Previous Article | Next Article ![]()
Infect. Immun., May 1995, 1745-1753, Vol 63, No. 5
P Yenbutr and AL Scott
The antigens produced by the infective-stage larvae of filarial parasites
are potentially important targets for a protective immune response. A major
impediment to studies on the biochemistry and molecular biology of antigens
from infective larvae is a lack of parasite material. By employing a
reverse transcription PCR-based strategy which exploited the presence of a
conserved 22-nucleotide spliced leader sequence present at the 5' end of a
proportion of nematode transcripts, spliced leader-containing cDNAs were
amplified from the late-vector-stage larvae of the filarial nematode Brugia
malayi. A major 1.4-kb PCR product was cloned into pBluescript. One of the
PCR cDNA clones (BmY8) contained a 1,287-bp insert that encoded the first
member of the serine proteinase inhibitor (serpin) superfamily to be
described from nematodes. Reverse transcription PCR analysis of RNA
isolated from different developmental stages of the parasite showed that
transcription of the B. malayi serpin (Bmserpin) begins between days 8 and
9 of larval development within the insect vector and continues through to
the adult and microfilarial stages. In immunoblot analyses of B. malayi
somatic extracts, the native protein was estimated to have a molecular
weight of 44,000. In immunoblots using excretory-secretory products from
infective- and fourth-stage larvae, a single band with an estimated
molecular weight of 75,000 was detected. A quantitative analysis of somatic
extracts demonstrated that infective- stage larvae contained 10- to
16-fold-more Bmserpin than adults or microfilariae. Bmserpin was
immunogenic in gerbils and was recognized strongly by sera from immunized
animals. Bmserpin, which has the potential for modifying host defense
responses, may play an important role in parasite survival during the early
phase of vertebrate-stage development.
Copyright © 1995, American Society for Microbiology
Molecular cloning of a serine proteinase inhibitor from Brugia malayi
Department of Molecular Microbiology and Immunology, Johns Hopkins University School of Hygiene and Public Health, Baltimore, Maryland 21205, USA.
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|