The role of STAT1 in activation of IL-3- and IL-5-induced eosinophils by interferon gamma.
Tyrosine phosphorylation of STAT1alpha in eosinophils after IFN-gamma stimulation has been shown, but the biological significance of eosinophil STAT1alpha activation in transmitting the signals through the IFN-gamma receptor remains unknown. The purpose of this study is to determine whether STAT1 is involved in the regulation of eosinophils by IFN-gamma-IFN-gamma receptor interaction. rhIL-3- and rhIL-5-induced eosinophils from CD34+ cells of cord blood on day 28 of culture were used. The cells were washed and further incubated in IL-3- and IL-5-free medium for 48 h. The induced eosinophils constitutively expressed CD69 and lost this expression after a further 48-hour incubation without the cytokines. IFN-gamma significantly upregulated CD69 expression on the 48-hour incubated cells. In inhibitory experiments on STAT1, a phosphorothioate oligo antisense DNA against STAT1alpha was added to IL-3- and IL-5-containing medium from day 15 to day 28 of culture. The oligo DNAs altered neither the expressions of myeloid cell marker CD9 and 13 nor the expression of IFN-gamma receptor on the cells. The added STAT1alpha antisense, but not sense, DNA significantly reduced STAT1alpha mRNA expression in the cells. The STAT1 antisense also significantly inhibited IFN-gamma-induced CD69 expression on the 48-hour incubated eosinophils. In conclusion, these results indicate that IFN-gamma induces CD69 expression in the induced eosinophils through STAT1alpha, suggesting that STAT1alpha may play a significant role in eosinophil regulation by IFN-gamma.
Ochiai
K
K
Department of Internal Medicine, Toho University School of Medicine, Sakura Hospital, Sakura, Japan. kochiai-kkr@umin.ac.jp
Otaka
K
K
Ito
M
M
Tomioka
H
H
D015703:Antigens, CD / Q000096:biosynthesis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000096:biosynthesis; D002454:Cell Differentiation; D002478:Cells, Cultured; D004804:Eosinophils / Q000187:drug effects / Q000276:immunology*; D006412:Hematopoietic Stem Cells / Q000166:cytology; D006801:Humans; D050832:Interferon-Stimulated Gene Factor 3; D007371:Interferon-gamma / Q000494:pharmacology*; D007377:Interleukin-3 / Q000494:pharmacology*; D015848:Interleukin-5 / Q000494:pharmacology*; D037181:Lectins, C-Type; D020319:Oligodeoxyribonucleotides, Antisense / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D000099192:CD69 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D050832:Interferon-Stimulated Gene Factor 3; D007371:Interferon-gamma; D007377:Interleukin-3; D015848:Interleukin-5; D037181:Lectins, C-Type; D020319:Oligodeoxyribonucleotides, Antisense; D012333:RNA, Messenger; D014157:Transcription Factors; D000099192:CD69 Antigens; C079868:gamma interferon activation factor