Department of Pathobiology, School of Veterinary Medicine, Shiraz University, P.O. Box 1731, Shiraz, 71345, Iran.
Vet Res Commun. 2010 Oct;34(7):579-87. doi: 10.1007/s11259-010-9429-7. Epub 2010 Jul 6.
The infection with protozoan parasite Theileria annulata induces changes triggering the activation and/or proliferation of the host lymphocytes. In order to find out the possible correlations among peripheral circulatory lymphocytes, cytokine activities and the level of sialic acids, 50 dairy Holstein cattle, naturally infected with T. annulata, were divided into 4 subgroups according to their parasitemia rates (<1%, 1-3%, 3-5% and >5%). Also, ten non-infected cattle were sampled as control group. Blood samples were taken from jugular vein into acid citrate dextrose-containing tubes for measuring hematological parameters and B and T (CD(4) and CD(8)) cell populations and without anticoagulant for TNF-alpha, IFN-gamma and sialic acid concentrations. Remarkable decreases observed in red blood cells (RBCs), white blood cells (WBCs) and packed cell volume (PCV) in infected cattle compared to healthy ones (P < 0.05). Also, with increase in parasitemia rate, total lymphocytes and monocytes alleviated in the diseased groups. By contrast, total neutrohpils and the concentrations of TNF-alpha, IFN-gamma and total sialic acids were significantly elevated (P < 0.05) in infected animals. Accordingly, the circulatory populations of CD(4) and CD(8) T cells and B cells showed a substantial decrease, while a significant increase was observed in T (CD(4) and CD(8)) cells in cattle infected with <1% parasitemia rates. Decreased circulatory T cell population shows the ineffective responses of T cells to the stimulatory cytokines such as IFN-gamma or TNF-alpha. On the other hand, the elevation of cytokines (particularly IFN-gamma) and sialic acids have presumably an inhibitory role on circulatory B cell population in infected cattle. In addition, a high level of sialic acid concentration indicates the probable role of sialic acid to regulate the parasite-host cell adhesion during sporozoites invasion.
感染原生动物寄生虫环形泰勒虫会引起变化，触发宿主淋巴细胞的激活和/或增殖。为了找出外周循环淋巴细胞、细胞因子活性和唾液酸水平之间可能存在的相关性，将 50 头自然感染环形泰勒虫的荷斯坦奶牛根据其寄生虫血症率（<1%、1-3%、3-5%和>5%）分为 4 组。此外，还采集了 10 头未感染的奶牛作为对照组。从颈静脉采集血液样本到含有柠檬酸葡萄糖的管中，用于测量血液学参数和 B 和 T（CD（4）和 CD（8））细胞群，并且不抗凝用于 TNF-α、IFN-γ和唾液酸浓度。与健康奶牛相比，感染奶牛的红细胞（RBC）、白细胞（WBC）和红细胞压积（PCV）显著下降（P<0.05）。此外，随着寄生虫血症率的增加，患病组的总淋巴细胞和单核细胞减轻。相比之下，感染动物的总中性粒细胞和 TNF-α、IFN-γ和总唾液酸浓度显著升高（P<0.05）。因此，CD（4）和 CD（8）T 细胞和 B 细胞的循环群体显著减少，而感染<1%寄生虫血症率的牛中 T（CD（4）和 CD（8））细胞显著增加。循环 T 细胞群体减少表明 T 细胞对刺激细胞因子（如 IFN-γ或 TNF-α）的反应无效。另一方面，细胞因子（特别是 IFN-γ）和唾液酸的升高可能对感染牛的循环 B 细胞群体具有抑制作用。此外，高浓度的唾液酸表明唾液酸可能在裂殖子入侵期间调节寄生虫-宿主细胞黏附中发挥作用。
