Rabbit Anti-STAT6 monoclonal antibody, clone TZ03-83

Alternatively activated macrophages (AAMs) can contribute to wound healing, regulation of glucose and fat metabolism, resolution of inflammation, and protective immunity against helminths. Their differentiation, tissue distribution, and effector functions are incompletely understood. Murine AAMs express high levels of resistin-like molecule (RELM) alpha, an effector protein with potent immunomodulatory functions. To visualize RELM alpha(+) macrophages (M Phi s) in vivo and evaluate their role in defense against helminths, we generated RELM alpha reporter/deleter mice. Infection with the helminth Nippostrongylus brasiliensis induced expansion of RELM alpha(+) lung interstitial but not alveolar M Phi s in a STAT6-dependent manner. RELM alpha(+) M Phi s were required for prevention of fatal lung damage during primary infection. Furthermore, protective immunity was lost upon specific deletion of RELM alpha(+) M Phi s during secondary infection. Thus, RELM alpha reporter/deleter mice reveal compartmentalization of AAMs in different tissues and demonstrate their critical role in resolution of severe lung inflammation and protection against migrating helminths.

Background: Curcumin (Cur), derived from Curcuma species, exhibits anti-inflammatory, antioxidant, and anticancer effects. Although Cur has some beneficial effects on asthma, its clinical application is limited by its low bioavailability. Tetrahydrocurcumin (THC), the major active metabolite of Cur, has multiple biological functions, similarly to Cur, and importantly, it showed enhanced bioavailability in tissues and plasma. However, the effect of THC on asthma has not been reported. Objective: The current study sought to investigate the efficacy of dietary THC on allergic asthma compared to that of Cur in an animal model. Methods: The anti-inflammatory effects of Cur and THC were evaluated in an ovalbumin-induced asthmatic mouse model. The nasal symptoms, pathological alterations of the lung tissues, oxidants and antioxidants, cytokine production, T cell subsets, and Th2-related signalling pathway activity were assessed. Results: Both THC and Cur had beneficial effects on asthmatic mice with regard to nasal symptoms, pathological changes (eosinophils and mucus hyper-production), oxidative stress (malondialdehyde), cytokine production (IL-13), Th17 and cytotoxic T cell subsets, and Th2 signalling pathway (IL-4R alpha-Jak1-STAT6 and Jagged1/Jagged2-Notch1/Notch2 axis) activity. THC was more effective than Cur in suppressing tissue eosinophilia, mucus production, and IL-4R alpha/Jak1/STAT6 pathway activity. Furthermore, only THC inhibited peripheral eosinophil levels, Th2 cytokines (IL-4 and IL-5), and Th2 cell subsets and enhanced an antioxidant enzyme (glutathione). Conclusion and Clinical Relevance: The above results demonstrated for the first time that THC was superior to Cur in modulating allergic asthmatic phenotypes, especially attenuating the Th2 response. THC might be a potentially effective agent for asthma treatment.