|Lewis, Erin - Jean Mayer Human Nutrition Research Center On Aging At Tufts University|
|Ren, Zhihong - National Institute For Communicable Diseases (NICD)|
|Defuria, Jason - Jean Mayer Human Nutrition Research Center On Aging At Tufts University|
|Obin, Martin - Jean Mayer Human Nutrition Research Center On Aging At Tufts University|
|Meydani, Simin - Jean Mayer Human Nutrition Research Center On Aging At Tufts University|
|Wu, Dayong - Jean Mayer Human Nutrition Research Center On Aging At Tufts University|
Submitted to: British Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/23/2018
Publication Date: 6/1/2018
Citation: Lewis, E.D., Ren, Z., DeFuria, J., Obin, M.S., Meydani, S.N., Wu, D. 2018. Dietary supplementation with blueberry partially restores T cell-mediated function in high fat diet-induced obese mice. British Journal of Nutrition. 119(12):1393-1399. https://doi.org/10.1017/S0007114518001034.
DOI: https://doi.org/10.1017/S0007114518001034 Interpretive Summary: An impaired immune system may be one reason obese individuals are more susceptible to infection. New evidence suggests that a high fat diet and/or obesity may impair the immune system's function and its ability to protect and restore an individual's health. Since blueberries have been shown to reduce inflammation in fat tissue, our research intended to uncover the impact of blueberries on systemic immune function and their potential to restore function of an impaired immune system caused by obesity. In a 12 week study, mice were divided into 3 dietary groups: low fat, high fat and high fat supplemented with blueberries. After 12 weeks, the immune system's function was significantly lower in both high fat groups compared to the low fat group. Of note, reduction in the function of an important type of immune cells called T cells was partially prevented by 10-50 percent in the mice fed a high fat diet supplemented with blueberries. Our research has shown the negative impact of a high fat diet on the immune system's functionality, and it gives us insight into how a high fat diet and/or obesity can disrupt the immune system's function. Further, the protective effects of blueberries can strengthen the immune system's impaired response due to obesity, which may help to protect against infection and disease.
Technical Abstract: Blueberry, rich in antioxidant and anti-inflammatory phytochemicals, has been demonstrated to lower the inflammatory status in adipose tissue induced by high fat diet and obesity. However, the effect of blueberry on systemic immune functions has not been examined. C57BL/6 mice were randomized to 1 of 3 diets: low fat diet (LFD), high fat diet (HFD), or high fat diet plus 4 percent (w/w) blueberry (HFD+B), for 8 or 12 weeks. After 8 and 12 weeks, both HFD groups weighed more than LFD group, and at 12 weeks, HFD+B-fed mice weighed more and had significantly more adipose tissue than HFD-fed mice. After 12 weeks, T cell mitogen (Concanavalin A, phytohemagglutinin, anti-CD3 or anti-CD3/CD28)-stimulated T cell proliferation was significantly less in both HFD groups, compared to LFD group. Notably, HFD-associated decrements in T cell proliferation were partially (10-50 percent) prevented by blueberry supplementation. Moreover, in response to anti- CD3/CD28 stimulation at 12 weeks, splenocytes from HFD mice, but not from HFD+B mice, produced less IL-4 and interferon-gamma than splenocytes from LFD mice. In response to an acute LPS challenge, splenocytes from both HFD groups produced less IL-6 and TNF-alpha than splenocytes from LFD mice, indicating an impaired acute innate immune response. By demonstrating deleterious impacts of HFD feeding on T cell proliferation and splenocyte immune responses, our results provide new insight into how HFD/ obesity can disrupt systemic immune function. Moreover, the protective effects of blueberry reported suggest that dietary blueberry can buttress T cell and systemic immune function against HFD- and obesity-associated insults.