Xu De-Li, Hu Xiao-Kai, Tian Yufen
College of Life Sciences, Qufu Normal University, Qufu 273165, Shandong Province, China
College of Life Sciences, Qufu Normal University, Qufu 273165, Shandong Province, China.
Biol Open. 2018 Dec 10;7(12):bio038489. doi: 10.1242/bio.038489.
Animals in the non-tropical zone usually demonstrate seasonal variations in immune function, which is important for their survival. In the present study, seasonal changes in immunity in striped hamsters () were investigated to test the winter immunoenhancement hypothesis. Male hamsters were captured from the wild in the fall and winter of 2014 and in the spring and summer of 2015. Body mass, body fat mass and blood glucose levels of the hamsters were all highest in the summer, whereas relative fatness and thymus mass had no seasonal changes. Spleen mass was highest in the fall and white blood cells and phytohaemagglutinin (PHA) response indicative of cellular immunity were lowest in the summer among the four seasons, which supports the winter immunoenhancement hypothesis. IgG and IgM titers were lowest in the fall, which was against this hypothesis. Body fat mass had no correlations with cellular and humoral immunity, suggesting it was not the reason for seasonal changes in cellular and humoral immunity in males. Leptin titers were higher in spring and summer than in fall and winter. No correlation between leptin and cellular and humoral immunity suggested that leptin did not mediate their seasonal changes. Similarly, corticosterone levels were also higher in spring and summer than in fall and winter, which correlated negatively with cellular immunity but positively with IgG levels. This result implied that corticosterone has a suppressive effect on cellular immunity and an enhancing effect on humoral immunity. In summary, distinct components of immune systems exhibited different seasonal patterns. This article has an associated First Person interview with the first author of the paper.
非热带地区的动物通常表现出免疫功能的季节性变化，这对它们的生存至关重要。在本研究中，为了验证冬季免疫增强假说，对条纹仓鼠（）的免疫季节性变化进行了调查。雄性仓鼠于2014年秋冬以及2015年春夏从野外捕获。仓鼠的体重、体脂量和血糖水平在夏季均最高，而相对肥胖度和胸腺质量没有季节性变化。脾脏质量在秋季最高，在四个季节中，白细胞和指示细胞免疫的植物血凝素（PHA）反应在夏季最低，这支持了冬季免疫增强假说。IgG和IgM滴度在秋季最低，这与该假说相悖。体脂量与细胞免疫和体液免疫均无相关性，表明它不是雄性仓鼠细胞免疫和体液免疫季节性变化的原因。瘦素滴度在春夏高于秋冬。瘦素与细胞免疫和体液免疫之间无相关性，表明瘦素不介导它们的季节性变化。同样，皮质酮水平在春夏也高于秋冬，它与细胞免疫呈负相关，但与IgG水平呈正相关。这一结果表明皮质酮对细胞免疫有抑制作用，对体液免疫有增强作用。总之，免疫系统的不同组成部分表现出不同的季节性模式。本文配有对该论文第一作者的第一人称访谈。
