Quantitative Bio-Imaging Tools to Dissect the Interplay of Membrane and Cytoskeletal Actin Dynamics in Immune Cells

Abstract

Cellular function is reliant on the dynamic interplay between the plasma membrane and the actin cytoskeleton. This critical relationship is of particular importance in immune cells, where both the cytoskeleton and the plasma membrane work in concert to organize and potentiate immune signaling events. Despite their importance, there remains a critical gap in understanding how these respective dynamics are coupled, and how this coupling in turn may influence immune cell function from the bottom up. In this review, we highlight recent optical technologies that could provide strategies to investigate the simultaneous dynamics of both the cytoskeleton and membrane as well as their interplay, focusing on current and future applications in immune cells. We provide a guide of the spatio-temporal scale of each technique as well as highlighting novel probes and labels that have the potential to provide insights into membrane and cytoskeletal dynamics. The quantitative biophysical tools presented here provide a new and exciting route to uncover the relationship between plasma membrane and cytoskeletal dynamics that underlies immune cell function.

Aggregation and mobility of membrane proteins interplay with local lipid order in the plasma membrane of T cells

“…It therefore remains to be quantified whether the observed membrane remodelling affects the frequency of the earliest interactions between the investigated proteins, as well as with other negative regulators, such as Lck‐inactivating protein Csk (PAG) [4] and SHP‐1 [73] that also partition into ordered membrane environments. These formidable experimental challenges will eventually be overcome by advances on both the imaging/spectroscopy part [74, 75] as well as on the side of well controlled cell‐activating systems [76]. Such progress will help to determine the degree to which the suggested lipid‐mediated binding recognition upon receptors’ immobilisation can influence the final signalling outcome, and perhaps its relation to malfunctions such as immune disorders.…”

Molecular mapping of neuronal architecture using STORM microscopy and new fluorescent probes for SMLM imaging

“…Since our first paper in 2019, MemBright probes have been used by several other labs and cited in more than 60 articles and 39 reviews 29 – 57 It has been used in B lymphocytes, 58 in A431 cells, 59 and reused in neuronal cells to label growth cone and initial segments of hippocampal neurons, 60 presynaptic terminals, 29 and post-synaptic compartments 53 . It has also been used to label apoptotic bodies (AB), microvesicles (MV), and small EV (sEV) isolated from MIN6 pancreatic beta cells exposed to inflammatory, hypoxic, or genotoxic stressors 61 .…”

Journey to the Center of the Cell: Cytoplasmic and Nuclear Actin in Immune Cell Functions

“…The rapid development of biophysical and bioimaging tools to probe cell mechanics has enabled the study of mechanical properties in immune cells [reviewed in Schneider et al (2021)], greatly expanding our understanding of how mechanical forces can crosstalk with biochemical signals to regulate cell functions. This shift from an exclusively biochemical understanding of signaling reveals the necessity to incorporate the physical status of tissues and cells in our experimental designs to better elucidate physiology and treat pathologies.…”