Recovery from immunosuppression-related disorders in humans and animals by IP-PA1, an edible lipopolysaccharide.

Immunopotentiator from Pantoea agglomerans 1 (IP-PA1), an edible lipopolysaccharide (LPS) derived from symbiotic bacteria in crops, is a promising immunomodulator. It activates macrophages and protects from chemotherapeutic agent-induced growth inhibition in macrophages in vitro. We showed the immune-recovery effects of IP-PA1 in a chicken model of dexamethasone-induced stress in which IP-PA1 inhibited thymic and bursal atrophy and improved antibody production in response to vaccination. Furthermore, we showed IP-PA1 improved survival of melanoma-bearing, doxorubicin-treated mice, although not directly affecting the proliferation of melanoma cells, dominantly through the improvement of host antitumor immunity. These results suggest that IP-PA1 could have other possible applications in the treatment of various immunosuppression-related disorders in humans and animals.