An atopic dermatitis-like murine model by skin-brushed cockroach Per a 2 and oral tolerance induction by Lactococcus lactis-derived Per a 2

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.

N-benzyl-N-methyldecan-1-amine, derived from garlic, and its derivative alleviate 2,4-dinitrochlorobenzene-induced atopic dermatitis-like skin lesions in mice

Given the intricate etiology and pathogenesis of atopic dermatitis (AD), the complete cure of AD remains challenging. This study aimed to investigate if topically applying N-benzyl-N-methyldecan-1-amine (BMDA), derived from garlic, and its derivative [decyl-(4-methoxy-benzyl)-methyl-1-amine] (DMMA) could effectively alleviate AD-like skin lesions in 2,4-dinitrochlorobenzene (DNCB)-treated mice. Administering these compounds to the irritated skin of DNCB-treated mice significantly reduced swelling, rash, and excoriation severity, alongside a corresponding decrease in inflamed epidermis and dermis. Moreover, they inhibited spleen and lymph node enlargement and showed fewer infiltrated mast cells in the epidermis and dermis through toluidine-blue staining. Additionally, they led to a lower IgE titer in mouse sera as determined by ELISA, compared to vehicle treatment. Analyzing skin tissue from the mice revealed decreased transcript levels of inflammatory cytokines (TNF-α, IL-1β, and IL-6), IL-4, iNOS, and COX-2, compared to control mice. Simultaneously, the compounds impeded the activation of inflammation-related signaling molecules such as JNK, p38 MAPK, and NF-κB in the mouse skin. In summary, these findings suggest that BMDA and DMMA hold the potential to be developed as a novel treatment for healing inflammatory AD.