Improvement of allergic dermatitis via regulation of the Th1/Th2 immune system balance by macrophages activated with lipopolysaccharide derived from Pantoea agglomerans (IP-PA1).

Recently, the incidence of allergies has been increasing, especially in advanced countries. The cause of these allergies is believed to be a failure in the immune system balance that has been caused by changes in the living environment. The incidence of allergy shows a negative correlation with the decrease of infectious diseases in childhood. It has been suggested that the key to alleviating allergies is to activate innate immunity by exposure to microbial components such as lipopolysaccharides (LPS). The activation of innate immunity is expected to normalize the T-helper type 1 and 2 (Th1/Th2) immune system balance and to suppress the excessive reaction of Th2 type responses that cause immunoglobulin (Ig) E-dependent allergies. This study introduces information on how the activation of macrophages, which are important in innate immunity, by LPS derived from Pantoea agglomerans (IP-PA1) caused suppressive effects on type I allergic reactions and improved allergic dermatitis. We also summarize our hypothesis that regulating the immune system balance using LPS to stimulate macrophages may be an important procedure for preventing and improving allergic dermatitis.