To identify the dynamics of neutrophil autoimmunity, here we focus on anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis and perform single-cell transcriptome and surface proteome analyses on peripheral white blood cells from patients with new-onset microscopic polyangiitis (MPA). Compared with controls, two neutrophil populations, immature neutrophils and neutrophils with type II interferon signature genes (Neu_T2ISG), are increased in patients with MPA. Trajectory and cell-cell interaction analyses identify Neu_T2ISG as a subset that differentiates from mature neutrophils upon stimulation with IFN-γ and TNF, which synergize to induce myeloperoxidase and Fcγ receptors expression on the neutrophil cell surface and promote ANCA-induced neutrophil extracellular trap formation. Case-by-case analysis indicates that patients with a high proportion of the Neu_T2ISG subset are associated with persistent vasculitis symptoms. A larger cohort analysis shows that serum IFN-γ levels at disease onset correlate with susceptibility to disease relapse. Our findings thus identify neutrophil diversity at the single cell level and implicate a biomarker for predicting relapse in small vessel vasculitis.
© 2025. The Author(s).

Abstract Single cell analysis in autoimmune disease has largely focused on mononuclear cells and diseased tissues, leaving the diversity of neutrophils poorly understood. To identify the dynamics of neutrophil autoimmunity, we focus on an autoimmune disease characterized by abnormal neutrophil activation, anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis. Single-cell transcriptome and surface proteome analyses are performed on 179,664 peripheral white blood cells from treatment-naïve patients with new-onset microscopic polyangiitis (MPA) and healthy donors. Neutrophils are classified into seven subsets, two of which are significantly increased in MPA patients: immature neutrophils (Neu_Immature) and neutrophils characterized by type II interferon signature genes (Neu_T2ISG). The Neu_T2ISG subset shows increased expression of interferon (IFN)-γ response genes, many of which are identified as differentially expressed genes in neutrophils from MPA patients compared to those from healthy donors. Trajectory and cell–cell interaction analyses identify Neu_T2ISG as a uniquely primed subset that differentiates from mature neutrophils upon stimulation with IFN-γ and tumor necrosis factor (TNF)-α. The combined effect of these cytokines simultaneously exposes myeloperoxidase and Fcγ receptors on the neutrophil cell surface and promotes ANCA–induced neutrophil extracellular trap formation. Case-by-case analysis indicates that patients with a high proportion of the Neu_T2ISG subset are associated with persistent vasculitis symptoms. In a larger cohort using stored sera, serum IFN-γ levels at disease onset significantly correlate with susceptibility to disease relapse. Our findings identify neutrophil diversity at the single cell level and bridge the data to a clinically applicable biomarker for predicting relapse in small vessel vasculitis.

The aim of this study was to examine whether colchicine's anti-inflammatory effects would improve measures of lipolysis and distribution of leukocyte populations in subcutaneous adipose tissue (SAT).
A secondary analysis was conducted for a double-blind, randomized, placebo-controlled pilot study in which 40 adults with obesity and metabolic syndrome (MetS) were randomized to colchicine 0.6 mg or placebo twice daily for 3 months. Non-insulin-suppressible (l0 ), insulin-suppressible (l2 ), and maximal (l0 +l2 ) lipolysis rates were calculated by minimal model analysis. Body composition was determined by dual-energy x-ray absorptiometry. SAT leukocyte populations were characterized by flow cytometry analysis from biopsied samples obtained before and after the intervention.
Colchicine treatment significantly decreased l2 and l0 +l2 versus placebo (p < 0.05). These changes were associated with a significant reduction in markers of systemic inflammation, including high-sensitivity C-reactive protein, resistin, and circulating monocytes and neutrophils (p < 0.01). Colchicine did not significantly alter SAT leukocyte population distributions (p > 0.05).
In adults with obesity and MetS, colchicine appears to improve insulin regulation of lipolysis and reduce markers of systemic inflammation independent of an effect on local leukocyte distributions in SAT. Further studies are needed to better understand the mechanisms by which colchicine affects adipose tissue metabolic pathways in adults with obesity and MetS.
Published 2021. This article is a U.S.Government work and is in the public domain in the USA.

Conventional vaccine design has been based on trial-and-error approaches, which have been generally successful. However, there have been some major failures in vaccine development and we still do not have highly effective licensed vaccines for tuberculosis, HIV, respiratory syncytial virus, and other major infections of global significance. Approaches at rational vaccine design have been limited by our understanding of the immune response to vaccination at the molecular level. Tools now exist to undertake in-depth analysis using systems biology approaches, but to be fully realized, studies are required in humans with intensive blood and tissue sampling. Methods that support this intensive sampling need to be developed and validated as feasible. To this end, we describe here a detailed approach that was applied in a study of 15 healthy adults, who were immunized with hepatitis B vaccine. Sampling included ~350 mL of blood, 12 microbiome samples, and lymph node fine needle aspirates obtained over a ~7-month period, enabling comprehensive analysis of the immune response at the molecular level, including single cell and tissue sample analysis. Samples were collected for analysis of immune phenotyping, whole blood and single cell gene expression, proteomics, lipidomics, epigenetics, whole blood response to key immune stimuli, cytokine responses, in vitro T cell responses, antibody repertoire analysis and the microbiome. Data integration was undertaken using different approaches-NetworkAnalyst and DIABLO. Our results demonstrate that such intensive sampling studies are feasible in healthy adults, and data integration tools exist to analyze the vast amount of data generated from a multi-omics systems biology approach. This will provide the basis for a better understanding of vaccine-induced immunity and accelerate future rational vaccine design.
Copyright © 2020 Ben-Othman, Cai, Liu, Varankovich, He, Blimkie, Lee, Gill, Novotny, Aevermann, Drissler, Shannon, McCann, Marty, Bjornson, Edgar, Lin, Gladish, Maclsaac, Amenyogbe, Chan, Llibre, Collin, Landais, Le, Reiss, Koff, Havenar-Daughton, Heran, Sangha, Walt, Krajden, Crotty, Sok, Briney, Burton, Duffy, Foster, Mohn, Kobor, Tebbutt, Brinkman, Scheuermann, Hancock, Kollmann and Sadarangani.

Recent reports highlight a new clinical syndrome in children related to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)1-multisystem inflammatory syndrome in children (MIS-C)-which comprises multiorgan dysfunction and systemic inflammation2-13. We performed peripheral leukocyte phenotyping in 25 children with MIS-C, in the acute (n = 23; worst illness within 72 h of admission), resolution (n = 14; clinical improvement) and convalescent (n = 10; first outpatient visit) phases of the illness and used samples from seven age-matched healthy controls for comparisons. Among the MIS-C cohort, 17 (68%) children were SARS-CoV-2 seropositive, suggesting previous SARS-CoV-2 infections14,15, and these children had more severe disease. In the acute phase of MIS-C, we observed high levels of interleukin-1β (IL-1β), IL-6, IL-8, IL-10, IL-17, interferon-γ and differential T and B cell subset lymphopenia. High CD64 expression on neutrophils and monocytes, and high HLA-DR expression on γδ and CD4+CCR7+ T cells in the acute phase, suggested that these immune cell populations were activated. Antigen-presenting cells had low HLA-DR and CD86 expression, potentially indicative of impaired antigen presentation. These features normalized over the resolution and convalescence phases. Overall, MIS-C presents as an immunopathogenic illness1 and appears distinct from Kawasaki disease.