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Updated: May 30, 2026
Traction Force Microscopy to Study B Lymphocyte Activation
Published on: July 23, 2020
AFM detection of mitogen-induced morphological changes in human B lymphocyte
Qiulan Wang1, Mu Wang, Shengpu Li
1Department of Chemistry, Life Science and Technology College, Jinan University, Guangzhou, Guangdong 510632, People's Republic of China.
Insights
Human B-lymphocyte activation alters cell structure and increases adhesion forces. Atomic force microscopy revealed changes in cell morphology and membrane protein distribution after stimulation with pokeweed mitogen (PWM) and Staphylococcus aureus Cowan strain I (SAC).
Area of Science:
- Immunology
- Cell Biology
- Biophysics
Background:
- B-lymphocyte activation is crucial for humoral immunity.
- Previous studies focused on in vivo and in vitro activation processes.
- Ultrastructural and adhesion property changes during B-lymphocyte activation were not well understood.
Purpose of the Study:
- To investigate the morphological and mechanical property changes of human peripheral blood B lymphocytes during activation.
- To analyze ultrastructural alterations and adhesion force variations in stimulated B lymphocytes.
Main Methods:
- Human peripheral blood B lymphocytes were treated with pokeweed mitogen (PWM) and Staphylococcus aureus Cowan strain I (SAC) for 24 hours.
- Atomic force microscopy (AFM) was employed to study changes in cell morphology and mechanical properties.
- Cell height, diameter, volume, membrane roughness, and adhesion forces were measured.
Main Results:
- B-lymphocyte stimulation by PWM and SAC led to significant changes in cell height, diameter, and volume.
- Ultrastructural analysis revealed protein aggregation on the B-lymphocyte membrane, increasing average roughness and particle height.
- Adhesion forces increased significantly in treated cells (304.16 ± 60.30 pN for PWM, 249.63 ± 58.03 pN for SAC) compared to controls (104.28 ± 21.77 pN).
Conclusions:
- B-lymphocyte activation induces distinct changes in cell morphology and membrane ultrastructure.
- Increased adhesion force is a key mechanical property change associated with B-lymphocyte activation.
- These findings offer novel insights into B-lymphocyte activation mechanisms and structure-function relationships.
Abstract:
B-lymphocyte activation plays an important role in humoral immune system, and its process has been studied well in vivo and in vitro. However, the ultrastructure and adhesion property changes remain unclear. In this study, changes in the morphology and mechanical properties of human peripheral blood B lymphocytes were first studied by atomic force microscopy (AFM). B lymphocytes were treated with the mitogen, pokeweed mitogen (PWM), and Staphylococcus aureus Cowan strain I (SAC) for 24 hr. After B lymphocyte is stimulated by the mitogen, the cell height, diameter, and volume are changed in different degree. The ultrastructure of the B lymphocytes membrane obviously displayed proteins gathering, corresponding with larger changes of average roughness and mean height of particles on cell membrane. Meanwhile, we detected the adhesion force of B lymphocytes after being stimulated by PWM and SAC. We found that the treated cells had a higher adhesion force of 304.16 ± 60.30 pN (PWM) and 249.63 ± 58.03 pN (SAC) than that of control group (104.28 ± 21.77 pN). Therefore, our results could provide new information to further understand the B-lymphocyte activation process and their structure-function analyses.
