Regulation of T cell differentiation and function by long noncoding RNAs in homeostasis and cancer.

Long noncoding RNAs (lncRNAs) increase in genomes of complex organisms and represent the largest group of RNA genes transcribed in mammalian cells. Previously considered only transcriptional noise, lncRNAs comprise a heterogeneous class of transcripts that are emerging as critical regulators of T cell-mediated immunity. Here we summarize the lncRNA expression landscape of different T cell subsets and highlight recent advances in the role of lncRNAs in regulating T cell differentiation, function and exhaustion during homeostasis and cancer. We discuss the different molecular mechanisms of lncRNAs and highlight lncRNAs that can serve as novel targets to modulate T cell function or to improve the response to cancer immunotherapies by modulating the immunosuppressive tumor microenvironment.

CEBPA phase separation links transcriptional activity and 3D chromatin hubs.

Cell identity is orchestrated through an interplay between transcription factor (TF) action and genome architecture. The mechanisms used by TFs to shape three-dimensional (3D) genome organization remain incompletely understood. Here we present evidence that the lineage-instructive TF CEBPA drives extensive chromatin compartment switching and promotes the formation of long-range chromatin hubs during induced B cell-to-macrophage transdifferentiation. Mechanistically, we find that the intrinsically disordered region (IDR) of CEBPA undergoes in vitro phase separation (PS) dependent on aromatic residues. Both overexpressing B cells and native CEBPA-expressing cell types such as primary granulocyte-macrophage progenitors, liver cells, and trophectoderm cells reveal nuclear CEBPA foci and long-range 3D chromatin hubs at CEBPA-bound regions. In short, we show that CEBPA can undergo PS through its IDR, which may underlie in vivo foci formation and suggest a potential role of PS in regulating CEBPA function.

Analyses of human granulosa cell vitality by fluorescence activated cell sorting after rapid cooling.

In reproductive medicine, the technique of rapid cooling becomes increasingly important for the preservation of tissue and cells. In order to protect the cells, incubation in different cryopreservation solutions is essential. The speed of the cooling process also makes a pivotal contribution to the success of this method. Using Flourescence Activated Cell Sorting (FACS), we investigated the impact of an open rapid and a closed rapid cooling technique on the vitality of human granulosa cells. Furthermore, we examined effects of the different solutions used for rapid cooling and warming before and after rapid cooling. We found a significant lower proportion of vital cells after rapid cooling compared to untreated controls independently of the technique and the tube size. However, we did not find any significant differences between open and closed rapid cooling. In both, a lower proportion of vital granulosa cells were found after incubation in rapid cooling solution only compared to warming solution only. Our results lend support to the conclusion that the difference of cooling-speed between open and closed rapid cooling is, in our settings, not crucial for the success of the procedure and that cryoprotective agents in the rapid cooling solutions have a higher potential to cause severe cell damage than agents used for warming.