Oral Administration of Lactococcus lactis Expressing Mite and Cockroach Major Allergens Alleviates Progression of Atopic March in a Mouse Model.

Purpose: Atopic march is defined as the development of atopic dermatitis in early childhood. We recently developed an atopic march mouse model through skin sensitization with aeroallergens from house dust mites and cockroaches. Using this model, this study aimed to evaluate the oral immunotherapy efficacy of Lactococcus lactis harboring specific antigens on the progression of atopic march.

Methods: Dust mite major allergen Der p 2 and cockroach Per a 2-372 were expressed in L. lactis as a fusion recombinant clone (D2P2). L. lactis-D2P2 was administered intragastrically to Aeroallergen patch-sensitized mice once a day for a total of 35 times. The immunological variables in sera, scratching behavior, airway hyperresponsiveness (AHR), and pathology of lungs and skin were evaluated.

Results: Our data showed that L. lactis-D2P2 significantly lowered total immunoglobulin E levels, decreased scratch bouts, and relieved AHR compared with the control mice. Histological analysis of the skin and lung tissue demonstrated the therapeutic effects of L. lactis-D2P2 to modulate immune responses via decreased eosinophil infiltration and reduced expression of key cytokines, interleukin (IL)-31 and IL-13, respectively.

Conclusions: The results imply that mucosal allergen-specific immunotherapy of L. lactis-D2P2 is a more cost-effective alternative to conventional subcutaneous allergen-specific immunotherapy. This study provides a promising platform for the development of novel oral protein-based vaccines in the early prevention of allergies.