zaremba, S., & Schlom, J. (1996). Identification of overlapping epitopes in mutant ras oncogene peptides that activate CD4+ and CD8+ T cell responses. European Journal of Immunology, 26(2), pp. 435-43.
Abrams SI, et al. Identification of Overlapping Epitopes in Mutant Ras Oncogene Peptides That Activate CD4+ and CD8+ T Cell Responses. Eur J Immunol. 1996;26(2):435-43. PubMed PMID: 8617315.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Identification of overlapping epitopes in mutant ras oncogene peptides that activate CD4+ and CD8+ T cell responses. AU - Abrams,S I, AU - Stanziale,S F, AU - Lunin,S D, AU - Zaremba,S, AU - Schlom,J, PY - 1996/2/1/pubmed PY - 1996/2/1/medline PY - 1996/2/1/entrez SP - 435 EP - 43 JF - European journal of immunology JO - Eur. J. Immunol. VL - 26 IS - 2 N2 - Mutant ras p21 proteins contain sequences which distinguish them from normal endogenous ras and, thus, may represent unique epitopes for T cell recognition of antigen bearing tumor cells. Here, we examined the capacity of a mutant K-ras 9-mer peptide to induce in vivo CD8+ cytotoxic T lymphocytes (CTL). The peptide chosen reflected positions 4-12 of the point-mutated sequence of the K-ras oncogene encoding the Gly to Val substitution at codon 12. The overall rationale for selecting this particular 9-mer sequence was threefold: the mutant peptide contained a putative major histocompatibility complex (MHC) class I consensus anchor motif for murine H-2Kd; specific binding to MHC class I may then create an immunogenic complex for the induction of anti-ras CD8+ CTL; and finally, the mutant sequence overlapped with a newly characterized anti-ras CD4+ T helper type 1 epitope, which may have implications for the coordination and activation of both anti-ras immune mechanisms against the same target cell antigenic determinant. A functional interaction with H-2Kd was demonstrated with the mutant ras4-12(V12) peptide, but not the normal ras4-12(G12) peptide, which specifically inhibited an H-2Kd-restricted, anti-nucleoprotein NP147-155 CTL response in a dose-dependent fashion. An anti-ras CD8+ T cell line was then established from immune splenocytes of BALB/c (H-2d) mice injected with ras4-12 (V12) in adjuvant, which mediated peptide-specific lysis of syngeneic P815 tumor targets. Cytotoxicity was restricted by H-2Kd and strongly specific for the mutant ras peptide. Importantly, these anti-ras CTL specifically lysed a syngeneic tumor line (i.e. A20 lymphoma) transduced with the corresponding point-mutated ras oncogene, suggesting T cell receptor recognition of endogenously derived antigen. Overall, these data demonstrated that mutant ras p21 at codon 12(Gly-->Val) contained a peptide sequence which exhibited specific functional binding to a murine MHC class I molecule; the ability of the mutant, but not the normal sequence to bind selectively to murine MHC class I likely reflected the generation of a C-terminal anchor residue; and the ras4-12(V12) peptide was immunogenic for the production of antigen-specific CD8+ CTL, which lysed in vitro a syngeneic tumor cell line harboring the mutant K-ras oncogene. SN - 0014-2980 UR - https://www.unboundmedicine.com/medline/citation/8617315/Identification_of_overlapping_epitopes_in_mutant_ras_oncogene_peptides_that_activate_CD4+_and_CD8+_T_cell_responses_ L2 - https://doi.org/10.1002/eji.1830260225 DB - PRIME DP - Unbound Medicine ER -