Airway Exposure to Polyethyleneimine Nanoparticles Induces Type 2 Immunity by a Mechanism Involving Oxidative Stress and ATP Release

Abstract

Polyethyleneimine (PEI) induced immune responses were investigated in human bronchial epithelial (hBE) cells and mice. PEI rapidly induced ATP release from hBE cells and pretreatment with glutathione (GSH) blocked the response. PEI activated two conductive pathways, VDAC-1 and pannexin 1, which completely accounted for ATP efflux across the plasma membrane. Moreover, PEI increased intracellular Ca2+ concentration ([Ca2+]i), which was reduced by the pannexin 1 inhibitor, 10Panx (50 μM), the VDAC-1 inhibitor, DIDS (100 μM), and was nearly abolished by pretreatment with GSH (5 mM). The increase in [Ca2+]i involved Ca2+ uptake through two pathways, one blocked by oxidized ATP (oATP, 300 μM) and another that was blocked by the TRPV-1 antagonist A784168 (100 nM). PEI stimulation also increased IL-33 mRNA expression and protein secretion. In vivo experiments showed that acute (4.5 h) PEI exposure stimulated secretion of Th2 cytokines (IL-5 and IL-13) into bronchoalveolar lavage (BAL) fluid. Conjugation of PEI with ovalbumin also induced eosinophil recruitment and secretion of IL-5 and IL-13 into BAL fluid, which was inhibited in IL-33 receptor (ST2) deficient mice. In conclusion, PEI-induced oxidative stress stimulated type 2 immune responses by activating ATP-dependent Ca2+ uptake leading to IL-33 secretion, similar to allergens derived from Alternaria.

Scaffold Vaccines for Generating Robust and Tunable Antibody Responses

“…[18,[47][48][49] PEI has also been shown to stimulate type-2 immunity and secretion of IL-5 and IL-10, among other cytokines. [49][50][51] These reports are broadly consistent with our finding that PLG scaffolds containing GM-CSF, OVA, and PEI alone (without CpG) induced an IL-5, Th2-biased response (Figure 2f,g). Moreover, vaccination against glycoprotein antigens using PEI alone as an adjuvant led to higher IgG1/IgG2a antibody ratios than with CpG alone or PEI complexed with CpG.…”

Route of self-amplifying mRNA vaccination modulates the establishment of pulmonary resident memory CD8 and CD4 T cells

“…A previous report of self-amplifying RNA delivery by the IN route using multiple delivery systems including LNPs showed poor immunogenicity relative to more typical IM or intradermal injections, and was associated with rapid clearance (56). For the most part, intranasal delivery of mRNA vaccines have been attempted using well-established polymer-based transfection reagents, though such polymer-based approaches have not historically reached clinical application successfully, possibly in part due to toxicity issues (57)(58)(59)(60). Moreover, IN LNP can induce lethal inflammatory responses in mice, complicating studies of alternative administration routes (48).…”

Damage-associated molecular patterns in vitiligo: igniter fuse from oxidative stress to melanocyte loss

“…Genome-wide association analysis of patients with vitiligo showed the inflammasome pathway was involved in vitiligo pathogenesis, and that ATP was the most important link during inflammasome activation [ 59 ]. During vitiligo, the hyperoxidative stress state stimulates keratinocytes to release ATP outside the cell [ 60 , 61 ]. Treatment with ATP induces inflammasome and caspase-1 activation, and the production of active IL-1β and IL-18 forms via P2X7Rs in keratinocytes and melanocytes [ 62 ] [ 63-65 ].…”