Characterization of Cloned Class I MHC-restricted, CD8+ Anti-Meth A Cytotoxic T-Lymphocytes: Recognition of an Epitope Derived from the Meth A gpllO Tumor Rejection Antigen

Meth A gpllO has been tentatively identified as a tumor rejection antigen. Following isolation of a class I major histocompatibility complex (MHC)-restricted, CD8+ anti-Meth A cytotoxic T-lymphocyte (CTL), we sought to determine whether the determinant recognized by this CTL was: (a) functional in tumor rejection of Meth A sarcoma; and Un derived from Meth A gpllO. Initially, we isolated an anti-Meth A CTL-resistant variant of Meth A sarcoma, Meth A4R, by immunoselection. The results of the subsequent analysis of Meth A4R cells showed the ( "l'I.-(It-fined determinant as having a functional role in transplantation rejection of Meth A sarcoma. Walker et al. (Proc. Nati. Acad. Sci. USA, 89: 7915-7918, 1993) showed that the cationic lipid, Ar-[l-(2rJ-dioleoyloxy)propyl]-JV,AyV-trimethylammonium-methyl sulfate, mediated delivery of a recombinant glycoprotein into the cytosol of target cells, making it available for processing and presentation by class I MHC molecules. As a result, the cells were sensi tized for cytolysis by a class I MHC-restricted CD8+ CTL, which recog nized an epitope expressed by the glycoprotein. In a similar manner, we treated the SV40-transformed HAI .It r cell line, SVBalb, which is rela tively insensitive to cytolysis by the anti-Meth A CTL, with Meth A gpllO and V-l l-(2,3-(li()lt-o\lii\\ ipri)pyll-V..\,.V-tnmeth\l:unni(iniiini methyl sul fate. The sensitivities of the treated cells and control cell lines to the anti-Meth A CTL were then examined. The results of these experiments permit us to conclude that the determinant recognized by the anti-Meth A CTL line is derived from Meth A gpllO.