A5045407180- Monoclonal and Polyclonal Antibodies Research
- Advanced Fluorescence Microscopy Techniques
- Advanced Biosensing Techniques and Applications
- Receptor Mechanisms and Signaling
- HER2/EGFR in Cancer Research
- Glycosylation and Glycoproteins Research
- Advanced biosensing and bioanalysis techniques
- Mast cells and histamine
- Near-Field Optical Microscopy
- Lipid Membrane Structure and Behavior
- Force Microscopy Techniques and Applications
- Cell Adhesion Molecules Research
- Advanced Electron Microscopy Techniques and Applications
- Quantum Dots Synthesis And Properties
- Cell Image Analysis Techniques
- Molecular Junctions and Nanostructures
- T-cell and B-cell Immunology
- Cellular Mechanics and Interactions
- Optical Coherence Tomography Applications
- Immunotherapy and Immune Responses
- Phagocytosis and Immune Regulation
- Biosensors and Analytical Detection
- PI3K/AKT/mTOR signaling in cancer
- Photoreceptor and optogenetics research
- RNA and protein synthesis mechanisms
New Mexico Cancer Center
2016-2025
University of New Mexico
2016-2025
UNM Comprehensive Cancer Center
2025
Comprehensive Blood & Cancer Center
2018-2020
Carnegie Mellon University
2014
Imaging Center
2014
Cancer Research Center
2014
University of New Mexico Hospital
2013
Max Planck Institute for Biophysical Chemistry
2002-2009
Monsanto (United States)
2009
ErbB1 receptors situated on cellular filopodia undergo systematic retrograde transport after binding of the epidermal growth factor (EGF) and activation receptor tyrosine kinase. Specific inhibitors erbB1 kinase as well cytochalasin D, a disruptor actin cytoskeleton, abolish but not free diffusion receptor–ligand complex. Diffusion constants rates were determined with single molecule sensitivity by tracking labeled EGF conjugated to fluorescent quantum dots. Retrograde precedes endocytosis,...
Podosomes are multimolecular mechanosensory assemblies that coordinate mesenchymal migration of tissue-resident dendritic cells. They have a protrusive actin core and an adhesive ring integrins adaptor proteins, such as talin vinculin. We recently demonstrated oscillations correlate with intensity fluctuations vinculin but not talin, suggesting different molecular rearrangements for these components. Detailed information on the mutual localization components at nanoscale is lacking. By...
SARS-CoV-2 infection depends on binding its spike (S) protein to angiotensin-converting enzyme 2 (ACE2). The S expresses an RGD motif, suggesting that integrins may be co-receptors. Here, we UV-inactivated and fluorescently labeled the envelope membrane with octadecyl rhodamine B (R18) explore role of integrin activation in mediating cell entry productive infection. We used flow cytometry confocal microscopy show
In this work, we characterized streptavidin-conjugated quantum dots (QDs) manufactured by Quantum Dot Corporation. We present data on: (1) two-photon excitation; (2) fluorescence lifetimes; (3) ensemble and single QD emission anisotropy; (4) QDs as donors for Forster resonance energy transfer (FRET); (5) spectral conversion of exposed to high-intensity illumination. also demonstrate the utility imaging binding uptake biotinylated transferrin on living cells, resolving lifetime microscopy...
We report a method for tracking individual quantum dot (QD) labeled proteins inside of live cells that uses four overlapping confocal volume elements and active feedback once every 5 ms to follow three-dimensional molecular motion. This has substantial advantages over methods based upon charge-coupled device cameras, including increased Z-tracking range (10 μm demonstrated here), substantially lower excitation powers (15 μW used the ability perform time-resolved spectroscopy (such as...
Upon activation, ERKs translocate from the cytoplasm to nucleus. This process is required for induction of many cellular responses, yet molecular mechanisms that regulate ERK nuclear translocation are not fully understood. We have used a mouse embryo fibroblast ERK1-knock-out cell line expressing green fluorescent protein (GFP)-tagged ERK1 probe spatio-temporal regulation ERK1. Real time fluorescence microscopy and correlation spectroscopy revealed accumulation increased upon serum...
The dendritic cell (DC) specific pathogen-uptake receptor (DC-SIGN) internalizes antigens for degradation and presentation onto MHC molecules. At the membrane, DC-SIGN forms nanoclusters that facilitate virus capture. However, internalized viruses, such as HIV-1, escape degradation. Here, we exploit ligand-conjugated, virus-sized, highly photostable quantum dots (QDs) to monitor in living cells antigen binding, entry, trafficking. antigen-coated QDs uptake persistence live DCs open...
Often considered to be a "dead" kinase, erbB3 is implicated in escape from erbB-targeted cancer therapies. Here, heregulin stimulation shown markedly upregulate kinase activity immunoprecipitates. Intact, activated phosphorylates tyrosine sites an exogenous peptide substrate, and this abolished by mutagenesis of lysine 723 the catalytic domain. Enhanced linked heterointeractions with catalytically active erbB2, since it largely blocked cells pretreated lapatinib or pertuzumab. erbB2...
Many cellular signaling processes are initiated by dimerization or oligomerization of membrane proteins. However, since the spatial scale these interactions is below diffraction limit light microscope, dynamics have been difficult to study on living cells. We developed a novel high-speed hyperspectral microscope (HSM) perform single particle tracking up 8 spectrally distinct species quantum dots (QDs) at 27 frames per second. The emission spectra QDs allows localization with ∼10 nm precision...
Mast cells (MCs) produce soluble mediators such as histamine and prostaglandins that are known to influence dendritic cell (DC) function by stimulating maturation antigen processing. Whether direct cell–cell interactions important in modulating MC/DC is unclear. In this paper, we show contact between MCs DCs occurs plays an role the immune response. Activation of through FcεRI cross-linking triggers formation stable with immature reminiscent immunological synapse. Direct cellular...
Mutations within the epidermal growth factor receptor (EGFR/erbB1/Her1) are often associated with tumorigenesis. In particular, a number of EGFR mutants that demonstrate ligand-independent signaling common in non–small cell lung cancer (NSCLC), including kinase domain mutations L858R (also called L834R) and exon 19 deletions (e.g., ΔL747-P753insS), which collectively make up nearly 90% NSCLC. The molecular mechanisms by these confer constitutive activity remain unresolved. Using multiple...
γ9δ2T cells play a major role in cancer immune surveillance, yet the clinical translation of their vitro promise remains challenging. To address limitations previous attempts using expanded cells, we explored clonal diversity cell repertoires and characterized target. We demonstrated that only fraction was active against activity parental clone, or functional avidity selected γ9δ2 T receptors (γ9δ2TCRs), not associated with frequency. Furthermore, analyzed target-receptor interface provided...
Abstract The use of therapeutic monoclonal antibodies is constrained because single antigen targets often do not provide sufficient selectivity to distinguish diseased from healthy tissues. We present HexElect ® , an approach enhance the functional by making their activity dependent on clustering after binding two different antigens expressed same target cell. lmmunoglobulin G (lgG)-mediated membrane receptors naturally occurs cell surfaces trigger complement- or cell-mediated effector...
Distributions of ErbB receptors on membranes SKBR3 breast cancer cells were mapped by immunoelectron microscopy. The most abundant receptor, ErbB2, is phosphorylated, clustered and active. Kinase inhibitors ablate ErbB2 phosphorylation without dispersing clusters. Modest co-clustering EGFR, even after EGF treatment, suggests that both are predominantly involved in homointeractions. Heregulin leads to dramatic clusters ErbB3 contain some EGFR PI 3-kinase. Other docking proteins, such as Shc...
Inspired by recent developments in localization microscopy that applied averaging of identical particles 2D for increasing the resolution even further, we discuss considerations alignment (registration) methods general and 3D particular. We detail traditional techniques particle registration from cryo electron based on cross-correlation are not suitable, as underlying image formation process is fundamentally different. argue only localizations, i.e. a set coordinates with associated...
Fluorescence superresolution (SR) microscopy, or fluorescence nanoscopy, provides nanometer scale detail of cellular structures and allows for imaging biological processes at the molecular level. Specific SR methods, such as localization-based imaging, rely on stochastic transitions between (fluorescent) off (dark) states fluorophores. Imaging multiple using multi-color is complicated limited by differing properties various organic dyes including their fluorescent state duty cycle, photons...