Human in vitro-induced regulatory T cells display Dlgh1dependent and PKC-θ restrained suppressive activity

Cell Polarity Regulators, Multifunctional Organizers of Lymphocyte Activation and Function

Cell polarity regulators are ubiquitous, evolutionary conserved multifunctional proteins. They contain a variety of protein–protein interaction domains endowing them the capacity to interact with cytoskeleton structures, membrane components and multiple regulatory proteins. In this way, they act in complexes and are pivotal for cell growth and differentiation, tissue formation, stability and turnover, cell migration, wound healing, and others. Hence some of these proteins are tumor suppressors.

These cellular processes rely on the establishment of cell polarity characterized by the asymmetric localization of proteins, RNAs, membrane domains, or organelles that together condition cell shape and function. Whether apparently stable, as in epithelia or neurons, or very dynamic, as in immune cells, cell polarity is an active process. It involves cytoskeleton reorganization and targeted intracellular traffic, and results in cellular events such as protein synthesis, secretion and assembly taking place at defined cell poles. Multiple polarity regulators orchestrate these processes.

Immune cells are particularly versatile in rapidly polarizing and assuming different shapes, so to swiftly adopt specialized behaviors and functions. Polarity regulators act in various ways in different immune cell types and at their distinct differentiation states. Here we review how cell polarity regulators control different processes and functions along T lymphocyte physiology, including cell migration through different tissues, immunological synapse formation and effector functions.

Family-effects in the epigenomic response of red blood cells to a challenge test in the European sea bass (Dicentrarchus labrax, L.)

Abstract

Background

In fish, minimally invasive blood sampling is widely used to monitor physiological stress with blood plasma biomarkers. As fish blood cells are nucleated, they might be a source a potential new markers derived from ‘omics technologies. We modified the epiGBS (epiGenotyping By Sequencing) technique to explore changes in genome-wide cytosine methylation in the red blood cells (RBCs) of challenged European sea bass (Dicentrarchus labrax), a species widely studied in both natural and farmed environments.

Results

We retrieved 501,108,033 sequencing reads after trimming, with a mean mapping efficiency of 73.0% (unique best hits). Minor changes in RBC methylome appeared to manifest after the challenge test and a family-effect was detected. Only fifty-seven differentially methylated cytosines (DMCs) close to 51 distinct genes distributed on 17 of 24 linkage groups (LGs) were detected between RBCs of pre- and post-challenge individuals. Thirty-seven of these genes were previously reported as differentially expressed in the brain of zebrafish, most of them involved in stress coping differences. While further investigation remains necessary, few DMC-related genes associated to the Brain Derived Neurotrophic Factor, a protein that favors stress adaptation and fear memory, appear relevant to integrate a centrally produced stress response in RBCs.

Conclusion

Our modified epiGBS protocol was powerful to analyze patterns of cytosine methylation in RBCs of D. labrax and to evaluate the impact of a challenge using minimally invasive blood samples. This study is the first approximation to identify epigenetic biomarkers of exposure to stress in fish.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-07420-9.

Rapamycin and abundant TCR stimulation are required for the generation of stable human induced regulatory T cells

OBJECTIVES

Regulatory T cells (Tregs) are a vital sub-population of CD4+ T cells with major roles in immune tolerance and homeostasis. Given such properties, the use of regulatory T cells for immunotherapies has been extensively investigated, with a focus on adoptive transfer of ex vivo expanded natural Tregs (nTregs). For immunotherapies, induced Tregs (iTregs), generated in vitro from naïve CD4+ T cells, provide an attractive alternative, given the ease of generating cell numbers required for clinical dosage. While the combination of TGF-β, ATRA and rapamycin has been shown to generate highly suppressive iTregs, the challenge for therapeutic iTreg generation has been their instability. Here, we investigate the impact of rapamycin concentrations and α-CD3/CD28 bead ratios on human iTreg stability.

METHODS

We assess iTregs generated with various concentrations of rapamycin and differing ratios of α-CD3/CD28 beads for their differentiation, stability, expression of Treg signature molecules and T helper effector cytokines, and Treg-specific demethylation region (TSDR) status.

RESULTS

iTregs generated in the presence of TGF-β, ATRA, rapamycin and a higher ratio of α-CD3/CD28 beads were highly suppressive and stable upon in vitro re-stimulation. These iTregs exhibited a similar expression profile of Treg signature molecules and T helper effector cytokines to nTregs, in the absence of TSDR demethylation.

CONCLUSION

This work establishes a method to generate human iTregs which maintain stable phenotype and function upon in vitro re-stimulation. Further validation in pre-clinical models will be needed to ensure its suitability for applications in adoptive transfer.

Differential expression of DLG1 as a common trait in different human diseases: an encouraging issue in molecular pathology

Human disc large (DLG1) is a scaffolding protein that through the interaction with diverse cell partners participates in the control of key cellular processes such as polarity, proliferation and migration. Experimental data have mainly identified DLG1 as a tumor suppressor. An outstanding point for DLG1 protein is that altered DLG1 expression and DLG1 gene mutations were observed in different pathologies, including cancer and neurological and immunological disorders. Evident changes in DLG1 abundance and/or cell localization were identified in a number of studies suggesting its participation in molecular mechanisms responsible for the development of such illnesses. In this review, we focus on some of the latest findings regarding DLG1 alterations in different diseases as well as its potential use as a biomarker for pathological progression. We further address the current knowledge on the molecular mechanisms regulating DLG1 expression and the posttranslational modifications that may affect DLG1 cell localization and functions. Despite the advances in this field, there are still open questions about the precise molecular link between alterations in DLG1 expression and the development of each specific pathology. The complete understanding of this concern will give us new scenarios for the design of promising diagnosis and therapeutic tools.