IL-2 receptor and Fc epsilon R2 gene activation in lymphocyte transformation: possible roles of ATL-derived factor.
Lymphocyte transformation/activation is accompanied by the induction of a variety of the inducible receptors associated with the activation antigens. The p55 chain of the interleukin-2 receptor (IL-2R/p55) recognized by anti-Tac monoclonal antibody (mAb) is expressed on activated T and B cells as well as natural killer (NK) cells. IL-2R/p55(Tac) is constitutively expressed on T4(+) T cells transformed by human T-lymphotropic virus I (HTLV-I), which is a causative agent for adult T-cell leukemia (ATL). Low affinity Fc receptor for IgE (Fc epsilon R2/CD23) is another inducible receptor binding IgE and is expressed on various hematopoietic cell types. While the physiological expression of Fc epsilon R2 and its soluble form (IgE Binding Factor; IgE BF) is variably regulated by cytokines and IgE, there is a constitutive expression of Fc epsilon R2 on Epstein-Barr virus (EBV) transformed B cell lines and some of HTLV-I (+) T cell lines. ATL-derived factor (ADF) has been characterized as an IL-2R/p55(Tac) inducing factor derived from HTLV-I(+) T cell lines. Purification of ADF protein and the cDNA cloning proved that ADF is closely related to the autocrine growth factor produced by an EBV(+) B cell line 3B6 (H. Wakasugi and T. Tursz) and belonging to the family of thiol reducing co-enzyme thioredoxin which is involved in many biological reactions. Recombinant ADF produced by COS cells and E. coli showed both IL-2R inducing and reducing activities. We will discuss the biological roles of ADF in viral and normal lymphocyte activation and transformation in relation to the receptor gene activation.
Yodoi
J
J
Institute for Immunology, Faculty of Medicine, Kyoto University, Japan.
Tagaya
Y
Y
Masutani
H
H
Maeda
Y
Y
Kawabe
T
T
D000595:Amino Acid Sequence; D000944:Antigens, Differentiation, B-Lymphocyte / Q000096:biosynthesis / Q000235:genetics*; D002472:Cell Transformation, Viral; D016207:Cytokines; D004247:DNA / Q000032:analysis; D005786:Gene Expression Regulation; D015490:HTLV-I Infections / Q000276:immunology; D006801:Humans; D008213:Lymphocyte Activation; D009363:Neoplasm Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D011961:Receptors, Fc / Q000096:biosynthesis / Q000235:genetics*; D017455:Receptors, IgE; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis / Q000235:genetics*; D013879:Thioredoxins / Q000032:analysis; D015533:Transcriptional Activation
D000944:Antigens, Differentiation, B-Lymphocyte; D016207:Cytokines; D009363:Neoplasm Proteins; D011961:Receptors, Fc; D017455:Receptors, IgE; D015375:Receptors, Interleukin-2; C055533:adult T cell leukemia-derived factor; D013879:Thioredoxins; D004247:DNA