Organ Mapping Antibody Panels: a community resource for standardized multiplexed tissue imaging.

Multiplexed antibody-based imaging enables the detailed characterization of molecular and cellular organization in tissues. Advances in the field now allow high-parameter data collection (>60 targets); however, considerable expertise and capital are needed to construct the antibody panels employed by these methods. Organ mapping antibody panels are community-validated resources that save time and money, increase reproducibility, accelerate discovery and support the construction of a Human Reference Atlas.

Spatial mapping of protein composition and tissue organization: a primer for multiplexed antibody-based imaging.

Tissues and organs are composed of distinct cell types that must operate in concert to perform physiological functions. Efforts to create high-dimensional biomarker catalogs of these cells have been largely based on single-cell sequencing approaches, which lack the spatial context required to understand critical cellular communication and correlated structural organization. To probe in situ biology with sufficient depth, several multiplexed protein imaging methods have been recently developed. Though these technologies differ in strategy and mode of immunolabeling and detection tags, they commonly utilize antibodies directed against protein biomarkers to provide detailed spatial and functional maps of complex tissues. As these promising antibody-based multiplexing approaches become more widely adopted, new frameworks and considerations are critical for training future users, generating molecular tools, validating antibody panels, and harmonizing datasets. In this Perspective, we provide essential resources, key considerations for obtaining robust and reproducible imaging data, and specialized knowledge from domain experts and technology developers.

Distinctive nuclear organisation of centromeres and regions involved in pluripotency in human embryonic stem cells.

Nuclear organisation is thought to be important in regulating gene expression. Here we investigate whether human embryonic stem cells (hES) have a particular nuclear organisation, which could be important for maintaining their pluripotent state. We found that whereas the nuclei of hES cells have a general gene-density-related radial organisation of chromosomes, as is seen in differentiated cells, there are also distinctive localisations for chromosome regions and gene loci with a role in pluripotency. Chromosome 12p, a region of the human genome that contains clustered pluripotency genes including NANOG, has a more central nuclear localisation in ES cells than in differentiated cells. On chromosome 6p we find no overall change in nuclear chromosome position, but instead we detect a relocalisation of the OCT4 locus, to a position outside its chromosome territory. There is also a smaller proportion of centromeres located close to the nuclear periphery in hES cells compared to differentiated cells. We conclude that hES cell nuclei have a distinct nuclear architecture, especially at loci involved in maintaining pluripotency. Understanding this level of hES cell biology provides a framework within which other large-scale chromatin changes that may accompany differentiation can be considered.