Franci O, Amici A, Margarit R, Merendino N, Piccolella E
Centro Interuniversitario di Immunodiagnostica Sperimentale, Università della Tuscia, Viterbo, Italy.
J Anim Sci. 1996 Jul;74(7):1523-9. doi: 10.2527/1996.7471523x.
With the aim of analyzing the effects of prolonged thermal stress or food intake reduction on lymphoid cell proliferation and antibody synthesis, New Zealand White (NZW) male rabbits, both immunized and nonimmunized with Mycobacterium tuberculosis, were kept in individual cages for 24 d at controlled climatic conditions. Both immunized and nonimmunized rabbits were divided into two experimental groups and one control group. The thermal-stressed rabbits (TS) were exposed to a room temperature of 33.5 degrees C, and dietary restricted rabbits (DR) were pair-fed on the basis of the average feed intake of the TS groups and maintained at a room temperature of 18.0 degrees C. The control group (Ctr) was maintained at 18.0 degrees C and was given ad libitum access to feed. All rabbits were maintained at relative humidity 62 +/- 5%. Sera and peripheral blood mononuclear cells (PBMC) were isolated from blood samples collected on d 0, 6, 12, and 24. Sera were used for determining total proteins and immunoglobulins (Ig) specific or not to mycobacterial antigens. Antibodies to heat-shock protein (HSP) were also determined. The PBMC were used to measure cell proliferation and in vitro Ig synthesis. Both experiments in vivo and in vitro suggest that thermal stress and dietary restriction severely affect the immune cell functions. In fact, both stress treatments decreased the capacity of PBMC to proliferate and inhibited the differentiation of B lymphocytes in antibody-secreting cells. However, a recovery of immune cell functions was only observed in vivo after 12 d of treatment, suggesting that other defensive mechanisms may come into play in vivo. Sera collected from both TS and DR rabbits after 24 d presented antibodies to HSP70, suggesting that the analysis of anti-HSP antibodies could represent a useful indicator to reveal the effects of different stress effectors regardless of the nature of the stress.
为了分析长期热应激或食物摄入量减少对淋巴细胞增殖和抗体合成的影响，将已接种和未接种结核分枝杆菌的新西兰白兔（NZW）雄性兔子置于可控气候条件下的单独笼子中饲养24天。已接种和未接种的兔子均分为两个实验组和一个对照组。热应激组（TS）暴露于33.5摄氏度的室温下，饮食限制组（DR）根据TS组的平均采食量进行配对喂养，并维持在18.0摄氏度的室温下。对照组（Ctr）维持在18.0摄氏度，并可自由采食。所有兔子均维持在相对湿度62±5%的环境中。在第0、6、12和24天采集血样，分离血清和外周血单核细胞（PBMC）。血清用于测定总蛋白和针对或不针对分枝杆菌抗原的免疫球蛋白（Ig）。还测定了热休克蛋白（HSP）抗体。PBMC用于测量细胞增殖和体外Ig合成。体内和体外实验均表明，热应激和饮食限制严重影响免疫细胞功能。事实上，两种应激处理均降低了PBMC的增殖能力，并抑制了B淋巴细胞向抗体分泌细胞的分化。然而，仅在治疗12天后在体内观察到免疫细胞功能的恢复，这表明体内可能有其他防御机制发挥作用。24天后从TS和DR兔子采集的血清中均出现了HSP70抗体，这表明抗HSP抗体的分析可能是一种有用的指标，可揭示不同应激因素的影响，而与应激的性质无关。
