Highly multiplexed 3D profiling of immune niches in human tumours

This Learning Wednesday paper note highlights “Highly Multiplexed 3D Profiling of Cell States and Immune Niches in Human Tumours.” The study is relevant to multiplexed 3D profiling of immune niches in human tumors, with a focus on how three-dimensional tissue context can change what researchers see and measure.

Selected notes from the paper

“Diseases like cancer involve alterations in cell proportions, states, and local interactions as well as complex changes in 3D tissue architecture.”

“However, disease diagnosis and most multiplexed spatial profiling studies rely on inspecting thin (4-5 micron) tissue specimens.”

“We use confocal microscopy and cyclic immunofluorescence (3D CyCIF) to show that few if any cells are intact in these thin sections; this reduces the accuracy of cell phenotyping and interaction analysis.”

“Many discrepancies were observed between the 2D and 3D data.”

“Imaging incomplete cells can result in inaccurate phenotyping, especially for markers with non-uniform distributions.”

“Fragmentation of cells in cut at 5 µm sections also impacted the number of cell-cell interactions identified by proximity analysis, which fell as section thickness decreased.”

“In contrast, high-plex 3D CyCIF imaging of intact cells in thick tissue sections enables accurate quantification of marker proteins and detailed analysis of intracellular structures and organelles.”

“Multiple layers of intact nuclei were visible in 30-40 μm tissue sections… but fewer than 5% of nuclei were intact in sections cut at 5 μm thickness.”

“By increasing section thickness only 4-5-fold (to a hydrated thickness of 30-40 µm), it is possible to overcome this inaccuracy and describe precise cell morphology, enumerate intracellular organelles, and classify cell types and states at a level of detail normally associated with cultured cells.”

“Thick section 3D imaging made it possible to dissect components of the tissue microarchitecture not generally visible in 2D.”

“Precise imaging of cell membranes also makes it possible to detect juxtacrine signalling among interacting tumour and immune cells and reveals the formation of spatially-restricted cytokine niches.”

“3D imaging made it possible to unambiguously score combinations of nuclear and cell surface markers at a single cell level.”

“Our data show that 3D high-plex imaging data of tissues and tumours substantially impacts how we understand the physical organization of tissues, assign precise single-cell phenotypes, and study multi-cellular communities.”

“Even a limited number of accurate 3D datasets on specific tissues and tumours will make it possible to correct for limitations in 2D images and identify those errors that confound accurate biological interpretation.”

From an Alpenglow perspective, this paper is useful because it connects multiplexed 3D profiling of immune niches in human tumors with a broader need in 3D spatial biology, measuring tissue architecture across depth while preserving context for quantitative analysis.