Inokuma H, Kerlin R L, Kemp D H, Willadsen P
National Livestock Breeding Center, Ministry of Agriculture, Forestry and Fisheries, Fukushima, Japan.
Vet Parasitol. 1993 Mar;47(1-2):107-18. doi: 10.1016/0304-4017(93)90181-l.
The immunosuppressive effect of experimental Boophilus microplus infestation on bovine peripheral blood lymphocytes (PBL) and on host antibody production to a protein antigen (ovalbumin) was examined. Boophilus microplus infestation caused a marginal decrease in the percentage of T lymphocytes in PBL, which was observed in both lightly (5000 larvae) and heavily (40,000 larvae) infested cattle, and began at the second infestation and continued until the end of the fourth infestation. The percentage of B lymphocytes in heavily tick-infested cattle was less than that in non-infested control cattle after the fourth infestation. The response of PBL from tick-infested cattle to phytohemagglutinin (PHA) was always less than that of tick-free cattle after the second infestation. No noteworthy differences were detected between the three stages of tick infestation, that is, 1 week before the peak of adult engorgement, the middle of the peak and 1 week after all ticks had dropped. Boophilus microplus saliva (100 microliters ml-1) suppressed 47% of the response of bovine PBL to PHA in vitro. This suppressive effect of saliva may contribute to the lower responsiveness of PBL from tick-infested cattle. Antibody production by tick-infested cattle was examined during the third and fourth heavy tick infestation. Tick-infested cattle showed a diminished response against ovalbumin after the second immunization. The immunosuppressive effects of tick infestation may play an important role in tick survival or in the transmission of tick-borne diseases in the field.
研究了实验性微小牛蜱感染对牛外周血淋巴细胞（PBL）以及宿主针对蛋白质抗原（卵清蛋白）产生抗体的免疫抑制作用。微小牛蜱感染导致PBL中T淋巴细胞百分比略有下降，在轻度（5000只幼虫）和重度（40000只幼虫）感染的牛中均观察到这种情况，且从第二次感染开始出现，一直持续到第四次感染结束。第四次感染后，重度蜱感染牛的B淋巴细胞百分比低于未感染的对照牛。第二次感染后，蜱感染牛的PBL对植物血凝素（PHA）的反应始终低于无蜱牛。在蜱感染的三个阶段，即成年蜱饱血高峰前1周、高峰中期和所有蜱掉落1周后，未检测到显著差异。微小牛蜱唾液（100微升/毫升）在体外抑制了47%的牛PBL对PHA的反应。唾液的这种抑制作用可能导致蜱感染牛的PBL反应性降低。在第三次和第四次重度蜱感染期间，检测了蜱感染牛的抗体产生情况。蜱感染牛在第二次免疫后对卵清蛋白的反应减弱。蜱感染的免疫抑制作用可能在蜱的存活或蜱传疾病在野外的传播中起重要作用。
