Lymphocyte electrotaxis in vitro and in vivo

Area of Science:

• Immunology
• Cell Biology
• Biophysics

Background:

• Physiologic and pathologic conditions generate electric fields in vivo.
• Applied electric fields can induce electrotaxis in various cell types, including epithelial cells, endothelial cells, fibroblasts, and neutrophils, suggesting a role in wound healing.
• The response of lymphocytes to electric fields remains largely unexplored.

Purpose of the Study:

• To investigate the electrotactic response of lymphocytes to applied direct current (DC) electric fields.
• To determine if electrical stimulation activates intracellular signaling pathways in lymphocytes.
• To visualize and quantify lymphocyte migration in response to electric fields in vivo.

Main Methods:

• Modified Transwell assay to assess lymphocyte migration.
• Microfluidic device to apply controlled DC electric fields.
• Video microscopy and GFP-tagging of immunocytes for in vivo tracking in mouse skin.

Main Results:

• Human peripheral blood lymphocytes (PBLs) demonstrated cathode-directed migration in physiologically relevant DC electric fields.
• Electrical stimulation activated intracellular kinase signaling pathways in lymphocytes, similar to chemotactic responses.
• Motile cutaneous T cells in mouse ear skin actively migrated towards the cathode of an applied DC electric field.

Conclusions:

• Lymphocytes, including PBLs and cutaneous T cells, exhibit electrotaxis, migrating towards the cathode in DC electric fields.
• Externally applied electric fields can manipulate lymphocyte positioning within tissues.
• Endogenous electrical potential gradients may influence lymphocyte positioning in vivo.