Wang H, Nuttall P A
NERC Institute of Virology and Environmental Microbiology, Oxford.
Parasitology. 1994 Nov;109 ( Pt 4):525-30. doi: 10.1017/s0031182000080781.
Host immunoglobulin G (IgG) crossed the gut wall into the haemocoel of adult Rhipicephalus appendiculatus female ticks when they fed on guinea-pigs. Guinea-pig IgG was also found in saliva of the feeding ticks. The concentration and antibody activity of IgG in haemolymph, salivary gland extract (SGE) and saliva at different stages of tick feeding were detected by enzyme-linked immunoassay. Specific activity of the IgG in tick samples was determined by feeding ticks on guinea-pigs which were immunized with killed Escherichia coli: 35-42% of the antibody activity in guinea-pig immune serum remained in the tick samples. The high relative concentration of IgG in tick saliva at later stages of feeding suggests that the tick may have a mechanism for getting rid of foreign proteins via the salivary gland. Such a mechanism could involve IgG binding proteins (IGBPs) which were found in both haemolymph and SGE of female ticks at day 6 of feeding using a guinea-pig IgG-agarose affinity column. In female ticks, the M(r) of IGBPs in SGE (23 and 57 kDa) were less than those in haemolymph (78 and > 100 kDa). The existence of IGBPs in both the tick salivary gland and haemolymph indicate that haemolymph and salivary gland cooperate to remove foreign proteins, e.g. host immunoglobulin, from the body during feeding. This mechanism may be a part of the tick self-defence system.
成年雌性微小牛蜱在以豚鼠为食时，宿主免疫球蛋白G（IgG）穿过肠壁进入其血腔。在进食的蜱虫唾液中也发现了豚鼠IgG。通过酶联免疫吸附测定法检测蜱虫进食不同阶段血淋巴、唾液腺提取物（SGE）和唾液中IgG的浓度和抗体活性。通过让蜱虫以用灭活大肠杆菌免疫的豚鼠为食来测定蜱虫样本中IgG的比活性：豚鼠免疫血清中35 - 42%的抗体活性保留在蜱虫样本中。进食后期蜱虫唾液中IgG的相对浓度较高，这表明蜱虫可能有一种通过唾液腺清除外来蛋白质的机制。这种机制可能涉及IgG结合蛋白（IGBPs），在进食第6天的雌性蜱虫血淋巴和SGE中，使用豚鼠IgG - 琼脂糖亲和柱发现了这些蛋白。在雌性蜱虫中，SGE中IGBPs的分子量（23和57 kDa）小于血淋巴中的（78和>100 kDa）。蜱虫唾液腺和血淋巴中均存在IGBPs，这表明血淋巴和唾液腺在进食期间协同作用以从体内清除外来蛋白质，例如宿主免疫球蛋白。这种机制可能是蜱虫自我防御系统的一部分。
