Display Settings:

Format

Send to:

Choose Destination
We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Int Arch Allergy Immunol. 2007;142(1):40-50. Epub 2006 Oct 2.

Factors affecting human IgE and IgG responses to allergen-like Schistosoma mansoni antigens: Molecular structure and patterns of in vivo exposure.

Author information

  • 1Department of Pathology, University of Cambridge, Cambridge, UK. cmf1000@cam.ac.uk

Abstract

BACKGROUND:

The human IgE response is associated with allergy and with host defence against parasitic worms. A response to Sm22.6, the dominant IgE antigen in adult Schistosoma mansoni worms, correlates with resistance to re-infection after treatment. Sm22.6 is one of a family of EF-hand containing parasite proteins with sequence similarity to dynein light chain (DLC) and with major non-parasite allergens. Here we compare human IgE and IgG responses to other family members, Sm20.8 and Sm21.7, as well as to SmDLC1, relating these to antigen structure and expression in parasite life stages.

METHODS:

Recombinant antigens were used in ELISA to measure antibody isotype responses in 177 cases from an endemic area, before and 7 weeks after treatment. Parasite antigen expression was assessed by RT-PCR and Western blotting.

RESULTS:

Levels of antibodies to Sm22.6 and Sm20.8 (but not to Sm21.7 or SmDLC1) showed posttreatment increases in all but young children. Many produced IgE to Sm22.6 and Sm20.8 (2 EF-hands), few to Sm21.7 (1 EF-hand) or SmDLC1 (no EF-hands). Sm21.7 was expressed in cercariae, adults and eggs, Sm22.6 and Sm20.8 were concentrated in the adult.

CONCLUSIONS:

These studies suggest that IgE antigens Sm22.6 and Sm20.8 are only released to boost antibodies when adult worms die, whilst Sm21.7 and SmDLC1 are released constantly from eggs dying in host tissue. IgE responses to these allergen-like molecules may be influenced by patterns of exposure and the number of EF-hand motifs.

Copyright 2007 S. Karger AG, Basel.

PMID:
17019080
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for S. Karger AG, Basel, Switzerland
    Loading ...
    Write to the Help Desk