Related Experiment Video

Updated: Aug 7, 2026

Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death
09:18

Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death

Published on: December 27, 2016

CD20-mediated apoptosis: signalling through lipid rafts

Julie P Deans1, Haidong Li, Maria J Polyak

  • 1Immunology Research Group, Department of Biochemistry and Molecular Biology, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, Canada T2N 4N1. jdeans@ucalgary.ca

Immunology
|October 18, 2002
PubMed

Insights

CD20 monoclonal antibodies deplete B-cells. This study suggests CD20 cross-linking activates src-family kinases within lipid rafts, potentially inducing B-cell apoptosis indirectly.

Area of Science:

  • Immunology
  • Cell Biology
  • Molecular Medicine

Background:

  • CD20 is a validated target for B-cell depletion therapies using monoclonal antibodies.
  • Therapeutic mechanisms may involve direct cytotoxicity via tyrosine kinase signaling pathways.
  • CD20 localizes to membrane microdomains called lipid rafts, which are signaling hubs.

Purpose of the Study:

  • To investigate the role of CD20 localization in lipid rafts in anti-CD20 antibody mechanisms.
  • To explore the potential involvement of src-family kinases in CD20-mediated signaling and apoptosis.

Main Methods:

  • Analysis of CD20 association with lipid rafts.
  • Investigation of tyrosine kinase activation upon CD20 cross-linking.
  • Assessment of signaling pathways downstream of CD20 engagement.

Main Results:

  • CD20 is associated with lipid rafts, co-localizing with src-family tyrosine kinases.
  • Cross-linking of CD20 leads to clustering of lipid rafts.
  • This clustering is linked to the activation of src-family kinases.

Conclusions:

  • Anti-CD20 antibody action may involve indirect cytotoxicity.
  • Activation of src-family kinases, consequent to lipid raft clustering, is a proposed mechanism.
  • Understanding this pathway could refine B-cell depletion therapies.

More Related Videos

Identification of Mediators of T-cell Receptor Signaling via the Screening of Chemical Inhibitor Libraries08:49

Identification of Mediators of T-cell Receptor Signaling via the Screening of Chemical Inhibitor Libraries

Published on: January 22, 2019

Measuring Composition of CD95 Death-Inducing Signaling Complex and Processing of Procaspase-8 in this Complex07:17

Measuring Composition of CD95 Death-Inducing Signaling Complex and Processing of Procaspase-8 in this Complex

Published on: August 2, 2021

Related Concept Videos

Apoptosis01:30

Apoptosis

Apoptosis is a combination of two Greek words, 'apo' and 'ptosis,' meaning separation and falling off, respectively. Hippocrates used this word to describe gangrene, which was caused due to bandaging of fractured bones. Apoptosis was distinguished from necrosis in 1970 when John Kerr reported observations of morphological changes occurring during apoptosis. During one experiment, he observed that the disruption of blood supply to the liver tissue resulted in a size reduction of the tissue.
The Extrinsic Apoptotic Pathway01:17

The Extrinsic Apoptotic Pathway

The extrinsic apoptotic pathway is initiated when extracellular death-inducing signals, such as specific cytokines, activate the death receptors expressed on the cell surface. The immune cells involved in this pathway are natural killer cells (NK cells) and cytotoxic T-lymphocytes. NK cells are critical in innate immune response, while cytotoxic T-lymphocytes are associated with adaptive immune response. These cells recognize specific receptors expressed on the altered cells and activate...
The Intrinsic Apoptotic Pathway01:31

The Intrinsic Apoptotic Pathway

Internal cellular stress, such as cellular injury or hypoxia, triggers intrinsic apoptosis. The B-cell lymphoma 2 (Bcl-2) family of proteins are the primary regulators of the intrinsic apoptotic pathway. For example, during DNA damage, checkpoint proteins, such as Ataxia Telangiectasia Mutated (ATM protein) and Checkpoints Factor-2 (Chk2) proteins, are activated. These proteins phosphorylate p53 which further activates pro-apoptotic proteins, such as Bax, Bak, PUMA, and Noxa, and inhibits...
Phagocytosis of Apoptotic Cells01:17

Phagocytosis of Apoptotic Cells

Cells undergoing apoptosis form apoptotic bodies that must be removed immediately to prevent inflammation, autoimmune diseases, and necrosis. Phagocytosis is carried out by professional phagocytes such as macrophages or  immature dendritic cells. Non-professional phagocytes such as  epithelial cells and fibroblasts also take part in this process; however, they are not as effective as professional phagocytes. 
Normal cells contain receptors that prevent them from being recognized by phagocytes.
MAPK Signaling Cascades01:07

MAPK Signaling Cascades

Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...
Cellular Injury V: Apoptosis and Autophagy01:22

Cellular Injury V: Apoptosis and Autophagy

Cells respond to damage and stress through highly coordinated processes that decide whether they survive or undergo controlled self-destruction. Two major pathways involved in this regulation are apoptosis, a type of programmed cell death, and autophagy, a survival mechanism that helps cells adapt to adverse conditions.ApoptosisApoptosis removes aged or injured cells to maintain tissue balance. During this process, the cell shrinks, chromatin condenses and fragments, and membrane-bound...