Role of major histocompatibility complex class I expression and natural killer-like T cells in the genetic control of endometriosis.
OBJECTIVE
To evaluate whether the expression of human leukocyte antigen (HLA) class I on eutopic and ectopic endometrial cells modify the susceptibility to lysis mediated by lymphocytes.


METHODS
Evaluation of T lymphocyte cytotoxic activity and HLA class I expression on endometrial cells.


METHODS
Subjects were recruited at laparoscopy.


METHODS
Patients with endometriosis (n = 7). Healthy women as controls (n = 10).


METHODS
Human leukocyte antigen class I molecule analysis of endometrial cells was carried out by immunofluorescence and flow cytometry. Phenotyping of T lymphocytes was performed to analyze T-cell subsets. Cytotoxicity was performed to determine cytolytic activity against endometrial cells.


RESULTS
In vitro culture of endometrial cells down-regulates the expression of HLA class I molecules and enhances the susceptibility to lysis mediated by natural killer (NK)-like T lymphocytes. Cytolytic T-cell clones, expressing the CD94 antigen, are inhibited by the HLA-B7 allele on endometrial cells. Ectopic endometrial cells modulate the expression of HLA class I molecules.


CONCLUSIONS
The resistance to lysis of endometrial cells is related to expression of surface HLA class I molecules, which send a negative signal for lysis mediated by NK-like T lymphocytes. The HLA-B7 allele inhibits the cytotoxic activity, suggesting that the growth of ectopic endometrial cells might be under a genetic control.
Semino
C
C
Servizio di Citometria, Istituto Nazionale per la Ricerca sul Cancro, Genova, Italy.
Semino
A
A
Pietra
G
G
Mingari
M C
MC
Barocci
S
S
Venturini
P L
PL
Ragni
N
N
Melioli
G
G
D000483:Alleles; D002478:Cells, Cultured; D015536:Down-Regulation; D004715:Endometriosis / Q000209:etiology / Q000235:genetics* / Q000503:physiopathology*; D004717:Endometrium / Q000737:chemistry / Q000378:metabolism / Q000473:pathology; D005260:Female; D005434:Flow Cytometry; D019084:Fluorescent Antibody Technique, Indirect; D005786:Gene Expression Regulation; D005805:Genes, MHC Class I; D015793:HLA-B7 Antigen / Q000032:analysis / Q000235:genetics; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000276:immunology / Q000473:pathology / Q000502:physiology*; D010641:Phenotype; D013602:T-Lymphocytes, Cytotoxic / Q000473:pathology / Q000502:physiology
D015793:HLA-B7 Antigen; D015395:Histocompatibility Antigens Class I; D007371:Interferon-gamma