Animals usually use photoperiod as an important environmental cue to time the year. In terms of the winter immunocompetence enhancement hypothesis, animals in the non-tropical zone would actively enhance their immune function to decrease the negative influence of stressors such as low temperature and food shortage in winter. In the
Animals usually use photoperiod as an important environmental cue to time the year. In terms of the winter immunocompetence enhancement hypothesis, animals in the non-tropical zone would actively enhance their immune function to decrease the negative influence of stressors such as low temperature and food shortage in winter. In the present study, we mimicked the transition from summer to winter by decreasing photoperiod gradually and examined the variations of immune repsonses in Siberian hamsters (Phodopus sungorus) to test this hypothesis. Twenty two female adult hamsters were randomly divided into the control (12h light: 12h dark, Control, n=11) and the gradually decreasing photoperiod group (Experiment, n=11). In the experiment group, day length was decreased from 12 h: 12 h light-dark cycle to 8 h: 16 h light-dark cycle at the pace of half an hour per week. We found that gradually decreasing photoperiod had no effect on body composition (wet carcass mass, subcutaneous, retroperitoneal, mesenteric and total body fat mass) and the masses of the organs detected such as brain, heart, liver and so on in hamsters. Similarly, immunological parameters including immune organs (thymus and spleen), white blood cells and serum bacteria killing capacity indicative of innate immunity were also not influenced by gradually decreasing photoperiod, which did not support the winter immunocompetence enhancement hypothesis. However, gradually decreasing photoperiod increased phytohaemagglutinin response post-24h of PHA challenge, which supported this hypothesis. There was no correlation between cellular, innate immunity and body fat mass, suggesting that body fat was not the reasons of the changes of cellular immunity. In summary, distinct components of immune system respond to gradually decreasing photoperiod differently in Siberian hamsters. Full article
Nelson, R.J. 2004. Seasonal immune function and sickness responses. Trends Immunol. 25, 187-192.
Dobrowolska, A., Adamczewska-Andrzejewska, K.A., 1991. Seasonal and long term changes in serum gamma globulin levels in comparing the physiology and population density of the common vole, Microtus arvalis Pall.1779. J. Interdis. Cycle Res, 22, 1-19.
Moshkin, M.P., Dobrotvorsky, A.K., Mak, V.V., Panov, V.V., Dobrotvorskaya, E.A., 1998. Variability of immune response to heterologous erythrocytes during population cycles of red (Clethrionom ys rutilus) and bank (C. glareolus) voles. Oikos 82, 131-138.
Sinclair, J.A., Lochmiller, R.L., 2000. The winter immunoenhancement hypothesis: associations among immunity, density, and survival in Prairie vole (Microtus ochrogaster) populations. Can. J. Zool. 78, 254-264.
Zhang, Z.Q., Wang, D.H., 2006. Seasonal changes in immune function, body fat mass and organ mass in Mongolian gerbils (Meriones unguiculatus). Acta, Theriol. Sin.26,338-345. (In Chinese with English summary).
Newson, J., 1962. Seasonal differences in reticulocyte count, hemoglobin levels and spleen weight in wild voles. Bri. J. Haemat.8, 296-302.
Lochmiller RL, VesteyM R, McMurry ST. 1994. Temporal variation in humoral and cell-mediated immune response in a Sigmodon hispidus population. Ecology 75: 236-245.
Mann DR, Akinbami MA, Gould KG, Ansari AA. 2000. Seasonal variations in cytokine expression and cell-mediated immunity in male rhesus monkeys. Cell Immunol 200: 105-115.
Brainard, G.C., Knobler, R.I., Podolin, P.L., Lavasa, M., Lubin, F.D., 1987. Neuroimmunology: modulation of the hamster immune system by photoperiod. Life Sci.40, 1319-1326.
Drazen, D.L., Jasnow, A.M., Nelson, R.J., Demas, G.E.. 2002. Exposure to short days, but not short-term melatonin, enhances humoral immunity of male Syrian hamsters (Mesocricetus auratus) J. Pineal Res. 33, 118-124.
Bilbo, S.D., Dhabhar, F.S., Viswanathan, K., Saul, A., Yellon, S.M., Nelson,R.J., 2002. Short day lengths augment stress-induced leukocyte trafficking and stress-induced enhancement of skin immune function. Proc. Natl. Acad. Sci. 99, 4067- 4072.
Yellon, S.M., Fagoaga, O.R., Nehlsen-Cannarella, S.L., 1999. Influence of photoperiod on immune cell functions in the male Siberian hamster. Am. J. Physiol. 276, R97-R102.
Drazen, D.L., Kriegsfeld, L.J., Schneider, J.E., Nelson, R.J., 2000. Leptin, but not immune function, is linked to reproductive responsiveness to photoperiod. Am. J. Physiol. Regul. Integr. Comp. Physiol. 278, R1401-R1407.
Tieleman BI, Williams JB, Ricklefs RE, Klasing KC, (2005). Constitutive innate immunity is a component of the pace-of-life syndrome in tropical birds. Proc.Roy. Soc.B 272, 1715-1720.
Demas GE, Zysling DA, Beechler BR, Muehlenbein MP, French SS. (2011). Beyond phytohaemagglutinin: assessing vertebrate immune function across ecological contexts. JAnim. Ecol.80, 710-730.
Xu DL, Hu XK. 2017. Photoperiod and temperature differently affect immune function in striped hamsters (Cricetulus barabensis). Comp. Physiol. Part A 204: 211-218.
Bellocq, J.G., Krasnov, B.R., Khokhlova, I.S., Pinshow, B., 2006. Temporal dynamics of a T-cell mediated immune response in desert rodents. Comp. Biochem. Physiol. A 145, 554-559.
Calder, P.C., Kew, S., 2002. The immune system: a target for functional foods? Bri. J. Nutr. 88, S165-S176.
Savino, W., Dardenne, M., 2000. Neuroendocrine control of thymus physiology. Endocr. Rev. 21, 412-443.
Smith KG, Hunt JL (2004). On the use of spleen mass as a measure of avian immune system strength. Oecologia 138, 28-31.
Ahima R.S., J.S. Flier., 2000. Adipose tissue as an endocrine organ. Trends Endocrinol. Metab.11, 327-332.
Fantuzzi, G., 2005. Adipose tissue, adipokines, and inflammation. J. Allergy Clin. Immunol.115, 911-919.
Sch?ffler A, Sch?lmerich J, Salzberger B (2007). Adipose tissue as an immunological organ: Toll-like receptors, C1q/TNFs and CTRPs. TrendsImmunol.28, 393-99.
Dong WH, Hou XX, Zhang PL, Zhou YL, Yang YP, Xue XP (1990). A study on population quantity compostion and reproduction of striped hairy-footed hamster. Acta Theriol. Sin. 1990, 10(3):221-226. (In Chinese with English abstract)
Dong WH, Hou XX, Zhou YL, Zhang YX, Lang BJ, Xue XP. (1998). Studies on population dynamics and prediction of Phodopus sungorus. Acta Agrest Sinica.. 6(3):207-211. (In Chinese with English abstract)
Demas GE. (2002) Splenic denervation blocks leptin induced enhancement of humoral immunity in Siberian hamsters (Phodopus sungorus). Neuroendocrinology76, 178-184.
Xu DL, Hu XK, Tian YF (2017). Effect of temperature and food restriction on immune function in striped hamsters (Cricetulus barabensis). JExp. Biol.doi:10.1242/jeb.153601.
Gatien ML, Hotchkiss AK, Dhabhar FS, Nelson RJ. 2005. Skeleton photoperiods alter delayed-type hypersensitivity responses and reproductive function of siberian hamsters (Phodopus sungorus). J Neuroendocri.17: 733?739.
Demas G.E., Nelson R.J. 2003. Lack of immunological responsiveness to photoperiod in a tropical rodent, Peromyscus aztecus hylocetes. J Comp. Physiol. B 173: 171?176.
Yellon, S.M., 2007. Melatonin mediates photoperiod control of endocrine adaptationsand humoral immunity in male Siberian hamsters. J. Pineal Res. 43, 109-114.
Weil, Z.M., Borniger, J.C., Cisse, Y.M., Salloum, B.A., Nelson, R.J., 2015. Neuroendocrine control of photoperiodic changes in immune function. Front. Neuroendocr. 37,108-118.