Poster abstracts

Poster number 81 submitted by Yasmine-marie Cisse

Parental exposure to dim light at night prior to mating alters offspring adaptive immunity

Yasmine M. Cisse (Department of Neuroscience, Behavioral Neuroendocrinology Group, The Neuroscience Research Institute, The Ohio State University Wexner Medical Center, Columbus OH 43210), Randy J. Nelson (Department of Neuroscience, Behavioral Neuroendocrinology Group, The Neuroscience Research Institute, The Ohio State University Wexner Medical Center, Columbus OH 43210)

Abstract:
Environmental light is the most potent signal for synchronizing the circadian system. Adoption of electrical lighting has occurred without understanding the physiological effects of light at night (LAN). Disruption of natural light/dark cycles by LAN dampens endogenous biological rhythms that maintain optimal function of various systems, including the immune system. Dim LAN (dLAN) exposure impairs innate and cell mediated immune responses in Siberian hamsters (Phodopus sungorus). Studies on the effects of circadian disruption have thus far focused on adults, but impaired maternal immune and endocrine function has downstream effects on offspring immune phenotype. The circadian system exerts an organizational role in these systems and dLAN exposure impairs their function. Thus, we hypothesized that parental exposure to dLAN prior to mating impairs offspring immune function. Adult male and female Siberian hamsters were exposed to either dark nights (DA) or dLAN (DI) for 9 weeks, at which point they were paired, mated, and thereafter housed in dark nights. Pairings resulted in four groups: DA/DA (Male/Female), DA/DI, DI/DA, and DI/DI. Adult offspring were tested for cell-mediated, humoral and innate immunity. Male offspring of dams exposed to dLAN suppressed cell-mediated swelling reactions. Male offspring of DA/DI and DI/DA parents produced more antibodies in response to a novel antigen. In female offspring, maternal and paternal exposure to dLAN decreased swelling response. Female offspring of dams exposed to dLAN produced more antibodies in response to challenge. No deficits in plasma bactericidal capacity were observed. Overall, parental exposure to dLAN decreased offspring cell-mediated immunity and enhanced humoral immunity in a parent and offspring sex-specific manner. Altered immune responsiveness in offspring that have experienced dLAN in the germline indicates that seemingly innocuous nighttime lighting may have transgenerational effects on immune function.

Keywords: circadian disruption, immunity, transgenerational