Engelsma Marc Y, Hougee Sander, Nap Dagmar, Hofenk Marloes, Rombout Jan H W M, van Muiswinkel Willem B, Lidy Verburg-van Kemenade B M
Cell Biology and Immunology Group, Wageningen Institute of Animal Sciences, Wageningen University, P.O. Box 338, 6700 AH Wageningen, The Netherlands.
Fish Shellfish Immunol. 2003 Nov;15(5):397-410. doi: 10.1016/s1050-4648(03)00006-8.
Stress is a potential factor causing increased susceptibility of fish to pathogens. In this study, stress-induced immunological changes that may contribute to a decreased immune status were investigated. A 3 h drop in ambient water temperature of 9 degrees C was used as a relative mild and acute stress model for carp. Effects of this stressor on the dynamics of leucocyte populations were determined with specific monoclonal antibodies. The relative number of circulating B-lymphocytes in the total leucocyte population decreased significantly within 4 h after the onset of single or multiple cold shocks. This decrease was reversible, as B-lymphocyte numbers were restored within 24 h. Most probably, a redistribution of B-lymphocytes contributed to this phenomenon. In head kidney, an increase was measured in the relative number of B-lymphocytes. Granulocyte numbers showed opposite reactions: the percentage of granulocytes in the total leucocyte population nearly doubled in circulation and decreased significantly in the head kidney. This demonstrates that in vivo, a mild stressor differentially alters the distribution of leucocytes. In stressed carp, the percentage of apoptotic lymphocytes in blood is significantly higher compared with the unstressed animals. B-lymphocytes as well as Ig- lymphoid cells contributed to this increased apoptosis. Labelling of blood lymphocytes with a polyclonal antiserum against the glucocorticoid receptor also showed, besides B-lymphocytes, part of the Ig- lymphoid cell population to be glucocorticoid receptor positive. As the distribution of B-lymphocytes was substantially affected, the effect of temperature stress on T-lymphocyte-independent (trinitrophenyl-lipopolysaccharide) and T-lymphocyte-dependent (dinitrophenyl-keyhole limpet hemocyanin) humoral antibody responses was determined. Kinetics of the primary antibody response to the T-lymphocyte-independent antigen showed lower antibody titres in stressed carp during the onset of the immune response, implying a slower development of the antibody response against the T-lymphocyte-independent antigen.
应激是导致鱼类对病原体易感性增加的一个潜在因素。在本研究中，对可能导致免疫状态下降的应激诱导免疫变化进行了调查。将环境水温9℃下降3小时用作鲤鱼相对温和的急性应激模型。用特异性单克隆抗体测定该应激源对白细胞群体动态的影响。在单次或多次冷休克开始后4小时内，总白细胞群体中循环B淋巴细胞的相对数量显著下降。这种下降是可逆的，因为B淋巴细胞数量在24小时内恢复。很可能是B淋巴细胞的重新分布导致了这一现象。在头肾中，B淋巴细胞的相对数量有所增加。粒细胞数量表现出相反的反应：总白细胞群体中粒细胞的百分比在循环中几乎增加了一倍，而在头肾中则显著下降。这表明在体内，轻度应激源会差异性地改变白细胞的分布。与未应激的动物相比，应激鲤鱼血液中凋亡淋巴细胞的百分比显著更高。B淋巴细胞以及Ig⁺淋巴细胞都导致了这种凋亡增加。用抗糖皮质激素受体的多克隆抗血清标记血液淋巴细胞还显示，除了B淋巴细胞外，部分Ig⁺淋巴细胞群体也是糖皮质激素受体阳性。由于B淋巴细胞的分布受到显著影响，因此测定了温度应激对非T淋巴细胞依赖性（三硝基苯基-脂多糖）和T淋巴细胞依赖性（二硝基苯基-钥孔戚血蓝蛋白）体液抗体反应的影响。对非T淋巴细胞依赖性抗原的初次抗体反应动力学表明，在免疫反应开始时，应激鲤鱼的抗体滴度较低，这意味着针对非T淋巴细胞依赖性抗原的抗体反应发展较慢。
