Echinococcus granulosus: oncosphere-specific transcription of genes encoding a host-protective antigen.
A recombinant antigen vaccine has been developed which is effective in preventing the hydatid parasite, Echinococcus granulosus from infecting its animal intermediate hosts. The vaccine antigen, designated EG95, is expressed by a cDNA cloned from E. granulosus oncosphere mRNA. The gene encoding EG95 belongs to a small gene family where six of the members are transcribed in the oncosphere. Conditions were established which allowed specific RT-PCR amplification of mRNA for each gene family member and these conditions were applied to determine transcription patterns for each gene family member in gravid adult worms, oncospheres, and protoscoleces. The four eg95 gene family members which encode an identical EG95 protein, were transcribed only in the oncosphere. In contrast, two gene family members that encode variant EG95 proteins did not have transcription patterns confined to the oncosphere. These findings suggest a common biological role for four genes in the gene family and a separate role for the other, more variant gene family members.
Chow
Conan
C
University of Melbourne, Veterinary Clinical Centre, Princes Highway, Werribee, Vic. 3030, Australia.
Gauci
Charles G
CG
Cowman
Alan F
AF
Lightowlers
Marshall W
MW
D000818:Animals; D000947:Antigens, Helminth / Q000235:genetics* / Q000276:immunology; D015139:Blotting, Southern; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004199:Disease Vectors; D004285:Dogs; D004443:Echinococcosis / Q000517:prevention & control / Q000635:transmission; D004446:Echinococcus / Q000235:genetics* / Q000254:growth & development / Q000276:immunology; D015801:Helminth Proteins / Q000235:genetics* / Q000276:immunology; D006801:Humans; D008018:Life Cycle Stages; D005810:Multigene Family; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012756:Sheep; D014158:Transcription, Genetic; D014614:Vaccines, Synthetic / Q000235:genetics / Q000276:immunology
D000947:Antigens, Helminth; D018076:DNA, Complementary; C446034:EG95 protein, Echinococcus granulosus; D015801:Helminth Proteins; D012333:RNA, Messenger; D014614:Vaccines, Synthetic