Interleukin-18 enhances the production of interleukin-8 by eosinophils.
Interleukin-18 (IL-18), a proinflammatory cytokine, leads to IFN-gamma production by NK or T cells, induces Th1 differentiation and suppresses IgE synthesis by B cells when acting on responding cells together with IL-12. IL-18 also exhibits biological activities related to allergic inflammation such as histamine or IL-4 release from basophils and accumulation of eosinophils in localized lesions in allergic model mice. In this study, Reverse transcription (RT)-PCR analysis revealed that IL-18 receptor alpha chain mRNA was expressed in both freshly prepared eosinophils and two eosinophilic cell lines (YY-1 and EoL-1 cells). Flow cytometry and RT-PCR analyses revealed that the treatment of YY-1 cells with n-butyric acid promoted cell maturation and caused an enhancement of IL-18 receptor alpha chain expression. IL-18 had little effect on the survival of peripheral eosinophils, but it dose-dependently augmented IL-8 synthesis by YY-1 cells. In addition, IL-18-mediated up-regulation of IL-8 expression in eosinophils from a patient suffering from hyper-eosinophilic syndrome was confirmed. Our findings using peripheral blood eosinophils and eosinophilic cell line suggest the functional importance of IL-18 in the induction of IL-8 and a potential proinflammatory role in allergy.
Wang
W
W
Department of Internal Medicine III, Osaka University Medical School, Osaka, Japan.
Tanaka
T
T
Okamura
H
H
Sugita
M
M
Higa
S
S
Kishimoto
T
T
Suemura
M
M
D020148:Butyric Acid / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D004804:Eosinophils / Q000187:drug effects* / Q000378:metabolism* / Q000473:pathology; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D017681:Hypereosinophilic Syndrome / Q000378:metabolism / Q000473:pathology; D020382:Interleukin-18 / Q000494:pharmacology*; D053727:Interleukin-18 Receptor alpha Subunit; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018123:Receptors, Interleukin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D053724:Receptors, Interleukin-18; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
C508572:IL18R1 protein, human; D020382:Interleukin-18; D053727:Interleukin-18 Receptor alpha Subunit; D016209:Interleukin-8; D012333:RNA, Messenger; D018123:Receptors, Interleukin; D053724:Receptors, Interleukin-18; D020148:Butyric Acid