The role of the monocyte marker CD14 in the regulation of obesity is increasingly recognized. Our observations indicated that Cd14-/- mice exhibited a leaner body shape compared to their wild-type (WT) counterparts. And the loss of CD14 alleviated high-fat diet-induced obesity in mice. In human subjects, CD14 level was tested to be positively correlated with overweight and obesity. However, the relationship between CD14 and the development of obesity remains only partially understood. To investigate the underlying mechanisms, adipose tissues (ATs) from Cd14-/- and WT mice were subjected to deep RNA sequencing. Gene Ontology enrichment analysis revealed a significant enhancement of angiogenesis-related function in the Cd14-/- epididymal adipose tissues compared to WT counterpart, which was accompanied by an upregulation of Cd301b. Subsequent assays confirmed the enhanced angiogenesis and more accumulation of CD301b+ macrophages in Cd14-/- epididymal adipose tissues. Because Igf1 expression has been suggested to be associated with Cd301b expression through pseudotime analysis, we found it was insulin-like growth factor 1 secreted from Cd14-/- macrophages that mediated the angiogenesis enhancement. Collectively, our findings indicate that CD14 deficiency increased the accumulation of CD14loCD301b+ macrophages in ATs, which may serve as a proangiogenic marker, providing novel insights into the relationship between CD14 and obesity development.
Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.

Interferon regulatory factor (IRF) family genes play a critical role in colorectal cancer (CRC) development and impact patient survival. This study evaluated the influence of functional single nucleotide polymorphisms (SNPs) in IRF genes on CRC survival, including functional predictions and experimental validations. Multivariate Cox regression analysis identified three linked SNPs as significant survival predictors, with the rs141112353 T/T genotype in the 3'UTR region of IRF6 significantly associated with decreased survival (HR = 1.60, P = 6E-04). Expression quantitative trait loci (eQTL) analysis indicated that the rs141112353 TA > T alteration reduced IRF6 expression. Dual luciferase assays showed lower activity for the T allele in the presence of hsa-miR-548ap-3p. Data from The Cancer Genome Atlas (TCGA) and other databases confirmed lower IRF6 levels in CRC tissues, correlating with worse survival and inversely with M2 macrophage infiltration. In vitro, IRF6 overexpression inhibited CRC cell proliferation and M2 macrophage polarization by downregulating MIF expression. These findings suggest that the IRF6 rs141112353 TA > T variant significantly affects CRC survival, potentially by enhancing miR-548-ap-3p binding affinity.
© 2024 Wiley Periodicals LLC.

Novel chimeric antigen receptor (CAR) T-cell approaches are needed to improve therapeutic efficacy in solid tumors. High-risk neuroblastoma is an aggressive pediatric solid tumor that expresses cell-surface GPC2 and GD2 with a tumor microenvironment infiltrated by CD16a-expressing innate immune cells. Here we engineer T-cells to express a GPC2-directed CAR and simultaneously secrete a bispecific innate immune cell engager (BiCE) targeting both GD2 and CD16a. In vitro, GPC2.CAR-GD2.BiCE T-cells induce GPC2-dependent cytotoxicity and secrete GD2.BiCE that promotes GD2-dependent activation of antitumor innate immunity. In vivo, GPC2.CAR-GD2.BiCE T-cells locally deliver GD2.BiCE and increase intratumor retention of NK-cells. In mice bearing neuroblastoma patient-derived xenografts and reconstituted with human CD16a-expressing immune cells, GD2.BiCEs enhance GPC2.CAR antitumor efficacy. A CAR.BiCE strategy should be considered for tumor histologies where antigen escape limits CAR efficacy, especially for solid tumors like neuroblastoma that are infiltrated by innate immune cells.
© 2024. The Author(s).

Protective immunity to dengue virus (DENV) requires antibody response to all four serotypes. Systems vaccinology identifies a multi-OMICs pre-vaccination signature and mechanisms predictive of broad antibody responses after immunization with a tetravalent live attenuated DENV vaccine candidate (Butantan-DV/TV003). Anti-inflammatory pathways, including TGF-β signaling expressed by CD68low monocytes, and the metabolites phosphatidylcholine (PC) and phosphatidylethanolamine (PE) positively correlate with broadly neutralizing antibody responses against DENV. In contrast, expression of pro-inflammatory pathways and cytokines (IFN and IL-1) in CD68hi monocytes and primary and secondary bile acids negatively correlates with broad DENV-specific antibody responses. Induction of TGF-β and IFNs is done respectively by PC/PE and bile acids in CD68low and CD68hi monocytes. The inhibition of viral sensing by PC/PE-induced TGF-β is confirmed in vitro. Our studies show that the balance between metabolites and the pro- or anti-inflammatory state of innate immune cells drives broad and protective B cell response to a live attenuated dengue vaccine.
Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.

Monocyte/macrophage (Mo/Mp) is a critical cell population involved in immune modulation of rheumatoid synovitis (RA) across different pathotypes. This study aims to investigate the contribution of Mo/Mp clusters to RA activity, and the biological function of particular subtypes in RA remission.
We integrated single-cell RNA sequencing datasets from 4 published and 1 in-house studies using Liger selected by comparison. We estimated the abundance of Mo/Mp subtypes in bulk RNA-seq data from the 81 patients of the Pathobiology of Early Arthritis Cohort (PEAC) using deconvolution analysis. Correlations between Mo/Mp subtypes and RA clinical metrics were assessed. A particular cell type was identified using multicolor immunofluorescence and flow cytometry in vivo and successfully induced from a cell line in vitro. Potential immune modulation function of it was performed using immunohistochemical staining, adhesion assay, and RT-qPCR.
We identified 8 Mo/Mp clusters. As a particular subtype among them, COL3A1+ Mp (CD68+, COL3A1+, ACTA2-) enriched in myeloid pathotype and negatively correlated with RA severity metrics in all pathotypes. Flow cytometry and multicolor immunofluorescence evidenced the enrichment and M2-like phenotype of COL3A1+ Mp in the myeloid pathotype. Further assays suggested that COL3A1+ Mp potentially attenuates RA severity via expressing anti-inflammatory cytokines, enhancing Mp adhesion, and forming a physical barrier at the synovial lining.
This study reported unexplored associations between different pathologies and myeloid cell subtypes. We also identified a fibroblast-and-M2-like cluster named COL3A1+ Mp, which potentially contributes to synovial immune homeostasis. Targeting the development of COL3A1+ Mp may hold promise for inducing RA remission.
Copyright © 2024 Hu, Zhang, Long, Gu, Chen, Pan, Wu, Wang, Li, Zheng and Sheng.