Regulation of CD31 expression and interleukin-4 production by human cord blood CD4+ T cells with interleukin-4 and interleukin-7.
BACKGROUND
T helper 2 cell type cytokines, such as interleukin (IL)-4 and IL-5, play pivotal roles in the development of allergic diseases. However, the mechanism by which naive CD4+ T cells acquire the ability to produce these cytokines remains unclear. Recently, it was reported that IL-7 induces the ability to produce IL-4 as well as interferon (IFN)-gamma and IL-5 in naive CD4+ T cells without TCR stimulation. To further analyze the mechanism of acquiring IL-4-producing ability by naive CD4+ T cells, the effects of IL-7 on human cord blood CD4+ T cells were compared with those of IL-4, which induced the ability to produce IFN-gamma but not IL-4.


RESULTS
Interleukin-7 preserved the population of CD4+CD31- T cells in cord blood and induced their IL-4-producing ability without T cell receptor (TCR) stimulation, while IL-4 induced CD31 on CD31- T cells and could not induce their IL-4-producing ability. Both the CD31-inducing effect and the inhibitory priming effect for IL-4-production by IL-4 were also observed after cord blood CD4+ T cells had been primed with IL-7 and acquired the IL-4-producing ability.


CONCLUSIONS
Interleukin-7 induced the IL-4-producing ability in naive CD4+CD31- T cells without TCR stimulation, suggesting that the signal transduction via CD31 may have an inhibitory effect on the acquisition of the IL-4-producing ability by cord blood CD4+ T cells in the absence of TCR stimulation.
Katamura
K
K
Department of Pediatrics, Faculty of Medicine, Kyoto University, Japan. kkenji@kuhp.kyoto-u.ac.jp
Fukui
T
T
Kiyomasu
T
T
Ohmura
K
K
Iio
J
J
Ueno
H
H
D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism*; D002478:Cells, Cultured; D005312:Fetal Blood / Q000166:cytology*; D006801:Humans; D015847:Interleukin-4 / Q000097:blood* / Q000494:pharmacology*; D015851:Interleukin-7 / Q000494:pharmacology*; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000097:blood*
D015851:Interleukin-7; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D015847:Interleukin-4