Interleukin-10 Gene Transfer to the Airway Regulates Allergic Mucosal Sensitization in Mice

Abstract

The objective of this study was to investigate the effect of airway gene transfer of interleukin (IL)-10, a cytokine with potent anti-inflammatory and immunoregulatory activities, on allergic mucosal sensitization. We used a recently described murine model that involves repeated exposures to aerosolized ovalbumin (OVA), daily for 10 d, in the context of granulocyte macrophage colony-stimulating factor (GM-CSF) expression in the airway environment achieved by intranasal delivery of a replication-deficient adenovirus carrying the GM-CSF transgene. The resulting inflammatory response was characterized by a T-helper 2 cytokine profile and marked airway eosinophilia. After complete resolution of the inflammatory response (Day 28), a single exposure to OVA reconstituted airway eosinophilia and induced airway hyperresponsiveness. We show that concurrent expression of IL-10 inhibited GM-CSF-driven OVA-specific inflammation in a dose-dependent manner. Specifically, IL-10 decreased the number of mononuclear cells, neutrophils, and eosinophils in the bronchoalveolar lavage fluid (BALF). Histologic evaluation of the tissue corroborated the findings in the BALF. Concurrent expression of IL-10 at the time of mucosal sensitization abrogated both the cellular and physiologic recall responses in vivo. Studies in interferon (IFN)-gamma knockout mice demonstrated that prevention of airway eosinophilia by IL-10 was IFN-gamma-independent and that expression of IL-10 was associated with decreased levels of IL-4, IL-5, and tumor necrosis factor-alpha in the BALF. Flow cytometric analysis of dispersed lung cells showed that expression of IL-10 in the airway reduced the absolute number of Class II major histocompatibility complex (MHC)(+)/CD11c(+) (dendritic cells) and Class II MHC(+)/Mac-1(bright) (macrophages) cells expressing the costimulatory molecules B7.1 and B7.2 by 30%. However, IL-10 coexpression did not prevent expansion of CD4 and CD8 T cells or expression of the early activation marker CD69 on T cells. Thus, airway gene transfer of IL-10 altered the immune response to OVA in a way that resulted in inhibition of airway inflammation. These findings suggest that development of an immunoregulatory strategy based on IL-10, alone or in combination with GM-CSF, warrants further consideration.

Alterations in Nitric Oxide and Cytokine Production with Airway Inflammation in the Absence of IL-10

“…Although our AR and inflammation responses generally agree with those of prior studies (30,31,34), they are not consistent with one study in which IL-10 Ϫ/Ϫ mice demonstrated significantly decreased BAL macrophage counts and increased eosinophilia and AR, as compared with the C57 mice (41). Those responses were consistent with what would be expected with a lack of IL-10 as an anti-inflammatory cytokine and are in agreement with phenotypic expectations that would come from human data demonstrating a lack of IL-10 production in asthmatics (7,8).…”

“…Earlier studies have shown that elevations in Penh are correlated with eosinophilia in BALB/c mice (37); however, this association has been reported recently to be weak or absent, and there has been some controversy as to whether Penh can accurately reflect alterations in airway responsiveness in C57 mice (38,39). Our data suggest that alterations in AR associated with AI were consistent with expectations of airway hyporesponsiveness in IL-10 Ϫ/Ϫ mice, relative to their C57 IL-10-sufficient counterparts (30,31,33,34). Although we acknowledge some limitations to the Penh technique, we agree with the assertion by DeLorme and Moss (40) that the choice of the Penh measurement should be linked to the study objective and the ability to track alterations in AR previously verified by more invasive measures of lung resistance.…”

“…The effect of IL-10 on allergen-driven AR has been reported in several previous in vivo and in vitro animal studies (30,31,33,34). The evidence from those studies suggests that IL-10 influences or acts in concert with one or more inflammatory factors to increase smooth muscle activity (31), perhaps involving airway smooth muscle autocrine signaling through IL-5 (33) or regulation of surfactant protein D (35).…”

Fine mapping and single nucleotide polymorphism association results of candidate genes for asthma and related phenotypes

“…IL10 is located on chromosome 1q31.1 and functions as a cytokine inhibitory factor decreasing the synthesis of proinflammatory molecules [Stampfli et al, 1999]. IL10 reduces IL4 and IL5 expression as well as IgE titers and eosinophil rates [Moore et al, 1993;van Scott et al, 2000].…”

Allergen immunotherapy with nanoparticles containing lipopolysaccharide from Brucella ovis

“…Anaphylactic symptoms (activity, bristly hair, and cyanosis) were evaluated 30 min after the challenge using a scoring system modified from previous reports [29,30]. Reactions severity was classified in following categories depending on their gravity: i) (-) absent; ii) (+) weak; iii) (++) moderate; and iv) (+++) strong, and the mobility was classified in i) low or ii) normal, depending on the activity of the animals.…”