Identification of estrogen receptor beta-positive intraepithelial lymphocytes and their possible roles in normal and tubal pregnancy oviducts.
BACKGROUND
Although intraepithelial lymphocytes (IELs) in human oviductal epithelium have been implicated in the regulation of local immunity, the precise kinetics and mechanism of steroid regulation of IEL are largely unknown.


METHODS
We examined the localization of estrogen receptors (ERs) and progesterone receptors (PRs) in 41 human oviducts by immunohistochemistry. These tissues were obtained from various menstrual cycles, also from both post-menopausal women and tubal pregnancies. The expressions of ERbeta mRNA and membrane (m)PR mRNA were examined by in situ hybridization and RT-PCR, respectively.


RESULTS
Most of the IEL expressed ERbeta at both mRNA and protein levels. The number of ERbeta-positive IEL, which were identified as CD8-positive T lymphocytes and also were mPR positive, was increased in the late proliferative, the mid-secretory and late secretory phases in normally cycling women (P < 0.05). Interestingly, in tubal pregnancy, ERbeta-positive IELs were consistently abundant. In addition, we found a high Ki-67-labelling index for IEL, although ERalpha was entirely absent in the tubal pregnancy oviducts.


CONCLUSIONS
These results suggest that the number of IEL fluctuated because of estrogen and progesterone levels probably through ERbeta and mPR, respectively. ERbeta-positive IEL may be involved in regulating immune tolerance in tubal pregnancy oviducts.
Ulziibat
Shirendeb
S
Division of Histology and Cell Biology, Department of Developmental and Reconstructive Medicine, Nagasaki University Graduate School of Biomedical Sciences, Japan.
Ejima
Kuniaki
K
Shibata
Yasuaki
Y
Hishikawa
Yoshitaka
Y
Kitajima
Michio
M
Fujishita
Akira
A
Ishimaru
Tadayuki
T
Koji
Takehiko
T
D000328:Adult; D000368:Aged; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism; D004848:Epithelium / Q000378:metabolism*; D047629:Estrogen Receptor beta / Q000096:biosynthesis*; D005187:Fallopian Tubes / Q000378:metabolism*; D005260:Female; D006801:Humans; D007108:Immune Tolerance; D019394:Ki-67 Antigen / Q000096:biosynthesis; D008214:Lymphocytes / Q000378:metabolism*; D008593:Menopause; D008875:Middle Aged; D011247:Pregnancy; D011274:Pregnancy, Tubal / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism
D047629:Estrogen Receptor beta; D019394:Ki-67 Antigen; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone