Oral administration of Hsp65-producing Lactococcus lactis attenuates allergic asthma in a murine model.

Aims: Allergic asthma is a chronic inflammatory lung disease characterized by a Th2-type immune response pattern. The development of nonspecific immunotherapy is one of the primary goals for the control of this disease.

Methods And Results: In this study, we evaluated the therapeutic effects of Lactococcus lactis-producing mycobacterial heat shock protein 65 (LLHsp65) in an ovalbumin (OVA)-induced allergic asthma model. OVA-challenged BALB/c mice were orally administrated with LLHsp65 for 10 consecutive days. The results demonstrate that LLhsp65 attenuates critical features of allergic inflammation, like airway hyperresponsiveness and mucus production. Likewise, the treatment decreases the pulmonary eosinophilia and the serum level of OVA-specific IgE. In addition to deviating immune responses towards Th1-cytokine profile, increase regulatory T cells, and cytokine levels, such as IL-6 and IL-10.

Conclusions: Our results reveal that the mucosal immunotherapy of LLHsp65 significantly reduces the overall burden of airway allergic inflammation, suggesting a promising therapeutic strategy for allergic asthma treatment.

Significance And Impact Of The Study: This research reveals new perspectives on nonspecific immunotherapy based on the delivery of recombinant proteins by lactic acid bacteria to treat of allergic disorders.