The Food Additive tBHQ Impairs NK Cell Cytotoxicity Against Influenza Infection (FS12-02-19).

Abstract

Objectives\nWe examined the effects of the food preservative, tert-Butylhydroquinone (tBHQ), on natural killer (NK) cells when infected with influenza in C57Bl/6 mice. Previously, we found tBHQ to negatively impact splenic NK cell effector function in vitro. Therefore, we hypothesized that the consumption of tBHQ would impair the NK cell response against a primary influenza virus infection.\n\n\nMethods\nFemale, C57Bl/6 mice were fed either a diet containing 0.0014% tBHQ or a control diet two weeks prior to infection. Mice were instilled intranasally with 21.78 HAU of influenza A/PR/8/34 (H1N1) and were monitored for two days. Body weight was recorded as a measurement for infection. After day two of infection, lungs were collected and processed for analysis by flow cytometry, enzyme-linked immunosorbent assay (ELISA), and total antioxidant capacity (TAC).\n\n\nResults\nThe NK cell activation markers, CD25 and CD69, were not affected by tBHQ consumption. Additionally, tBHQ did not have an effect on maturation of NK cells or interferon (IFN)γ production. Notably, NK cell expression of granzyme B was significantly decreased with tBHQ in infected mice. Furthermore, mice on the tBHQ diet showed decreased TAC after two days of infection compared to mice on the control diet, suggesting increased oxidative stress in the tBHQ group.\n\n\nConclusions\ntBHQ had no effect on NK cell activation, maturation, and IFNγ production after two days of influenza infection. However, decreased expression of granzyme B by NK cells suggests tBHQ may impair NK cell cytoxicity during the infection. Moreover, the decrease in TAC suggests increased oxidative stress in the tBHQ-treated mice.\n\n\nFunding Sources\nThis study was funded by National Institute of Environmental Health Sciences (ES024966).