Neutralizing Oxidized Phosphatidylcholine Reduces Airway Inflammation and Hyperreactivity in a Murine Model of Allergic Asthma

Abstract

Oxidative stress is associated with asthma pathobiology. We reported that oxidized phosphatidylcholines (OxPCs) are mediators of oxidative stress and accumulate in the lung in response to allergen challenge. The current study begins to unravel mechanisms for OxPC accumulation in the lung, providing the first insights about how OxPCs underpin allergic airway pathophysiology, and pre-clinical testing of selective neutralization of OxPCs in a murine model of allergic asthma. We hypothesized that intranasal delivery of E06, a natural IgM antibody that neutralizes the biological activity of OxPCs, can ameliorate allergen-induced airway inflammation and airway hyperresponsiveness. Adult BALB/c mice were intranasally (i.n.) challenged with house dust mite (HDM) (25 μg/mouse, 2 weeks). Some animals also received E06 monoclonal antibody (mAb) (10 µg) i.n. 1 hr before each HDM challenge. HDM challenge reduced mRNA for anti-oxidant genes (SOD1, SOD2, HO-1, and NFE2L2) in the lung by several orders of magnitude (p p p p p p p p p p < 0.05) and a trend to diminish accumulation of other cytokines (e.g., IL-4, -10, and -33, and IFN-γ). E06 mAb treatment also inhibited HDM exposure-induced increases in total respiratory resistance and small airway resistance by 24% and 26%, respectively. In conclusion, prophylactic treatment with an OxPC-neutralizing antibody significantly limits allergen-induced airway inflammation and airway hyperresponsiveness, suggesting that OxPCs are important mediators of oxidative stress-associated allergic lung pathophysiology.

Keywords

• oxidized phosphatidylcholines
• allergic asthma
• neutralizing IgM
• oxidative stress