Mucosal antigen-specific T cells are pivotal for pathogen clearance and immune modulation in respiratory infections. Dysregulated T cell responses exacerbate coronavirus disease 2019 severity, marked by cytokine storms and respiratory failure. Despite extensive description in peripheral blood, the characteristics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T cells in the lungs remain elusive. Here we conducted integrated single-cell profiling of SARS-CoV-2-specific T cells in 122 bronchoalveolar lavage fluid (BALF) and 280 blood samples from 159 patients, including 27 paired BALF and blood samples from 24 patients. SARS-CoV-2-specific T cells were robustly elicited in BALF irrespective of prior vaccination, correlating with diminished viral loads, lessened systemic inflammation and improved respiratory function. SARS-CoV-2-specific T cells in BALF exhibited profound activation, along with proliferative and multi-cytokine-producing capabilities and a glycolysis-driven metabolic signature, which were distinct from those observed in peripheral blood mononuclear cells. After viral clearance, these specific T cells maintained a polyfunctional tissue-resident memory phenotype, highlighting their critical roles in infection control and long-term protection.
© 2025. The Author(s).

Despite most acute myeloid leukemia (AML) patients entering remission following chemotherapy, outcomes remain poor due to surviving leukemic cells that contribute to relapse. The nature of these enduring cells is poorly understood. Here, through temporal single-cell transcriptomic characterization of AML hierarchical regeneration in response to chemotherapy, we reveal a cell population: AML regeneration enriched cells (RECs). RECs are defined by CD74/CD68 expression, and although derived from leukemic stem cells (LSCs), are devoid of stem/progenitor capacity. Based on REC in situ proximity to CD34-expressing cells identified using spatial transcriptomics on AML patient bone marrow samples, RECs demonstrate the ability to augment or reduce leukemic regeneration in vivo based on transfusion or depletion, respectively. Furthermore, RECs are prognostic for patient survival as well as predictive of treatment failure in AML cohorts. Our study reveals RECs as a previously unknown functional catalyst of LSC-driven regeneration contributing to the non-canonical framework of AML regeneration.
Crown Copyright © 2024. Published by Elsevier Inc. All rights reserved.

One rare type of autoimmune disease is called neuromyelitis optica spectrum disorder (NMOSD) and the peripheral immune characteristics of NMOSD remain unclear.
Here, single-cell RNA sequencing (scRNA-seq) is used to characterize peripheral blood mononuclear cells from individuals with NMOSD.
The differentiation and activation of lymphocytes, expansion of myeloid cells, and an excessive inflammatory response in innate immunity are observed. Flow cytometry analyses confirm a significant increase in the percentage of plasma cells among B cells in NMOSD. NMOSD patients exhibit an elevated percentage of CD8+ T cells within the T cell population. Oligoclonal expansions of B cell receptors are observed after therapy. Additionally, individuals with NMOSD exhibit elevated expression of CXCL8, IL7, IL18, TNFSF13, IFNG, and NLRP3.
Peripheral immune response high-dimensional single-cell profiling identifies immune cell subsets specific to a certain disease and identifies possible new targets for NMOSD.
Copyright © 2024 Jiang, Dai, Pang, Qin, Zhang, Liu, Wang, Zhang, Peng, Wang and Li.

Colchicine is known to reduce inflammation and improve endothelial cell function and atherosclerosis in obesity, but there is little knowledge of the specific circulating leukocyte populations that are modulated by colchicine.
A secondary analysis of a double-blind randomized controlled trial of colchicine 0.6 mg or placebo twice daily for 3 months on circulating leukocyte populations and regulation of the immune secretome in 35 adults with obesity was performed.
Colchicine altered multiple innate immune cell populations, including dendritic cells and lymphoid progenitor cells, monocytes, and natural killer cells when compared with placebo. Among all subjects and within the colchicine group, changes in natural killer cells were significantly positively associated with reductions in biomarkers of inflammation, including cyclooxygenase 2, pulmonary surfactant-associated protein D, myeloperoxidase, proteinase 3, interleukin-16, and resistin. Changes in dendritic cells were positively correlated with changes in serum heart-type fatty acid-binding protein concentrations. Additionally, colchicine treatment reduced cluster of differentiation (CD) CD4+ T effector cells and CD8+ T cytotoxic cells. Conversely, colchicine increased CD4+ and CD8+ T central memory cells and activated CD38High CD8+ T cells. Changes in CD4+ T effector cells were associated with changes in serum heart-type fatty acid-binding protein.
In adults with obesity, colchicine significantly affects circulating leukocyte populations involved in both innate and adaptive immune systems along with the associated inflammatory secretome.
Published 2023. This article is a U.S. Government work and is in the public domain in the USA.

Neuroblastoma (NB) is the most common paediatric extracranial solid malignancy. We analysed the role of the epitope detection in monocytes (EDIM) technique for liquid biopsy in NB patients.
Tumour epitopes transketolase-like 1 (TKTL1), Apo10 (DNaseX) and GD2 were assessed: expression levels in seven NB tumour samples and five NB cell lines were analysed using RT-PCR and flow cytometry. LAN-1 cells were co-cultured with blood and assessed using EDIM. Peripheral blood macrophages of patients with neuroblastoma (n = 38) and healthy individuals (control group, n = 37) were labelled (CD14+/CD16+) and assessed for TKTL1, Apo10 and GD2 using the EDIM technology.
mRNA expression of TKTL1 and DNaseX/Apo10 was elevated in 6/7 NB samples. Spike experiments showed upregulation of TKTL1, Apo10 and GD2 in LAN-1 cells following co-culturing with blood. TKTL1 and Apo10 were present in macrophages of 36/38 patients, and GD2 in 15/19 patients. The 37 control samples were all negative. EDIM expression scores of the three epitopes allowed differentiation between NB patients and healthy individuals.
The EDIM test might serve as a non-invasive tool for liquid biopsy in children suffering from NB. Future studies are necessary for assessing risk stratification, tumour biology, treatment monitoring, and early detection of tumour relapses.
© 2022. The Author(s).