Role of NK cells and HLA-G in endometriosis

Nagamasa Maeda, Chiaki Izumiya, Kayo Taniguchi, Sachio Matsushima, Takao Fukaya
Frontiers in bioscience (Scholar edition) · 2012 · vol. S4(4) , pp. 1568–1581 · doi:10.2741/s353 · PMID:22652893 · W1977958838
review OA: bronze CC0 ⤵ 27 in-corpus citations
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⚙ AI-generated summary by claude@2026-06, 2026-06-08 ⓘ

This review discusses how HLA-G expression on eutopic endometrium during menstruation may impair NK cell activity, potentially contributing to endometriosis development through retrograde menstruation.

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⚙ AI-generated deep summary by claude@2026-06, 2026-06-09 ⓘ

This review discusses endometriosis pathogenesis through intraperitoneal immune interactions between natural killer (NK) cell receptors and human leukocyte antigen (HLA)-G. It focuses on evidence that HLA-G is expressed on eutopic endometrium only during the menstrual phase (not proliferative or secretory phases) and that HLA-G–expressing cells are also detected in peritoneal fluid during menstruation, suggesting retrograde menstruation could introduce HLA-G–positive tissue into the peritoneal cavity where it may be reduced by immunosurveillance. The paper links this process to impaired NK cytotoxicity via HLA-G as a mechanism that could permit endometrial cell survival and implantation, while acknowledging that the specific mechanisms behind decreased NK activity are not fully clarified. This paper is centrally about endometriosis — it specifically focuses on NK cells and HLA-G expression during the menstrual cycle and their proposed role in retrograde menstruation and immune evasion.

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Abstract

Impaired natural killer (NK) activity in women with endometriosis is thought to promote implantation and progression of endometrial tissue, in accord with Sampson's hypothesis. However, the mechanisms responsible for decreased NK cell activity and the antigens recognized by NK cells are not clear.We focused on human leukocyte antigen (HLA)-G, a ligand of NK receptors, expression and its menstrual cycle changes by eutopic endometrium. Interestingly, HLA-G expression was identified on eutopic endometrium only in the menstrual phase but not in the proliferative or secretory phases. Furthermore, HLA-G expressing cells were also detected in peritoneal fluid during the menstrual period. During retrograde menstruation, HLA-G expressing endometrial tissue may enter the peritoneal cavity, and may be reduced by immunosurveillance system. Although peritoneal NK cells play an important role in this system, impairment of NK cytotoxicity via HLA-G may allow peritoneal endometrial cell survival and implantation. In this review, we discuss the pathogenesis of endometriosis from the viewpoint of intraperitoneal immune interaction between NK cell receptors and HLA-G that can enter into peritoneal cavity from eutopic endometrium through retrograde menstruation.

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Condition tags

endometriosis

MeSH descriptors

Endometriosis HLA-G Antigens Killer Cells, Natural Endometriosis Endometriosis Endometriosis Endometrium Endometrium Endometrium Endometrium Female HLA-G Antigens Humans Killer Cells, Natural Killer Cells, Natural Killer Cells, Natural

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Papers in the corpus that this work cites (lower rings, blue) and that cite this one (upper rings, green). Dot size scales with the paper's in-corpus citation count — bigger dot = more influential within the endo/adeno field. Click a dot to open that paper. [ expand to 2 hops ] — adds papers reached through this work's immediate citers/citees. Heavier; up to 60 extra dots.

Cited by (27)

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