Macrophage-associated immune checkpoint CD47 blocking ameliorates endometriosis

Area of Science:

• Immunology
• Gynecology
• Cell Biology

Background:

• Peritoneal macrophages are implicated in endometriosis (EM) progression but exhibit impaired phagocytosis.
• Immune checkpoints CD47-SIRPα and PD-L1-PD-1 regulate macrophage phagocytosis, with CD47 blockade showing promise in cancer treatment.

Purpose of the Study:

• To investigate the role of CD47 and PD-L1 in EM and evaluate the therapeutic potential of targeting these pathways.
• To determine if targeting CD47 can enhance macrophage phagocytosis of ectopic endometrial stromal cells and delay EM progression.

Main Methods:

• Comprehensive evaluation of CD47 and PD-L1 expression (mRNA and protein) in ectopic endometrium.
• In vitro and in vivo co-culture experiments of endometrial stromal cells and macrophages.
• Assessment of macrophage phagocytic capacity and apoptosis induction upon CD47 targeting.

Main Results:

• CD47 expression was significantly increased in ectopic endometrium from EM patients, while PD-L1 expression was not altered.
• Targeting CD47 enhanced macrophage phagocytosis of ectopic endometrial stromal cells.
• Reduced CD47 expression promoted apoptosis of endometrial stromal cells.

Conclusions:

• Targeting CD47 presents a dual therapeutic strategy for EM by increasing macrophage phagocytosis and inducing apoptosis of ectopic endometrial cells.
• The CD47-SIRPα signaling pathway holds potential for EM immunotherapy, warranting further investigation for specific antibody development.