Excretion of host immunoglobulin in tick saliva and detection of IgG-binding proteins in tick haemolymph and salivary glands

• Published in: Parasitology 1994-11, Vol.109 (4), p.525-530
• Main Authors: Wang, H., Nuttall, P. A.
• Format: Article
• Language: English
• Subjects: Animals; Arachnida; binding proteins; Biochemistry. Physiology. Immunology; Biological and medical sciences; Carrier Proteins - chemistry; Carrier Proteins - metabolism; defense mechanisms; enzyme-linked immunosorbent assay; Female; females; Fundamental and applied biological sciences. Psychology; Guinea Pigs; hematophagy; hemolymph; Hemolymph - immunology; Hemolymph - metabolism; Host-Parasite Interactions - immunology; Host-Parasite Interactions - physiology; immunoblotting; immunoglobulin; immunoglobulin binding protein; immunoglobulin binding proteins; immunoglobulin G; Immunoglobulin G - metabolism; Immunoglobulin Heavy Chains - metabolism; Invertebrates; Male; Molecular Weight; Physiology. Development; Rhipicephalus appendiculatus; Saliva - immunology; salivary glands; Salivary Glands - immunology; Salivary Glands - metabolism; Salvia; tick haemolymph; tick saliva; Ticks - immunology; Ticks - metabolism
• ISSN: 0031-1820; 1469-8161
• 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 lgG binding proteins (1GBPs) 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 Mr of 1GBPs in SGE (23 and 57 kDa) were less than those in haemolymph (78 and > 100 kDa). The existence of 1GBPs 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.