Cryptic CTL epitope on a murine sarcoma Meth A generated by exon extension as a novel mechanism.
Using the recently developed ELISPOT cloning methodology, we obtained cDNA clone S35 coding for the Ag epitope recognized by a murine sarcoma Meth A-specific CTL clone AT-1. Analysis of truncated S35 constructs and overlapping peptides revealed that the peptide epitope was LGAEAIFRL. AT-1 CTL lysed peptide-pulsed CMS8 cells at a nanomolar concentration, and the peptide strongly stimulated IFN-gamma production in AT-1 CTL. Sequence homology indicated that the S35 was derived from a mouse homologue of human retinoic acid-regulated nuclear matrix-associated protein (ramp). The ramp gene consisted of 15 exons. The majority of the ramp mRNA was the transcript normally spliced between exons 14 and 15, but a minor population of mRNA with an extended exon 14 was also present in Meth A cells. The epitope was derived from the newly created open reading frame, which resulted from extension of exon 14 after splicing of the adjacent intronic sequence.
Uenaka
Akiko
A
Department of Immunology, Okayama University Graduate School of Medicine and Dentistry, Okayama, Japan.
Hirano
Yoshiki
Y
Hata
Hidenori
H
Win
Sanda
S
Aji
Toshiki
T
Tanaka
Motoyuki
M
Ono
Toshiro
T
Skipper
Jonathan C A
JC
Shimizu
Kenji
K
Nakayama
Eiichi
E
D000595:Amino Acid Sequence; D000818:Animals; D000951:Antigens, Neoplasm / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D001483:Base Sequence; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D002999:Clone Cells; D003001:Cloning, Molecular; D003601:Cytotoxicity Tests, Immunologic; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D018984:Epitopes, T-Lymphocyte / Q000096:biosynthesis* / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D005091:Exons / Q000235:genetics* / Q000276:immunology; D015723:Gene Library; D006801:Humans; D007371:Interferon-gamma / Q000032:analysis; D008748:Methylcholanthrene; D051379:Mice; D008807:Mice, Inbred BALB C; D008811:Mice, Inbred DBA; D008969:Molecular Sequence Data; D012513:Sarcoma, Experimental / Q000139:chemically induced / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014157:Transcription Factors
D000951:Antigens, Neoplasm; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D018984:Epitopes, T-Lymphocyte; D014157:Transcription Factors; C111777:ZMYM2 protein, human; C498438:Zmym2 protein, mouse; D008748:Methylcholanthrene; D007371:Interferon-gamma