Early-life immune development is critical to long-term host health. However, the mechanisms that determine the pace of postnatal immune maturation are not fully resolved. Here, we analyzed mononuclear phagocytes (MNPs) in small intestinal Peyer's patches (PPs), the primary inductive site of intestinal immunity. Conventional type 1 and 2 dendritic cells (cDC1 and cDC2) and RORgt+ antigen-presenting cells (RORgt+ APC) exhibited significant age-dependent changes in subset composition, tissue distribution, and reduced cell maturation, subsequently resulting in a lack in CD4+ T cell priming during the postnatal period. Microbial cues contributed but could not fully explain the discrepancies in MNP maturation. Type I interferon (IFN) accelerated MNP maturation but IFN signaling did not represent the physiological stimulus. Instead, follicle-associated epithelium (FAE) M cell differentiation was required and sufficient to drive postweaning PP MNP maturation. Together, our results highlight the role of FAE M cell differentiation and MNP maturation in postnatal immune development.
Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.

Extracellular ATP binds to purinergic receptors and promotes inflammatory responses. We tested whether oxidized ATP (oATP), P2X7 receptor antagonist can attenuate acute kidney allograft rejection.
Brown Norway kidney allografts were transplanted into Lewis recipients. Three groups were defined: oATP (n=8), cyclosporine A (n=6), and no treatment (n=8). On day 7, we assessed kidney allograft survival, function, and rejection characteristics. We further determined T-cell, B-cell, and macrophage response to oATP in vivo and in vitro and examined intragraft inflammatory gene transcripts.
Kaplan-Meier survival analyses demonstrated significantly better graft survival rates in oATP and CsA groups compared with no treatment (P<0.05). Similarly, serum creatinine (Scr) and BUN levels were significantly lower in oATP and CsA groups (P<0.05). oATP reduced both T cell-mediated rejection and antibody-mediated rejection, inhibited B-cell and T-cell activation, and downregulated intragraft IL-6 mRNA levels (P<0.0001). In vitro, oATP prevented proliferation in mixed lymphocyte reaction assays, and inhibited macrophage P2X7R activity in a dose-dependent manner.
Our findings suggest that oATP mitigates kidney allograft rejection by inhibiting T-cell, B-cell, and macrophage activity and indicate a potential role for the purinergic system and oATP in solid organ transplantation.
Copyright © 2020 by the American Society of Nephrology.

The occurrence of pelvic organ prolapse (POP) is closely associated with alterations in the extracellular matrix proteins of the supporting ligament. Bone marrow mesenchymal stem cells (BMSCs) have the potential to differentiate into a variety of cell types, including osteoblasts, chondroblasts and adipocytes. Therefore, BMSCs have the potential to improve the clinical outcomes of POP. Tenascin‑C is a large glycoprotein that is present in the ECM and is involved in morphogenetic movements, and tissue patterning and repair. The aim of the present study was to investigate the effect of mechanical stretching on tenascin‑C expression during the differentiation of BMSCs induced by pelvic ligament fibroblasts. BMSCs were isolated from 7‑day‑old Sprague Dawley rats. Fibroblasts were obtained from rat pelvic ligaments and, at the fourth passage, were subjected to 10% deformation with 1 Hz, periodic one‑way mechanical stretch stimulation, followed by co‑culture with BMSCs. The co‑culture with stretched fibroblasts increased tenascin‑C and transforming growth factor (TGF)‑β expression levels, compared with groups without mechanical stimulation. Neutralizing anti‑TGF‑β1 antibodies, and inhibitors of TGF‑β receptor, mitogen‑activated protein kinase (MAPK) kinase and MAPK, decreased tenascin‑C expression levels induced by TGF‑β and mechanical stretching. The results of the present study suggested that the regulation of tenascin‑C expression levels in BMSCs co‑cultured with mechanically stretched pelvic ligament fibroblasts is mediated via the soluble growth factor TGF‑β and the MAPK signaling pathway. In addition, these results indicated that in an indirect co‑culture system, pelvic ligament fibroblasts with mechanical stretch stimulation may promote the synthesis of tenascin‑C and BMSC differentiation into pelvic ligament fibroblasts.

Flow cytometry is a valuable tool for the detection and characterization of proteins expressed by individual cells. Flow cytometry can be used to measure cell expression of 2 intracellular proteins that are involved in the regulation of immune homeostasis, SLAM-associated protein (SAP) and X-linked inhibitor of apoptosis (XIAP). These proteins are defective in patients with the immune deficiency X-linked lymphoproliferative disease (XLP), due to mutations in the SH2D1A and XIAP/BIRC4 genes, respectively (Coffey et al. Nat Genet 20:129-135 1998; Nichols et al. Proc Natl Acad Sci U S A 95:13765-13770, 1998; Sayos et al. Nature 395:462-469, 1998; Rigaud et al. Nature 444:110-114, 2006). This procedure describes a technique that can be efficiently used to detect SAP and XIAP by flow cytometry.

Recent reports have revealed that CD4(+) T(h) cell subsets have the ability to alter their gene expression pattern in response to extracellular stimuli. We previously highlighted the plasticity of T(h)1 cells by demonstrating that T(h)1 cells gain the capacity to produce IL-3, IL-9, IL-13 and granulocyte macrophage colony-stimulating factor in response to antigen, IL-2 and IL-18, and based on their unique function, we designated these activated T(h)1 cells as 'super T(h)1 cells'. However, the precise molecular mechanism underlying IL-13 production by super T(h)1 cells has not been elucidated. Here, we show that the GATA-binding protein 3 (Gata3) is essentially required for II13 gene expression in super T(h)1 cells. Gata3 is synergistically induced in T-box expressed in T-cells (T-bet)-expressing T(h)1 cells when co-stimulated with anti-CD3, IL-18 and IL-4 through the activation of nuclear factor of activated T cells, nuclear factor kappa-light-chain-enhancer of activated B cells and signal transducer and activator of transcription 6, respectively. However, Gata3 induction is not satisfactory, and additional TCR or anti-CD3 signaling is prerequisite for triggering IL-13 production by Gata3 plus T-bet-expressing T(h)1 cells. These findings suggest that Gata3, which is not originally expressed in T(h)1 cells, alters the cytokine production profile by T(h)1 cells.