Mesenchymal stromal cells (MSCs) are known for their immunomodulatory activity. Here, we report that MSCs isolated from the amniotic membrane of human term placenta (hAMSCs) impact CD8 T cell fate through a multifaceted mechanism. We observed that hAMSCs are able to impact the metabolism of naive CD8 lymphocytes by downregulating the phosphorylation of mTOR and AKT, thus blocking cell differentiation. This effect is due to the ability of hAMSCs to reduce the expression of two receptors, IL-12Rβ1 and IL-2RA, resulting in reduced phosphorylation of STAT4 and STAT5. In addition, hAMSCs reduce the expression of two transcriptional factors, Tbet and Eomes, directly involved in early effector cell commitment. Our results unravel an unknown feature of MSCs, offering alternative mechanistic insights into the effects of MSCs for the treatment of diseases characterized by an altered activation of memory subsets, such as autoimmune diseases and graft versus host disease.
© 2023 The Author(s).

Systemic lupus erythematosus (SLE) is a typical autoimmune disease characterized by the involvement of multiple organs and the production of antinuclear antibodies. This study aimed to investigate the molecular mechanism of SLE.
We retrieved genome-wide gene expression levels from five public datasets with relatively large sample sizes from the Gene Expression Omnibus (GEO), and we compared the expression profiles of peripheral blood mononuclear cells (PBMCs) from SLE patients and healthy controls (HCs). The expression of seven target genes in PBMCs from 25 cases and 3 HCs was further validated by reverse-transcription quantitative PCR (RT‒qPCR). Flow cytometry was used for verifying the proportion of naive CD4(+) T cells and M2 macrophages in PBMCs from 5 cases and 4 HCs.
We found 14 genes (TRIM5, FAM8A1, SHFL, LHFPL2, PARP14, IFIT5, PARP12, DDX60, IRF7, IF144, OAS1, OAS3, RHBDF2, and RSAD2) that were differentially expressed among all five datasets. The heterogeneity test under the fixed effect model showed no obvious heterogeneity of TRIM5, FAM8A1, and SHFL across different populations. TRIM5 was positively correlated with the remaining 13 genes. By separating patient samples into TRIM5-high and TRIM5-low groups, we found that up-regulated genes in the TRIM5-high group were mainly enriched in virus-related pathways. Immune cell proportion analysis and flow cytometry revealed that naive CD4(+) T cells were significantly decreased while M2 macrophages were increased in the SLE group. TRIM5 expression levels were negatively correlated with naive CD4(+) T cells but positively correlated with M2 macrophages.
Our data indicated that TRIM5 might be a key factor that modulates SLE etiology, possibly through naive CD4(+) T cells and M2 macrophages.
© 2023 Pan et al.

CD44v6 chimeric antigen receptor T (CD44v6 CAR-T) cells demonstrate strong anti-tumor ability and safety in acute myeloid leukemia (AML). However, the expression of CD44v6 on T cells leads to transient fratricide and exhaustion of CD44v6 CAR-T cells, which affect the application of CD44v6 CAR-T. The exhaustion and function of T cells and CD44v6 expression of AML cells are associated with DNA methylation. Hypomethylating agents (HAMs) decitabine (Dec) and azacitidine (Aza) have been widely used to treat AML. Therefore, there may be synergy between CD44v6 CAR-T cells and HAMs in the treatment of AML.
CD44v6 CAR-T cells pretreated with Dec or Aza were co-cultured with CD44v6+ AML cells. Dec or aza pretreated AML cells were co-cultured with CD44v6 CAR-T cells. The cytotoxicity, exhaustion, differentiation and transduction efficiency of CAR-T cells, and CD44v6 expression and apoptosis in AML cells were detected by flow cytometry. The subcutaneous tumor models were used to evaluate the anti-tumor effect of CD44v6 CAR-T cells combined with Dec in vivo. The effects of Dec or Aza on gene expression profile of CD44v6 CAR-T cells were analyzed by RNA-seq.
Our results revealed that Dec and Aza improved the function of CD44v6 CAR-T cells through increasing the absolute output of CAR+ cells and persistence, promoting activation and memory phenotype of CD44v6 CAR-T cells, and Dec had a more pronounced effect. Dec and Aza promoted the apoptosis of AML cells, particularly with DNA methyltransferase 3A (DNMT3A) mutation. Dec and Aza also enhanced the CD44v6 CAR-T response to AML by upregulating CD44v6 expression of AML cells regardless of FMS-like tyrosine kinase 3 (FLT3) or DNMT3A mutations. The combination of Dec or Aza pretreated CD44v6 CAR-T with pretreated AML cells demonstrated the most potent anti-tumor ability against AML.
Dec or Aza in combination with CD44v6 CAR-T cells is a promising combination therapy for AML patients.
Copyright © 2023 Tang, Kong, Wang, Zou, Sun, Liu, Zhang, Jin, Mao, Zhu, Wang, Meng and You.

Chimeric antigen receptor-engineered T cell (CAR-T) therapy has shown promising potential for anti-cancer treatment. However, for pancreatic ductal adenocarcinoma (PDAC), the lack of infiltrative ability of these CAR-T cells leads to sub-optimal treatment outcome.Chemokine (C-C motif) ligand 19 (CCL19), the expression of which is regulated by the nuclear factor of activated T cell pathway, was transfected into targeting mesothelin CAR-T cells (mesoCAR-N19) using NFAT regulating element. It was expressed in activated CAR-T cells by OKT3 or mesothelin+ tumor cells but not in inactive cells. The migratory ability of these CAR-T cells was then measured. Subsequently, functional identification of these CAR-T cells was performed in vivo. In addition, the tumor lytic activity and proliferation of the CAR-T cells were measured in vitro. The degree of CAR-T cell infiltration and distribution into the PDAC tumors was examined using the immunohistochemical staining of hCD3 and the detection of CAR gene copy number by quantitative PCR. Finally, the functional assessment of chemokine (C-C motif) receptor 7 knock-out was performed in the CAR-T cells.Through in vitro Transwell assays, it was demonstrated that mesoCAR-N19 can be specifically expressed in CAR-T cells activated by tumor cells compared with conventional mesothelin CAR-T (mesoCAR) cells. We also observed that upregulating the expression of CCL19 can increase the recruitment of additional T cells. In vivo studies subsequently revealed that this highly specific recruitment of T cell infiltration is associated with enhanced tumor-suppressive activities downstream.Induced expression of CCL19 can promote the anti-tumor ability of CAR-T cells by increasing their infiltrative ability. This study potentially uncovered novel method of activating CAR-T cells to enhance their infiltrative capacities, which offers a novel direction for PDAC treatment.Copyright © 2022 Hu, Wang, Liao, Chen, Kang, Lin, Lin, Huang, Tian and Chen.

The identification of patients with coronavirus disease 2019 and high risk of severe disease is a challenge in routine care. We performed cell phenotypic, serum, and RNA sequencing gene expression analyses in severe hospitalized patients (n = 61). Relative to healthy donors, results showed abnormalities of 27 cell populations and an elevation of 42 cytokines, neutrophil chemo-attractants, and inflammatory components in patients. Supervised and unsupervised analyses revealed a high abundance of CD177, a specific neutrophil activation marker, contributing to the clustering of severe patients. Gene abundance correlated with high serum levels of CD177 in severe patients. Higher levels were confirmed in a second cohort and in intensive care unit (ICU) than non-ICU patients (P < 0.001). Longitudinal measurements discriminated between patients with the worst prognosis, leading to death, and those who recovered (P = 0.01). These results highlight neutrophil activation as a hallmark of severe disease and CD177 assessment as a reliable prognostic marker for routine care.
© 2021 The Author(s).