Cytokines in rodent reproduction and the cytokine-endocrine interaction

Recurrent urinary tract infections in women: How promising is the use of probiotics?

Urinary tract infections (UTIs) currently rank amongst the most prevalent bacterial infections, representing a major health hazard. UTIs in females usually start as vaginal infections and ascend to the urethra and bladder. Recurrent UTIs (rUTIs) can be defined as at least three episodes of UTI in 1 year or two episodes in 6 months. Various antibiotics have been the mainstay of therapy in ameliorating the incidence of UTIs, but recurrent infections continue to afflict many women. It necessitates the exploitation of alternative antimicrobial therapy. Probiotics have been shown to be effective in varied clinical trials for long-term preventions of rUTI. Because Escherichia coli is the primary pathogen involved in UTIs which spreads from the rectum to vagina and then ascends up the sterile urinary tract, improving the gut or vaginal flora will thus impact the urinary tract. Since a healthy vaginal microbiota is mainly dominated by Lactobacillus species, in this context, exogenously administered probiotics containing Lactobacilli play a pivotal role in reducing the risk of rUTI. The concept of artificially boosting the Lactobacilli numbers through probiotic administration has long been conceived but has been recently shown to be possible. Lactobacilli may especially be useful for women with a history of recurrent, complicated UTIs or on prolonged antibiotic use. Probiotics do not cause antibiotic resistance and may offer other health benefits due to vaginal re-colonisation with Lactobacilli. However, more comprehensive research is still needed, to recommend for probiotics as an alternative to antibiotics.

Expression and localization of interleukin 1 beta and interleukin 1 receptor (type I) in the bovine endometrium and embryo

The interleukin-1 (IL1) system likely mediates mammalian embryo-maternal communication. In cattle, we have reported that the uterine fluid of heifers carrying early embryos shows downregulated IL1 beta (IL1B), which could lead to reduced NFkB expression and dampening of maternal innate immune responses. In this work, we assessed the expression of IL 1 beta (IL1B) and its receptor, interleukin 1 receptor type I (IL1R1) in the bovine endometrium and embryos by RT-PCR, immunohistochemistry and Western blot at the time of blastocyst development. Day 8 endometrium, both collected from animals after transfer of day 5 embryos (ET) and sham transferred (ST), showed IL1B and IL1R1 mRNA transcription and protein co-localization. Similarly, day 8 blastocyst, from ET animals and entirely produced in vitro, showed IL1R1 mRNA transcription and IL1B and IL1R1 protein co-localization. IL1B mRNA was detected in the analyzed blastocysts, but at very low levels that precluded its quantification. IL1B and IL1R1 immunostaining was observed in luminal epithelial cells, glandular epithelium and stromal cells. The presence of embryos increased endometrial IL1B protein locally, while no differences regarding IL1R1 protein and IL1B and IL1R1 mRNA were detected. These results suggest that the early preimplantation bovine embryo in the maternal tract might interact with the maternal immune system through the IL1 system. Such a mechanism may allow the embryo to elicit local endometrial responses at early stages, which are required for the development of a receptive endometrium.

Seminal fluid and the generation of regulatory T cells for embryo implantation

T regulatory (Treg) cells are essential mediators of the maternal immune adaptation necessary for embryo implantation. In mice, insufficient Treg cell activity results in implantation failure, or constrains placental function and fetal growth. In women, Treg cell deficiency is linked with unexplained infertility, miscarriage, and pre-eclampsia. To devise strategies to improve Treg cell function, it is essential to define the origin of the Treg cells in gestational tissues, and the regulators that control their functional competence and recruitment. Male seminal fluid is a potent source of the Treg cell-inducing agents TGFβ and prostaglandin E, and coitus is one key factor involved in expanding the pool of inducible Treg cells that react with paternal alloantigens shared by conceptus tissues. In mice, coitus initiates a sequence of events whereby female dendritic cells cross-present seminal fluid antigens and activate T cells, which in turn circulate via the blood to be sequestered into the endometrium. Similar events may occur in the human genital tract, where seminal fluid induces immune cell changes that appear competent to prime Treg cells. Improved understanding of how seminal fluid influences Treg cells in women should ultimately assist in the development of new therapies for immune-mediated pathologies of pregnancy.

Probiotic therapy: immunomodulating approach toward urinary tract infection

Urinary tract infection (UTI) is an extremely common health problem, with an unpredictable history. Members of enterobacteriaceae family such as Escherichia coli, which are normal inhabitants of human intestines, account for the majority of these uncomplicated infections. Rarely, UTI can result from virus or fungus. There is a close correlation between loss of the normal genital microbiota, particularly Lactobacillus species, and an increased incidence of genital and bladder infections. Although antimicrobial agents are generally effective in eradicating these infections, there is a high incidence of recurrence. Use of Lactobacillus species to combat UTI is now giving modern concept of modern genitourinary vaccine with the facts that it not only maintains low pH of the genital area, produces hydrogen peroxide and hinders the growth of E. coli but also activates Toll-like receptor-2 (TLR2), which produces interleukin-10 (IL-10) and myeloid differentiation factor 88 (MyD88). E. coli activates TLR4, which is responsible for the activation of IL-12, extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK). This process downregulates inflammatory reactions caused due to pathogens. Current review covers the probiotics-based TLR therapy and shed some knowledge for the use of Lactobacillus species as probiotics.

Leukocytes: essential cells in ovarian function and ovulation

The disciplines of reproduction and immunology, once quite discrete, are now closely associated, with compelling evidence to suggest that immune mechanisms play important roles in the cervix, uterus, fallopian tubes and ovary. Cells and mediators classically described as part of the immune system are found throughout the reproductive tract. Disorders of reproduction, including pre-eclampsia, unexplained infertility, endometriosis, recurrent miscarriage and disturbed fetal growth almost certainly have some of their origins in the dysfunction of immune regulation. There appears to be some evidence that immune disorders, such as rheumatoid arthritis and scleroderma, can manifest as infertility, before clinical disease becomes apparent.

Expression of Toll-like receptors (TLR) and responsiveness to TLR agonists by polarized mouse uterine epithelial cells in culture

The objective of the present study was to examine the expression of Toll-like receptors (TLRs) by mouse uterine epithelial cells and to determine if stimulation of the expressed TLR induces changes in cytokine and/or chemokine secretion. Using RT-PCR, the expression of TLRs 1-6 by mouse uterine epithelial cells was demonstrated, with TLRs 7-9 expressed only periodically. In the absence of pathogen-associated molecular patterns, polarized uterine epithelial cells constitutively secrete interleukin (IL) 1A, cysteine-cysteine ligand (CCL) 2, IL6, granulocyte-macrophage colony-stimulating factor 2 (CSF2), tumor necrosis factor A (TNFA), CSF3, and IL8 in vitro, with levels of cytokines/chemokines secreted into the apical compartment being significantly greater than those released into the basolateral compartment. When added to the apical surface for 48 h before analysis, the TLR2-agonist Pam3Cys-Ser-(Lys)4 and TLR1/6-agonist peptidoglycan increased epithelial cell apical secretion of IL1A, CCL2, and IL6 and apical/basolateral bidirectional secretion of CSF2, TNFA, CSF3, and IL8 when compared to controls. The TLR3-agonist poly (I:C) significantly increased bidirectional secretion of CCL2, IL6, TNFA, and CSF2 and basolateral secretion of CSF3. Lastly, the TLR4-agonist lipopolysaccharide increased bidirectional secretion CCL2, CSF2, TNFA, CSF3, and IL8 and apical secretion of IL6. These results indicate that mRNAs for Tlr1 through Tlr6 are expressed by uterine epithelial cells and that treatment with specific TLR agonists alters the expression of key chemokines and proinflammatory cytokines that contribute to the defense of the uterus against potential pathogens.

Progesterone and the immunology of pregnancy

The foetal-placental unit is a semi-allograft and the immunological recognition of pregnancy, together with the subsequent response of the maternal immune system, is necessary for a successful pregnancy. This recognition of pregnancy results in an upregulation of progesterone receptors on activated lymphocytes amongst placental cells and decidual CD56+ cells. In the presence of sufficient progesterone, these cells synthesise progesterone induced blocking factor (PIBF), a mediator that exerts substantial anti-abortive activities. PIBF affects B cells and induces an increased production of asymmetric, non-cytotoxic antibodies. It also alters the profile of cytokine secretion by activated lymphocytes resulting in an increase in the production of non-inflammatory, non-cytotoxic interleukins (IL) (e.g. IL-3, IL-4 and IL-10) and a reduction in the production of inflammatory, cytotoxic cytokines (e.g. interferon (IFN)-delta, tumour necrosis factor (TNF)-alpha and IL-2). PIBF also inhibits the cytotoxicity of natural killer (NK) cells by blocking their degranulation and perforin release, as well as inhibiting IFN-delta, TNF-alpha and IL-2-mediated transformation of NK cells into detrimental lymphokine activated killer (LAK) cells.

Mifepristone (Ru486) antagonizes monocyte chemotactic protein-3 down-regulation at early mouse pregnancy revealing immunomodulatory events in Ru486 induced abortion

PROBLEM

The survival of an embryo bearing the paternal antigens within the immunocompetent environment of the maternal uterus renders 'pregnancy' to be a state of immunological paradox. The ratio of Th1/Th2 responses is crucial for pregnancy maintenance. Monocyte Chemotactic Protein-3 (MCP3) is a pro-inflammatory, CC chemokine and a Th1 effector which is capable of eliciting significant anti-tumoral immune responses.

METHOD OF STUDY

MCP3 expression was investigated in the murine uterine tissue at different days of initial pregnancy and the effect of RU 486 in immature and delayed implantation model studied using Western blotting and Immunocytochemical techniques.

RESULTS AND CONCLUSION

Our results show very high uterine MCP3 expression during pre-implantation followed by a significant MCP3 down-regulation at peri-implantation and low levels of MCP3 during post-implantation period. At the peri-implantation stage, embryos exhibited lowered MCP3 expression when compared with the pre-implantation stage. Ru486, a progesterone antagonist when given in a competitive mode with progesterone resulted in a massive surge in MCP3 expression in both immature mice and delayed implantation models. We hypothesize that it is imperative for MCP3 expression to be down-regulated for the success of pregnancy. The cross-talk between Ru486 and amplified MCP3 expression may be one of the mechanisms by way of which RU486 performs its abortificient and anti tumor role.

Immunoglobulins and cytokines level in follicular fluid in relation to etiology of infertility and their relevance to IVF outcome

OBJECTIVE

The aims of the present study were to (i) determine the presence and concentration of albumin fractions (alpha1, alpha2, beta, gamma), immunoglobulins (IgA, IgG, IgM) and cytokines [interleukin (IL)-6, IL-8, granulocyte-macrophage colony-stimulating factor (GM-CSF)] in periovulatory ovarian follicular fluid (FF) of in vitro fertilization (IVF) patients, (ii) examine the relationship between these parameters and the etiology of infertility as well as the IVF outcome and (iii) find out if these parameters in FF could be used as a predictive factor of IVF outcome.

DESIGN

The levels of albumin fractions, immunoglobulin and cytokines were measured from women who underwent IVF therapy for various indications and the results were compared between the patient groups and IVF outcome.

MATERIALS AND METHODS

Follicular fluid was obtained from 160 IVF patients. A total of 79 patients underwent controlled ovarian hyperstimulations (COH) either with follicle-stimulating hormone (FSH) or HMG. Whereas, the HMG was used for the second set of patients (n=81) - after down regulation with gondotropin-releasing hormone agonists (Gn-RHa) - the protein fractions were determined using electrophoresis separation. Immunoglobulins were measured using a commercial kits and the concentration of cytokines was determined by the highly sensitive enzyme-linked immunosorbent assay (ELISA) methods.

RESULTS

The stimulation regimens used have no effect on albumin (alpha1, alpha2, beta, gamma) and immunoglobulin (IgA, IgG, IgM) concentrations, as no significant difference was observed between the two groups. Besides, no specific relationship was found between the concentration of these investigated parameter in FF and etiology of infertility or fertilization, cleavage and pregnancy rate. Besides, there were no significant differences between the groups for any cytokine investigated. Moreover, there were no correlations between the concentration of IL-6, IL-8 and GM-CSF in FF and steroid hormone concentration in the blood at the day of oocytes retrieval or IVF outcome.

IN CONCLUSION

Total protein, albumin fraction, immunoglobulins and cytokines level in FF of patients undergoing COH for IVF therapy for various etiology of infertility could not be a useful parameter for predicting IVF outcome.

Follicular fluid concentrations of interleukin-12 and interleukin-8 in IVF cycles

OBJECTIVE

To investigate the role of interleukin-12 (IL-12) and IL-8 in the periovulatory follicular fluid during in vitro fertilization cycles.

DESIGN

A prospective study.

SETTING

Reproductive Medicine Unit, Liverpool Women's Hospital, United Kingdom.

PATIENT(S)

Women undergoing in vitro fertilization treatment.

INTERVENTION(S)

IL-8 and IL-12 concentrations in follicular fluid samples that had been collected during transvaginal oocyte retrieval were measured using an enzyme-linked immunosorbent assay (ELISA). Cytokine concentrations were correlated to fertilization rates and treatment outcome.

MAIN OUTCOME MEASURE(S)

Fertilization rates and ultrasonographic evidence of intrauterine pregnancy by 4 weeks after embryo transfer.

RESULT(S)

Failed fertilization in women with detectable IL-12 was significantly higher (45.5%) than in the IL-12 negative group (6.1%), P=.01. None of the women with detectable IL-12 achieved a pregnancy at the end of the treatment (P=.01). IL-8 was present in the follicular fluid of all women, and no difference in its concentrations was found between the pregnant and nonpregnant groups. No correlation was found between the follicular fluid concentrations of IL-8 and fertilization rates.

CONCLUSION(S)

The presence of IL-12 in the follicular fluid appears to be associated with a negative outcome in IVF treatment. Interleukin-8 appears to be an essential part of folliculogenesis, although its concentration is not associated with fertilization or implantation rates.

Regulation of fas ligand expression in breast cancer cells by estrogen: functional differences between estradiol and tamoxifen

During neoplastic growth and metastasis, the immune system responds to the tumor by developing both cellular and humoral immune responses. In spite of this active response, tumor cells escape immune surveillance. We previously showed that FasL expression by breast tumor plays a central role in the induction of apoptosis of infiltrating Fas-immune cells providing the mechanism for tumor immune privilege. In the present study, we showed that FasL in breast tissue is functionally active, and estrogen and tamoxifen regulate its expression. We identified an estrogen recognizing element like-motif in the promoter region of the FasL gene, suggesting direct estrogen effects on FasL expression. This was confirmed by an increase in FasL expression in both RNA and protein levels in hormone sensitive breast cancer cells treated with estradiol. This effect is receptor mediated since tamoxifen blocked the estrogenic effect. Interestingly, tamoxifen also inhibited FasL expression in estrogen-depleted conditions. Moreover, an increase in FasL in breast cancer cells induces apoptosis in Fas bearing T cells and, tamoxifen blocks the induction of apoptosis. These studies provide evidence that tamoxifen inhibits FasL expression, allowing the killing of cancer cells by activated lymphocytes. This partially explains the protective effect of tamoxifen against breast cancer.

Mitogen-induced cytokine responses of maternal peripheral blood lymphocytes indicate a differential Th-type bias in normal pregnancy and pregnancy failure

PROBLEM

Profiles of Th1- and Th2-type cytokines were studied in women with a history of successful pregnancy and in women with a history of unexplained recurrent spontaneous abortions (RSA) with the objective of elucidating Th1- and Th2-type bias in normal pregnancy and pregnancy failure.

METHOD OF STUDY

Peripheral blood mononuclear cells (PBMCs) from 54 women with a history of normal pregnancy and 23 women with a history of unexplained RSA, obtained at delivery or on the day of abortion, respectively, were stimulated with phytohemagglutinin (PHA), followed by the estimation of four Th2 cytokines and four Th1 cytokines.

RESULTS

Significantly greater levels of Th2 cytokines were produced by the normal group than by the RSA group. On the other hand, significantly higher levels of Th1 cytokines were produced by the RSA group than by the normal pregnancy group.

CONCLUSIONS

These data support the concept that unexplained recurrent spontaneous abortion is associated with an increase in Th1-type reactivity, while Th2 dominance is a feature of successful pregnancy.

The expression of granulocyte macrophage-colony stimulating factor (GM-CSF) and receptors in human endometrium

PROBLEM

To determine the temporal and spatial expression of granulocyte macrophage-colony stimulating factor (GM-CSF) and GM-CSF alpha and beta receptor mRNA and protein in human endometrium.

METHOD OF STUDY

The endometrial expression of GM-CSF and GM-CSF receptor mRNA and protein was determined using competitive quantitative reverse transcription polymerase chain reaction (Q-RT-PCR), in situ hybridization, and immunohistochemistry.

RESULTS

Endometrium expresses GM-CSF and GM-CSF alpha receptor mRNA with maximal expression occurring during the mid-secretory phase (21.1 +/- 4.2 and 32.2 +/- 7.7 x 10(6) mRNA copies/microg total RNA) compared to the proliferative phase (1.46 +/- 0.4 and 7.5 +/- 0.5 x 10(6) copies) of the menstrual cycle, with a significant reduction (0.67 +/- 0.1 and 1.7 +/- 0.2 x 10(6) mRNA copies) during the post-menopausal period (P < 0.05). The endometrium expresses a significantly lower level of GM-CSF beta receptor mRNA (approximately 0.01 x 10(5) mRNA copies). Endometrial luminal and glandular epithelial cells are the primary site of GM-CSF mRNA and protein expression, while arteriole endothelial, stromal, and inflammatory cells are the primary site of GM-CSF alpha receptor protein. GM-CSF beta receptor protein has a similar cellular distribution as GM-CSF.

CONCLUSION

Temporal and spatial expression of GM-CSF and GM-CSF receptors in human endometrium during the menstrual cycle suggests that epithelial-derived GM-CSF in an autocrine/paracrine manner may influence various endometrial biological activities, local inflammatory response, and macrophage survival.

Maternal Th1- and Th2-type reactivity to placental antigens in normal human pregnancy and unexplained recurrent spontaneous abortions

Spontaneous abortion is the most common complication of pregnancy, but the etiology of a significant proportion of abortions is still unknown. We have examined the production of Th1- and Th2-type cytokines by women with unexplained recurrent spontaneous abortion (RSA) since it appears that successful murine pregnancy occurs in a Th2-dominant situation and that Th1-type immunity is associated with pregnancy failure. We have compared maternal reactivity toward placental antigens in women with a history of successful pregnancy with that in women with a history of RSA. This was done by coculturing maternal peripheral blood mononuclear cells (PBMC) with autologous placental cells and also by stimulating maternal PBMC with antigens from a choriocarcinoma cell line of trophoblastic origin. We detected significantly greater levels of the Th2 cytokines IL-6 and IL-10 in normal pregnancy compared to unexplained RSA and significantly higher levels of the Th1 cytokine IFN-gamma in RSA compared to normal pregnancy. These results suggest that women with normal pregnancy have a higher Th2 bias, while women with a history of RSA evince a bias toward Th1-type reactivity.

Variations in peripheral blood levels of immunoreactive tumor necrosis factor alpha (TNFalpha) throughout the menstrual cycle and secretion of TNFalpha from the human corpus luteum

OBJECTIVE

Several cytokines have been implicated as important mediators in the cyclic processes occurring in the reproductive organs. In the present study the peripheral blood concentrations of the cytokines interleukin(IL)-2, IL-6, and tumor necrosis factor (TNF) alpha, as well as the secretion of TNFalpha from the human corpus luteum were investigated.

STUDY DESIGN

The study was undertaken at infertility clinics at large teaching hospitals. Eight women with unexplained infertility undergoing investigations with measurements of endocrine profiles throughout a cycle prior to IVF treatment were included in the study of blood concentrations of cytokines. Blood plasma were taken daily or every second day from a time 3-4 days before expected LH peak until menstruation. The levels of immunoreactive IL-2, IL-6 and TNFalpha were measured by ELISA technique and evaluated (repeated measures ANOVA and Scheffes test) in relation to levels on the day of the LH surge. To investigate a possible ovarian source of TNFalpha, corpus luteum (CL) tissue and cells obtained during the luteal phase from another group of women during abdominal surgery for benign uterine diseases, were cultured for 24 h to assess (ANOVA and Bonferroni test) the release of TNFalpha.

RESULTS

There were no significant fluctuations in the levels of IL-2 and IL-6 throughout the menstrual cycle. The concentration of TNFalpha showed significant fluctuations over the menstrual cycle. Compared to the values on the day of the LH surge, the concentrations were significantly increased during the late follicular phase and during the mid luteal phase. In the early luteal phase the levels were significantly decreased. Measurable levels of TNFalpha were found in the conditioned media from one out of three CL obtained from the early luteal phase, and in all media from CL obtained from mid- and late-luteal phases. Luteal cells in culture secreted TNFalpha, and the levels in the media were not influenced by the presence of hCG (100 IU/L). The conditioned media of luteal cells from late luteal phase contained higher levels than media of cells from early luteal phase, with the levels being higher in media of a mixture of all luteal cells, and large luteal cells as compared to small luteal cells.

CONCLUSION

This study demonstrates that there are marked fluctuations of blood levels of TNFalpha during the menstrual cycle and that the human CL secretes TNFalpha, with indications of higher secretion during late luteal phase as compared to early luteal phase.

Cytokine-leukocyte networks and the establishment of pregnancy

PROBLEM

Factors in seminal plasma stimulate an intense but transient inflammatory response in the murine endometrium at mating. The aim of our current studies is to delineate the cytokine-leukocyte interactions comprising this response and to elucidate the significance of these events in changes in the maternal immune system and as determinants of pregnancy outcome.

METHOD

We have reviewed our recent findings.

RESULTS

Transforming growth factor (TGF)-beta1 has been identified as the inflammation-inducing moiety in seminal plasma. Seminal TGFbeta1 initiates endometrial leukocyte infiltration by up-regulating epithelial cell expression of granulocyte-macrophage colony-stimulating factor. Other cytokines and chemokines including regulated and normal T-cell expressed and secreted (RANTES), macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, and monocyte chemotactic protein-1 are also implicated as mediators of macrophage and granulocyte recruitment and activation. One consequence of this inflammatory response is the induction of a transient state of hyporesponsiveness to paternal major histocompatibility class I antigens.

CONCLUSION

Our studies suggest that semen may play a critical role in providing the antigenic and environmental signals necessary to initiate an appropriate maternal immune response to the conceptus during pregnancy.

Reduction of ovulation rate in the rat by administration of a neutrophil-depleting monoclonal antibody

To investigate the effect of systemic neutrophil depletion on ovulation rate, rats were synchronised with eCG and hCG, and concurrently were administered neutrophil-specific, cytotoxic RP-3 monoclonal antibody (mAb), or an irrelevant, class-matched mAb. Neutrophils in the peripheral blood and in the thecal-luteal area of corpora lutea were detected by immunohistochemical analysis with the neutrophil-specific mAb MCA149 and were found to be reduced in number by 70% and 38% respectively following RP-3 treatment compared to the control group. Ovulation rate, as assessed by counting the number of oocytes in the ampullary region of the oviduct 20 h after hCG administration, was found to be reduced by 27% in the neutrophil-depleted rats. This result provides further evidence that neutrophilic granulocytes play an active role in ovulation in the rat.

Effect of substance P on uterine mast cell cytokine release during the reproductive cycle

There is increasing evidence that neuropeptides, steroid hormones and inflammatory cytokines influence the immune response during the reproductive cycle. In the present study, we focus on the effects of neuropeptide Substance P (SP) during the pre-implantation stage of embryo development (day 4 of pregnancy), at pro-estrus and di-estrus (two phases with different hormonal states). We found heterogeneous responses to SP and anti-IgE by the rat uterine mast cells (MCs), as detected by ELISA. In fact, MCs purified from uteri on day 4 of pregnancy released histamine, granulocyte macrophage-colony stimulating factor (GM-CSF) and tumor necrosis factor-alpha (TNF-alpha) in response to anti-IgE, but not to SP. When pre-incubated with SP, the release to anti-IgE was significantly enhanced compared to anti-IgE alone. Exposure of SP to antibodies to SP, prior to pre-incubation with MCs, negated the SP effect on IgE-mediated release. At the pro-estrus phase SP showed similar behavior as on day 4 of pregnancy, whereas at the di-estrus phase SP alone was capable of inducing release of histamine and cytokines from purified uterine MCs. Moreover, non-quantitative RT-PCR analysis of the TNF-alpha mRNA level suggested an SP stimulation at the di-estrus phase, but neither on day 4 of pregnancy nor at the pro-estrus phase. Taken together, these data strongly suggest that SP can modulate IgE-mediated uterine MC release of histamine and inflammatory cytokines in different ways, depending on the phase of the reproductive cycle.

Cellular immune responses in the pig uterus during pregnancy

In pigs, little is known about the role of the uterine immune system during pregnancy. Immunohistochemical studies were conducted using a panel of monoclonal antibodies to pig leukocytes on uterine tissues taken from gilts after fertile mating and at different stages of pregnancy. Acute inflammation in the endometrium in response to fertile mating which included marked changes in the tissue and immune cell components of the endometrium was observed. Throughout pregnancy the pig uterus contained a substantial population of leukocytes. MHC class II staining was prominent in the endometrium at all stages examined and included macrophages, dendritic and fibroblast-like cells, lymphocytes and the endothelial lining of many uterine blood vessels. The majority of lymphoid cells were CD2+, indicating the prevalence of T cells. In early pregnancy specific changes were seen in the tissue distribution of uterine immune cells. Following placentation distinct cellular changes in the local immune cell environment of the uterus were also observed despite the non-invasive nature of the pig placenta. There appears to be suppression and activation of various immune cell components in the uteri of pregnant pigs. This phenomenon is presumably in response to foetal or trophoblast antigens, suggesting that the local immune system is involved in the uterine response to pregnancy.

Functional and biochemical properties of a mouse placental immunoregulatory factor

The authors have a long standing interest in immune regulations which control the absence of rejection of a semi-allogeneic fetus by the mother. A previous work described a soluble 40 kDa factor extracted from mouse placenta and capable of inhibiting secondary immune responses in vitro. The present paper reports the following on its mode of action in vivo: (1) it is active even in a fully allogeneic host; (2) it can be administered i.v. or i.p. along with antigen; and (3) the injections of factor and antigen must not be more than 2 days apart for maximum efficacy. Moreover, the results of the study described here indicate also that this factor is a concanavalin A-binding glycoprotein, sensitive to heat and pronase, and different from interleukin 10 (IL-10). Thus, this placental factor appears to be different from previously described immune regulators such as IL-10 and could contribute significantly to immune regulations at the level of the placenta.

Constitutive expression of TNF-alpha and -beta genes in mouse embryo: roles of cytokines as regulator and effector on development

1. Using the RT/PCR method, we examined mRNA expression of several inflammatory factors in mouse embryos during mid-late embryonal development. mRNAs of tumor necrosis factor (TNF)-alpha, TNF-beta, their receptors (TNF-RI, TNF-RII), transforming growth factor (TGF)-beta, were expressed constitutively in most of the embryonic tissues. 2. While mRNAs of other factors, interleukin (IL)-1 alpha, IL-1 beta, IL-3, IL-6, granurocyte-colony stimulating factor (G-CSF), leukaemia inhibitory factor (LIF), and interferon (IFN)-gamma were only limitedly expressed. 3. The mRNAs of several complement components (C2, C3, C4, C5) and receptors (CR1, CR2) were also detected. Among them, the expression of C3 and CR1 were prominent. These results strongly support our idea that inflammation-like system play an important role to regulate embryogenesis.

Identification of transforming growth factor-beta 1 mRNA in virgin and pregnant rat uteri by in situ hybridization

Transforming growth factor-beta 1 (TGF-beta 1) has major effects on hematopoietic cell proliferation, migration and function. In an effort to learn whether or not TGF-beta 1 might be among the cytokines that influence uterine, placental and embryonic hematopoietic cells, in situ hybridization was used to map expression of the TGF-beta 1 gene through gestation in the rat. In cycling uteri, hybridization signals with a biotinylated TGF-beta 1 antisense RNA probe were comparatively weak and were restricted to myometrium. During pregnancy, TGF-beta 1 mRNA appeared in specific cell lineages in an ordered temporal sequence. In early post-implantation tissues (g.d. 5-8), TGF-beta 1 transcripts were prominent in uterine epithelial cells, muscle and decidual cells. At g.d. 15, hybridization signals were particularly strong in uterine epithelial cells, muscle and placental trophoblast cells. At this stage, TGF-beta 1 mRNA was also present in uterine cells resembling macrophages and in natural killer-like (GMG) cells. Steady state levels of specific message in uteri and placentas declined at late stages of gestation (g.d. 18, 21). In rat embryos, specific transcripts were identified at g.d. 9 and were prominently displayed in various types of embryonic cells from mid-gestation onwards. The results of this study are consistent with the postulate that throughout pregnancy in the rat, TGF-beta 1 may, in addition to its other functions, influence the proportions, patterns of distribution and activities of maternal and fetal hematopoietic cells.

Cells adherent to IUDs produce tumor necrosis factor alpha

The nature of adherent cells obtained from the surface of intrauterine contraceptive devices (IUD) was investigated by immunofluorescence using antibodies directed against tumor necrosis factor alpha (TNF), leukocyte differentiation antigens, immunoglobulin isotypes and J chain. Macrophages/monocytes, lymphocytes and neutrophils were found in all fifty samples. Macrophages were characterized by CD14, CD15 and CD71 positivity, DAKO macrophage antibody and HLA-DR, CD11c and CD45 expression. B cells contained secretory IgA with J chain or IgG and some cells expressed surface IgM. Neither IgD nor IgE were found. T-antigens CD3, CD4 and CD5 were not detected, the CD8 was faintly expressed. The CD56 molecule identifying NK cells was found on small lymphocytes. Cytoplasmic C3 protein was detected in neutrophils. Tumor necrosis factor alpha (TNF) was visualized in 14.3 +/- 8.8% of nucleated IUD cells. This cytokine was localized in the cytoplasm of the macrophages and the lymphocytes.