Changes in lectin receptor lateral mobilities accompany lymphocyte stimulation

Area of Science:

• Immunology
• Cell Biology
• Biophysics

Background:

• Lymphocyte membrane component mobility is crucial for immune cell function.
• Succinyl Concanavalin A (S Con A) is a lectin used to probe cell surface interactions.
• Understanding receptor dynamics is key to deciphering immune cell signaling.

Purpose of the Study:

• To investigate the changes in lateral mobilities of rabbit lymphocyte membrane components in response to S Con A.
• To differentiate the recovery mechanisms of T and B lymphocyte receptor mobilities.
• To explore the role of lectin presence and cell metabolism in receptor mobility.

Main Methods:

• Fluorescence Photobleaching Recovery (FPR) was employed to measure lateral mobilities.
• Rabbit lymphocytes (T and B cells) were treated with S Con A.
• Metabolic inhibitors and cytoskeletal disruptors were used to assess their effects on receptor mobility.
• DNA synthesis was monitored in parallel to correlate with cell stimulation.

Main Results:

• S Con A exposure reduced lectin receptor mobilities on both T and B cells by approximately 2-fold within 3 hours.
• T cell receptor mobility reduction persisted until 18 hours, with rapid recovery only if lectin remained present.
• B cells showed gradual recovery of receptor mobility over 4 to 48 hours; metabolic inhibitors restored mobility, while cytoskeletal disruptors affected T cells.
• Lectin removal was effective in restoring T cell receptor mobility only up to 15 hours; S Con A reduced surface Ig mobility, indicating unique anchorage modulation.

Conclusions:

• S Con A induces distinct temporal and recovery patterns in T and B lymphocyte receptor mobilities.
• Lectin presence and cell metabolic state are critical for regulating T cell receptor mobility recovery.
• Concanavalin A receptors appear to uniquely modulate the anchorage of other membrane molecules, including surface Ig on B cells.