A selective 7 nicotinic acetylcholine receptor agonist, PNU-282987,
attenuates ILC2s activation and Alternaria induced airway inflammation
Abstract
Background: The anti-inflammatory effect of the α7nAChR agonist,
PNU-282987, has previously been explored in the context of inflammatory
disease. However, the impact of PNU-282987 on type 2 innate lymphoid
cells (ILC2s)-mediated allergic airway inflammation has not been
established. Aims: To determine the effects of PNU-282987 on the
function of ILC2s in the context of IL-33 or Alternaria Alternata
(AA)-induced airway inflammation. Methods: PNU-282987 was administered
to mice that received recombinant IL-33 or AA intranasal challenge.
Whole lung was collected from mice for histological analysis, and ILC2
populations were quantified in the lungs and BALF of these mice.
Additionally, ILC2s were isolated from murine lung tissue and cultured
in vitro in the presence of IL-33, IL-2 and IL-7 with or without
PNU-282987, and the expression of the transcription factors GATA3, IKK,
and NF-κB was determined in these cells. Results: PNU-282987
significantly reduced airway goblet cell hyperplasia, eosinophil
infiltration, and ILC2s numbers in BALF in response to IL-33 or AA. In
vitro IL-33 stimulation of isolated lung ILC2s showed a reduction of
GATA3 and Ki67 in response to PNU-282987 treatments. When compared to
the established α7nAChR agonist, GTS-21, there was a notable reduction
in IKK and NF-κB phosphorylation in the PNU-282987 treated group when
compared to the GTS-21 treated ILC2s. Conclusion: PNU-282987 inhibits
ILC2s-associated airway inflammation by inhibiting ILC2s cell
proliferation and the initiation of inflammatory cascades.