Ovarian follicular cells have innate immune capabilities that modulate their endocrine function.

Oestrogens are pivotal in ovarian follicular growth, development and function, with fundamental roles in steroidogenesis, nurturing the oocyte and ovulation. Infections with bacteria such as Escherichia coli cause infertility in mammals at least in part by perturbing ovarian follicle function, characterised by suppression of oestradiol production. Ovarian follicle granulosa cells produce oestradiol by aromatisation of androstenedione from the theca cells, under the regulation of gonadotrophins such as FSH. Many of the effects of E. coli are mediated by its surface molecule lipopolysaccharide (LPS) binding to the Toll-like receptor-4 (TLR4), CD14, MD-2 receptor complex on immune cells, but immune cells are not present inside ovarian follicles. The present study tested the hypothesis that granulosa cells express the TLR4 complex and LPS directly perturbs their secretion of oestradiol. Granulosa cells from recruited or dominant follicles are exposed to LPS in vivo and when they were cultured in the absence of immune cell contamination in vitro they produced less oestradiol when challenged with LPS, although theca cell androstenedione production was unchanged. The suppression of oestradiol production by LPS was associated with down-regulation of transcripts for aromatase in granulosa cells, and did not affect cell survival. Furthermore, these cells expressed TLR4, CD14 and MD-2 transcripts throughout the key stages of follicle growth and development. It appears that granulosa cells have an immune capability to detect bacterial infection, which perturbs follicle steroidogenesis, and this is a likely mechanism by which ovarian follicle growth and function is perturbed during bacterial infection.

Periovulatory expression of intercellular adhesion molecule-1 in the rat ovary.

Leukocytes, especially neutrophils and macrophages, traditional cellular regulators of the immune system, reside within the tissue architecture of the rodent and human ovary and dramatically increase in number, in response to gonadotropin, in the theca of preovulatory follicles. Evidence strongly suggests a modulatory role for leukocytes in ovarian tissue remodeling events, such as ovulation, luteinization, and luteolysis. The present study investigates the ovarian localization and potential gonadotropin regulation of intercellular adhesion molecule-1 (ICAM-1), an important factor in neutrophil and monocyte attachment to endothelium. Reverse transcription-polymerase chain reaction and immunohistochemical detection and quantification of ICAM-1 mRNA and protein were carried out in ovaries of immature and eCG/hCG-primed rats during the periovulatory period (0, 6, 12, and 24 h post-hCG). While whole ovarian ICAM-1 mRNA levels did not vary significantly during the preovulatory period, ovarian follicles exhibited ICAM-1 mRNA and protein specifically within the thecal region, where mRNA expression increased 5-fold and protein expression increased 6-fold when comparing pre-hCG levels with those at the estimated time of ovulation (12 h post-hCG). Thecal ICAM-1 was most prevalent in highly vascularized regions as evidenced by serial staining with an endothelium-specific antibody. Granulosa layer ICAM-1 immunoactivity was acquired only during/after follicle rupture. These results show ICAM-1 is localized within the ovarian theca and its expression is associated with follicular development in periovulatory follicles, peaking in expression at the time of rupture. Additionally, ICAM-1 is expressed among granulosa-lutein cells of the ovulating follicle and developing corpus luteum. Taken together, these findings suggest rat ovarian ICAM-1 may be instrumental in the active recruitment of leukocytes into the preovulatory ovary and may have a role in corpus luteum formation.

Ovarian cell-mediated immune response to Salmonella enteritidis infection in laying hens (Gallus domesticus).

The aim of this study was to examine the response of cell-mediated ovarian immunity against Salmonella infection in hens. Laying hens were injected intraperitoneally with PBS (control) or Salmonella enteritidis (SE). Ovarian stroma containing stromal follicles, small white follicles (SWF), and third largest (F3) and the largest (F1) follicles were collected 12 or 24 h after inoculation and fixed in periodate-lysine-paraformaldehyde. Frozen sections were stained first for CD3+, CD4+, or CD8+ T cells and then for SE by a double immunostaining method. Immunoreaction products for SE were detected in the ovarian stroma, theca of stromal follicles, SWF, F3, and F1 at 12 and 24 h after inoculation. Immunopositive T-cell subsets were localized in the stroma and theca of follicles in birds inoculated with or without SE. The populations of CD3+, CD4+, and CD8+ T cells were significantly greater in the stroma and the theca of follicles 12 h after SE inoculation than in those of control birds (P < 0.01). Their frequencies were further increased in those tissues 24 h after inoculation (P < 0.01). Injection of SE did not cause significant differences in the CD4+:CD8+ T-cell ratio as both subsets increased proportionately. The current results indicate that the population of T-cell subsets increases in the ovarian stroma and the follicular tissues in response to SE invasion within 12 h of inoculation. Thus, cell-mediated immune response against SE, their products, or both may be induced in the hen ovary.

Changes in the localization of MHC class II positive cells in hen ovarian follicles during the processes of follicular growth, postovulatory regression and atresia.

The aim of this study was to determine the changes in the population of major histocompatibility complex class II positive (MHC-II(+)) cells in ovarian follicles during the processes of follicular growth, postovulatory regression and follicular atresia in hens. Cryostat sections of ovarian stroma containing cortical follicles, small white follicles, the largest (F(1)) and third largest (F(3)) preovulatory follicles, postovulatory and atretic follicles of laying hens were prepared. The sections were immunostained for MHC-II molecules using mouse anti-chicken MHC-II monoclonal antibody and positive cells were counted using a computer-assisted image analyser under a light microscope. MHC-II(+) cells were localized in the theca layer of normally growing follicles including cortical follicles, small white follicles and F(3) and F(1) preovulatory follicles, whereas they were found in both the theca and granulosa layers in postovulatory and atretic follicles. The frequency of MHC-II(+) cells in the theca layer was significantly increased during follicular growth from cortical follicles to F(3) preovulatory follicles. Although the population of MHC-II(+) cells did not differ between F(3) and F(1) preovulatory follicles, it increased significantly in postovulatory follicles (P < 0.01). The population of MHC-II(+) cells was significantly greater in the theca layer of atretic follicles than in non-atretic follicles (P < 0.01). These results indicate that the antigen-presenting function via MHC-II increases in association with follicular growth. A marked increase in MHC-II(+) cells indicates that these cells may be involved in regression of postovulatory and atretic follicular tissues.

Gonadotropin- and cytokine-regulated expression of the chemokine interleukin 8 in the human preovulatory follicle of the menstrual cycle.

Interleukin 8 (IL-8) is a chemotactic cytokine involved in the recruitment and activation of neutrophils as well as in cell proliferation and angiogenesis. Because these events are essential components of folliculogenesis, ovulation, and subsequent repair of the ruptured follicle, the presence and regulation of IL-8 in the human follicle of the menstrual cycle was investigated. The concentrations of IL-8 were higher in follicular fluids from dominant follicles of late follicular/ovulatory phase compared with those of midfollicular phase. IL-8 was detected in the media from cultured granulosa and theca cells, with 10-fold higher levels in the theca cell cultures. Exposure to FSH and LH increased the IL-8 secretion from granulosa cells, but no effect was seen in theca cell cultures. Estradiol and progesterone did not affect IL-8 secretion from any cell type. The cytokines IL-1alpha and IL-1beta, but not tumor necrosis factor alpha, enhanced IL-8 secretion from both cell types. IL-8 levels in cultures of granulosa-lutein cells from hyperstimulated in vitro fertilization cycles were not affected by either gonadotropins or steroids. These data provide evidence that ovarian IL-8 is gonadotropin and cytokine induced and may be involved in the hormonally regulated stages of follicular development and ovulation.

Compartmentalization of steroidogen esis by the equine corpus luteum.

The presence of cytochrome P450C17 within equine follicles and corpora lutea (CL) was detected by immunostaining. Two different antibodies were used which had previously been shown by immunoblotting to cross-react with equine P450C17. Strong positive immunostaining was present in the theca-derived cells of the CL during the estrous cycle and pregnancy. In the CL from mares after Day 40 of pregnancy there were also occasional bands of positively stained cells which resembled the polyhedral-shaped theca cells seen in preovulatory follicles. The pattern of immunostaining suggested compartmentalization of steroidogenesis within the equine CL with small cells possessing the potential to produce androgen which could then be aromatized to estrogen by the large luteal cells.

Immunolocalization of MHC-II+ cells in the ovary of immature, young laying and old laying hens Gallus domesticus.

The aim of this study was to localize major histocompatibility complex class II positive (MHC-II+) cells in the hen ovary, and to determine the effects of ageing and sex steroids on their frequency. Cryostat sections of ovarian tissues of immature, young laying and old laying hens and those of immature hens treated with or without diethylstilboestrol or progesterone were prepared. Sections were immunostained for MHC class II antigens using mouse anti-chicken MHC class II monoclonal antibody and observed under a light microscope. Positive cells were counted using a computer-assisted image analyser. MHC-II+ cells were localized in the ovarian stroma and theca layer of primary follicles in all birds examined. The frequency of MHC-II+ cells in the stroma and theca of primary follicles (approximately 400-600 microns in diameter) was significantly greater in young laying hens than it was in immature and old laying hens (P < 0.01). In the stroma and the theca of primary follicles of diethylstilboestrol-treated birds, the frequency of MHC-II+ cells was significantly greater than it was in the stroma and theca of control and progesterone-treated birds (P < 0.01). Progesterone had no significant effect when compared with controls. These results indicate that both the ovarian stroma and theca of follicles in the hen ovary contain MHC-II+ cells, the frequency of MHC-II+ cells increases in association with sexual maturation and decreases thereafter during ageing, and oestrogen may be one of the factors enhancing the induction of MHC-II+ cells in the ovary.

Effects of ageing and oestrogen on the localization of immunoglobulin-containing cells in the chicken ovary.

Immunoglobulins in the chicken ovary are important for transfer of immunity to chicks through the egg and for protection of the ovary from infection. The aim of this study was to examine the effects of ageing and oestrogen on the population of Ig-containing cells in the chicken ovary. The ovarian tissue of immature, young laying and old laying hens and that of immature birds treated with diethylstilboestrol (DES), progesterone or sesame oil (vehicle) was processed for paraffin wax sections. The sections were stained for IgG, IgM and IgA by an indirect immunostaining method and the population of cells positive for each Ig was analysed under a light microscope. The number of cells positive for IgG, IgM and IgA was significantly greater in the ovarian stromal tissue of young laying hens than in immature or old laying hens (P < 0.01). The number of IgG- and IgM-positive cells in the thecal layer of primary follicles of young laying hens was significantly greater than that in immature and old laying hens (P < 0.01) and there were significantly more (P < 0.05) IgA-positive cells in young laying hens than in immature birds. The number of IgG-, IgM- and IgA-positive cells was significantly (P < 0.01) greater in both the stromal tissue and the thecal layer of DES-treated birds than in the vehicle-treated birds. Progesterone had no significant effect (P < 0.05) on the population of Ig-positive cells. These results indicate that the number of Ig-positive cells increases as chickens mature and decreases with ageing, and that oestrogen may be involved in this process.

The effect of microtubule and microfilament-disrupting drugs on prolactin-stimulated progesterone synthesis and secretion by cultured porcine theca cells.

The effect of microtubule- and microfilament-disrupting drugs (colchicine, cytochalasin B and D) on basal and prolactin (Prl)-stimulated progesterone synthesis and secretion was studied. Microtubules were visualized immunocytochemically using a monoclonal antibody against the alpha-subunits of tubulin, while microfilaments were detected using a polyclonal antibody against actin. The second antibody was conjugated with FITC. Progesterone, androgen and estradiol concentration were detected in tissue and culture medium by appropriate radioimmunoassays. In Prl-treated cultures microtubules formed a network with more radial organisation than in the controls. After colchicine-treatment the cells were round, regular in shape and microfilaments were disintegrated and replaced by punctate aggregates. Actin filaments formed typical stress fibers in theca cells (Tc). In Prl-treated cells some microfilaments were broken resulting in a diffuse immunofluorescent pattern. After treatment with cytochalasin B and D many of the stress fibers disappeared, the cells became rounded and diffuse microfilaments were seen. Prl added to the culture medium increased synthesis of all investigated steroids and additionally stimulated progesterone secretion. Exposure of theca cells to colchicine caused an increase of basal progesterone secretion into the incubation medium which simultaneously decreased the steroid content in the cells. Colchicine suppressed Prl-stimulated synthesis of all three steroids studied and did not have any effect on their secretion. Exposure of theca tissue to cytochalasin B increased basal progesterone and androgen synthesis but drastically decreased basal estradiol synthesis by these cells. The opposite effect was observed after the addition of cytochalasin D, when estradiol synthesis increased and progesterone and androgen synthesis by theca cells was not affected. Microtubule and microfilaments-disrupting drugs had no effect on the secretion of the investigated steroids in Prl-treated cells. Our results suggest that microtubules and microfilaments are involved in Prl-stimulated steroid synthesis but not in steroid secretion.

[Evaluation of autoantibodies against oocyte theca cells in peritoneal effusion and serum of women with endometriosis]. / Ocena autoprzeciwcial przeciw oslonce przejrzystej oocytu w plynie otrzewnowym i surowicy kobiet z endometrioza.

The aim of the study was evaluation of presence of the antibodies against theca of the oocyte in peritoneal effusion and in serum in fertile and infertile women with minimal endometriosis in luteal phase of the menstrual cycle. Antibodies were measured by means of ELISA method. Median of the antibodies against theca was three-fold higher in peritoneal effusion in infertile women. No differences were stated in serum.

Anamnestic development of lymphocytic infiltration in murine experimental autoimmune oophoritis is primarily localized in the stroma and theca.

PROBLEM: Neonatal thymectomy performed on day 3 of life (NTX3) induces autoimmune oophoritis and ovarian failure in B6A mice. These mice develop high-titer autoantibodies specific to oocytes, and ultimately the ovaries become fibrotic and devoid of primordial follicles. These findings implicate the oocyte as a primary target of the autoimmune process. However, in previous work we demonstrated that in developing disease the lymphocytic infiltration was confined to the stroma and theca, and not found involving oocytes. Here, we investigate the possibility that lymphocytic infiltration involving oocytes develops as part of end-stage disease. METHOD: We transplanted normal syngeneic ovaries to B6A mice with confirmed autoimmune ovarian failure, and, as a control, to normal oophorectomized mice. We then defined the time course and histologic distribution of lymphocytic infiltration in the transplanted ovaries. Lymphocytes were identified by morphology with the aid of an immunohistochemical leukocyte marker (CD45). RESULTS: Autoimmune oophoritis developed by 7 days after transplantation to the NTX3 mice. Compared to control mice, in these mice we found significantly increased stromal and thecal lymphocytic infiltration. In no case did we observe lymphocytic infiltration involving oocytes. CONCLUSIONS: Our findings agree with our previous report and suggest that the ovarian failure in this model is not mediated by a direct lymphocytic attack against intact oocytes. Other immune-mediated mechanisms are responsible. The paradoxical development of high-titer oocyte-specific antibodies despite the stromal and thecal location of the lymphocytic infiltration remains to be explained.

Murine experimental autoimmune oophoritis develops independently of gonadotropin stimulation and is primarily localized in the stroma and theca.

PROBLEM: Neonatal thymectomy performed on day 3 of life (NTX3) induces experimental autoimmune oophoritis in certain strains of mice. The disease has its onset around the time of the first estrous, suggesting the process may be gonadotropin dependent. Furthermore, one study reported that gonadotropin stimulation exacerbated the ovarian lymphocytic infiltration in NTX3 mice. Here we examine the possibility that gonadotropin stimulation of the ovary plays a role in the development of post-thymectomy autoimmune oophoritis. METHOD: Using immunohistochemistry we defined the time course and histologic distribution of the post-thymectomy ovarian lymphocytic infiltration that develops in B6A mice ([C57BL6 X A/J]F1). We detected ovarian leukocytes using a monoclonal antibody against mouse CD45/T200 and counted those positive staining cells that had the morphologic appearance of lymphocytes. We then treated NTX3 mice to determine if gonadotropin stimulation could exacerbate the disease or cause the disease to appear earlier. We also treated NTX3 mice to determine if gonadotropin suppression could reduce the severity of the disease. RESULTS: Ovarian lymphocytic infiltration was observed as early as 3 weeks after thymectomy, and, during the course of the disease, was primarily located in the stroma and theca. Gonadotropin stimulation did not exacerbate existing disease or induce an earlier onset of severe disease. Furthermore, gonadotropin suppression did not reduce the degree of lymphocytic infiltration or oocyte destruction. CONCLUSIONS: Our findings suggest that murine experimental autoimmune oophoritis develops independently of gonadotropin stimulation of the ovary.

Distribution of the adrenocortical inner zone antigen.

Previous studies using a mouse monoclonal antibody (IZAb) have identified inner zone-specific antigens (IZAg 1 and 2) in the rat adrenal cortex. The expression of IZAg1 is enhanced by dibutyryl-cyclic AMP or ACTH in vitro and by in vivo ACTH treatment. These studies also suggest that IZAg may be involved in steriogenesis in rat adrenals. Using sensitive detection methods, the distribution of IZAg in adrenals from other species and in other rat tissues was studied. Pig and rabbit adrenals expressed an IZAb-immunoreactive protein with molecular mass identical with that of IZAg1, but no immunoreactivity was detected in bovine, guinea-pig or mouse adrenals. In the rabbit adrenal, as in the rat, IZAb bound only to zonae fasciculata/reticularis cells. However, the whole adrenal cortex in the pig immunoreacted with IZAb. Although immunofluorescence was observed in human adrenal sections, predominantly in the zona reticularis, no significant immunoreactive protein band was detected by immunoblot analysis. Apart from the zonae fasciculata/reticularis in the adrenal gland, an IZAb-immunoreactive protein with a molecular mass of 26,000 Da, corresponding to IZAg1, was also found in rat hepatocytes, renal tubules, ovary (corpus luteum, interstitial cells, theca interna of mature follicles) and Leydig cells. The observations suggest that IZAg may be involved in the processes of biosynthesis, metabolism and/or excretion of steroid hormones.

A new monoclonal antibody (POG-1) detects a differentiation antigen of porcine granulosa and thecal cells and indicates heterogeneity of thecal-stromal cells.

To identify the differentiation antigen of ovarian cells, we raised a murine monoclonal antibody (POG-1 antibody) reactive to porcine granulosa and thecal cells in the ovary. Immunofluorescence staining showed that expression of the POG-1 antigen on granulosa and theca interna cells increased gradually in accordance with follicular development. The thecal cells just outside the basal lamina surrounding the follicles did not express the antigen, whereas some stromal cells around the theca externa layer in the large follicles did express it. These expression profiles indicated the heterogeneity of thecal-stromal cells and that the POG-1 antigen was a differentiation-related antigen of granulosa and thecal cells. Luteal cells also expressed the antigen. In organs other than the ovary, some endocrine and exocrine cells, such as Leydig cells and secretory cells of the breast, expressed the antigen. The POG-1 antigen was purified from granulosa cells by immunoaffinity chromatography. Polyacrylamide gel electrophoresis profiles showed that the antigen consisted of two specific proteins; the major one had a molecular mass of 77, and the other had a molecular mass of 81 kilodaltons. Analysis of the purified POG-1 antigen may contribute to understanding the differentiation mechanism of granulosa and thecal cells.

Premature ovarian failure: autoimmunity and natural history.

OBJECTIVE: We studied the association of clinical and latent autoimmune diseases with circulating steroid-producing cells autoantibodies (SCA) in patients with premature ovarian failure (Group I). We investigated the presence of SCA in patients with organ-specific autoimmune diseases but without hypogonadism (Group II). We assessed whether SCA can be considered markers of hypergonadotrophic hypogonadism. DESIGN: In Groups I and II blood samples were taken at diagnosis. In a subset of patients with SCA without hypogonadism blood samples were taken at least yearly for 6 years for immunological and functional tests. PATIENTS: Group I included 50 females, aged 16-39 years; Group II included 3677 patients, aged 6-79 years, divided into Subgroup IIA (99 with Addison's disease alone or associated with other endocrinopathies or with hypoparathyroidism) and Subgroup IIB (3578 with insulin-dependent diabetes mellitus or thyroid autoimmune diseases). The follow-up group included nine subjects, aged 5-31 years (seven females and two males). MEASUREMENTS: SCA and other organ-specific autoantibodies were detected by standard indirect immunofluorescence using normal human tissues or passive haemagglutination tests. Gonadal functional tests included evaluation of FSH and LH levels by a RIA method; adrenocortical function included evaluation of cortisol and ACTH plasma levels by a RIA method. RESULTS: Three subgroups were identified in Group I on the basis of clinical autoimmune disease. 9/50 (18%) patients were found to have an Addison's disease (Subgroup IA) and in this subgroup SCA were present in 7/9 (78%); 10/50 (20%) had other autoimmune diseases (Subgroup IB) and SCA were found in 1/10 (10%); 31/50 (62%) did not have other clinical autoimmune diseases (Subgroup IC) and 1/31 (3%) had SCA. SCA were significantly increased in Subgroup IA vs IB (P = 0.017) and vs IC (P = 0.00002). In Group II, SCA were found in 20/3677 (0.5%); in particular, SCA were detected in 18/99 (18%) of the patients in Subgroup IIA and in 2/3578 (0.06%) of the patients in Subgroup IIB. The frequency of SCA in Subgroup IIA was found to be significantly increased with respect to that found in Subgroup IIB (P = 0.001 x 10(-5)). During follow-up, 3/7 females (42.8%) but 0/2 males developed hypergonadotrophic hypogonadism with a latency period of 10, 13 and 15 years, respectively. Three females and two males lacked clinical Addison's disease at the beginning of the study, but during follow-up 1/3 female and 2/2 males developed clinical Addison's disease with a mean latency period of 13 months. CONCLUSIONS: The results confirm the strong relationship between premature ovarian failure and other clinical autoimmune diseases, as well as the strong link existing between primary ovarian failure, Addison's disease and antibodies to steroid-producing cells. The study also suggests that in females antibodies to steroid-producing cells are serological markers of both potential hypergonadotrophic hypogonadism, and Addison's disease; however, in males these antibodies may be considered only as markers of potential Addison's disease.

Antibodies to microbial, leukocyte and organ antigens.

Hemagglutinating antibodies to Mycoplasma hominis were present in 30 of 83 infertile, 15 of 40 pregnant and 5 of 20 post-partum females and 20 of 82 infertile males in contrast to only 2 of 21 fertile females and 5 of 25 fertile males. Their presence correlated with sperm antibody detection by TAT in Lab. 4, the immunobead-binding assay of Lab. 1 and the SIT of Lab. 11, but not with other sperm antibody assays. Immunofluorescent antibodies to Chlamydia trachomatis, on the other hand, did not correlate with the incidence of sperm antibodies. Among 305 serum samples tested, 12 were positive for testicular antibodies, 8 had antibodies to kidney, 7 to ovary and 15 to endometrium. A majority of serum samples positive for antibodies to testis and ovary, but not endometrium, reacted against sperm in different assays. Eight of 135 samples tested had antibodies to human leukocyte antigenic HLA-Aw19 (Aw19, A28, A29, A30 and A32) and/or B35 (B35, B5 and B15) complexes. Six of these samples were also positive for sperm antibodies by one or more antibody assays. Cross-reactive antigens may be present in sperm, M. hominis, testis, ovary and leukocytes.

Origin of different cell types in the bovine corpus luteum as characterized by specific monoclonal antibodies.

Specific monoclonal antibodies to granulosa and thecal cell surface antigens were produced and used to determine the contributions of theca and granulosa cells to the bovine corpus luteum (CL). Binding of each antibody was examined on collagenase-dispersed luteal cells from 18 cycling and 14 pregnant heifers by indirect immunofluorescence. The percent binding of the large luteal cells to granulosa antibody (GrAb) declined (P less than 0.01) as the age of the CL advanced: 77 +/- 6, 47.5 +/- 3, and 30 +/- 2 for Days 4-6, 10-12 and 16-18, respectively. Further reduction in binding of GrAb to large cells occurred between 50 and 100 days of pregnancy and no labeling was seen thereafter. Fourteen percent of the small luteal cells were bound by GrAb on Days 4-6 of the cycle, and none were labeled during subsequent stages. In contrast, when thecal antibody (TAb) was used, the proportions of large cells that were labeled increased (P less than 0.01) between Days 4-6 (10 +/- 1.3%) and 10-12 (46 +/- 3%). The percentage of large cells bound by TAb then remained unchanged until midpregnancy, declined as pregnancy advanced, and disappeared during late gestation. A majority of small luteal cells were bound by TAb throughout the estrous cycle: 70 +/- 4%, 69 +/- 3% and 58 +/- 6% at Days 4-6, 10-12, 16-18, respectively. Labeling of small cells by TAb occurred throughout pregnancy but declined (P less than 0.05) as gestation advanced. These studies suggest that the large cells of the early cyclic CL are derived from granulosa cells, while most of the small cells are of thecal origin. Small cells develop into large cells as the age of the CL increases. Granulosa-derived cells disappear during early pregnancy, while cells of thecal origin persist throughout pregnancy.

The localization of Thy-1.1, MRC OX 2 and Ia antigens in the rat ovary and fallopian tube.

The localization of Thy-1, MRC OX 2 and Ia antigens as defined by monoclonal antibodies MRC OX 7, MRC OX 2 and MRC OX 6 was determined by an indirect immunoperoxidase technique on cryostat sections of rat ovaries. Thy-1 antigen was present significantly in the theca interna of growing antral follicles. Developing corpora lutea exhibited an increasing presence of Thy-1 antigen and it was still present in degenerating ones. Thy-1 antigen was constantly present in fallopian tube tunica propria. The MRC OX 2 antigen was expressed most on ovarian structures that do not develop further, i.e. granulosa of degenerating antral follicles and third generation of corpora lutea. MRC OX 2 antibody stained the capillaries of the fallopian tube; the most heavily MRC OX 2+ were the cells of ovarian germinal epithelium. The Ia+ cells were occasionally found within the growing ovarian structures but they were more frequent in degenerating ones. Rare or no la+ cells within the ovary and heavily Ia-depleted thymus medulla and Ia areas in the spleen were, however, observed in some rats. The role of these antigens with respect to the structures they label is discussed.

Autoimmunity to endometrium and ovary in endometriosis.

Antibody titres to whole ovary, theca cells, granulosa cells and endometrium were determined by passive haemagglutination and immunofluorescence assays in sera and in cervical and vaginal secretions from 13 patients with endometriosis. Antibody titres to endometrium (mean log2 +/- s.e.m., 7.08 +/- 0.80; P less than 0.0001), ovary (3.58 +/- 0.87; P = 0.0092), theca cells (4.42 +/- 0.73; P less than 0.0001) and granulosa cells (3.33 +/- 0.63; P = 0.0024) were significantly higher in the patients' sera than in sera from 15 normal non-pregnant females. Antibody titres to granulosa cells were elevated (7.97 +/- 1.46; P = 0.0424) in their cervical secretions. Antibody titres to all tissues tested were similar in vaginal secretions of patients and controls. Immunofluorescent antibody assay of biopsied endometrial tissue and sera from the patients revealed the antibodies to be primarily IgG and IgA. The results suggest that autoantibodies to endometrium and ovary are present in patients with endometriosis.