The Nonphagocytic NADPH Oxidase Duox1 Mediates a Positive Feedback Loop During T Cell Receptor Signaling

Abstract

Production of reactive oxygen species, often by NADPH (reduced form of nicotinamide adenine dinucleotide phosphate) oxidases, plays a role in the signaling responses of cells to many receptor stimuli. Here, we describe the function of the calcium-dependent, nonphagocytic NADPH oxidase Duox1 in primary human CD4 + T cells and cultured T cell lines. Duox1 bound to inositol 1,4,5-trisphosphate receptor 1 and was required for early T cell receptor (TCR)-stimulated production of hydrogen peroxide (H 2 O 2 ) through a pathway that was dependent on TCR-proximal kinases. Transient or stable knockdown of Duox1 inhibited TCR signaling, especially phosphorylation of tyrosine-319 of ζ chain-associated protein kinase of 70 kilodaltons (ZAP-70), store-operated entry of calcium ions (Ca 2+ ), and activation of extracellular signal-regulated kinase. The production of cytokines was also inhibited by knockdown of Duox1. Duox1-mediated inactivation of Src homology 2 domain-containing protein tyrosine phosphatase 2 promoted the phosphorylation of ZAP-70 and its association with the Src family tyrosine kinase Lck and the CD3ζ chain of the TCR complex. Thus, we suggest that activation of Duox1, downstream of proximal TCR signals, generates H 2 O 2 that acts in a positive feedback loop to enhance and sustain further TCR signaling.

IFNβ/TNFα synergism induces a non-canonical STAT2/IRF9-dependent pathway triggering a novel DUOX2 NADPH Oxidase-mediated airway antiviral response

“…The closelyrelated homolog of DUOX2, DUOX1 that is also expressed in AECs was previously shown to regulate EG-FR-dependent signaling [46,47]. Additionally, DUOX1-derived H 2 O 2 was shown to regulate intracellular protein phosphatase activities [48,49]. Although intracellular signaling modulation is a likely mechanism, regulation of IFN expression in our system is not due to altered transcriptional regulation, as IFNβ and IFNλ mRNA levels were not affected by the specific knockdown of DUOX2 using siRNA.…”

DUOX1 mediates persistent epithelial EGFR activation, mucous cell metaplasia, and airway remodeling during allergic asthma

“…The mechanism by which DUOX1 promotes IL-33-dependent signaling will need to be addressed in future studies but potentially involves amplification of IL33R-dependent JAK/STAT signaling by oxidative inhibition of protein tyrosine phosphatases, analogous to other cytokine signaling pathways (51). Moreover, the observed expression of DUOX1 in ILC2s, combined with recent reports indicating the presence of DUOX1 in T cells (51) and macrophages (52), implies that the involvement of DUOX1 in lung biology extends beyond its well-studied role(s) in epithelial host responses (53) and likely also includes regulatory functions in other cell lineages. Future studies, using transgenic models of targeted DUOX1 deletion in these various cell lineages, for example, will be required to unravel the specific contribution of DUOX1-dependent signaling in these specific cell types.…”

Epidermal growth factor-induced hydrogen peroxide production is mediated by dual oxidase 1

“…Next we examined the specific role of Duox1 in the above described ROS responses. Duox1-derived H 2 O 2 was described to modulate calcium signaling in Jurkat cells (16), although in our previous experiments we did not observe altered calcium signaling in epithelial cells prepared from Duox1 knockout animals (17). Supplementary Figure 3. shows, that siRNAmediated downregulation of Duox1 did not modify the calcium signal elicited by EGF.…”