IL-1 serves as a secondary signal for IL-9 expression.
IL-9 is produced in vitro by activated CD4+ T cell lines of the Th2 subtype and by naive CD4+ T cells. Here we show that T cell lines stimulated with Con A in the presence of accessory cells (AC) such as irradiated spleen cells or bone marrow-derived macrophages produced substantially more IL-9 than T cells stimulated with Con A alone. These data suggest that AC influence the production of IL-9 through accessory signals that result in an at least 10-fold increase of IL-9 secretion by the respective T cells. Addition of IL-1 to T cells activated by Con A, PHA, or anti-CD3 antibodies revealed that this monokine was responsible for the potentiation of IL-9 production. This finding was confirmed by applying anti-IL-1 antibodies. The production of other lymphokines, namely, IL-3, IL-4, and IL-6, by activated T cells was not or only marginally enhanced in the presence of AC or IL-1, thus indicating that the synthesis of IL-9 is regulated differently from that of other Th2-derived lymphokines. Furthermore, it was demonstrated by Northern blot analysis that IL-1 increases IL-9 expression at the pretranslational level. Because IL-1 alone failed to induce the production of IL-9 by T cells, this monokine acts as a costimulator in combination with a T cell receptor-mediated signal.
Schmitt
E
E
Institute for Immunology, Johannes Gutenberg Universität, Mainz, Federal Republic of Germany.
Beuscher
H U
HU
Huels
C
C
Monteyne
P
P
van Brandwijk
R
R
van Snick
J
J
Ruede
E
E
D000818:Animals; D000938:Antigen-Presenting Cells / Q000502:physiology; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D015870:Gene Expression; D007375:Interleukin-1 / Q000502:physiology*; D007376:Interleukin-2 / Q000235:genetics; D007377:Interleukin-3 / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis / Q000235:genetics; D015850:Interleukin-6 / Q000096:biosynthesis; D016906:Interleukin-9 / Q000235:genetics / Q000378:metabolism*; D008213:Lymphocyte Activation; D008565:Membrane Proteins / Q000502:physiology; D051379:Mice; D008815:Mice, Inbred Strains; D012333:RNA, Messenger / Q000235:genetics; D011994:Recombinant Proteins; D016176:T-Lymphocyte Subsets / Q000378:metabolism*; D006377:T-Lymphocytes, Helper-Inducer / Q000378:metabolism*
D007375:Interleukin-1; D007376:Interleukin-2; D007377:Interleukin-3; D015850:Interleukin-6; D016906:Interleukin-9; D008565:Membrane Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D015847:Interleukin-4