ALLERGIC ASTHMA AFTER INGESTION OF FRUITS
Researchers at the UPM suggest that the interaction between
two proteins can be the responsible for the allergic asthma episodes after
eating an infected fruit.
A
research group of the Centre for Plant Biotechnology and Genomics (CBGP) of
Universidad Politécnica de Madrid (UPM) conducted infection assays of
commercial kiwis with Alternaria alternataspores
which is a pathogenic fungus involved in chronic asthma in children.
Researchers studied the behavior of this fruit and they found that the infected
kiwis had the major allergen of the fungus, although symptoms of rot were not
seen. This could trigger the involuntary ingestion of the fungus found in this
fruit causing an asthmatic crisis in people allergic to Alternaria.
Alternaria alternata is a fungus that proliferates in fruit and vegetables crops and
also when are collected and are on sale for the final consumer. A protein known
as Alt a 1 and related to the virulence is found in the spores, this protein is
described as the major allergen of this fungus. According to this research,
this protein can be a major cause of childhood asthma in US.
When
a pathogen infects a plant, the defense response is activated producing an
increase of certain proteins related to the defense (known as protein 5).
Likewise, the fungus increases the production of the proteins involved in
attacks or virulence. However, the symptoms of rot by Alternaria
alternata are not
seen in some fruits, for example, in kiwifruit. All this can cause the
involuntary ingestion of the fungus when eating the fruit.
Researchers
conducted tests by infecting commercial kiwifruit with spores ofAlternaria alternata and they detected the presence of Alt
a 1, a protein of fungal virulence. Also, researchers studied how this protein
is involved in the activation of defense protein 5 in kiwifruit. Fourteen days
after the infection, the kiwifruits showed a regular aspect without apparent
development of the fungus, but through tests conducted in lab (microscopy of
specific staining fungus and Kiwi proteins) they detected the presence of Alt a
1 in the pulp.
What
is more, they observed that this fungal protein is found in the same areas that
the defense protein of the kiwifruit. Using computer modeling techniques, they
identified a surface area in Alt a 1 susceptible to interact with the defense
protein. In that interaction, Alt a 1 is joined to a region of the protein 5 of
the kiwifruit causing a remarkable decrease of its defense activity. These
results reveal that Alt a 1 is an inhibitor of the defense proteins of family 5
which is particularly important in processes of fungal infection.
Researchers
did not observed development of the fungus in kiwifruit, but they indeed
detected the presence of its major allergen through specific staining. From health
point of view, the presence of Alt a 1 in apparently healthy kiwis is important
since Alternariais described as a major cause
of chronic asthma in children. These results suggest that patients allergic to Alternaria can suffer an allergy attack after
eating infected kiwifruit.
Comments
Post a Comment