Human peripheral eosinophils express functional interferon-gamma receptors (IFN-gammaR).
In order to determine whether or not IFN-gammaR is associated with regulatory mechanisms on human eosinophil function, we examined the expression of functional IFN-gammaR on human peripheral eosinophils. In this study, peripheral blood eosinophils were obtained from seven normal controls and 12 patients (bronchial asthma, n = 9, and hypereosinophilic syndrome (HES), n = 3), and the purity of eosinophils was 97.11 +/- 2.31%, n = 19. We first showed that anti-IFN-gammaR alpha-chain MoAb reacted with all tested eosinophils of both normal controls and patients by flow cytometry analysis. We also showed expression of mRNA for the alpha-chain of IFN-gammaR in all purified eosinophils of six individuals. Further, to characterize IFN-gammaR on eosinophils, we did binding experiments with 125I-IFN-gamma on purified peripheral eosinophils. The linear Scatchard plot indicated a single type of high-affinity binding sites (dissociation constant (Kd) = 3.89-4.95 x 10(-10) M, numbers of binding sites = 183-233/cell, n = 3). To determine whether IFN-gammaR on eosinophils is functional, we examined surface eosinophilic cationic protein (ECP) and CD69 induction after IFN-gammaR ligation with recombinant human IFN-gamma (rhIFN-gamma) on eosinophils by flow cytometry. rhIFN-gamma stimulation significantly induced both ECP and CD69 expression on the 2-18 h-cultured eosinophils in a dose-dependent manner. Further, the effects of rhIFN-gamma stimulation were significantly blocked by both a neutralizing anti-IFN-gamma MoAb and a blocking anti-IFN-gammaR MoAb. These results suggest that human peripheral eosinophils express functional IFN-gammaR.
Ishihara
C
C
Department of Paediatrics, Toho University School of Medicine, Sakura Hospital, Chiba, Japan.
Ochiai
K
K
Kagami
M
M
Takashahi
H
H
Matsuyama
G
G
Yoshida
S
S
Tomioka
H
H
Koya
N
N
D000293:Adolescent; D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000096:biosynthesis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000096:biosynthesis; D001798:Blood Proteins / Q000096:biosynthesis; D002648:Child; D002675:Child, Preschool; D047091:Eosinophil Granule Proteins; D004804:Eosinophils / Q000737:chemistry*; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D037181:Lectins, C-Type; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis; D017471:Receptors, Interferon / Q000032:analysis* / Q000235:genetics; D011994:Recombinant Proteins; D012260:Ribonucleases; D000096743:Interferon gamma Receptor; D000099192:CD69 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D001798:Blood Proteins; D047091:Eosinophil Granule Proteins; D007371:Interferon-gamma; D037181:Lectins, C-Type; D012333:RNA, Messenger; D017471:Receptors, Interferon; D011994:Recombinant Proteins; D012260:Ribonucleases; D000096743:Interferon gamma Receptor; D000099192:CD69 Antigens