IL-9 induces expression of granzymes and high-affinity IgE receptor in murine T helper clones.
Interleukin 9 (IL-9) is a TH2 cytokine that has been shown to promote the antigen-independent growth of some mouse T helper clones. To characterize the specificity of IL-9-mediated T cell activation, we used a murine T cell clone that could grow with either IL-9 or IL-2. After differential hybridization of a cDNA library, we isolated three genes that were expressed preferentially in the presence of IL-9. Two of them correspond respectively to granzyme A and granzyme B, two proteases expressed by activated T cells. By Northern blot hybridization and functional assays, we found that IL-9 induced the expression of granzyme B in several T cell clones as well as in mast cell lines. In addition, other proteases such as the mouse mast cell proteases were also found to be expressed by IL-9-activated T cell clones. The third IL-9-induced cDNA corresponds to the alpha-chain of the high-affinity receptor for IgE. Several T cell clones expressed this IgE receptor mRNA and were able to bind IgE with high affinity. Taken together, our results indicate that IL-9 induces a mast cell-like phenotype in T cell clones.
Louahed
J
J
Ludwig Institute for Cancer Research, University of Louvain, Brussels, Belgium.
Kermouni
A
A
Van Snick
J
J
Renauld
J C
JC
D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002460:Cell Line; D053818:Chymases; D002999:Clone Cells; D004790:Enzyme Induction / Q000276:immunology; D015723:Gene Library; D053804:Granzymes; D016906:Interleukin-9 / Q000502:physiology*; D008407:Mast Cells / Q000201:enzymology; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D017455:Receptors, IgE / Q000096:biosynthesis*; D012697:Serine Endopeptidases / Q000096:biosynthesis*; D006377:T-Lymphocytes, Helper-Inducer / Q000201:enzymology* / Q000276:immunology*; D015854:Up-Regulation / Q000276:immunology
D016906:Interleukin-9; D012333:RNA, Messenger; D017455:Receptors, IgE; D053804:Granzymes; C509214:Gzmb protein, mouse; D012697:Serine Endopeptidases; D053818:Chymases