Molecular and Functional Characterization of Human Intestinal Organoids and Monolayers for Modeling Epithelial Barrier

Patient-derived organoid models can transform drug discovery for inflammatory bowel disease, but differentiation and functional characterization inconsistencies limit that transformation. Jelinsky et al. profiled molecular and cellular features across a range of intestinal organoid models using bulk RNA sequencing, among other technologies, and examined differentiation and establishing a functional epithelial barrier.

A single cell transcriptional roadmap of human pacemaker cell differentiation

Wiesinger et al. combine SORT-seq analysis with trajectory inference to reconstruct lineage decisions of sinoatrial node–like cardiomyocytes (derived from induced pluripotent stem cells). WNT and TGFb signaling seem to play a role in these lineage decisions, the authors find.

Molecular and electrophysiological evaluation of human cardiomyocyte subtypes to facilitate generation of composite cardiac models

The authors directed the differentiation of human induced pluripotent stem cells to three types of heart cell: sinoatrial nodal, atrial and ventricular cardyomyocytes. SORT-seq established that the protocols indeed yielded distinct cell populations in line with expected identities. Such models can progress the use of cardiomyocytes in drug development.

Human regulatory T cells locally differentiate and are functionally heterogeneous within the inflamed arthritic joint

The authors combined SORT-seq and T cell receptor sequencing to investigate the heterogeneity of regulatory T cells (Tregs) derived from synovial fluid of three patients with juvenile idiopathic arthritis. Results indicate Tregs differentiate to classical effector Tregs or GRP56+CD161+CXCL13+ Tregs. They also found novel predicted drivers of local Treg differentiation.

Human anti-smallpox long-lived memory B cells are defined by dynamic interactions in the splenic niche and long-lasting germinal center imprinting

Immune memory in humans has been shown to extend well beyond decades. Using SORT-seq, Chappert et al. elucidate an extensive functional characterization of human splenic smallpox/vaccinia protein B5-specific memory B cells generated more than 40 years ago. This can be used to decipher the distinct selection and survival mechanisms associated with their longevity.

A public antibody class recognizes an S2 epitope exposed on open conformations of SARS-CoV-2 spike

Claireaux et al. aimed to guide vaccine improvement by finding out how the unexposed immune system reacts to the SARS-CoV-2 spike protein. Single-cell RNA sequencing and flow cytometry helped them describe the reactive B cell repertoire. They identified a non-neutralizing antibody class as a main factor in the unexposed SARS-CoV-2 response.

Uncovering the mode of action of engineered T cells in patient cancer organoids

The authors developed a system called BEHAV3D to study the dynamic interactions of engineered T cells cultured with patient-derived solid-tumor organoids by imaging and (single-cell) transcriptomics. They identified a ‘super engager’ behavioral cluster of T cells with potent serial killing capacity. Then, they uncovered a behavior-specific gene expression signature in cancer metabolome-sensing engineered T cells and, finally, showed that type I interferon can prime resistant tumors for T cell killing.

Exposure to the Amino Acids Histidine, Lysine, and Threonine Reduces mTOR Activity and Affects Neurodevelopment in a Human Cerebral Organoid Model

The authors pioneered the use of human cerebral organoids to investigate the impact of amino acid supplementation on neurodevelopment. RNA sequencing identified gene expression changes after supplementation, with enrichment in genes related to mTOR signaling and immune function, a.o., and to specific cell types, including proliferative precursor cells, microglia, and astrocytes.

Single-cell transcriptomics provides insights into hypertrophic cardiomyopathy

Wehrens et al. perform single-cell RNA sequencing on the hearts of patients who suffer from hypertrophic cardiomyopathy (HCM). This reveals cardiomyocyte subpopulations, gene regulatory networks, transcription factors, and hypertrophy-related genes that might be relevant to the pathogenesis of the disease.

Characterization of HIV-1 Infection in Microglia-Containing Human Cerebral Organoids

Gumbs et al. study the molecular mechanisms of HIV entry into central nervous system organoids and identify microglia as the primary target cell. Single-cell RNA sequencing confirmed the presence of microglia, among other cell types, and HIV-entry receptor expression in brain organoids.

Linking the genotypes and phenotypes of cancer cells in heterogenous populations via real-time optical tagging and image analysis

This paper describes how cells can be optically tagged in real-time based on specific functional cell dynamics, such as fast migration or morphological variation. Moreover, it documents how you can combine optical tagging with single-cell RNA sequencing to link the genotypes and phenotypes of heterogenous tumor populations.

BMP gradient along the intestinal villus axis controls zonated enterocyte and goblet cell states

Beumer et al. show that the bone morphogenetic protein (BMP) signaling pathway controls the creation of functional zones along the crypt-villus axis. A gene lipid uptake gene signature is enriched in the villus tip and could be therapeutically exploited with BMP inhibitors.