Biology Reference
In-Depth Information
conducted under this premise has found some supporting data.
169,170
However, looking at the problem from another perspective, whether
genes associated with clinical allergy or the immune responses to aller-
gens are associated with resistance to
Ascaris
should be explored empir-
ically. In this regard, a case
e
control study evaluating for the first time, in
the same population and under the same environmental exposures,
polymorphisms possibly associated with the IgE responses to
Ascaris
antigens, domestic mite allergens and asthma, found variants associated
only with the IgE responses to
Ascaris
.
171
Since this study was focused on
particular genes (
TNFSF13B
,
LIG4
and
IRS2
) located in a region previ-
ously found to be linked to ascariasis resistance,
172,173
further research on
other chromosomes of this population is ongoing.
In spite of the great progress on allergy, immunoparasitology, and
genomics during the last decade, important theoretical aspects of the
evolutionary relationships between ascariasis and allergy remain
unsolved and testing more hypotheses is guaranteed. For example, the
existence of a population strongly resistant to
Ascaris
and non-atopic
should be kept in mind. Further studies on this subgroup will help to
elucidate the resistance mechanisms of human helminthiases and,
besides, the genetics of allergic diseases, which involves more genes than
those of type 2 immunity. In addition, polymorphisms implicated in the
resistance to ascariasis have been searched for among immune-related
genes, but exploring genetic variations in the pathways of parasite-
induced immunomodulation may provide interesting information about
the genetics of human
eAscaris
relationships. Empirical genomic research
in populations affected with both helminthiases and allergy, as well as
bioinformatics analyses oriented by evolutionary genetic concepts, will
provide significant signals deserving confirmation by functional studies.
THE POSSIBLE THERAPEUTIC IMPACT OF ASCARIS
IMMUNO
MODULATORY PRODUCTS ON A
LLERGY
It is now widely recognized and well documented that helminth
infections, including ascariasis, are associated with variable degrees of
immune response downregulation. However, the parasite-derived prod-
ucts that dampen the immune system are not fully recognized. It is known
that helminths produce immunomodulator substances (downregulators
being the best studied) that can modify phenotypes of the immune
responses. The possibility of using them for controlling the adverse effects
of the inflammation associated with human immune disorders, such as
autoimmunity or allergy, is currently under investigation. Detailed
aspects of the immunomodulation induced by
Ascaris
can be found in
Chapter 1. Here, some general comments about the possibility of using
