Related Experiment Video
Updated: Aug 15, 2026
Rapid Magnetic-microbead Method for Efficient Purification of Low-density Neutrophils
Published on: November 11, 2025
CD16b associates with high-density, detergent-resistant membranes in human neutrophils
Maria J G Fernandes1, Emmanuelle Rollet-Labelle, Guillaume Paré
1Department of Rheumatology and Immunology, CHUL Research Centre, Laval University, 2705 boulevarde Laurier, Sainte-Foy, Québec, Canada, G1V 4G2. maria.fernandes@crchul.ulaval.ca
Abstract:
CD16b is unique in that it is the only Fc receptor linked to the plasma membrane by a GPI (glycosylphosphatidylinositol) anchor. GPI-anchored proteins often preferentially localize to DRMs (detergent-resistant membranes) that are rich in sphingolipids and cholesterol and play an important role in signal transduction. Even though the responses to CD16b engagement have been intensively investigated, the importance of DRM integrity for CD16b signalling has not been characterized in human neutrophils. We provide direct evidence that CD16b constitutively partitions with both low- and high-density DRMs. Moreover, upon CD16b engagement, a significant increase in the amount of the receptor is observed in high-density DRMs. Similarly to CD16b, CD11b also resides in low- and high-density DRMs. In contrast with CD16b, the partitioning of CD11b in DRMs does not change in response to CD16b engagement. We also provide evidence for the implication of Syk in CD16b signalling and its partitioning to DRMs in resting and activated PMNs (polymorphonuclear neutrophils). Additionally, DRM-disrupting agents, such as nystatin and methyl-beta-cyclodextrin, alter cellular responses to CD16b receptor ligation. Notably, a significant increase in the mobilization of intracellular Ca2+ and in tyrosine phosphorylation of intracellular substrates after CD16b engagement is observed. Altogether, the results of this study provide evidence that high-density DRMs play a role in CD16b signalling in human neutrophils.
Insights
Detergent-resistant membranes (DRMs) are crucial for CD16b signaling in neutrophils. Disrupting DRMs affects cellular responses, indicating their role in CD16b receptor function.
Area of Science:
- Immunology
- Cell Biology
- Biochemistry
Background:
- CD16b is a unique GPI-anchored Fc receptor in human neutrophils.
- GPI-anchored proteins often localize to detergent-resistant membranes (DRMs), important for signal transduction.
- The role of DRM integrity in CD16b signaling remains uncharacterized.
Purpose of the Study:
- To investigate the role of DRM integrity in CD16b signaling in human neutrophils.
- To determine CD16b and CD11b partitioning in DRMs upon activation.
- To assess the impact of DRM disruption on cellular responses to CD16b ligation.
Main Methods:
- Characterization of CD16b and CD11b partitioning in low- and high-density DRMs.
- Analysis of Syk recruitment to DRMs in resting and activated polymorphonuclear neutrophils (PMNs).
- Assessment of cellular responses (Ca2+ mobilization, tyrosine phosphorylation) after CD16b engagement using DRM-disrupting agents.
Main Results:
- CD16b constitutively partitions to low- and high-density DRMs, with increased presence in high-density DRMs upon engagement.
- CD11b also resides in DRMs, but its partitioning is unaffected by CD16b engagement.
- Syk is implicated in CD16b signaling and partitions to DRMs.
- DRM disruption alters cellular responses, including increased intracellular Ca2+ mobilization and tyrosine phosphorylation.
Conclusions:
- High-density DRMs play a significant role in CD16b signaling in human neutrophils.
- DRM integrity is essential for proper cellular responses following CD16b receptor activation.
