Cyclophosphamide-induced suppressor cells in nude mice

Area of Science:

• Immunology
• Cell Biology

Background:

• Cyclophosphamide (CY) is an immunosuppressive drug used in chemotherapy.
• Understanding the regeneration of immune cells post-CY treatment is crucial for managing side effects and developing therapeutic strategies.

Purpose of the Study:

• To characterize lymphocytes that regenerate after high-dose cyclophosphamide (CY) treatment in nude mice.
• To identify the properties and functions of these regenerated suppressor cells.

Main Methods:

• Nude mice were administered a single high dose of CY (200 mg/kg).
• Spleen cells were analyzed 10 days post-treatment for antibody production, natural killer (NK) activity, B and T cell content, cell surface charge (electrophoretic mobility - EPM), and histamine receptors.
• Suppressor cell activity was assessed by testing the effect of cell depletion using anti-Thy-1 plus complement (C) and antiasialo GM1 (aGM1) plus C.

Main Results:

• Regenerated spleen cells from CY-treated mice suppressed in vitro antibody production.
• These cells exhibited normal natural killer (NK) activity but had very low B and T cell content.
• Increased cell surface charge (electrophoretic mobility - EPM) and histamine receptors were observed on CY-treated spleen cells.
• Depletion of NK cells using anti-Thy-1 plus C or antiasialo GM1 plus C did not remove the suppressor cells.

Conclusions:

• The regenerated suppressor cells following CY treatment are characterized by high electrophoretic mobility (EPM) and histamine receptors.
• These cells are identified as natural suppressor cells, lacking Ig, Thy-1, and aGM-1 markers.