Abstract
Cats (Felis domesticus) are rich source of airborne allergens that prevailed in the environment and sensitized a number of people to allergy. In this study, a mouse model of allergic rhinitis caused by the cat allergens was developed for the first time and the model was used for testing therapeutic efficacy of a novel intranasal liposome-entrapped vaccines made of native Fel d 1 (major cat allergen) in comparison with the vaccine made of crude cat hair extract (cCE). BALB/c mice were sensitized with cCE mixed with alum intraperitoneally and intranasally. The allergic mice were treated with eight doses of either liposome (L)-entrapped native Fel d 1 (L-nFD1), L-cCE), or placebo on every alternate day. Vaccine efficacy evaluation was performed one day after provoking the treated mice with aerosolic cCE. All allergenized mice developed histological features of allergic rhinitis with rises of serum specific-IgE and Th2 cytokine gene expression. Serum IgE and intranasal mucus production of allergic mice reduced significantly after vaccination in comparison with the placebo mice. The vaccines also caused a shift of the Th2 response (reduction of Th2 cytokine expressions) towards the non-pathogenic responses: Th1 (down-regulation of the Th1 suppressive cytokine gene, IL-35) and Treg (up-regulation of IL-10 and TGF-β). In conclusions, a mouse model of allergic rhinitis to cat allergens was successfully developed. The intranasal, liposome-adjuvanted vaccines, especially the refined single allergen formulation, assuaged the allergic manifestations in the modeled mice. The prototype vaccine is worthwhile testing further for clinical use in the pet allergic patients.
Highlights
Cats contribute a rich source of airborne allergens that sensitize about 5–20% of atopic patients [1,2]
RNAlater RNA stabilization reagent (RNA laterTM) was from QIAGEN GmbH, Hilden, Germany; Phusion Hot Start II DNA Polymerase, Anchored Oligo dT, RevertAid First Strand Complementary DNA (cDNA) Synthesis Kit, HisPurTM Nickel-nitrilotriacetic acid (Ni-NTA) Resin and ImjectTM Alum Adjuvant were from Thermo Fisher Scientific, MA, USA; Isopropyl-β-D-Thiogalactopyranoside (IPTG) was from affymetrix, USB, CA, USA; Total RNA Mini Kit from Geneaid Biotech, Taiwan; cholesterol, dichloromethane, paraformaldehyde and Tween-20 were from Sigma-Aldrich, Germany
Fel d 1-specific mouse monoclonal antibody (mAb) was added to the CNBr-activated Sepharose 4B resin (GE Healthcare, UK) and the preparation was rotated at 25°C for 1 h
Summary
ReagentsCNBr-activated Sepharose 4B resin was from GE Healthcare, UK; didodecyldimethylammonium bromide (DDAB) was from Fluka, Germany; phosphatidylcholine (soybean lecithin, Lipoid-S-100) was from Lipoid AG, Switzerland. Preparation of crude cat hair extract, and native and recombinant Fel d 1. Native Fel d 1 (nFel d 1) was purified from the cCE by mouse monoclonal antibody (mAb) based-affinity resin. Fel d 1-specific mouse mAb was added to the CNBr-activated Sepharose 4B resin (GE Healthcare, UK) and the preparation was rotated at 25°C for 1 h. Excess antibody was removed; the resin was washed with the coupling buffer and blocked with 0.1 M Tris-HCl, pH 8.0, for 2 h. After washing several times with 0.1 M acetic acid/sodium acetate, pH 4.0 containing 0.5 M NaCl followed by 0.1 M Tris-HCl, pH 8.0 containing 0.5 M NaCl, cCE was mixed with the mAb-adsorbed resin and rotated at 25°C for 2 h.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
