Molecular cloning of a cysteine proteinase cDNA from adult Ancylostoma ceylanicum by the method of rapid amplification of cDNA ends using polymerase chain reaction

The hookworm Ancylostoma ceylanicum is a parasite of great importance in hu man and veterinary medicine. The most promising vaccination trials against hookworm infections are based on antigens belonging to the proteinase famil y. The aim of the present research was to isolate a cysteine proteinase gen e from A. ceylanicum. This was achieved by rapid amplification of cDNA ends using polymerase chain reaction (RACE-PCR). A set of consensus oligonucleo tide primers was designed to anneal to the conserved coding regions of cyst eine proteinase. The PCR products were cloned and sequenced. The novel sequ ence displayed a high degree of homology with genes of cysteine proteinases known from other hookworm species. In the coding region the nucleotide ide ntity with accp-1, the cysteine proteinase gene of A. caninum, reaches 84.3 %. Analysis of the expression of acey-1, the cysteine proteinase gene of A. ceylanicum, suggests that it is produced exclusively in the gland cells of either adult worms or blood-feeding stages of A. ceylanicum.