Differential regulation of human T lymphoblast functions by IL-2 and IL-15.
Interleukin 15 (IL-15) shares many functional properties with interleukin 2 (IL-2), although both cytokines probably also exert distinct functions. In order to screen for functional differences between IL-2 and IL-15 with respect to the control of T cell functions, we have stimulated human T lymphoblasts (hTBl) with IL-2 and/or IL-15 and have assessed the resulting changes in the following parameters: T cell proliferation; expression of various relevant surface markers; cytokine and receptor (alpha-chain) transcription; and IL-2 and IL-15 activity. Both cytokines equally upregulate standard activation markers such as CD25 and CD95 and downregulate CD27. However, IL-2 upregulates CD30, TNF receptor type II and CD40L expression significantly stronger than IL-15. IL-15 potentiates Con A-induced IL-2 secretion. Even though hTBl transcribe the IL-15 gene, they do not secrete IL-15 activity. These observations suggest that both cytokines can differentially regulate T cells, e.g. T cell functions relevant to the control of cell cycle progression and apoptosis, and/or that they can stimulate different T cell subsets. Moreover, IL-15 may potentiate IL-2-driven T cell responses.
Bulfone-Paus
S
S
Institute of Immunology, University Hospital Benjamin Franklin, Freie Universität Berlin, Germany. bulfone@zedat.fu-berlin.de
Dürkop
H
H
Paus
R
R
Krause
H
H
Pohl
T
T
Onu
A
A
D015703:Antigens, CD / Q000096:biosynthesis; D023201:CD40 Ligand; D015536:Down-Regulation; D006801:Humans; D019409:Interleukin-15 / Q000378:metabolism / Q000502:physiology*; D007376:Interleukin-2 / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D017730:Ki-1 Antigen / Q000096:biosynthesis; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000096:biosynthesis; D012333:RNA, Messenger; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis / Q000235:genetics; D018124:Receptors, Tumor Necrosis Factor / Q000096:biosynthesis; D047889:Receptors, Tumor Necrosis Factor, Type II; D013601:T-Lymphocytes / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000096:biosynthesis; D015854:Up-Regulation; D019014:fas Receptor / Q000096:biosynthesis
D015703:Antigens, CD; D019409:Interleukin-15; D007376:Interleukin-2; D017730:Ki-1 Antigen; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D015375:Receptors, Interleukin-2; D018124:Receptors, Tumor Necrosis Factor; D047889:Receptors, Tumor Necrosis Factor, Type II; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D019014:fas Receptor; D023201:CD40 Ligand