Researchers have discovered a new genetic target for asthma
treatment.
The work, led by scientists at the Medical Research Council's
National Institute for Medical Research (NIMR; now part of
the Francis Crick Institute), provides pre-clinical evidence
that targeting a micro RNA (miRNA) called miR-155 could alleviate
asthma while avoiding the side effects of the broad-scale steroids
that are currently used to treat this common and often debilitating
condition.
Dr Mark Wilson of NIMR said: "Allergic diseases, such as asthma
and allergic rhinitis, are some of the most common global chronic
diseases. Currently, therapeutic intervention relies upon
broad-scale steroids, which have indiscriminate impact and many
side effects."
Dr Wilson's team studied a group of immune cells called Th2
cells, which are responsible for initiating and orchestrating the
allergic cascade - a domino effect of reactions that occur in the
body in response to an allergen.
They isolated Th2 cells from mice with allergic airway
inflammation, which enabled them to identify new features of the
allergic cascade, including new genes and miRNAs that are
associated with Th2 cells but not other T cell populations.
The team found that inhibiting one of these miRNAS - miR-155 -
prevented it from carrying out its function and significantly
reduced the severity of airway inflammation in the mice.
Dr Wilson said: "This breakthrough study identifies a new
therapeutic target, miR-155, that could be exploited to alleviate
many of the symptoms associated with asthma.
"While this work focused on allergic asthma, the broader
implications suggest that targeting miRNAs could be useful to treat
many other inflammatory diseases, including multiple sclerosis,
arthritis or diabetes."
The paper, Transcriptomics identified a critical role for Th2 cell-intrinsic
miR-155 in mediating allergy and antihelminth immunity, is
published in the Proceedings of the National Academy of
Sciences.