Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/28/2013
Publication Date: 1/12/2014
Citation: Wang, J., Niu, X., Du, X., Smith, D., Meydani, S.N., Wu, D. 2014. Dietary supplementation with white button mushroom augments the protective immune response to Salmonella vaccine in mice. Journal of Nutrition. 144(1):98-105. DOI:10.3945/jn.113.185165. Interpretive Summary: Food and water can be contaminated by microorganisms that cause infection in humans and animals. One of these well-known organisms called Salmonella is among the most common food borne microbes and is the leading cause of death due to contaminated food. Vaccination is an effective way of preventing Salmonella infection. Since diet can also affect the immune system’s response, we sought to investigate the effect of a method that combined vaccination and nutritional interventions on occurrence of illness from salmonella. We determined the effect of consuming white button mushrooms (WBM) on immune response to salmonella vaccination. We showed that mice supplemented with WBM had significantly better immune response (antibody titer) to salmonella vaccine compared to mice fed a control diet. Furthermore, mice fed WBM had less recurrence of illness from the next exposure to salmonella infection compared to those fed a control diet. These findings suggest that increasing consumption of WBM may improve the effectiveness of the Salmonella vaccine and thus help reduce deaths that occur from this foodborne pathogen.
Technical Abstract: We previously showed that dietary white button mushrooms (WBM) enhanced natural killer cell activity and that in vitro WBM supplementation promotes maturation and function of dendritic cells (DC). The current study investigated whether WBM consumption would enhance pathogen-specific immune response using a Salmonella vaccination and infection animal model. C57BL/6 mice were fed diets containing 0, 2, or 5 percent WBM for 4 wk before oral vaccination with live attenuated Salmonella typhimurium SL1479. Four wk after immunization, mice were orally infected with virulent Salmonella typhimurium SL1344. Immunization increased animal survival and among immunized mice, the 2 percent WBM group had a higher survival rate than the other groups. Next, we fed mice 2 percent WBM to determine the immunological mechanism underlying the WBM-potentiated protective effect. We found that WBM supplementation increased both total and Salmonella-specific blood IgG and fecal IgA levels. WBM-fed mice also had a higher IgG2a and unchanged IgG1 production leading to an elevated IgG2a/IgG1 ratio, indicating an enhanced Th1 response. Consistent with these results, WBM-fed mice had higher IFN-gamma, TNF-alpha, and IL-17A production and unchanged IL-4 production in their splenocytes after polyclonal (anti-CD3/CD28) or antigen (heating-killed Salmonella typhimurium)-specific stimulation. Furthermore, WBM-fed mice had more DC in the spleen, and these DC expressed higher levels of activation markers CD40 and MHC-II. These mice also produced more IL-12 and TNF-alpha post-immunization. Together, these results suggest that WBM may improve Salmonella vaccine efficacy through an enhanced adaptive immune response.