Gata2 heterozygous mutant mice exhibit reduced inflammatory responses and impaired bacterial clearance

Abstract

Summary Infectious diseases continually pose global medical challenges. The transcription factor GATA2 establishes gene networks and defines cellular identity in hematopoietic stem/progenitor cells and in progeny committed to specific lineages. GATA2-haploinsufficient patients exhibit a spectrum of immunodeficiencies associated with bacterial, viral, and fungal infections. Despite accumulating clinical knowledge of the consequences of GATA2 haploinsufficiency in humans, it is unclear how GATA2 haploinsufficiency compromises host anti-infectious defenses. To address this issue, we examined Gata2 -heterozygous mutant ( G2 Het ) mice as a model for human GATA2 haploinsufficiency. In vivo inflammation imaging and cytokine multiplex analysis demonstrated that G2 Het mice had attenuated inflammatory responses with reduced levels of inflammatory cytokines, particularly IFN-γ, IL-12p40, and IL-17A, during lipopolysaccharide-induced acute inflammation. Consequently, bacterial clearance was significantly impaired in G2 Het mice after cecal ligation and puncture-induced polymicrobial peritonitis. These results provide direct molecular insights into GATA2-directed host defenses and the pathogenic mechanisms underlying observed immunodeficiencies in GATA2-haploinsufficient patients.

The Il6 -39 kb enhancer containing clustered GATA2- and PU.1-binding sites is essential for Il6 expression in murine mast cells

“…We previously reported that a cohort of peritoneal cytokines was decreased in LPS-treated Gata2 heterozygous mutant mice ( Takai et al., 2021 ). Notably, many of the gene loci of these cytokines, including Il4 , Il13 , and Tnf , were enriched in the 646 GATA2 binding enhancer peaks.…”

“…Our ChIP data showed that GATA2 and PU.1 robustly bound to the -39 kb region, which suggests that the regulatory activity of the -39 kb region relies on GATA2 and PU.1. PU.1 is abundantly expressed in macrophages, whereas GATA2 levels are much lower in macrophages than in mast cells ( Takai et al., 2021 ). GATA2-deficient yolk sac progenitors still give rise to macrophages, which supports that GATA2 is dispensable for macrophage development ( Kaimakis et al., 2016 ).…”

“…GATA2 and PU.1 mRNA expression levels were slightly increased at 2 h after LPS treatment, and this expression was not affected in the del/del mutant (Figure 7B). Macrophages are a major source of IL-6 at inflammatory sites, but GATA2 is rarely expressed in peritoneal macrophages (Takai et al, 2021). To address differences in cytokine gene regulation in mast cells and macrophages, we examined the induced expression profile of Il6, Tnf, and Il1b after LPS treatment in the RAW264.7 murine macrophage cell line.…”

“…However, recent studies demonstrated that these factors cooperatively activate the expression of several genes in mast cells, including Il1rl1 , which encodes a transmembrane receptor for IL33, and Ms4a2 , which encodes the β-chain of the high-affinity IgE receptor (FcεRI) ( Baba et al., 2012 ; Ohmori et al., 2019 ). We recently demonstrated that the LPS-mediated induction of multiple peritoneal cytokines was under an intense regulatory influence of GATA2 ( Takai et al., 2021 ). Heterozygous GATA2 mutant mice showed attenuated inflammatory responses with reduced levels of multiple cytokines ( Takai et al., 2021 ).…”

“…We recently demonstrated that the LPS-mediated induction of multiple peritoneal cytokines was under an intense regulatory influence of GATA2 ( Takai et al., 2021 ). Heterozygous GATA2 mutant mice showed attenuated inflammatory responses with reduced levels of multiple cytokines ( Takai et al., 2021 ). These results suggest that GATA2 collaborates with PU.1 in the regulatory processes of inflammation-related genes in immune cells.…”