IL-5 synthesis by T cells of allergic subjects is regulated at the transcriptional level.
BACKGROUND
IL-5 plays a central role in allergic diseases associated with eosinophilic inflammation. We have previously reported that IL-5 production by peripheral blood mononuclear cells (PBMC) is greatly enhanced in both atopic and nonatopic asthmatics compared to control subjects.


METHODS
Concanavalin A (Con A) blast lymphocytes were derived from PBMC of allergic and control subjects. Transcriptional regulation of the IL-5 gene was investigated by transient transfection assay.


RESULTS
A significant amount of IL-5 was produced by Con A blast lymphocytes derived from allergic subjects upon stimulation with phorbol ester and Ca(2+) ionophore, whereas the cells derived from control subjects did not produce a detectable amount of IL-5. Production of IL-2 and IL-4 was not significantly different between the two groups. A luciferase reporter plasmid containing the human IL-5 promoter/enhancer region was transcribed by Con A blast lymphocytes derived from allergic subjects, but not by the cells from control subjects, upon activation.


CONCLUSIONS
IL-5 synthesis by nontransformed T cells of allergic subjects is enhanced at the level of gene transcription. Elucidation of the molecular mechanism of IL-5 gene transcription by allergic T cells may delineate the pathogenesis of allergic disease for the future therapeutic intervention.
Ogawa
K
K
Discovery Research Laboratory, Tanabe Seiyaku Co., Ltd., Toda, Saitama, Japan.
Kaminuma
O
O
Kikkawa
H
H
Akiyama
K
K
Mori
A
A
D000328:Adult; D003208:Concanavalin A / Q000494:pharmacology; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D015848:Interleukin-5 / Q000096:biosynthesis* / Q000235:genetics; D008875:Middle Aged; D013601:T-Lymphocytes / Q000378:metabolism*; D014158:Transcription, Genetic
D015848:Interleukin-5; D003208:Concanavalin A