Cell-mediated immunity to trophoblast antigens in women with recurrent spontaneous abortion

Interplay of immune components and their association with recurrent pregnancy loss

Maintenance and progression of pregnancy is an intricate process governed by a variety of developmental cues. Recurrent pregnancy loss (RPL) is a complication experienced by expecting mothers that is defined as three or more consecutive pregnancy losses. This review focuses on the dysfunctions of the immune system as one of the key contributors towards RPL. The current data suggests that the alloimmune and autoimmune factors contribute to the loss of fetus. Such causes despite being recognized as a definitive reason for recurrent pregnancy loss, are still under extensive investigation with new parameters being discovered and scrutinized for their association with RPLs. More in-depth and high throughput studies are required for devising better diagnostic tools and management strategies for the affected female so that they can carry their pregnancy to term.

Evaluation of T cell cytokines and their role in recurrent miscarriage

Recurrent miscarriage (RM) is defined as two or more consecutive pregnancy losses that affect approximately 5% of conceived women worldwide. RM is a multi-factorial reproductive problem and has been associated with parental chromosomal abnormalities, embryonic chromosomal rearrangements, uterine anomalies, autoimmune disorders, endocrine dysfunction, thrombophilia, life style factors, and maternal infections. However, the exact cause is still undecided in remaining 50% of cases. Immunological rejection of the embryo due to exacerbated maternal immune reaction against paternal embryonic antigens has been set forth as one of the significant reason for RM. The accurate means that shield the embryo during normal pregnancy from the attack of maternal immune network and dismissal are inadequately implicit. However, it is suggested that the genetically irreconcilable embryo escapes maternal immune rejection due to communication among many vital cytokines exuded at maternal-embryonic interface both by maternal and embryonic cells. Previous investigations suggested the Th1/Th2 dominance in altered immunity of RM patients, according to which the allogenic embryo flees maternal T cell reaction by inclining the Th0 differentiation toward Th2 pathway resulting into diminished pro-inflammatory Th1 immunity. However, recently pro-inflammatory Th17 cells and immunoregulatory Treg cells have been discovered as essential immune players in RM besides Th1/Th2 components. Cytokines are believed to develop a complicated regulatory network so as to establish a state of homeostasis between the semi-allogenic embryo and the maternal immune system. However, an adverse imbalance among cytokines at maternal-embryonic interface perhaps due to their gene polymorphisms may render immunoregulatory means not enough to re-establish homeostasis and thus may collapse pregnancy.

Association of tumor necrosis factor-alpha 308G/A polymorphism with recurrent miscarriages in women

BACKGROUND

Recurrent miscarriage (RM) is the most common pregnancy loss in the first trimester affecting approximately 0.5-2% of women. It is a heterogeneous condition and remains an enigma as the underlying cause is still difficult to track down.

AIM

This study was aimed to investigate the distribution of tumor necrosis factor-alpha (TNF-α) 308G/A polymorphism and its association with RM in females. The comparative picture was also demonstrated by comparing genotyping results with healthy control women having no history of miscarriage.

METHODS

This clinical study was conducted among 115 women aged 21-44 years with history of recurrence of miscarriage. The samples were collected from women attending the outpatient departments of various hospitals, nursing homes, and infertility clinics of this region. In the present study, 111 fertile healthy women aged 24-46 years with at least one live birth and no history of miscarriage were also included.

RESULTS

Mean age of women with RM was found to be 28 ± 5.6 years by recall method, whereas it was found to be 30 ± 7.4 in context to healthy women with no history of pregnancy loss. In the present study, 66% of women with RM had homozygous wild type genotype (GG) while 30% and 4% of women had heterozygous (GA) and homozygous mutant genotype (AA), respectively. Among control group, 79%, 16%, and 5% of women showed GG, GA, and AA genotype, respectively.

CONCLUSION

The current study supports the concept of TNF-α 308G/A variant in particular with reproductive failure, GG and GA alleles showing 1-fold risk association with RM (odds ratio: 1.86 and 1.43, respectively).

Cytokines in recurrent pregnancy loss

BACKGROUND

Recurrent pregnancy loss (RPL) is defined as the occurrence of three or more consecutive miscarriages prior to 20 weeks gestation. Exaggerated maternal immune response to fetal antigens has been proposed to be one of the mechanisms underlying recurrent pregnancy loss.

METHOD

A comprehensive literature search was conducted from the websites of the National Library of Medicine (http://www.ncbl.nlm.nih.gov) and Pubmed Central, the US National Library of Medicine's digital archive of life sciences literature (http://www.pubmedcentral.nih.gov/). The data was assessed from books and journals that published relevant articles in this field.

RESULT

In normal pregnancy, tolerance of the genetically incompatible fetus by the maternal immune system depends on the interactions of an array of cytokines secreted by maternal and fetal cells at the site of implantation. Earlier research indicated that altered immunity in RPL is dominated by the Th1/Th2 hypothesis, which proposed that the fetus escapes maternal-derived T-cell responses through skewing the Th0 differentiation toward Th2 pathway which dampens pro-inflammatory Th1-type immunity. Recent studies indicate the role of proinflammatory Th17 cells and immunoregulatory Treg cells in RPL in addition to Th1/Th2 interactions.

CONCLUSION

Cytokines form a complex regulatory network which maintains homeostasis between the fetal unit and the maternal immune system. If this delicate balance is adversely affected, immunoregulatory mechanisms may be insufficient to restore homeostasis and this may lead to pregnancy failure.

Reduced expression of IL-6 and IL-1α mRNAs in secretory phase endometrium of women with recurrent miscarriage

A diverse array of cytokines is implicated in regulating the immune adaptation and endometrial tissue remodelling events that facilitate successful embryo implantation and early placental development. The aim of this study was to evaluate expression of mRNAs encoding a panel of immunoregulatory cytokines in the endometrium of fertile women and women experiencing recurrent miscarriage using highly sensitive, quantitative RT-PCR assays. Endometrial biopsies were collected during the mid-secretory phase of the menstrual cycle from women classified as proven fertile (control; n=12) and women experiencing unexplained recurrent miscarriage (RM; n=9). Reduced IL-6 mRNA and reduced IL-1alpha mRNA were independently associated with recurrent miscarriage. Altered expression was evident after accounting for variation in the composition of endometrial biopsies by normalization of data to epithelial and mesenchymal cell-specific transcripts, cytokeratin-18 mRNA and vimentin mRNA, respectively. The relative abundance of mRNAs encoding LIF, GM-CSF, IFNgamma, IL-1beta, IL-4, IL-5, IL-10, IL-12p40, TNFalpha, TGFbeta1, TGFbeta2 and TGFbeta3 were not altered in recurrent miscarriage tissue. Associations between expression of IL-10, LIF, GM-CSF and TGFbeta2 suggest that regulatory circuits link the transcription of these cytokine genes. Inadequate expression of IL-6 and IL-1alpha mRNAs in endometrial tissue may predispose to recurrent miscarriage through a perturbed maternal immune response, effects on decidual tissue remodeling and angiogenesis, or dysregulated trophoblast differentiation and invasion. Quantitative RT-PCR assays for these cytokines in endometrial biopsies may be a realistic strategy for development of novel diagnostics for predisposition to recurrent miscarriage.

Pure choriocarcinoma of testis with tumor-infiltrating lymphocytes and granulomas

Pure choriocarcinoma is very rare in the testes, and host immune responses including tumor infiltrating lymphocytes are unusual in choriocarcinoma. This study reports a case of pure testicular choriocarcinoma with extensive lymphocytic infiltrate and granulomatous inflammation. Scrotal ultrasonography revealed a heterogeneous, hyperechoic intratesticular mass. -human chorionic gonadotropin levels were elevated in a radioimmunoassay. The hemorrhagic and necrotic solid mass was composed of two cell populations - mononuclear pleomorphic cells and intimately admixed multinucleated smudged cells. The tumor cells were positive for cytokeratin 7, epidermal growth factor receptors, human placental lactogen and p57. Many inflammatory cells were present within the tumor. The majority of infiltrating cells were CD8-positive cytotoxic cells, which also expressed granzyme-B and TIA-1. The tumor cells were positive for FasL, but negative for Fas. Therefore, this case seemed to escape the host defense response to the tumor due to the loss of Fas, although the cellular host immune response was still active.

T-Helper 2 and 3 type immunity to trophoblast in successful in vitro fertilization-embryo transfer

OBJECTIVE

To determine whether peripheral blood mononuclear cell (PBMC) secretion of T-helper (Th)-1 type cytokines and Th-2 and Th-3 type cytokines in women undergoing in vitro fertilization-embryo transfer (IVF-ET) is associated with therapeutic failure and success, respectively.

DESIGN

Cohort study.

SETTING

Academic medical center.

PATIENT(S)

One hundred one women undergoing IVF-ET and 19 fertile controls.

INTERVENTION(S)

Peripheral blood was obtained from women undergoing IVF-ET before oocyte retrieval and from 19 nonpregnant fertile controls. The PBMCs were cultured in the presence or absence of a protein extract from either a trophoblast cell line or sperm membrane.

MAIN OUTCOME MEASURE(S)

Supernatants from PBMC cultures were tested by enzyme-linked immunoabsorbent assay (ELISA) for the Th-1 type cytokines tumor necrosis factor-alpha (TNF)-alpha) and interferon-gamma (IFN)-gamma), the Th-2 type cytokines interleukin (IL)-6 and IL-10, and the Th-3 type cytokine transforming growth factor (TGF)-beta1.

RESULT(S)

Levels of IL-6 and IL-10 were significantly higher in controls than in infertile women with endometriosis, and levels of IL-10 were higher in controls than in women with unexplained infertility. No differences were found in unstimulated levels of TNF-alpha, IFN-gamma, or TGF-beta1 between infertile patients and controls. In trophoblast-stimulated PBMC cultures, levels of TGF-beta1 were significantly lower in subjects who experienced failed compared with ongoing pregnancies.

CONCLUSION(S)

Baseline PBMC secretion of IL-6 and IL-10 is higher in fertile controls than in women with endometriosis, and IL-10 secretion is also higher than in women with unexplained infertility. Trophoblast-stimulated PBMC secretion of TGF-beta1 is positively associated with the establishment of successful pregnancy in women undergoing IVF-ET. Our study provides novel evidence to support a faciliatory role of Th-2 and Th-3 type responses to trophoblast in early pregnancy.

Natural killer cells in pregnancy and recurrent pregnancy loss: endocrine and immunologic perspectives

The endocrine system and the immune system interact closely during implantation and maintenance of pregnancy. One of the most striking examples of this communication is at the level of the decidua (endometrium of pregnancy). Here, under the influence of sex steroids, there is a dramatic increase of a unique population of lymphocytes, the uterine natural killer (uNK) cells, in early pregnancy. These cells derive predominantly from a subset of peripheral blood NK cells, which under hormonal influence gets recruited to the uterus. In mice, uNK cells play an important role in the development of placental vasculature. The role of these cells in human pregnancy is still not definitively established; however, they are believed to promote placental and trophoblast growth and provide immunomodulation at the maternal-fetal interface. In contrast to their presumptive role in the maintenance of a healthy pregnancy, uNK cells and peripheral NK cells are dysregulated in unexplained recurrent pregnancy loss. Herein, we review NK cell populations, their changes in number and function in altered endocrine environments during the menstrual cycle and pregnancy, the current data on their potential role in unexplained recurrent pregnancy loss, and mechanisms for potential therapies targeted to NK cell function for this enigmatic disorder.

New fetoproteins, as presumptive antigenic inducers of abortions and congenital anomalies. Temporal forking of immunological abortions. A working hypothesis

In a previous experimental study soluble alloantigens and soluble foreign (not recognized by the dam's immune system) transitory antigens in chick embryo have been detected. When a chick embryo extract was injected in hens and their eggs were incubated, the death or a delay in chick embryo development or congenital anomalies were observed. Based on the foregoing, the following working hypothesis is established: any fetoprotein not coming into contact with the fetal immune system during the central clonal selection period becomes a foreign antigen. If it is a female fetus that becomes pregnant at adult age, then passage to the maternal circulation or to the decidua of the same foreign fetoprotein from her fetus is a candidate to induce a humoral or cell-mediated response. If specific IgG or toxic factors of the different cells activated by cell-mediated immunity in the mother access the inductive antigen (e.g., an enzyme) in the conceptus, there functions may be cancelled or the antigen-carrier cell may undergo lysis. This will result in damage to tissues leading to abortion or to a viable but morphologically or functionally abnormal offspring. This can occurs with some of soluble foreign transitory antigens existents. The soluble alloantigens are foreign for the mother because are coded by paternal genes and act of similar way.

Helicobacter pylori infection negatively influences pregnancy outcome in a mouse model

BACKGROUND

Helicobacter pylori infects the human stomach, causing gastritis, peptic ulcer, and gastric cancer. H. pylori infection has also been related to extra-gastric disorders. We investigated whether H. pylori infection can influence pregnancy in a murine model.

METHODS

Female CD1 mice were infected with the H. pylori SPM326 strain before mating, and then assessed throughout pregnancy for embryo/fetus characteristics and histopathological changes of the endometrium.

RESULTS

Infected mice showed higher numbers of resorption and lower fetal weights than noninfected controls. These pathological phenomena were accompanied by macrophage activation, and increases both of CD4+ and CD8+ lymphocytes and of interferon-gamma and major histocompatibility complex class II expression at the endometrial level, as evaluated by immunohistochemistry.

DISCUSSION

During pregnancy, preferential induction of Th2-type cytokines downregulates Th1-type responses, allowing fetal survival. Our results suggest that H. pylori infection can induce activation of resident uterine immune cells and/or recruitment of cells at the endometrial level. It can be hypothesized that the local Th1-type response induced by H. pylori infection could alter the systemic Th1/Th2-type cytokine balance at sites under particular physiopathological conditions of active tissue and/or vascular formation, such as pregnancy.

CONCLUSIONS

This is the first evidence in an animal model of the possible influence of H. pylori infection on pregnancy. Further work is required on its mechanism and its relevance for humans.

Lymphocyte-mediated lysis of sheep chorion: susceptibility of chorionic cells to third-party and maternal cytotoxic lymphocytes and presence of cells in the endometrium exhibiting cytotoxicity toward natural-killer cell targets

In several species, the trophoblast is resistant to lysis by cytotoxic lymphocytes. Such resistance is believed to contribute to survival of the semiallogenic conceptus. We tested whether ovine chorionic cells are susceptible to lysis by specific and nonspecific cytotoxic lymphocytes in peripheral blood (PBL) and whether cytotoxic cells that can lyse target cells for natural-killer cells are present in the endometrium. Primary chorionic cells from pregnant ewes at Days 51-91 of gestation were labeled with 51Cr and incubated for 20 h at 50:1 and 100:1 ratios with PBL from the pregnant mother or from a third-party ewe. In the absence of interleukin-2 (IL-2), there was no killing of primary chorionic cells by third-party PBL even after infection of chorionic cells with bovine herpes virus-1. Incubation with IL-2-induced cytotoxic action in third-party PBL towards one of six primary chorionic cell preparations only. Primary chorionic cells from two of four placentae were lysed by maternal PBL. Luminal epithelial cells from cyclic ewes and from the pregnant and nonpregnant uterine horns of unilaterally-pregnant ewes were evaluated for the presence of cells capable of killing D17 target cells (a natural-killer cell target). Killing was observed but there was no difference in activity between physiological stages. In contrast, there was intense immunochemical localization of perforin in glandular and luminal endometrial epithelial cells in pregnant ewes, and less intense staining in nonpregnant animals. It is concluded that ovine chorionic cells are generally resistant to killing by natural-killer-like cells and lymphokine-activated killer cells. Generation of maternal cytotoxic lymphocytes against trophoblast can occur in some cases and may contribute to pregnancy loss.

Cytokines of the placenta and extra-placental membranes: biosynthesis, secretion and roles in establishment of pregnancy in women

Virtually all known cytokines have been demonstrated to be expressed in the placenta and associated fetal and maternal membranes during normal gestation. In addition to playing their traditional roles as modulators of immunological function, cytokines derived from the placenta and extraplacental membranes, together with other locally-derived growth factors, appear to be implicated in various aspects of implantation and placental development. Imbalances in the intrauterine cytokine milieu around the time of implantation and invasion may play a causative role in disorders associated with early pregnancy failure, and are also associated with the abnormal trophoblast development seen in gestational trophoblastic disease. Cytokines thus appear to be an important component of a paracrine/autocrine communication network operating within the feto-maternal interface to ensure the successful establishment of pregnancy.

T helper 1-type immunity to trophoblast antigens in women with a history of recurrent pregnancy loss is associated with polymorphism of the IL1B promoter region

Recurrent pregnancy loss (RPL) is a common disorder during early gestation. Recent evidence suggests that T helper 1 (Th1)-type immunity is associated with unsuccessful pregnancy especially in women with RPL of otherwise unknown etiology, while Th2-type immunity is associated with pregnancy success. Interleukin (IL)-1 may influence Th1/Th2 immune responsiveness and has been implicated in the establishment of successful pregnancy. In the present study, we investigated polymorphism of the IL-1beta gene (IL1B) in women with a history of RPL. Significant increases in the frequencies of IL1B promoter region variants IL1-511C and IL1B-31T were found in women with a history of RPL. Increased frequencies of these two variants and their homozygotes were found only in cases having evidence of Th1 immunity to trophoblast as determined by IFN-gamma production of peripheral blood mononuclear cells (PBMCs) stimulated with a trophoblast cell-line extract. Significantly higher IFN-gamma production by PBMCs in response to trophoblast correlated with variant IL1B-511C and its homozygocity in women with RPL. These results suggest that variants -511C and -31T in the IL1B promoter region confer risk for RPL associated with Th1 immunity to trophoblast antigens.

Distribution of Th1 and Th2 cell populations in human peripheral and decidual T cells from normal and anembryonic pregnancies

OBJECTIVE

To examine whether maternal immune responses during normal pregnancy are Th2 biased and whether there are specific changes when anembryonic pregnancy occurs.

DESIGN

Prospective study.

SETTING

Department of Obstetrics and Gynecology at a university hospital.

PATIENT(S)

We studied 32 pregnant women receiving elective abortions of normal pregnancies and 35 women with anembryonic pregnancies between 6 weeks and 10 weeks of gestational age.

INTERVENTION(S)

Using the multilabeling capability of three-color flow cytometry, it is possible to measure intracellular cytokines and cell surface markers simultaneously to determine which cells are the cytokine-producing cells.

MAIN OUTCOME MEASURE(S)

We examined the extent and proportion of mononuclear cells expressing specific T-cell surface markers and cytokines, interferon gamma, and interleukin 4 in the peripheral blood and deciduae. Secreted cytokines in the supernatants after 24-hour culture were also compared.

RESULT(S)

During the unstimulated status, the proportion of IL-4-secreting cells significantly exceeded that of IFN-gamma-secreting cells in the peripheral blood and decidua in normal pregnancies and was significantly decreased when anembryonic pregnancies occurred. Consequently, the Th1/Th2 ratios were increased during anembryonic pregnancies. However, after 24-hour culture, only another Th2-type cytokine, IL-10, was markedly increased and exceeded IFN-gamma secretion in cultures from both the peripheral blood and decidua in normal pregnancies.

CONCLUSION(S)

The decidual T lymphocytes are Th2 predominant. When anembryonic pregnancy occurs, this Th2 predominance disappears.

Pregnancy and murine thyroiditis: thyroglobulin immunization leads to fetal loss in specific allogeneic pregnancies

Thyroid autoantibodies are risk factors in human pregnancy. To investigate the influence of autoimmune thyroiditis on pregnancy, we have studied the impact of murine experimental autoimmune thyroiditis (EAT) on pregnancy outcome by using thyroglobulin (Tg) immunized CBA/J (H2(k)) female mice. When Tg immunized mice were mated with BALB/c (H2(d)) males, only 57% (47/83) of pregnant mice maintained their conceptions compared with >85% of other strain combinations (P < 0.05). We also found that MHC class II antigens were expressed on placental cells from Tg immunized pregnant mice but not in control normal pregnancies. Furthermore, the frequency and severity of thyroiditis, assessed by histological analyses, was also increased in Tg immunized mice mated with the BALB/c strain compared with syngeneic pregnancies (P < 0.05). In these pregnant mice mated with BALB/c, interleukin-4 secretion by mitogen-stimulated spleen cells was significantly suppressed and interferon-gamma secretion by mixed lymphocyte reactions with BALB/c cells was significantly increased. These data demonstrated enhanced Th1 cell proliferation and fetal loss in CBA/J X BALB/c pregnancies. We concluded, therefore, that pregnancy loss was increased in experimental autoimmune thyroiditis in a manner that was dependent on paternal antigens. These observations have broad implications for understanding the immunology of pregnancy.

Cytokines and placental macrophages in regulation of birth activity

The article reviews present notions on functional activity of cytokines of the fetoplacental complex. Particular emphasis is placed on the role of these molecules in the regulation of gestation processes and in pregnancy incompetence. The mechanism of the involvement of placental macrophages and their products in gestation and delivery is discussed.

Interleukin-12 augments cytolytic activity of peripheral and decidual lymphocytes against choriocarcinoma cell lines and primary culture human placental trophoblasts

PROBLEM

Human trophoblasts are tolerant to the maternal immune system, but susceptible to interleukin (IL)-2-activated lymphocytes. IL-12 is also a key cytokine in the induction of cytotoxic responses. We administered IL-12 to peripheral blood lymphocytes (PBLs) and to decidual lymphocytes (DLs) and studied resulting cytotoxicity against trophoblasts.

METHOD OF STUDY

PBLs and DLs were stimulated with rIL-2 and/or rIL-12 for 48 hr in vitro. Cytotoxicity against the choriocarcinoma cell line JEG-3, JAR, and primary culture trophoblasts were examined by LDH release assay. The proliferative response was estimated by MTT assay. Expression of cytotoxic factors was studied by reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

Whereas IL-12 alone produced a modest enhancement in cytotoxicity of PBLs and DLs, the combination of IL-2 and IL-12 was most effective in trophoblast cell lysis. IL-12 enhanced the mRNA expression of T-cell specific serine protease (TSP, granzyme B) and FasL in DLs, but the expression of perforin was unchanged. Expression of these cytotoxic factors in PBLs was up-regulated by IL-12.

CONCLUSION

Our findings indicate critical roles of IL-12 in the activation of maternal lymphocytes, which could possibly result in pregnancy failure syndromes.

Pregnancy in SLE

The effect of pregnancy on disease activity in systemic lupus erythematosus remains controversial. Studies on lupus flares in pregnancy are discussed, including prospective data on severity of flares and organ involvement from the Hopkins Lupus Pregnancy Center. The major fetal concerns of miscarriage (due to the antiphospholipid antibody syndrome), pre-term birth (largely due to pre-eclampsia or premature rupture of membranes) and neonatal lupus, are reviewed.

Th1-type immunity is incompatible with successful pregnancy

Several years ago, the rather provocative question was raised: is successful pregnancy a T helper 2 (Th2) phenomenon? Implicit in this argument is the corollary that unsuccessful pregnancy is a Th1-type situation. Here, evidence from murine and human pregnancy is presented to show that, since Th1-type cytokines mediate pregnancy loss, a shift towards Th1-type immunity may help resolve 'unexplained' pregnancy failure.

Prevalence and biological effects of anti-trophoblast and anti-endothelial cell antibodies in patients with recurrent spontaneous abortions

PROBLEM

Trophoblasts and endothelial cells represent a potential target for antibodies in women with recurrent spontaneous abortions. These antibodies have been shown to be associated with anti-phospholipid antibodies. Are they also present in women with unexplained pregnancy losses in the absence of anti-phospholipid antibodies?

METHOD OF STUDY

The anti-trophoblast antibodies were tested by an immunofluorescence assay on cells purified from pooled first-trimester placentae, whereas the anti-endothelial cell antibodies were measured by enzyme-linked immunoadsorbent assay (ELISA) on cells isolated from the umbilical vein and were cultured to confluence. The cytotoxicity of trophoblasts was evaluated in a homologous system. The expression of adhesion molecules on endothelial cells was quantitated by ELISA using specific monoclonal antibodies, and the expression of tissue factor was quantitated by a chromogenic assay measuring the formation of factor Xa.

RESULTS AND CONCLUSIONS

Complement-fixing antibodies to trophoblast represent a better marker to discriminate patients with recurrent spontaneous abortions from controls and are cytotoxic for the target cells. Anti-endothelial antibodies are also present in these patients and exhibit pro-inflammatory and pro-coagulant activities.

Human autoantibodies recognizing human and mouse preimplantation stages

PROBLEM

To find out whether autoantibodies against human preimplantation stages are present in some human sera and, if so, whether the antibodies could be capable to affect the egg development and/or to trigger an activation of the complement system at the procedures of assisted conception.

METHODS

1. Immunohistochemistry on blots of human preimplantation stages. 2. Immunohistochemistry on paraffin sections of human and mouse preimplantation stages. 3. Culture of mouse morulae to analyze complement activation.

RESULTS

1. Some human sera contained autoantibodies against human preimplantation stages. 2. Human-mouse cross-reacting antibodies against preimplantation stages occurred. 3. Immune complexes, formed on mouse preimplantation stages, activated the complement systems in egg cultures, resulting in a damaging of the eggs.

CONCLUSION

The presence of natural autoantibodies to preimplantation stages may be associated with reproduction failure, caused by a direct effect by the autoantibodies and/or an activation of the uterine complement system by the immune complexes formed.

Immune interferon gamma inhibits translational mobility of a plasma membrane protein in preimplantation stage mouse embryos: a T-helper 1 mechanism for immunologic reproductive failure

OBJECTIVE

Immune interferon gamma adversely affects mouse embryo development and has been proposed as a mediator of reproductive failure involving T-helper 1 immunity. We hypothesized that one mechanism by which interferon gamma could exert an adverse effect on embryos was by altering plasma membrane organization and transmembrane protein mobility.

STUDY DESIGN

The fluorescence photobleaching recovery technique was used to measure the effect of the T-helper 1 cytokine interferon gamma on the translational mobility of a specific embryonic surface glycoprotein recognized by the monoclonal antibody S75.

RESULTS

Compared with controls interferon gamma significantly decreased the fractional mobility of fluorescein isothiocyanate S75 in one- and two-cell mouse embryos.

CONCLUSION

Interferon gamma may alter plasma membrane domains or cytoskeletal organization in early-stage embryos. By restricting plasma membrane protein mobility interferon gamma could effect T-helper 1-mediated reproductive failure.

Reproduction and sera embryotoxicity after immunization of monkeys with the laminin peptides YIGSR, RGD, and IKVAV

Monkeys with excellent reproductive histories were immunized with the laminin peptides YIGSR, RGD, IKVAV, and YD, a control sequence with no known biological function. Sera from the YIGSR-immunized monkey became toxic, causing neural tube defects in whole rat embryo cultures, and this monkey experienced fetal loss after immunization. Sera from the RGD-immunized monkey also became embryotoxic in culture after immunization, but this monkey appeared to become infertile as she failed to initiate a pregnancy for at least 2 years after immunization. In contrast, embryos cultured on sera from the IKVAV- or YD-immunized monkeys were predominantly normal and both monkeys completed successful pregnancies. Antibody levels to the respective peptides or to laminin were not predictive of embryotoxicity, but antibody binding to homogenized yolk sacs as well as to yolk sacs of cultured embryos was associated with sera embryotoxicity and reproductive outcomes in vivo. These observations suggested that the laminin sequences YIGSR and RGD may play a role in immune-mediated reproductive failure by reacting directly with embryonic tissue and could provide a basis for identifying individuals at risk for both spontaneous abortion and infertility.