Biology subjects

Cavalcanti-Adam, E. A.

Publications and source records attributed to Cavalcanti-Adam, E. A..

5 recordsLinked to original sources

bioRxiv2025

SiR-XActin: A fluorescent probe for imaging actin dynamics in live cells

Imaging actin-dependent processes in live cells is important for understanding numerous biological processes. However, currently used natural-product based fluorescent probes for actin filaments affect the dynamics of actin polymerization and can induce undesired cellular phenotypes. Here, we introduce SiR-XActin, a simplified jasplakinolide-based, far-red fluorescent probe that enables bright and photostable staining in various cell types without requiring genetic modifications. Due to its relatively weak binding affinity, the probe exhibits minimal cytotoxicity and labels actin filaments without significantly altering actin dynamics. Furthermore, SiR-XActin is suitable for time-resolved, live-cell super-resolution STED microscopy. Exchanging the SiR fluorophore in SiR-XActin for other fluorophores yields probes in different colors. All these properties make SiR-XActin and its analogs powerful tools for studying actin dynamics using live-cell fluorescence microscopy.

biochemistry↗

bioRxiv2024

Morphology-dependent entry kinetics and spread of influenza A virus

Influenza A viruses (IAV) display a broad variety of morphologies ranging from spherical to long filamentous virus particles. These diverse phenotypes are believed to allow the virus to overcome various immunological and pulmonary barriers during entry into the airway epithelium and influence the viral entry pathway. Remarkably, lab-adapted IAV strains lost this morphological variance and exhibit preferred spherical morphology. However, it remains unclear which factors lead to this lab-adapted preference and which pulmonary defense factors are responsible for the preferred filamentous morphology in physiological settings. In this study, we established fluorescent reporter viruses with spherical or filamentous morphology but with the same surface glycoproteins. We developed a correlative fluorescence and scanning electron microscopy workflow to analyze the impact of viral morphology on cell-to-cell spread and identify conditions under which IAV with either spherical or filamentous morphology confer an advantage. Our findings demonstrate that filamentous IAV cell-to-cell spread is significantly slower in various cell lines, which can explain the predominant spherical morphology in lab-adapted strains. This observation is consistent with delayed entry kinetics of filamentous viruses structurally analyzed by cellular cryo-electron tomography. We found that cellular junction integrity and mucin do not exert morphology-dependent inhibition of IAV cell-to-cell spread. On the other hand, filamentous virions confer an advantage under the pressure exerted by neutralizing antibodies against hemagglutinin.

microbiology↗

bioRxiv2023

Population context drives cell-to-cell variability in interferon response in epithelial cells

Isogenic cells respond in a heterogeneous manner to interferon. Using a micropatterning approach combined with high-content imaging and spatial analyses, we characterized how the population context (position of a cell with respect to the neighboring cells) of human intestinal epithelial cells affects single cell response to interferons. We identified that cells at the edge of a cellular colony are significantly more responsive than cells embedded within this colony. We determined that this spatial heterogeneity in IFN response was the result of the polarized basolateral distribution of the IFN receptors making cells located in the center of a cellular colony not responsive to ectopic IFN stimulation. We could demonstrate that this population context driven cell-to-cell variability influences the outcome of viral infection as cells embedded in a cellular colony are not protected by interferons and therefore more susceptible to infection. Our data highlights that the behavior of individual isolated cells does not directly translate to their behavior in a population, placing the population context as a key driver of cell-to-cell heterogeneity in IFN response.

immunology↗

bioRxiv2021

Tuning epithelial cell-cell adhesion and collective dynamics with functional DNA-E-cadherin hybrid linkers

The binding strength between epithelial cells is crucial for tissue integrity, signal transduction and collective cell dynamics. However, there is no experimental approach to precisely modulate cell-cell adhesion strength at the cellular and molecular level. Here, we establish DNA nanotechnology as tool to control cell-cell adhesion of epithelial cells. We designed a DNA-E-cadherin hybrid system consisting of complementary DNA strands covalently bound to a truncated E-cadherin with a modified extracellular domain. DNA sequence design allows to tune the DNA-E-cadherin hybrid molecular binding strength, while retaining its cytosolic interactions and downstream signaling capabilities. The DNA-E-cadherin hybrid facilitates strong and reversible cell-cell adhesion in E-cadherin deficient cells by forming mechanotransducive adherens junctions. We assess the direct influence of cell-cell adhesion strength on intracellular signaling and collective cell dynamics. This highlights the scope of DNA nanotechnology as a precision technology to study and engineer cell collectives.

bioengineering↗

bioRxiv2018

Focal adhesion-generated cues in extracellular matrix regulate cell migration by local induction of clathrin-coated plaques

Clathrin is a unique scaffold protein, which forms polyhedral lattices with flat and curved morphology. The function of curved clathrin-coated pits in forming endocytic structures is well studied. On the contrary, the role of large flat clathrin arrays, called clathrin-coated plaques, remains ambiguous. Previous studies suggested an involvement of plaques in cell adhesion. However, the molecular origin leading to their formation and their precise functions remain to be determined. Here, we study the origin and function of clathrin-coated plaques during cell migration. We revealed that plaque formation is intimately linked to extracellular matrix (ECM) modification by focal adhesions (FAs). We show that in migrating cells, FAs digest the ECM creating extracellular topographical cues that dictate the future location of clathrin-coated plaques. We identify Eps15 and Eps15R as key regulators for the formation of clathrin-coated plaques at locally remodelled ECM sites. Using a genetic silencing approach to abrogate plaque formation and 3D-micropatterns to spatially control the location of clathrin-coated plaques, we could directly correlate cell migration directionality with the formation of clathrin-coated plaques and their ability to recognize extracellular topographical cues. We here define the molecular mechanism regulating the functional interplay between FAs and plaques and propose that clathrin-coated plaques act as regulators of cell migration promoting contact guidance-mediated collective migration in a cell-to-cell contact independent manner.

cell biology↗