Project description:IL-12 and IL-18 synergize to promote TH1 responses and have been implicated as accelerators of autoimmune pathogenesis in type 1 diabetes (T1D). We therefore investigated the influence of these cytokines on phenotype and function of immune cells that are involved in disease progression. To understand how IL-12 and IL-18 may synergize to impair Treg function and phenotype, we conducted transcriptional profiling of Treg expanded under normal conditions or in the presence of IL-12 and IL-18. This analysis revealed increased expression of IFNG, GZMB, GZMA, and IL18RAP and decreased FOXP3 in Tregs expanded with IL-12 and IL-18.
Project description:To determine the differentially expressed genes between these subsets and identify the core human in vivo differentiated Tr1 cell gene signature
Project description:Purpose: To identify gene expression patterns in ex vivo isolated human Tr1 cells. Method: RNA sequencing of total mRNA. Results: Differential gene expression of Tr1 and non-Tr1 CD4+ T memory cells. Conclusions: ex vivo type 1 regulatory T cells have a distinct gene expression profile compared to non-Tr1 CD4+ T cell memory cells.
Project description:The potency of regulatory T cell (Treg) therapy has been transformed through use of chimeric antigen receptors (CAR). However, to date, CAR Treg therapy has not achieved long-lasting tolerance in mouse models, suggesting that additional engineering is required to unlock the full potential of these cells. We previously found that human Tregs produce minimal amounts of IL-10 and have a limited capacity to control innate immunity in comparison to type I regulatory (Tr1) cells. Seeking to create “hybrid” CAR Tregs that were engineered with Tr1-like properties, we examined whether the PDCD1 locus could be exploited to endow Tregs with the ability to secrete high levels of IL-10 in a CAR-regulated manner.
Project description:Treg cell therapy is a promising curative approach for a variety of immune-mediated conditions. CRISPR-based genome editing allows precise insertion of transgenes through homology-directed repair, but its use in human Tregs has been limited. We report an optimized protocol for CRISPR-mediated gene knock-in in human Tregs with high-yield expansion. To establish a benchmark of human Treg dysfunction, we target the master transcription factor FOXP3 in naive and memory Tregs. Although FOXP3-ablated Tregs upregulate cytokine expression, effects on suppressive capacity in vitro manifest slowly and primarily in memory Tregs. Moreover, FOXP3-ablated Tregs retain their characteristic protein, transcriptional, and DNA methylation profile. Instead, FOXP3 maintains DNA methylation at regions enriched for AP-1 binding sites. Thus, while FOXP3 is important for human Treg development, it has a limited role in maintaining mature Treg identity. Optimized gene knock-in with human Tregs will enable mechanistic studies and the development of tailored, next-generation Treg cell therapies.
Project description:Aging is a complex biological process that impacts various physiological functions, including the immune system. Our study investigated the impact of aging on CD8+ regulatory T cells (CD8+ Tregs), which showed a pattern of initial increase up to 12 months, then a decline by 24 months in a C57BL/6 mouse model, unlike memory T cells, which consistently increase with age. Functionally, CD8+ Tregs, irrespective of age, did not produce cytokines in response to TCR stimulation, highlighting a stark functional contrast with memory cells. However, upon IL-15 stimulation, CD8+ Tregs, unlike their memory cell counterparts, demonstrated enhanced cytokine production. Transcriptomic analysis revealed an abundance of Klrk1 (killer cell lectin-like receptor subfamily K member 1) gene transcripts in aging CD8+Tregs. Klrk1 gene encodes Natural Killer Group 2 Member D (NKG2D), an activating receptor NK cells express. This upregulation was specific to CD8+CD122hiLy49+ and absent in CD8+CD122hiLy49-. To explore this correlation further, we utilized a Klrk1-/- mouse and observed an increased CD8+Treg population, suggesting a potential negative regulatory role of NKG2D in CD8+Treg homeostasis. These findings provide critical insights into the aging immune system and underscore the importance of CD8+ Tregs in immune regulation and aging.
Project description:Background Lymphedema, a chronic and progressive disease, is characterized by lymphatic dysfunction, persistent inflammation, fibrosis, and pathological adipose tissue remodeling. Although adipose-derived stromal cells (ASCs) are implicated in disease progression, the stromal cell states and stromal–immune interactions that sustain chronic fibro-inflammatory remodeling remain poorly defined. Methods Single-cell RNA sequencing was performed of the stromal vascular fraction isolated from anatomically matched human subcutaneous adipose tissues. These tissues were obtained from patients with advanced-stage lymphedema and healthy individuals to delineate disease-associated stromal heterogeneity at single-cell resolution. Results A disease-expanded ASC progenitor population (ASC_c2) that exhibits pronounced transcriptional reprogramming in lymphedema was identified. The ASC_c2 population segregated into two mutually exclusive pathological subsets: a VCAM1⁺ vascular-interacting stromal population (V-ASCs) associated with ECM remodeling and CD74⁺HLA class II–expressing subset (I-ASCs) with antigen-presentation-like features. I-ASCs displayed a robust interferon-responsive transcriptional program consistent with immune priming and preferentially expressed the CXCL14 chemokine. Ligand–receptor interaction analysis revealed biased stromal–immune interactions between I-ASCs and CD8⁺ T cells, suggesting a skewed immune microenvironment in lymphedematous adipose tissue. Conclusions Our findings suggest an immune-skewed stromal–immune axis in lymphedema, driven by immune-primed, antigen-presentation-like ASCs. The study findings suggest a cellular framework linking stromal reprogramming to chronic immune dysregulation and fibrosis in human lymphedema, offering insights into potential therapeutic targets for interrupting pathological stromal–immune crosstalk.