CD8+ lymphocytes that kill allogeneic and xenogeneic major histocompatibility complex class I targets.
CD8+ CTLs generated in a two-way MLR should lyse target cells only if these targets share a class I MHC allele with the original stimulators. Using cattle PBMCs in a two-way MLR, we generated CD8+ CTLs that kill allogeneic and xenogeneic cell lines. We have named these cells MLK cells. PBMCs isolated from two unrelated animals were cultured together. After 14 days microfluorimetry analysis was performed on the MLK cells with results showing > 90% CD8+ cells. RFLP analysis revealed these cells to be predominately of one animal. MLK cells were then used as effector cells in cytotoxicity assays with syngeneic, allogeneic, and xenogeneic target cells. MLK cells were able to kill all targets. Incubating MLK cells with mAbs to CD8 markedly reduced killing, suggesting a TCR-mediated cytolytic pathway. Effective cytolysis of these targets by MLK cells was dependent on class I expression. MHC class I expression-impaired mutants of allogeneic and xenogeneic targets were not susceptible to cytolysis. Comparisons to LAK cells revealed similarities in phenotype and function to the NK1.1-, CD8+ subset.
Department of Animal Health and Biomedical Sciences, University of Wisconsin-Madison 53706, USA.
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D000595:Amino Acid Sequence; D000818:Animals; D016827:CD8 Antigens / Q000502:physiology; D002417:Cattle; D003602:Cytotoxicity, Immunologic; D005260:Female; D005805:Genes, MHC Class I; D015395:Histocompatibility Antigens Class I / Q000235:genetics / Q000276:immunology*; D015979:Killer Cells, Lymphokine-Activated / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology*; D007959:Lymphocyte Culture Test, Mixed; D008969:Molecular Sequence Data; D012150:Polymorphism, Restriction Fragment Length; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D016827:CD8 Antigens; D015395:Histocompatibility Antigens Class I