ELSEVIER zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA PII soo24-3205(98)00321-x Life .scirmq Vd. 63, No. a pp. m-m, 1998 cDpylight~1996Fbevicr~Iec. PrintcdintkusA AnTightsramhd ocrz4-32ns/98 $19.00 + .m EFFECTS OF SLEEP DEPRIVATION AND OTHER STRESSORS ON THE IMMUNE AND INFLAMMATORY RESPONSES OF INFLUENZA-INFECTED MICE Linda A. Totha and Jerold E. Rehg Department of Infectious Diseases, St. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONM Jude Children’s Research Hospital, Memphis, TN 38105 (Received in final form June 9,19!%) Summary Many stressors have well-documented effects on host immune competence. However, two important stressors that have not been extensively characterized in terms of their immune-modulatory properties are sleep deprivation and alterations in Iight:dark cycles. We therefore evaluated the effects of these stressors on the immune and inflammatory responses of mice inoculated intranasally with influenza virus. In contrast to a previous report, sleep deprivation did not significantly alter viral clearance or antibody titers of either virus-naive or immunized mice. Exposure to constant light also failed to affect these variables. However, repeated overnight restraint, a well-characterized stressor, reduced the pulmonary inflammatory response elicited by influenza virus, as previously reported. The data indicate that sleep deprivation and altered light cycles do not markedly influence selected host defense responses to influenza infection under the conditions tested. Key Words: sleep, influenza, stress, immune response, restraint, light cycle, mice A wide variety of stressful situations influence immune processes in humans and animals. Common perceptions that lack of sleep lowers resistance to infection and that infections develop more frequently during or after periods of sleep loss suggest that sleep deprivation (SD) is likely to impair immune function. Exposure to altered lightdark cycles, which occurs during shift work and jet lag, is associated with disruptions in normal sleep patterns. However, influences of circadian rhythm disturbances on immune function have not been studied extensively in animal models. Human and animal studies of the impact of SD on various immunologic parameters often differ “Corresponding author: Linda A. Toth, Department of Infectious Diseases, Comparative Medicine Division, St. Jude Children’s Research Hospital, 332 N. Lauderdale, Memphis, TN 38105; phone: 901-495-3385; fax: 901-495-3112; e-mail: linda.toth@stjude.org