Hostname: page-component-848d4c4894-x5gtn Total loading time: 0 Render date: 2024-05-18T14:04:34.502Z Has data issue: false hasContentIssue false

Molecular cloning and characterization of gut-derived cysteine proteinases associated with a host protective extract from Haemonchus contortus

Published online by Cambridge University Press:  01 October 1999

P. J. SKUCE
Affiliation:
Moredun Research Institute, International Research Centre, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ
D. L. REDMOND
Affiliation:
Moredun Research Institute, International Research Centre, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ
S. LIDDELL
Affiliation:
Moredun Research Institute, International Research Centre, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ
E. M. STEWART
Affiliation:
Moredun Research Institute, International Research Centre, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ
G. F. J. NEWLANDS
Affiliation:
Moredun Research Institute, International Research Centre, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ
W. D. SMITH
Affiliation:
Moredun Research Institute, International Research Centre, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ
D. P. KNOX
Affiliation:
Moredun Research Institute, International Research Centre, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ

Abstract

Cysteine proteinases have been implicated in the protection conferred by vaccination with detergent-soluble extracts of Haemonchus contortus. In the present study, antisera from sheep refractory to Haemonchus challenge following vaccination with a ‘proteinase-enriched’ Haemonchus gut membrane extract, were employed to screen a cDNA expression library of the adult parasite. This resulted in the isolation of 3 cDNAs (designated hmcp1, 4 and 6) encoding cathepsin B-like cysteine proteinases. Immunocytochemical studies specifically localized the products of these genes to the microvillar surface of the parasite's gut and RT–PCR experiments revealed that these were developmentally regulated, being expressed exclusively during the blood-feeding parasitic stages. In addition, a generic PCR approach was adopted in order to identify the predominant cysteine proteinases in a UK strain of Haemonchus. A panel of 5 cDNAs, including hmcp1 and 4, was amplified in this way. Genomic Southern blot analysis indicated that some of these enzymes were encoded by single-copy genes, whereas others were encoded by multi-copy genes. Subsequent sequence analysis revealed that the proteases identified in this study were distinct from those previously reported in USA strains of the parasite.

Type
Research Article
Copyright
1999 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)