Antigenic and Immunogenic Components of Haemonchus longistipes Identified by Western Immunobloting

Abstract

The present study aimed to examine the ways that the Haemonchus longistipes components interact with the host by investigating the components of the parasite which acted as antigens during infection and those who are capable of inducing immune response when administered as immunogens. Adult H. longistipes worms (300 females and 200 males) were obtained from the abomasums of naturally infected slaughtered camels. H. longistipes soluble extract was prepared and stored at -20°C until the time of analysis. Hyperimmune serum of H. longistipes crude soluble extract was raised in rabbits. H. longistipes soluble extract, were electrophoresed on 7-20% gradient polyacrylamide gels. Protein banding pattern on the gels was visualized by Coomassie Blue stain. After electrophoresis, Western blots were prepared by electro-blotting separated antigens in unstained gels onto nitrocellulose paper. Antigens were detected by western immunoblotting against infection serum and antisera raised against soluble extract. The antigenic components of the parasite were identified. Twenty three protein bands ranging from 126 to 18-kDa were detected in the parasite crude soluble extract using SDS-PAGE. Sixteen of these components were identified as immunogens using Western immunoblotting against sera from rabbits immunized with a range of soluble parasite materials. Three of these immunogens, 126, 76 and 18-kDa were also found to act as antigens during infection as revealed by immunoblotting against serum from infected camels. The 76-kDa and 18-kDa showed potent reaction with both types of antisera and necessitate further investigation in their role as diagnostic materials and as target antigens for production of vaccines. The present study suggests that the peptide bands 76 and 18-kDa represent useful candidates for serodignosis of cameline haemonchosis. The role of these peptides in serodiagnosis of cameline haemonchosis will be investigated by purifying these peptides and raising monospecific antisera against them which will be used to develop an antigen capture ELISA for detection of circulating H. longistipes antigens in camel serum. The ability of the developed assay to differentiate between infections with other helminthes parasites will also be investigated.