title: Interleukin-9 enhances interleukin-5 receptor expression, differentiation, and survival of human eosinophils.
abstract: Interleukin-9 (IL-9) has been implicated in the pathogenesis of allergic disorders. To examine the interaction between IL-9 and eosinophils, we evaluated mature peripheral blood eosinophils for their expression of the specific alpha-subunit of the IL-9 receptor (IL-9R-alpha). The expression of IL-9R-alpha by human eosinophils was detected at the messenger RNA (mRNA) and protein levels by reverse transcriptase-polymerase chain reaction (RT-PCR), flow cytometry, and immunocytochemical analysis, respectively. Functional analyses demonstrated that recombinant human (rh)IL-9 inhibited in vitro peripheral blood human eosinophil apoptosis in a concentration-dependent manner. We then examined the role of IL-9 in eosinophil differentiation using the human cord blood CD34(+) cells and human promyelocytic leukemia cells (HL-60). The addition of IL-9 to CD34(+) cells cultured in IL-3 and IL-5 enhanced eosinophil development, and IL-9 alone induced the expression of IL-5R-alpha. IL-9 also up-regulated the IL-5R-alpha chain cell surface expression during terminal eosinophil differentiation of the HL-60 cell line. Our findings suggest that IL-9 may potentiate in vivo eosinophil function by increasing their survival and IL-5-mediated differentiation and maturation. Taken together, these results suggest a mechanism by which IL-9 potentiates airway and tissue eosinophilia.
authors.affiliation: Meakins-Christie Laboratories, McGill University, Montreal, Quebec, Canada.
authors.forename: A S
authors.initials: AS
authors.lastname: Gounni
authors.forename: B
authors.initials: B
authors.lastname: Gregory
authors.forename: E
authors.initials: E
authors.lastname: Nutku
authors.forename: F
authors.initials: F
authors.lastname: Aris
authors.forename: K
authors.initials: K
authors.lastname: Latifa
authors.forename: E
authors.initials: E
authors.lastname: Minshall
authors.forename: J
authors.initials: J
authors.lastname: North
authors.forename: J
authors.initials: J
authors.lastname: Tavernier
authors.forename: R
authors.initials: R
authors.lastname: Levit
authors.forename: N
authors.initials: N
authors.lastname: Nicolaides
authors.forename: D
authors.initials: D
authors.lastname: Robinson
authors.forename: Q
authors.initials: Q
authors.lastname: Hamid
mesh_terms: D018952:Antigens, CD34; D002454:Cell Differentiation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004804:Eosinophils / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D018922:HL-60 Cells; D006412:Hematopoietic Stem Cells / Q000166:cytology; D006801:Humans; D016906:Interleukin-9 / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis; D018123:Receptors, Interleukin / Q000096:biosynthesis*; D053649:Receptors, Interleukin-5
chemical_list: D018952:Antigens, CD34; D016906:Interleukin-9; D012333:RNA, Messenger; D018123:Receptors, Interleukin; D053649:Receptors, Interleukin-5