Bromocriptine restores tolerance in estrogen-treated mice

Area of Science:

• Immunology
• Endocrinology
• Autoimmunity

Background:

• Estrogen influences autoimmunity in systemic lupus erythematosus models.
• Estrogen promotes survival and activation of anti-DNA B cells in a mouse model.
• The role of prolactin in estrogen's effects on B cells requires further investigation.

Purpose of the Study:

• To investigate if estrogen's effects on B-cell autoreactivity are mediated by prolactin.
• To characterize B-cell autoreactivity in transgenic mice treated with estradiol and bromocriptine.

Main Methods:

• Treatment of mice with estradiol and bromocriptine (prolactin inhibitor).
• Measurement of anti-DNA antibody titers and kidney IgG deposition.
• Analysis of B-cell populations, Bcl-2 expression, and hybridoma molecular profiles.

Main Results:

• Estradiol plus bromocriptine reduced anti-DNA antibodies and kidney IgG deposition compared to estradiol alone.
• Both treatments increased B-cell expansion and Bcl-2 expression.
• Bromocriptine induced anergy in high-affinity DNA-reactive B cells, abrogating estradiol's effect on B-cell tolerance.

Conclusions:

• Estrogen's effects on naive autoreactive B cells partially depend on prolactin.
• Bromocriptine can induce anergy in high-affinity autoreactive B cells.
• These findings suggest potential therapeutic strategies for lupus involving prolactin inhibition.