Macropinosome formation by tent pole ruffling in macrophages

Related Experiment Video

Updated: Feb 6, 2026

Visualizing Membrane Ruffle Formation using Scanning Electron Microscopy
08:05

Visualizing Membrane Ruffle Formation using Scanning Electron Microscopy

Published on: May 27, 2021

3.2K

Nicholas D Condon1, John M Heddleston2, Teng-Leong Chew2

  • 1Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, Australia.

The Journal of Cell Biology
|August 29, 2018
PubMed

Insights

Macrophages use F-actin tent poles to form large macropinosomes during innate immune responses. This process, crucial for pathogen detection, involves Rab13 and is visualized with lattice light sheet microscopy.

Area of Science:

  • Cell Biology
  • Immunology
  • Microscopy

Background:

  • Macrophages are key innate immune cells involved in pathogen recognition and clearance.
  • Macropinocytosis, a process involving large membraneപ്പം engulfments, is critical for macrophage environmental sampling.
  • Bacterial lipopolysaccharide (LPS) is a potent activator of macrophages, inducing surface ruffling and macropinosome formation.

Purpose of the Study:

  • To redefine the mechanisms of dorsal ruffle formation and macropinosome closure in LPS-activated macrophages.
  • To investigate the role of F-actin and Rab13 in macropinosome biogenesis.
  • To leverage high-resolution live imaging to visualize dynamic cellular processes.

Main Methods:

  • Lattice light sheet microscopy (LLSM) for high-resolution, live imaging of macrophages.
  • Bacterial lipopolysaccharide (LPS) stimulation of primary macrophages.
  • CRISPR-Cas9 gene editing to delete Rab13.
  • Fluorescence microscopy to visualize F-actin dynamics and Rab13 localization.

Main Results:

  • LLSM revealed F-actin tent poles supporting dorsal ruffles that constrict to form macropinosomes.
  • A novel model of macropinosome formation involving F-actin tent pole crossover and twisting was proposed.
  • Active Rab13 was enriched on tent pole ruffles.
  • CRISPR deletion of Rab13 disrupted tent pole ruffles and blocked large LPS-induced macropinosome formation.

Conclusions:

  • The study redefines macropinosome formation, highlighting the role of F-actin tent poles and Rab13.
  • LPS-induced macropinosome formation relies on a dynamic interplay of cytoskeletal rearrangements and Rab13.
  • LLSM provides unprecedented insights into the spatiotemporal dynamics of innate immune cell processes.

More Related Videos

Automated Imaging and Analysis for the Quantification of Fluorescently Labeled Macropinosomes11:01

Automated Imaging and Analysis for the Quantification of Fluorescently Labeled Macropinosomes

Published on: August 24, 2021

3.3K
Measuring the pH, Redox Chemistries, and Degradative Capacity of Macropinosomes using Dual-Fluorophore Ratiometric Microscopy07:31

Measuring the pH, Redox Chemistries, and Degradative Capacity of Macropinosomes using Dual-Fluorophore Ratiometric Microscopy

Published on: August 19, 2021

2.8K

Related Concept Videos

Pole and System Stability01:24

Pole and System Stability

The transfer function is a fundamental concept representing the ratio of two polynomials. The numerator and denominator encapsulate the system's dynamics. The zeros and poles of this transfer function are critical in determining the system's behavior and stability.
Simple poles are unique roots of the denominator polynomial. Each simple pole corresponds to a distinct solution to the system's characteristic equation, typically resulting in exponential decay terms in the system's...
975
Formation of Species01:31

Formation of Species

Speciation describes the formation of one or more new species from one or sometimes multiple original species. The resulting species are discrete from the parent species, and barriers to reproduction will typically exist. There are two primary mechanisms, speciation with and without geographic isolation—allopatric and sympatric speciation, respectively.
45.3K
Solution Formation02:16

Solution Formation

There is no one solvent that can dissolve every type of solute. Some substances that readily dissolve in a certain solvent might be insoluble in a different solvent. A simple way to predict which substances dissolve in which solvent is the phrase "like dissolves like". This means that polar substances, such as salt and sugar, dissolve in a polar substance like water. In contrast, non-polar substances are more soluble in non-polar solvents such as carbon tetrachloride.
This selective...
37.8K
Standard Enthalpy of Formation02:37

Standard Enthalpy of Formation

Enthalpy changes are typically tabulated for reactions in which both the reactants and products are at the same conditions. A standard state is a commonly accepted set of conditions used as a reference point for the determination of properties under other different conditions. For chemists, the IUPAC standard state refers to materials under a pressure of 1 bar and solutions at 1 M and does not specify a temperature. Many thermochemical tables list values with a standard state of 1 atm. Because...
49.3K
Formation of Complex Ions03:45

Formation of Complex Ions

A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
26.2K
Microtubule Formation01:23

Microtubule Formation

Microtubules are dynamic structures that undergo continuous assembly and disassembly. They originate from specialized multi-protein complexes known as microtubule organizing centers or MTOCs. Within the MTOC, the point of origin of the microtubule is known as the minus end, while the end radiating outward is the plus end. Microtubules serve two primary functions — the organization of spindle complexes to separate sister chromatids during mitotic or meiotic cell division and the formation...
7.7K