The role of CD23+ B cells in host protection against Schistosoma mansoni
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Authors
Hauslein, Elizabeth Ellen
Issue Date
2007
Type
Thesis
Language
en_US
Keywords
Alternative Title
Abstract
Schistosomiasis caused by three main species of parasitic trematodes affects over
207 million people worldwide. Individuals who are resistant to reinfection with
schistosomes have an increased percentage of CD23+ B cells, but it is currently unknown
what role CD23 plays in host defense. CD23 is the low affinity IgE receptor (FCeRII)
which has been shown to be involved in antigen presentation and the regulation of IgE
production by B cells. We hypothesized that CD23 expression on B cells has a protective
role in host immunity to schistosomes by enhancing IgE production. We first determined
the anatomical distribution of CD23+ B cells from unexposedluninfected donors and the
cellular phenotypes using flow cytometric methods and found that CD 19+ B cells in
whole blood and tonsils express high levels ofCD23, and these B cell populations exist
in different stages of activation and differentiation. We next assessed the effects of
CD23-bound IgE on B cell activation and signaling using flow cytometric methods and
Western blot analysis and found that the ability of B cells to bind exogenous IgE is
directly related to the level ofCD23 and that NP-BSA induced a stronger signaling
response at the level of BLNK whereas anit-IgE appears inhibit BLNK phosphorylation.
Our pilot studies indicate that the mechanism by which CD23-bound IgE is cross-linked
will determine the outcome of B cell development and ultimate IgE output. These results
have allowed us to model the possible fates of CD23+ B cells for a better understanding
of a potential role for these cells in human schistosomiasis, and gaining an understanding
of the development and maintenance of immunological resistance to schistosomes will be
beneficial in aiding in the development of a vaccination.
Description
v, 33 p.
Citation
Publisher
Kalamazoo College
License
U.S. copyright laws protect this material. Commercial use or distribution of this material is not permitted without prior written permission of the copyright holder.