Functional expression of IL-9 receptor by human neutrophils from asthmatic donors: role in IL-8 release.
Human polymorphonuclear neutrophils (PMNs) express surface receptors for various inflammatory mediators, including IgE and IL-4. Recently, the IL-9R locus has been genetically linked to asthma and bronchial hyperresponsiveness in humans. In this study, we evaluated expression of the IL-9R and the effect of IL-9 on human PMNs. RT-PCR analysis showed the presence of IL-9Ralpha-chain mRNA in PMN RNA preparations from asthmatic patients. Using FACS analysis, surface expression of IL-9Ralpha was detected on PMNs freshly isolated from asthmatics, and to a lesser extent on normal controls. In addition, protein expression of IL-9Ralpha was also detected in peripheral blood and bronchoalveolar lavage PMNs. Furthermore, functional studies showed that IL-9 stimulation of PMNs results in the release of IL-8 in a concentration-dependent manner. The anti-IL-9 neutralizing Ab suppressed this effect, but had no effect on GM-CSF-induced IL-8 release from PMNs. Taken together, these findings suggest a novel role for PMNs in allergic disease through the expression and activation of the IL-9R.
Abdelilah
S
S
Meakins-Christie Laboratories, McGill University, Montreal, Quebec, Canada.
Latifa
K
K
Esra
N
N
Cameron
L
L
Bouchaib
L
L
Nicolaides
N
N
Levitt
R
R
Hamid
Q
Q
D001249:Asthma / Q000097:blood / Q000276:immunology* / Q000378:metabolism* / Q000473:pathology; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000276:immunology; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism; D018922:HL-60 Cells; D006801:Humans; D007150:Immunohistochemistry; D016209:Interleukin-8 / Q000378:metabolism*; D016906:Interleukin-9 / Q000378:metabolism* / Q000502:physiology; D009504:Neutrophils / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D018123:Receptors, Interleukin / Q000096:biosynthesis* / Q000097:blood / Q000235:genetics / Q000502:physiology; D053651:Receptors, Interleukin-9
C508045:IL9R protein, human; D016209:Interleukin-8; D016906:Interleukin-9; D012333:RNA, Messenger; D018123:Receptors, Interleukin; D053651:Receptors, Interleukin-9