An important enigmatic promoter of endometriosis: immune dendritic cells

Immune dendritic cells may have an operative role in endometriosis lesions

Key Points

Highlights:

• Various immune disturbances are effective in endometriosis pathogenesis, and there is ample evidence for "dendritic cells" taking part in this process.
• Dendritic cells originate from bone marrow progenitors and are a heterogeneous group of immune cells.

Importance:

• The pro-endometriotic environment could interfere with dendritic cell maturation and induce them into macrophage phenotype, thus may enhance inflammation. 
• Immature dendritic cells could also play a role in initializing endometriosis development by enhancing local angiogenesis.

What’s done here:

•  This is a comprehensive review based on a systematic search in PubMed/Medline, Lilacs, and Cochrane databases for articles about dendritic cells in endometriosis.

Key results

• The published studies reveal that the dendritic cells are susceptible to pro-endometriotic changes that prevent maturation and induce a macrophage phenotype.
• Vascular development in endometriotic foci needs the presence of endogenous dendritic cells that secrete proangiogenic factors.
• Maturation of these cells inhibits this reaction.
• Thus, immature dendritic cells have an important role in angiogenesis, motivating the progression of endometriosis.

Lay Summary

Dr. Larinha and associates from a Brasilian academic center have published their comprehensive review on the role of immune dendritic cells in the pathogenesis of endometriosis in a recent issue of the "Journal of Reproductive Immunology".

Antigen-presenting dendritic cells of the immune system present processed antigens to T cells to mediate between innate and adaptive immunity. Dendritic cells originate from bone marrow progenitors and are a heterogeneous group of immune cells with the ability to migrate from blood to lymphoid and other tissues. Thus can be practically found in almost all tissues.

Search in PubMed/Medline, Lilacs, and Cochrane databases using “dendritic cells” AND “immunology” AND “endometriosis” resulted in 490 citations and after applying inclusion and exclusion criteria, a total of 13 studies were assessed.

These publications demonstrated that dendritic cells show susceptibility to pro-endometriotic changes inhibiting their maturation and thus inducing a macrophage phenotype. This is also reflected in a high concentration of macrophages at endometriotic inflammatory sites. It is a well-known fact that chronic inflammation observed in endometriotic foci seems to be caused by abnormal peritoneal milieu to immunologic deviations.

Also, the growth and vascularization of endometriotic foci need the presence of endogenous dendritic cells residing in the lesions promoting endothelial cell migration via proangiogenic factors when they gain a macrophage phenotype. On the other hand, maturation in dendritic cells inhibits this process. The current status of our knowledge regarding immune dendritic cells points to an urgent need to clarify the role of these cells in endometriosis development and progression.

Research Source: https://pubmed.ncbi.nlm.nih.gov/34915278/