Acute Anti-IgE Effect of Topical Application of Formulation of Herbal Extracts in a Peanut Allergic Murine Model

Abstract

S A T U R D A Y 89 Recombinant Probiotic Bacillus Subtilis Spores with Surface Expression of Ara h2 Reduce Peanut-Induced Anaphylaxis in Mice Zhenwen Zhou, PhD, Ying Song, MD, Chaoyi Mao, MD, Kamal D. Srivastava, PhD, Changda Liu, PhD, Nan Yang, PhD, Zhigang Liu, PhD, Xiu-Min Li, MD, MS; Pediatric Allergy and Immunology, Icahn School of Medicine at Mount Sinai, New York, NY, Guangzhou Women and Children’s Medical Center, Guangzhou, People’s Republic of China, Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA, New York, China Academy of Chinese Medicine Science, Beijing, P.R.China, Medicine school of Shenzhen University,Shenzhen, P.R.China. RATIONALE: Food allergy is a serious and sometimes fatal condition. Peanut allergy is the most common cause of fatal food-allergic reactions. Safe therapies for peanut allergy are urgently needed. Bacillus subtilis spores are regarded as a nonpathogenic and have beenwidely used as a probiotic in humans. Because of their safety and stability, they have recently been used as vehicle for delivery of heterologous antigens to the gastrointestinal tract. METHODS: The mucosal adjuvant cholera toxin B subunit (CTB) fused with the peanutmajor allergen Ara h2was co-expressed on the surface coat of Bacillus subtilis spores using molecular cloning strategies. SDS-PAGE and Western Blotting analyses were used to identify CTB-Ara h2 surface expression on spores. Peanut allergic C3H/HeJ mice were orally administered with these recombinant spores expressing CTB-Arah2 for 6 weeks and then challenged with peanut 4 weeks post therapy. Sham treated and na€ive mice were included as controls. RESULTS: CTB-Ara h2 fusion protein expression on the spores coat was verified by SDS-PAGE and Western blotting. Oral administration of recombinant spores significantly increased peanut specific IgA (P 0.05 vs sham) 4 weeks post treatment. Recombinant CTB-Ara h2 spores-treated mice showed significantly reduced symptom scores and plasma histamine levels than sham treated mice (P<0.05 for both). CONCLUSIONS: Oral administration of recombinant Bacillus subtilis spores expressing CTB-Arah2 protected against peanut induced anaphylaxis. Induction of peanut specific IgA was associated with the immunotherapeutic effects.