Inhibition of murine suppressor cell function by progesterone

Area of Science:

• Immunology
• Endocrinology

Background:

• Murine suppressor cells play a role in immune regulation.
• Allogeneic mixed lymphocyte cultures (MLCs) are used to study immune cell interactions.

Purpose of the Study:

• To investigate the effects of progesterone on murine suppressor cell function.
• To determine if progesterone influences alloantigen-specific and non-specific suppressor cells.

Main Methods:

• BALB/c splenic lymphocytes were stimulated in vitro with allogeneic or syngeneic cells to generate suppressor cells.
• The suppressive activity of these cells was assessed in secondary MLCs.
• Progesterone, estradiol, cortisol, and pyrilamine were added to cultures to evaluate their effects.

Main Results:

• Progesterone significantly inhibited both alloantigen-specific and non-specific suppressor cell activity.
• Estradiol and cortisol also demonstrated inhibitory effects on suppressor cells.
• Progesterone's inhibitory effect appeared independent of blocking cytotoxic T lymphocyte (CTL) induction.

Conclusions:

• Steroid hormones, including progesterone, can modulate suppressor cell function in mice.
• The findings suggest that the placental steroid hormone environment may impact maternal immune responses to the fetus.