Evidence of kinetic proofreading through allergen specific IgE at the
human mast cell IgE receptor
Abstract
Background Activation of mast cells through IgE results in secretion and
shedding of mast cell proteins and in vivo models suggest that these
processes are governed by IgE antibody affinity. Methods We passively
sensitized cultured primary human mast cells with recombinant human IgE
clones with either high or low affinity for Der p 2, with a 200-fold
affinity difference, and activated them with recombinant allergen.
Activation was assessed by CD63 upregulation and PGD 2
secretion. Supernatants collected from mast cells activated for 0, 3, 6
and 24 hours were assessed for PGD 2 and inflammatory
mediators on the OLINK platform at repeated time points. Results CD63
upregulation and PGD 2 synthesis scaled with affinity,
as did secretion of cytokines like IL-8 and IL-13. Secretion of
chemokines like CCL3 and CCL4 appeared to depend less on affinity,
whereas shedding of surface markers CD40, SLAMF4 and CD5, and secretion
of intracellular markers SIRT2 and CASP-8, were elevated by stimulation
through low affinity IgE compared with high affinity IgE, illustrating
differential responses dependent on the affinity of IgE. Conclusion
Cytokine secretion and shedding of surface receptors of sensitized,
cultured primary human mast cells is differentially regulated depending
on the affinity of IgE for the Der p 2 allergen and may shape the
chronic response to repeated allergic activation.