Mixed polysaccharides derived from Shiitake mushroom, Poriacocos, Ginger, and Tangerine peel enhanced protective immune responses in mice induced by inactivated influenza vaccine

Influenza viruses are responsible for severe respiratory tract infections of individuals and may cause pandemics with a high risk of mortality and morbidity. Although vaccination is a primary means for prevention of influenza virus infections, poor vaccine performance or inadequate immune responses limits the efficacy of current vaccines and raises question regarding whether a better correlates of protection procedures should be performed. Here, we want to evaluate whether mixed polysaccharides (MPs) derived from shiitake mushroom, poriacocos, ginger, and dried tangerine peel could promote the immune response of inactivated influenza vaccine. Firstly, MPs were given to mice each day and for a total of 30 days, during which two immunizations were performed on mice on days 14 and 21. The results showed that serum total IgG and IgG2a levels were increased in MPs-treated mice on day 30. Following A/WSN/33 (H1N1) virus challenge, we found that MPs pretreatment in mice could increase mice weight gain and attenuate their clinical symptoms. Additional protective factors were also observed including prevention of excessive lung inflammation, promotion of CD19+ and CD278+ cell proportions in lung, elimination of virus in lung, and elevation of IFN-γ levels in serum. The current study demonstrate that MPs from shiitake mushroom, poriacocos, ginger, and dried tangerine peel could promote the immune efficacy and alleviate lung inflammation in mice with vaccines against H1N1 virus infection by activating both humoral and cellular immunity.