Affiliation:
1. Department of Molecular Parasitology, Humboldt University Berlin, Berlin, Germany
Abstract
ABSTRACT
Chitinases of pathogens have been proposed as potential targets of vaccines or specific inhibitors. We studied the genomic organization, transcript levels, developmental expression, and biological function of chitinases in the rodent filarial nematode
Acanthocheilonema viteae
, a model organism for human-pathogenic filarial worms. Characterization of nine genomic clones from an
A. viteae
phage library and Southern blot experiments revealed the existence of three different chitinase genes, two of which could theoretically yield functional transcripts. The deduced proteins of these genes had the common modular organization of family 18 chitinases. Northern blot experiments and rapid amplification of cDNA ends-PCR with adult worms and larval stages showed that only one gene is expressed, with high variation in transcript levels, as determined by real-time PCR. Chitinase transcript levels were lowest in the late male stage 4 larva (L4) and peaked in the stage 3 larva (L3), which was corroborated by Western blotting. RNA interference (RNAi) experiments showed that treatment of L3 and adult female worms with double-stranded RNA of chitinase inhibited molting of L3 worms and hatching of microfilariae. RNAi also led to the death of 50% of female worms, revealing the essential role of chitinase in the life cycle of filarial nematodes.
Publisher
American Society for Microbiology
Subject
Infectious Diseases,Immunology,Microbiology,Parasitology
Reference30 articles.
1. Aboobaker, A. A., and M. L. Blaxter. 2003. Use of RNA interference to investigate gene function in the human filarial nematode parasite Brugia malayi. Mol. Biochem. Parasitol.129:41-51.
2. Adam, R., B. Drabner, and R. Lucius. 2001. Chitinase of filarial nematodes, p. 195-210. In M. Kennedy and W. Harnett (ed.), Parasitic nematodes: molecular biology, biochemistry and immunology. CAB International, Wallingford, United Kingdom.
3. Adam, R., B. Kaltmann, W. Rudin, T. Friedrich, T. Marti, and R. Lucius. 1996. Identification of chitinase as the immunodominant filarial antigen recognized by sera of vaccinated rodents. J. Biol. Chem.271:1441-1447.
4. Arakane, Y., Q. Zhu, M. Matsumiya, S. Muthukrishnan, and K. J. Kramer. 2003. Properties of catalytic, linker and chitin-binding domains of insect chitinase. Insect Biochem. Mol. Biol.33:631-648.
5. Arnold, K., L. J. Brydon, L. H. Chappell, and G. W. Gooday. 1993. Chitinolytic activities in Heligmosomoides polygyrus and their role in egg hatching. Mol. Biochem. Parasitol.58:317-323.
Cited by
39 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献