Premium
Interleukin‐16 inhibits interleukin‐13 production by allergen‐stimulated blood mononuclear cells
Author(s) -
El Bassam Souad,
Pinsonneault Stéphane,
Kornfeld Hardy,
Ren Fucheng,
Menezes José,
Laberge Sophie
Publication year - 2006
Publication title -
immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.297
H-Index - 133
eISSN - 1365-2567
pISSN - 0019-2805
DOI - 10.1111/j.1365-2567.2005.02269.x
Subject(s) - peripheral blood mononuclear cell , allergen , immunology , cytokine , interleukin 5 , interleukin , interleukin 4 , medicine , chemistry , allergy , in vitro , biochemistry
Summary Expression of interleukin (IL)‐16 is increased in bronchial mucosal biopsies of atopic asthmatics compared to normal controls. The functional significance of increased expression of IL‐16 at sites of allergic inflammation is not yet clear. We have previously shown that IL‐16 inhibits IL‐5 secretion by allergen‐stimulated peripheral blood mononuclear cells (PBMC). We investigated whether IL‐16 inhibits the production of other T helper 2 cytokines, namely IL‐13 and IL‐4, by allergen‐specific T cells. PBMC from ragweed‐sensitive atopic subjects were stimulated with allergen extract for cytokine production in the presence or absence of rhIL‐16. Production of cytokines was assessed by enzyme‐linked immunosorbent assay and reverse transcription–polymerase chain reaction. To evaluate whether the modulatory effect of IL‐16 on cytokine synthesis was mediated by interferon‐γ (IFN‐γ), IL‐10, IL‐12 or IL‐18, allergen‐stimulated PBMC were cultured in presence of IL‐16 and neutralizing concentrations of relevant antibodies. Allergen‐stimulated PBMC produced significantly elevated levels of IL‐13 (90–740 pg/ml) as compared to unstimulated PBMC (0–375 pg/ml, P < 0·01). Addition of rhIL‐16 resulted in down‐regulation of IL‐13 mRNA expression as well as significantly reduced amounts of IL‐13 released by allergen‐stimulated PBMC (0–457 pg/ml, P < 0·001), as observed for IL‐5. No effect of IL‐16 was observed on IL‐4 mRNA expression. Treatment with IL‐16 resulted in increased levels of IL‐10 and IL‐18 in allergen‐stimulated cell culture. Neutralization of IFN‐γ, IL‐12, IL‐10 or IL‐18 did not alter the inhibitory effects of IL‐16 on IL‐13 and IL‐5 secretion by allergen‐stimulated PBMC. IL‐16 did not modify IL‐13 synthesis by anti‐CD3‐stimulated CD4 + T cells, but it significantly reduced the production of IL‐5. These data suggest that IL‐16 may play an important immunoregulatory role in allergic states in response to allergen.