Migration of human lymphocytes. I. A model using the mouse as host

Area of Science:

• Immunology
• Cell Biology
• Radiopharmacology

Background:

• The reticuloendothelial system (RES) plays a crucial role in clearing foreign particles and cells from circulation.
• Understanding lymphocyte trafficking is essential for immunology and developing targeted therapies.
• Previous studies have not fully elucidated the factors influencing lymphocyte migration to lymphoid organs.

Purpose of the Study:

• To investigate the distribution and migration patterns of 51Cr-labelled human lymphocytes in mice.
• To determine the effect of reticuloendothelial system (RES) blockade on lymphocyte distribution.
• To establish a model for studying lymphocyte recirculation and factors influencing migration to lymph nodes.

Main Methods:

• Intravenous injection of 51Cr-labelled human lymphocytes into mice under various pre-treatment conditions (normal, irradiated, anti-platelet antiserum, colloidal carbon).
• Measurement of radioactivity distribution in various tissues, including spleen and lymph nodes.
• Comparison of radioactivity from viable lymphocytes versus dead cells and cell debris.

Main Results:

• Pre-treatment with colloidal carbon or anti-platelet antiserum reduced the uptake of human lymphocytes by the host's RES.
• Radioactivity in the spleen and lymph nodes was primarily attributed to the migration of viable lymphocytes.
• Carbon treatment allowed for a clear observation of lymphocyte migration into lymph nodes.

Conclusions:

• The reticuloendothelial system (RES) significantly influences the initial distribution of injected lymphocytes.
• Blocking the RES enhances the ability to track viable lymphocyte migration to lymphoid tissues.
• Measuring radioactivity in lymph nodes of RES-blocked mice provides a reliable model for studying lymphocyte recirculation and factors affecting it.