[Expression of functional human interleukin 2 receptor in mouse cells by using gene transfection].
Interleukin 2(IL-2), a lymphokine that is produced by helper T cells, plays a key role in the proliferation of T lymphocytes by interacting with a specific cell surface receptor. Recent studies demonstrated that the IL-2 receptor exists in two forms having different affinities to the ligand and the growth signal seems to be delivered by IL-2 bound to the high affinity, but not the low affinity, receptor. In man, both forms of the IL-2 receptor can be recognized by a monoclonal antibody, anti-Tac. Using this antibody, a cDNA that encodes Tac antigen has been cloned from ATL-derived T cell line. Transfection of the cloned cDNA into mammalian non-T cells, however, resulted in the expression of only a non-functional, low affinity IL-2 receptor. This observation raised a question whether or not the cloned cDNA for Tac antigen actually encodes the functional, high affinity IL-2 receptor. In order to clarify this problem, Tac antigen cDNA was obtained from human PBL cDNA library. This cDNA was connected to RSV-LTR and was transfected into mouse thymoma derived T-cell line EL4, and L929 fibroblast. Then transformants that constitutively express Tac antigen were established. IL-2 binding assay demonstrated that EL4 transformants expressed high affinity as well as low affinity human IL-2 receptor. In contrast, L929 transformants expressed only a low affinity receptor. The growth of the EL4 transformants harboring the high affinity human IL-2 receptor was inhibited by virtue of the specific interaction of the receptor with human, but not mouse, recombinant IL-2. These results demonstrate: the cloned cDNA dose encode a functional IL-2 receptor, the affinity of the IL-2 receptor is variably modified by post-translational events and 3. IL-2/receptor interaction leads to the reversal of the cell growth in EL4 cells. The reconstitution system described here will be of great use in elucidating the mechanism of T cell growth.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000957:Antigens, Viral, Tumor / Q000276:immunology; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D005786:Gene Expression Regulation; D006801:Humans; D051379:Mice; D011971:Receptors, Immunologic / Q000235:genetics*; D015375:Receptors, Interleukin-2; D011995:Recombination, Genetic; D013601:T-Lymphocytes / Q000276:immunology / Q000502:physiology; D014158:Transcription, Genetic
D000911:Antibodies, Monoclonal; D000957:Antigens, Viral, Tumor; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D004247:DNA