UBA1-depleted neutrophils disrupt immune homeostasis and induce VEXAS-like autoinflammatory disease in mice
Ge Dong, Jingjing Liu, Wenyan Jin, Hongxi Zhou, Yuchen Wen, Zhiqin Wang, Keyao Xia, Jianlin Zhang, Linxiang Ma, Yunxi Ma, Lorie Chen Cai, Qiufan Zhou, Huaquan Wang, Wei Wei, Ying Fu, Zhigang Cai
Ge Dong, Jingjing Liu, Wenyan Jin, Hongxi Zhou, Yuchen Wen, Zhiqin Wang, Keyao Xia, Jianlin Zhang, Linxiang Ma, Yunxi Ma, Lorie Chen Cai, Qiufan Zhou, Huaquan Wang, Wei Wei, Ying Fu, Zhigang Cai
View: Text | PDF
Research Article Hematology Inflammation

UBA1-depleted neutrophils disrupt immune homeostasis and induce VEXAS-like autoinflammatory disease in mice

Abstract

Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome is a hemato-rheumatoid disease caused by somatic UBA1 mutations in hematopoietic stem cells (HSCs). The pathogenic cell type(s) responsible for the syndrome are unknown, and murine models recapitulating the disease are lacking. We report that loss of Uba1 in various mouse hematopoietic cell types resulted in pleiotropic consequences and demonstrate that an approximate 70% loss of Uba1 in neutrophils (NEs) of murine mutants induced nonlethal VEXAS-like symptoms. Depletion of Uba1 in HSCs induced extensive hematopoietic cell loss, whereas depletion of Uba1 in B cells, T cells, or megakaryocytes induced corresponding cell death, but these mutant mice appeared normal. Depletion of Uba1 in monocytes and NEs failed to induce cell death, and the mutant mice were viable. Among the tested models, only depletion of Uba1 in NEs induced autoinflammatory symptoms including increased counts and percentages of NEs, increased proinflammatory cytokines, presence of vacuoles in myeloid cells, splenomegaly, and dermatitis. Residual Uba1 was approximately 30% in the mutant NEs, which disrupted cellular hemostasis. Finally, genetic loss of the myeloid prosurvival regulator Morrbid partially mitigated the VEXAS-like symptoms. The established VEXAS-like murine model will further our understanding and treatment of the newly identified autoinflammatory syndrome prevalent among aged men.

Authors

Ge Dong, Jingjing Liu, Wenyan Jin, Hongxi Zhou, Yuchen Wen, Zhiqin Wang, Keyao Xia, Jianlin Zhang, Linxiang Ma, Yunxi Ma, Lorie Chen Cai, Qiufan Zhou, Huaquan Wang, Wei Wei, Ying Fu, Zhigang Cai

×

Figure 8

NETs formation and phagocytosis in S100a8Cre-CKO NEs.

Options: View larger image (or click on image) Download as PowerPoint
NETs formation and phagocytosis in S100a8Cre-CKO NEs. (A) Mutant NEs man...
(A) Mutant NEs manifested increased level of NETs formation, which was determined by MPO and CitH3 staining. Purified NEs (1 × 106) were cultured in a 24-well plate with 1,000 μL medium. Phorbol 12-myristate 13-acetate was added to the medium to promote cell attachment. After a 6-hour culture, cells were fixed and stained by MPO and CitH3 antibody. MPO and CitH3 double-positive cells were counted for a standard area. Left panel shows representative microscopy images; right panel shows the quantification results. n = 3 biological repeats for the WT group; n = 8 biological repeats for the S100a8Cre-CKO group. Scale bars: 50 μm. (B and C) Mutant NEs showed an increased phagocytotic capability when cocultured with bacteria E. coli (GFP+). (B) Scheme for the phagocytosis assay. Time-lapse photography was performed every 10 minutes after the mixing. GFP dots (indication of E. coli) within the NEs were counted 40 minutes after the mixing of NEs and bacteria. (C) Phagocytosis of E. coli was improved in S100a8Cre-CKO NEs compared with WT. Data are presented as the percentages of cells with certain counts of internalized bacteria (GFP+). n = 3 biological repeats per group. ****P < 0.000, by Student’s t-test. n = 3~8 biological repeats. Scale bars: 20 μm.