The effect of season on inflammatory response in captive baboons

INTRODUCTION: Highly seasonal animals demonstrate predictable changes in immune function that coincide with changes in photoperiod. Little is known about the effect of season on immune response in baboons. The objective of this study was to determine the effect of season on inflammatory response in baboons.

MATERIALS AND METHODS: Peripheral blood mononuclear cell cytokine response following immune stimulation and serum markers of inflammation were assessed during each season in two groups of young male baboons: one housed under natural light and one in a controlled environment of 12 hours light:12 hours dark.

RESULTS: A seasonal immune rhythm was evident in both groups, with a greater TNF-α and IL-6 response to stimulation and serum CRP concentration in June and September compared with December.

CONCLUSIONS: Season is an important experimental confounder, and therefore, time of year should be controlled when designing studies and analyzing data from immune studies in baboons.