Related Experiment Videos
Membrane potential changes during mitogenic stimulation of mouse spleen lymphocytes
Summary
Lymphocyte membrane potential changes during mitogenic stimulation, initially depolarizing then repolarizing and hyperpolarizing. This membrane potential shift correlates with DNA synthesis and is specific to T or B cells depending on the mitogen.
Area of Science:
- Immunology
- Cell Biology
- Biophysics
Background:
- Lymphocyte activation is crucial for immune responses.
- Understanding the biophysical changes during lymphocyte activation is key.
- Membrane potential plays a role in cellular signaling.
Purpose of the Study:
- To investigate the dynamic changes in lymphocyte membrane potential during mitogenic stimulation.
- To correlate membrane potential shifts with DNA synthesis.
- To determine the specificity of mitogen-induced membrane potential changes in T and B cells.
Main Methods:
- Utilized the lipophilic cation [(3)H]tetraphenylphosphonium to measure membrane potential.
- Assessed membrane potential in normal mouse spleen lymphocytes (T and B cells).
- Monitored changes during stimulation with concanavalin A, lipopolysaccharide, and fetal calf serum.
Main Results:
- Normal lymphocytes exhibit a membrane potential of -65 +/- 2 mV.
- Mitogenic stimulation induced a pattern of early depolarization, followed by repolarization, and then hyperpolarization.
- Concanavalin A specifically depolarized T cells, while lipopolysaccharide depolarized B cells.
- A direct correlation was observed between membrane potential and DNA synthesis during repolarization and hyperpolarization phases.
Conclusions:
- Lymphocyte activation involves significant, dynamic changes in membrane potential.
- Mitogen-specific depolarization of T or B cells precedes their respective activation.
- Plasma membrane depolarization may initiate the transition of lymphocytes to mitotic activity.