The interleukin 2 gene is expressed in the syncytiotrophoblast of the human placenta

Different Lengths of Gestational Exposure to Secondhand Smoke or e-Cigarette Vapor Induce the Development of Placental Disease Symptoms

Exposure to cigarette smoke is known to induce disease during pregnancy. Recent evidence showed that exposure to secondhand smoke (SHS) negatively impacts fetal and placental weights, leading to the development of intrauterine growth restriction (IUGR). Electronic cigarettes (eCigs) represent a phenomenon that has recently emerged, and their use is also steadily rising. Even so, the effects of SHS or eCigs during gestation remain limited. In the present study, we wanted to characterize the effects of SHS or eCig exposure at two different important gestational points during mouse pregnancy. C57/Bl6 mice were exposed to SHS or eCigs via a nose-only delivery system for 4 days (from 14.5 to 17.5 gestational days (dGA) or for 6 days (from 12.5 dGA to 17.5 dGA)). At the time of necropsy (18.5 dGA), placental and fetal weights were recorded, maternal blood pressure was determined, and a dipstick test to measure proteinuria was performed. Placental tissues were collected, and inflammatory molecules in the placenta were identified. Treatment with SHS showed the following: (1) a significant decrease in placental and fetal weights following four days of exposure, (2) higher systolic and diastolic blood pressure following six days of exposure, and (3) increased proteinuria after six days of exposure. Treatment with eCigs showed the following: (1) a significant decrease in placental weight and fetal weight following four or six days of exposure, (2) higher systolic and diastolic blood pressure following six days of exposure, and (3) increased proteinuria after six days of exposure. We also observed different inflammatory markers associated with the development of IUGR or PE. We conclude that the detrimental effects of SHS or eCig treatment coincide with the length of maternal exposure. These results could be beneficial in understanding the long-term effects of SHS or eCig exposure in the development of placental diseases.

Human placental extract ameliorates cytokine and cytokine receptor signaling in the rat hippocampus upon Benzo[a]Pyrene exposure

Benzo[alpha]Pyrene (B[a]P) causes toxicity via Cytochrome P450 1A1 (CYP1A1) metabolic activity in the brain. Studies have shown that neuronal IL-2 and TNF-α are associated with the hippocampus development and regulation, but their association with the CYP1A1 activity remains unidentified. Limited action of human placental extract (HPE) in the activation of tissue repair and wound healing is known, but their role in B[a]P clearance in the hippocampus is not known so far. Our study has focused on two novel concepts: (1) association of CYP1A1 activity with the inflammatory response in the brain hippocampus and (2) role of HPE in the immunomodulatory mechanisms in the hippocampus upon B[a]P exposure at cytokine receptor and nuclear level. Intrathecal administration of different concentrations of B[a]P and HPE into male wistar rat pups has been conducted. An increased CYP1A1 activity was observed in the presence of 0.25 μM B[a]P alone but in case of HPE followed by 0.25 μM B[a]P, it was equal to control. Herein we report that 5 μl of 0.1 gm HPE followed by 0.25 μM B[a]P administration enabled down-regulation of IL-2 and TNF-α levels in the hippocampus thereby modulating TNFR2 and IL2Rγ_c signals via NF-κB activation. Besides, localization of IL-2, TNF-α, IL2Rγ_c, TNFR1 and TNFR2 in the CA1, CA3 and DG regions of the hippocampus are also depicted. Altogether, these findings will project the clinical importance of HPE in the neuroinflammation suppression in the hippocampus developed due to B[a]P toxicity.

The role of interleukins in preeclampsia: A comprehensive review

Preeclampsia is a multi-system hypertensive disorder of pregnancy, with significant rates of maternal and neonatal morbidity. It represents a major cause of preterm birth, as definitive treatment demands fetal delivery. Although its pathophysiology is complicated, placental hypoxia and endothelial dysfunction constitute established pathogenetic steps of the disease. Inflammation is considered to be a crucial mediator of preeclampsia process, as an imbalance between T_H 1, T_H 2, and T_H 17 immune responses is observed. The present review accumulates current knowledge about the contribution of interleukins in preeclampsia, summarizing the pathways through which each interleukin exerts its function in the disease. Also, the role of genetic polymorphisms is explored and the predictive efficacy of maternal serum interleukin levels is evaluated. Finally, recommendations about the safe interpretation of the outcomes, as well as guidance for future research, are provided.

Altered cytokine network in gestational diabetes mellitus affects maternal insulin and placental-fetal development

Pregnancy is characterized by an altered inflammatory profile, compared to the non-pregnant state with an adequate balance between pro-and anti-inflammatory cytokines needed for normal development. Cytokines are small secreted proteins expressed mainly in immunocompetent cells in the reproductive system. From early developmental stages onward, the secretory activity of placenta cells clearly contributes to increase local as well as systemic levels of cytokines. The placental production of cytokines may affect mother and fetus independently. In turn because of this unique position at the maternal fetal interface, the placenta is also exposed to the regulatory influence of cytokines from maternal and fetal circulations, and hence, may be affected by changes in any of these. Gestational diabetes mellitus (GDM) is associated with an overall alteration of the cytokine network. This review discusses the changes that occur in cytokines post GDM and their negative effects on maternal insulin and placental-fetal development.

Placenta-specific expression of the interleukin-2 (IL-2) receptor β subunit from an endogenous retroviral promoter

The long terminal repeat (LTR) sequences of endogenous retroviruses and retroelements contain promoter elements and are known to form chimeric transcripts with nearby cellular genes. Here we show that an LTR of the THE1D retroelement family has been domesticated as an alternative promoter of human IL2RB, the gene encoding the β subunit of the IL-2 receptor. The LTR promoter confers expression specifically in the placental trophoblast as opposed to its native transcription in the hematopoietic system. Rather than sequence-specific determinants, DNA methylation was found to regulate transcription initiation and splicing efficiency in a tissue-specific manner. Furthermore, we detected the cytoplasmic signaling domain of the IL-2Rβ protein in the placenta, suggesting that IL-2Rβ undergoes preferential proteolytic cleavage in this tissue. These findings implicate novel functions for this cytokine receptor subunit in the villous trophoblast and reveal an intriguing example of ancient LTR exaptation to drive tissue-specific gene expression.

Peptides and proteins in the human endometrium

Human endometrium is composed of three layers: stratum compactum, stratum spongiosum and stratum basale. Stratum compactum is the superficial layer made up of openings of the uterine glands and some stromal cells. Stratum spongiosum is the middle layer containing mainly dilated glands and little stroma. Stratum basale is the deepest layer adjoining the muscularis. It consists of primordial glands and compact stroma. Stratum compactum and stratum spongiosum form stratum functionale which is subject to cyclic changes and is removed during menstruation.

Colony stimulating factor-1 (CSF-1) in pregnancy

Uterine growth factors appear to play a role in the regulation of pregnancy. One of these, colony stimulating factor-1 (CSF-1), synthesized by the uterine epithelium under the control of female sex steroids, has been shown to have important functions both before implantation and during the formation of the placenta. In the female reproductive tract the CSF-1 receptor, the product of the c-fms proto-oncogene, is expressed in decidual cells, trophoblasts and macrophages, indicating that these cells are the primary targets for CSF-1. This article reviews the biology of CSF-1 during gestation as well as the possible involvement of CSF-1 and its receptor in the aetiology of gynaecological tumours.

Excessive ovarian response is associated with increased expression of interleukin-2 in the periimplantation endometrium

OBJECTIVE

To evaluate and compare in vivo expression of T helper type 1 (Th1) cytokines in the peri-implantation endometrium of infertile patients between natural and stimulated cycles.

DESIGN

An observational study.

SETTING

A tertiary assisted reproduction center.

PATIENT(S)

Infertile patients.

INTERVENTION(S)

Uterine flushings and endometrial biopsies were collected 7 days after LH surge in natural cycles or after hCG injection in stimulated cycles.

MAIN OUTCOME MEASURE(S)

T helper type 1 cytokines were determined by immunolocalization and by ELISA.

RESULT(S)

Natural cycles were classified as group A (n = 17), whereas stimulated cycles with peak serum E(2) of <or=20,000 pmol/L (moderate responders) and with peak serum E(2) of >20,000 pmol/L (excessive responders) were classified as group B (n = 32) and group C (n = 32), respectively. Higher serum E(2) concentration was associated with increased expressions of interleukin (IL)-2 in the endometrium and uterine flushing. Group C demonstrated a statistically significantly higher IL-2 expression in endometrial biopsies by glandular and stromal immunostaining and by ELISA, compared with group A and group B. There was no difference in IL-2 concentration between group A and group B. Interferon-gamma protein concentration was comparable for the three groups.

CONCLUSION(S)

Increased expression of IL-2 in the peri-implantation endometrium may account for the lower implantation rate in excessive responders.

Inhibition of term decidual NK cell cytotoxicity by soluble HLA-G1

OBJECTIVES

Soluble (s)HLA-G1 is produced by trophoblast cells. Aim was to analyze the capacities and mechanisms of sHLA-G1 to regulate interleukin (IL)-2-induced cytotoxicity of natural killer (NK) cells from human deciduas.

METHODS

Natural killer cells were isolated from decidual layers of term placentae, stimulated or not with IL-2 and supplemented with various concentrations of recombinant soluble HLA-G1 (sHLA-G1). For NK cell cytotoxicity assays, K562 cells were used as targets. Expression of signal transducer and activator of transcription 3 (STAT3) and perforin was analyzed by Western blotting. Apoptosis was examined by assessment of poly(ADP-ribose) polymerase cleavage. NK cells were analyzed by flow cytometry for IL-2receptor-alpha (IL-2R alpha; CD25) and transferrin receptor CD71 expression.

RESULTS

Interleukin-2 increases CD71, STAT3, perforin expression and cytotoxic potential of NK cells. Expression of CD71, STAT3 and perforin decreased simultaneously with cytotoxicity and dose-dependently when sHLA-G1 (1.6 micro g/mL-1.6 ng/mL) was added to IL-2 stimulated cultures. sHLA-G1 did not induce apoptosis and CD25 expression was not affected.

CONCLUSION

Interleukin-2R alpha expression is not controlled by sHLA-G1, but its signal transducer STAT3 as well as several downstream effects, such as perforin expression, proliferation and cytotoxicity. The control of STAT3 bioavailability through sHLA-G1 may be a key regulator of the mentioned effects.

Placental imbalance of Th1- and Th2-type cytokines in preeclampsia

OBJECTIVES

To characterize the changes in the level of T helper 1 (Th1)- [interleukin (IL)-2 and tumor necrosis factor (TNF)-alpha] and Th2-type cytokine (IL-10) and the ratios of Th1/Th2 (IL-2/IL-10 and TNF-alpha/IL-10) in placentae from women with preeclampsia and women with gestational hypertension.

METHODS

Placental levels of IL-2, TNF-alpha, and IL-10 were determined with radioimmunoassay and Th1/Th2 ratios (IL-2/IL-10 and TNF-alpha/IL-10) calculated in the placentae from 22 women with preeclampsia, 15 women with gestational hypertension, and 32 normal term pregnant women.

RESULTS

Although preeclampsia had the trend of the increase in the placental levels of IL-2 and TNF-alpha and the trend of the decrease in placental IL-10, there were not significant difference in placental levels of IL-2, IL-10, and TNF-alpha among preeclampsia, gestational hypertension, and normal pregnancy (P > 0.05 for all). Placental ratios of IL-2/IL-10 and TNF-alpha/IL-10 were significantly higher in preeclampsia than in normal pregnancy (P = 0.035 and P = 0.005, respectively). No differences of Th1/Th2 ratios were found between preeclampsia and gestational hypertension and between gestational hypertension and normal pregnancy (P > 0.05 for all).

CONCLUSIONS

Alterations of placental balances of cytokines with Th1 predominance were demonstrated in preeclampsia. These associations may offer insights into the pathogenesis of preeclampsia.

Synergistic effect of interleukin (IL)-1α and ceramide analogue on the production of IL-6, IL-8, and macrophage colony-stimulating factor by endometrial stromal cells

OBJECTIVE

To measure the level of interleukin 6 (IL-6), IL-8, and macrophage colony-stimulating factor (M-CSF) induced by IL-1alpha in endometrial stromal cells (ESC) following treatment with ceramide analogues.

DESIGN

The effects of IL-1alpha, IL-1 receptor antagonist (IL-1RA), C2-ceramide, and C6-ceramide on the production of IL-6, IL-8, and M-CSF by ESC.

SETTING

Research laboratory at Oita University Medical School.

PATIENT(S)

Eleven premenopausal women who had undergone hysterectomies for subserous myoma provided endometrial specimens in the secretory phase.

INTERVENTION(S)

The ESC were incubated for 24 hours with IL-1alpha, IL-1RA, C2-ceramide, and C6-ceramide.

MAIN OUTCOME MEASURE(S)

The levels of IL-6, IL-8, and M-CSF in the culture media were measured via enzyme-linked immunoabsorbent assay.

RESULT(S)

: Following stimulation by IL-1alpha, the production of IL-6, IL-8, and M-CSF showed a statistically significant increase, and they were suppressed by IL-1RA in a dose-dependent manner. Production of IL-6, IL-8, and M-CSF was not statistically significantly increased by IL-1alpha plus C2-ceramide as compared with IL-1alpha alone. Production of both IL-8 and M-CSF was statistically significantly increased by IL-1alpha plus C6-ceramide as compared with IL-1alpha alone; however, IL-6 production was not increased.

CONCLUSION(S)

The results suggest that IL-1alpha stimulates the production of IL-8 and M-CSF by a mechanism that involves the sphingomyelin-ceramide system. Ceramide may be important in increasing the production of IL-8 and M-CSF in the human endometrium.

Role of placental cytokines in transcriptional modulation of HIV type 1 in the isolated villous trophoblast

During pregnancy, a complex cytokine network is present at the maternal-fetal interface in order to support normal growth and development of the placenta and fetus. HIV can frequently infect placental trophoblast but the impact of cytokines produced locally by the placenta and decidua on virus expression and replication is unknown. We comprehensively assayed the cytokines typically present in the placental microenvironment for their potential to modulate HIV transcriptional activation in the isolated trophoblast cells employing a transient transfection assay with luciferase as a reporter gene. Long terminal repeats (LTRs) of two divergent virus strains, HIV-1 LAI and HIV-1 NDK, were used to analyze virus-specific features. Four cytokines, epidermal growth factor (EGF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin 1 beta (IL-1 beta), and tumor necrosis factor alpha (TNF-alpha), were found to stimulate promoters of both viruses, whereas interferon alpha (IFN-alpha) and IFN-beta were found to suppress the transcription driven from both promoters. The differences observed between the two viruses did not reach a statistically significant level. None of the remaining cytokines, including EGF; GM-CSF; insulin-like growth factor I (IGF-I); IFN-alpha, IFN-beta, and IFN-gamma; IL-1 alpha, IL-1 beta, IL-2, IL-6, and IL-10; leukemia inhibitory factor (LIF); macrophage colony-stimulating factor (M-CSF); platelet-derived growth factor BB (PDGF-BB); transforming growth factor beta (TGF-beta); and TNF-alpha, affected transcriptional expression of the promoter constructs. Our results demonstrate that the local balance of cytokines may be critical for activation of HIV in the syncytiotrophoblast-cytotrophoblast layer and thus play an important role in the transmission of virus across the placental barrier.

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.

Maternal tolerance is not critically dependent on interleukin-4

Pregnant animals can generate and maintain immune responses to fetal antigens. This however, does not usually lead to fetal loss. At least two types of immune response are recognized. T helper type 1 (Th1) responses support the generation of cellular cytotoxicity. In contrast, Th2-type responses support the production of non-cytotoxic antibody and suppress the Th1-type. One attempt to explain why the fetus is not generally rejected has been to suggest that during pregnancy Th2-type responses are dominant. These responses rely heavily on interleukin-4 (IL-4) for both functions. This work focuses on maternal immunity to the male antigen H-Y, which is expressed in male fetuses. When injected with male spleen cells, female mice of certain strains mount a cytotoxic immune response to H-Y. However, pregnant females immunized in this way do not deliver litters with fewer males. To help delineate the possible role of IL-4 in such maternal tolerance, female mice genetically deficient in IL-4 were studied. The results show that: (1) deficiency in maternal IL-4 does not affect fertility, (2) deficiency in IL-4 is not associated with selective loss of male offspring in unimmunized mice, (3) pregnancy does not obliterate anti-H-Y reactivity in immunized mice and (4) maternal immunity to H-Y in the absence of IL-4 does not result in loss of male offspring. The results suggest that IL-4-dependent Th2-type responses are not critical to maternal tolerance. Other cytokines must be examined for their role in this phenomenon.

Placental cellular immune response in women infected with human parvovirus B19 during pregnancy

Human parvovirus B19 can cause congenital infection with variable morbidity and mortality in the fetus and neonate. Although much information exists on the B19-specific antibody response in pregnant women, little information is available describing the cell-mediated immune (CMI) response at the maternal-fetal interface. The focus of this study was to characterize the CMI response within placentas from women who seroconverted to B19 during their pregnancies and compare it to controls. Immunohistochemical techniques were used to identify the various immune cells and the inflammatory cytokine present within placental tissue sections. Group 1 consisted of placentas from 25 women whose pregnancies were complicated by B19 infection; 6 women with good outcome (near-term or term delivery), and 19 with poor outcome (spontaneous abortion, nonimmune hydrops fetalis, or fetal death). Group 2 consisted of placentas from 20 women whose pregnancies were complicated with nonimmune hydrops fetalis of known, noninfectious etiology. Group 3 consisted of placentas from eight women whose pregnancies ended in either term delivery or elective abortion. The results of the study revealed a statistically significant increase in the number of CD3-positive T cells present within placentas from group 1 compared to group 2 or 3 (13.3 versus 2 and 1, respectively) (P < 0.001). In addition, the inflammatory cytokine interleukin 2 was detected in every placenta within group 1 but was absent from all placentas evaluated from groups 2 and 3. Together, these findings demonstrate evidence for an inflammation-mediated cellular immune response within placentas from women whose pregnancies are complicated with B19 infection.

Prenatal origins of allergic disease

The prevalence of asthma and related allergic disorders has increased considerably over the last 25 years. Because genetic stock has not changed, environmental factors must have influenced the phenotype. Infants who experience the development of allergy already have an altered immune response at birth. We have investigated the development of immune responses during gestation and the effect of maternal allergen exposure during pregnancy and infant exposure in the first month of life on the development of allergy and disease. There was higher specific peripheral blood mononuclear cell proliferation to house dust mite and birch pollen in the third trimester compared with the second trimester, with the first positive responses seen at 22 weeks gestation. Maternal exposure to birch pollen after 22 weeks resulted in higher infant peripheral blood mononuclear cell responses to birch pollen at birth. Infants born at term, with at least 1 atopic parent with asthma, who experienced the development of allergic symptoms and positive skin prick test by 1 year of age had raised proliferative responses to house dust mite at birth compared with those infants with no symptoms. In genetically predisposed individuals, antenatal factors including maternal and thereby fetal exposure to allergens and materno-placental-fetal immunologic interactions are active in determining whether an allergic predisposition is manifested as disease.

Granzymes D, E, F, and G Are Regulated Through Pregnancy and by IL-2 and IL-15 in Granulated Metrial Gland Cells

Granulated metrial gland (GMG) cells are NK cells that proliferate and differentiate within the murine uterus during pregnancy. They have been predicted to play important roles in nurturing the embryo, normal placentation, and uterine tissue remodeling. GMG cell differentiation is manifested by the accumulation of the cytolytic mediators, perforin, granzyme A, and granzyme B, within cytoplasmic granules. The signaling mechanisms required for GMG cell differentiation are largely unknown, although recent in vitro assays have implicated IL-15 in these events. In this report, we demonstrate that granzymes D, E, F, and G (granzymes D–G) are also expressed in GMG cells but at a later stage in pregnancy when compared with granzyme A expression. Whereas granzyme A is expressed in early to mid-gestation, the expression of granzymes D–G peak in mid- to late gestation. In addition, we show that the expression patterns of IL-2Rβ and the IL-2Rγ mRNAs overlap with that of granzyme D–G mRNAs in the pregnant uterus. Finally, we demonstrate that granzymes D–G are up-regulated by IL-2 and IL-15 in primary cultures containing GMG cells. Taken together, these results suggest that IL-2 and/or IL-15 may regulate GMG cell differentiation in vivo, and that granzymes D–G may have different functions than granzyme A during pregnancy.

Cytokines in implantation

Implantation is a complex process which involves the 'invasion' of the maternal endometrium by the trophoblast surrounding the developing blastocyst. In response to this interaction there is a cellular reaction within the endometrium which has some features analogous to invasion by a tumour and some which are more characteristic of an inflammatory response. In addition, and also in common with cancer and inflammation, there is a release of biologically active molecules, including cytokines, at and around the implantation site. The information on cytokines is complex and often contradictory but it is recognised that they play an important role in the successful establishment of pregnancy. The evidence for this role is examined in this review.

In situ changes in the relative abundance of human epidermal cytokine messenger RNA levels following exposure to the poison ivy/oak contact allergen urushiol

Abstract: Epidermal keratinocytes in culture have been shown to produce many cytokines, and their proteins have been identified in skin tissue samples. It has therefore been assumed that these cytokines are transcribed in vivo by the epidermis in response to contact allergens. In this report, in situ hybridization was used to detect the messenger RNAs for interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta) and tumour necrosis factor-alpha (TNF-alpha) in samples of human skin prior to and at various times after application of urushiol, the immunogenic component of poison ivy/oak. In sensitive subjects, IL-1 alpha and TNF-alpha mRNAs showed a progressive increase in transcript levels that paralleled the clinical and histological features of the inflammatory process. The time-course of the IL-1 beta response differed from that of IL-1 alpha and TNF-alpha, in that there was an early (by 6 h after urushiol administration) elevation in IL-1 beta mRNA that occurred before there was evidence of inflammation and had returned to background levels by 72 h when the reaction had reached its peak. In contrast to urushiol-sensitive subjects, urushiol-anergic individuals did not exhibit an increase in IL-1 alpha, IL-1 beta or TNF-alpha mRNA levels. The data provide evidence for an in vivo role for epidermal IL-1 alpha, IL-1 beta and TNF-alpha transcription in the regulation of IL-1 beta and TNF-alpha polypeptide levels in the epidermis in response to this common contact allergen.

Sequence of interleukin-2 isolated from human placental poly A+ RNA: possible role in maintenance of fetal allograft

There are several cell types within the placenta that produce cytokines which can contribute to the regulatory mechanisms that ensure normal pregnancy. The immunological milieu at the maternofetal interface is considered to be crucial for survival of the fetus. Interleukin-2 (IL-2) is expressed by the syncytiotrophoblast, the cell layer between the mother and the fetus. IL-2 appears to be a key factor in maintenance of pregnancy. Therefore, it was important to determine the sequence of human placental interleukin-2. Direct sequencing of human placental IL-2 cDNA was determined for the coding region. Subclone sequencing was carried out for the 5'- and 3'-untranslated regions (5'-UTR and 3'-UTR). The 5'-UTR for human placental IL-2 cDNA is 294 bp, which is 247 nucleotides longer than that reported for cDNA IL-2 derived from T cells. The sequence of the coding region is identical to that reported for T cell IL-2, while sequence analysis of the polymerase chain reaction (PCR) product showed that the cDNA from the 3' end was the same as that reported for cDNA from T cells. Human placental IL-2 cDNA is 1,028 base pairs (excluding the poly A tail), which is 247 bp longer at the 5' end than that reported for IL-2 T cell cDNA. Therefore, the extended 5'-UTR of the placental IL-2 cDNA may be a consequence of alternative promoter utilization in the placenta.

Polytene chromosomes in mammalian cells

This article deals with the structural and functional organization of polytene chromosomes in mammals. Based on cytophotometric, autoradiographic, and electron microscopic data, the authors put forward a concept of nonclassic polytene chromosomes, with special reference to polytene chromosomes in the mammalian placenta. In cells with nonclassic polytene chromosomes, two phases of the polytene nucleus cycle are described, such as the endointerphase (S phase) and endoprophase (G phase). The authors generalize that the main feature of nonclassic polytene chromosomes is that forces binding the sister chromatids are much weaker than in the Diptera classic polytene chromosomes. This concept is confirmed by comparative studies of human, mink, and fox polytene chromosomes. The final step of the trophoblast giant cell differentiation is characterized by a transition from polyteny to polyploidy, with subsequent fragmentation of the highly polyploid nucleus into fragments of low ploidy. Similarities and dissimilarities of pathways of formation and rearrangement of nonclassic polytene chromosomes in mammals, insects, plants, and protozoans are compared. The authors discuss the significance of polyteny as one of the intrinsic conditions for performance of the fixed genetic program of trophoblast giant cell development, a program that provides for the possibility of a long coexistence between maternal and fetal allogenic organisms during pregnancy.

Bidirectional enhancing activities between human T cell leukemia-lymphoma virus type I and human cytomegalovirus in human term syncytiotrophoblast cells cultured in vitro

The syncytiotrophoblast layer of the human placenta has an important role in limiting transplacental viral spread from mother to fetus. Human cytomegalovirus (HCMV) is capable of establishing a latent infection in syncytiotrophoblast cells, with restriction of gene expression to immediate-early and early proteins. We analyzed the extent of replication of human T cell leukemia-lymphoma virus type I (HTLV-I) in human term syncytiotrophoblasts infected with HTLV-I alone or coinfected with HTLV-I and HCMV. Although syncytiotrophoblasts could be infected with cell-free HTLV-I, no viral protein expression was found in the singly infected cells. On the contrary, coinfection of the cells with HTLV-I and HCMV resulted in simultaneous replication of both viruses. Bidirectional enhancing activities between HTLV-I and HCMV were mediated primarily by the Tax and immediate-early proteins, respectively. The stimulatory effect of HTLV-I Tax on HCMV replication appeared to be mediated partly by tumor necrosis factor beta and transforming growth factor beta-1. We observed formation of pseudotypes with HTLV-I nucleocapsids within HCMV envelopes, whereas HCMV was not pseudotyped by HTLV-I envelopes in dually infected syncytiotrophoblast cells. Our data suggest that in vivo dual infection of syncytiotrophoblast cells with HTLV-I and HCMV may facilitate the transplacental transmission of both viruses.

Histochemical demonstration of interleukin-2 in decidua cells of patients with preeclampsia

PROBLEM

The objective of this study was to gain insight into the immunological aspects of preeclampsia.

METHOD

The presence of interleukin-2 (IL-2) protein in the decidua was examined in five preeclamptic patients and seven normal pregnant women employing the immunohistochemistry.

RESULTS

The decidua cells were strongly stained for IL-2 in four out of five preeclamptic patients, while only very weak, if any, staining was observed in all the uncomplicated pregnant women.

CONCLUSIONS

IL-2 was clearly present in decidua cells in the preeclamptic setting, suggesting the possible involvement of immune-activation in the phathophysiology of preeclampsia.

Interactions between human immunodeficiency virus type 1 and human cytomegalovirus in human term syncytiotrophoblast cells coinfected with both viruses

Human cytomegalovirus (HCMV) and human immunodeficiency virus type 1 (HIV-1) may interact in the pathogenesis of AIDS. The placental syncytiotrophoblast layer serves as the first line of defense of the fetus against viruses. We analyzed the patterns of replication of HIV-1 and HCMV in singly an dually infected human term syncytiotrophoblast cells cultured in vitro. Syncytiotrophoblast cells exhibited restricted permissiveness for HIV-1, while HCMV replication was restricted at the level of immediate-early and early gene products in the singly infected cells. We found that the syncytiotrophoblasts as an overlapping cell population could be coinfected with HIV-1 and HCMV. HIV-1 replication was markedly upregulated by previous or simultaneous infection of the cells with HCMV, whereas prior HIV-1 infection of the cells converted HCMV infection from a nonpermissive to a permissive one. No simultaneous enhancement of HCMV and HIV-1 expression was observed in the dually infected cell cultures. Major immediate-early proteins of HCMV were necessary for enhancement of HIV-1 replication, and interleukin-6 production induced by HCMV and further increased by replicating HIV-1 synergized with these proteins to produce this effect. Permissive replication cycle of HCMV was induced by the HIV-1 tat gene product. We were unable to detect HIV-1 (HCMV) or HCMV (HIV-1) pseudotypes in supernatant fluids from dually infected cell cultures. Our results suggest that interactions between HIV-1 and HCMV in coinfected syncytiotrophoblast cells may contribute to the transplacental transmission of both viruses.

Epidermal growth factor receptor and human fetoplacental development

Alteration of placental development directly interferes with fetal growth. Epidermal growth factor (EGF) plays a major role in placental implantation, growth and differentiation. EGF acts on its placental target cells, i.e. the trophoblasts, via a specific receptor (EGFR) which belongs to the tyrosine kinase receptor family. Abundant placental EGF receptors are located in the brush border at the fetomaternal interface. EGFR expression is modulated by trophoblast differentiation and by hormones or toxic substances such as smoke. Interestingly, in microvilli purified from placentae of infants with intrauterine growth retardation (IUGR) a decrease or absence of tyrosine kinase activity is observed. This suggests that an alteration of EGFR biological activity might interfere with the fetoplacental unit development.

Immunological characterization of human decidual mononuclear cells: natural killer activity, response to interleukin-2 and distribution of interleukin-2 receptor subunits

We investigated the immunological character of mononuclear cells obtained from the decidua in the first trimester of normal pregnancy. These cells showed in vitro cytotoxicity against NK cell targets, although with lower activity than that of the peripheral blood mononuclear cells. Response to IL-2 was dose-dependent. Since decidual CD56-positive cells express two IL-2 receptor subunits, p55 and p75, it is concluded that these cells have high-affinity receptors to IL-2. Peripheral blood CD56-positive cells, which express p75 alone, might have intermediate-affinity IL-2 receptors. These results indicate that the decidual mononuclear cells have a function resembling that of the peripheral blood NK cells in vitro, moreover, that even low levels of IL-2 can affect the character of the decidual mononuclear cells through the high-affinity IL-2 receptor. It is considered that the NK activity of decidual mononuclear cells is suppressed in conditions of low IL-2 levels to permit the maintenance of pregnancy, but can be rapidly elicited by intrauterine infections or abortion, both of which elicit the secretion of IL-2.

In vitro cytotoxic activity of cord blood NK cells against herpes simplex virus type-1 infected purified human term villous cytotrophoblast

Transplacental infection of the fetus with herpes simplex virus (HSV) is associated with high morbidity. The present study was undertaken to shed light on the possible participation of the fetal immune system in the elimination of HSV from placental unit. In a chromium release assay cultured term villous trophoblast cells, regardless of infection with HSV-1, were found resistant to lysis by cord blood natural killer (CBNK) cells. In contrast to this, CBNK cells exhibited a basal level of cytotoxic activity against placental fibroblasts, which was significantly increased by preceding infection of the target cells with HSV-1. Stimulation of CBNK cells with interferon-beta purified from trophoblast (tro-IFN-beta) increased the killing of both HSV-1 infected and uninfected fibroblast, while HSV-1-infected and uninfected term villous trophoblast cells remained resistant to lysis. IL-2-stimulated CBNK cells were able to lyse villous trophoblast cells at a low level, but no significant difference in the susceptibility of the HSV-1-infected and uninfected trophoblast cell was detected.

Expression of different immunological markers by cultured human melanocytes

The expression of different immunological markers by cultured human melanocytes (MC) in relation to immune phenomena, were investigated on ten different MC cell lines from early (1st) to late (22nd) passage. Four melanocyte lines (MC-a) which had undergone changes in growth behaviour during prolonged culture were included in the study, together with two melanoma lines. Cytospin preparations of the cells were stained for the presence of a set of different immunological markers and a melanoma-associated antigen (MAA). All MC lines, including the MC-a and the melanoma lines, showed expression of MHC class I, IL-1, IL-2, ICAM-1 and the MAA, NKI-Beteb, during all passages tested. Interestingly, four of the MC lines showed staining for the Fc receptor. A tendency towards a stronger expression of ICAM-1 on a higher percentage of cells was observed on MC with increasing passage number, the MC-a and the melanoma lines. Expression of the MAA was strongly reduced for the MC-a lines in comparison with the MC and the M14 melanoma lines. Positive staining for the HLA class II molecules was obtained on MC of intermediate and late passages, and on the MC-a and the melanoma lines in the decreasing order HLA-DR, DP and DQ. Additionally, we carried out a preliminary study showing that cultured MC also produce IL-1 and IL-6. However, we were not able to show the production of biologically active IL-2 testing several cultured MC lines. Nevertheless, the overall results taken together suggest that MC are immunologically important cells that are susceptible to changes during long-term culture.

Cellular localization and regional distribution of an angiotensin II-forming chymase in the heart

The human heart is a target organ for the octapeptide hormone, angiotensin II (Ang II). Recent studies suggest that the human heart contains a dual pathway of Ang II formation in which the major Ang II-forming enzymes are angiotensin I-converting enzyme (ACE) and chymase. Human heart chymase has recently been purified and its cDNA and gene cloned. This cardiac serine proteinase is the most efficient and specific Ang II-forming enzyme described. To obtain insights into the cardiac sites of chymase-dependent Ang II formation, we examined the cellular localization and regional distribution of chymase in the human heart. Electron microscope immunocytochemistry using an anti-human chymase antibody showed the presence of chymase-like immunoreactivity in the cardiac interstitium and in cytosolic granules of mast cells, endothelial cells, and some mesenchymal interstitial cells. In the cardiac interstitium, chymase-like immunoreactivity is associated with the extracellular matrix. In situ hybridization studies further indicated that chymase mRNA is expressed in endothelial cells and in interstitial cells, including mast cells. Tissue chymase levels were determined by activity assays and by Western blot analyses. Chymase levels were approximately twofold higher in ventricles than in atria. There were no significant differences in chymase levels in ventricular tissues obtained from non-failing donor hearts, failing ischemic hearts, or hearts from patients with ischemic cardiomyopathy. These findings suggest that a major site of chymase-dependent Ang II formation in the heart is the interstitium and that cardiac mast cells, mesenchymal interstitial cells, and endothelial cells are the cellular sites of synthesis and storage of chymase. In the human heart, because ACE levels are highest in the atria and chymase levels are highest in ventricles, it is likely that the relative contribution of ACE and chymase to cardiac Ang II formation varies with the cardiac chamber. Such differences may lead to differential suppression of cardiac Ang II levels during chronic ACE inhibitor therapy in patients with congestive heart failure.

Transgenic strategies in reproductive endocrinology

The present discussion surveys some of the recently published studies utilizing transgenic strategies to address questions in reproductive endocrinology. Beginning with a brief introduction of the transgenic method itself, the following areas are covered: 1. Sexual development and Müllerian-inhibiting substance; 2. Hypogonadal mice and hypothalamic GnRH; 3. The GnRH neuron: generation of immortalized rare cell types; 4. Glycoprotein hormones: immortalized cells, development and evolution; 5. Growth hormone and reproduction; and, 6. Gestation and the insulin-like growth factors. In each section, the discussion attempts to be integrative with respect to the significance of the results to physiological, cellular and molecular biology. We believe this approach is appropriate, as transgenic science itself is necessarily an integration of all of these levels of investigation and participation from those working at all levels is needed.

Treatment and prevention of rat glioblastoma by immunogenic C6 cells expressing antisense insulin-like growth factor I RNA

Rat C6 glioma cells express insulin-like growth factor I (IGF-I) and form rapidly growing tumors in syngeneic animals. When transfected with an episome-based vector encoding antisense IGF-I complementary DNA, these cells lost tumorigenicity. Subcutaneous injection of IGF-I antisense-transfected C6 cells into rats prevented formation of both subcutaneous tumors and brain tumors induced by nontransfected C6 cells. The antisense-transfected cells also caused regression of established brain glioblastomas when injected at a point distal to the tumor. These antitumor effects result from a glioma-specific immune response involving CD8+ lymphocytes. Antisense blocking of IGF-I expression may reverse a phenotype that allows C6 glioma cells to evade the immune system.

Cryptococcal osteomyelitis and cellular immunodeficiency associated with interleukin-2 deficiency

We describe an unusual example of cellular immunodeficiency associated with interleukin-2 deficiency in an otherwise healthy 15-year-old boy who had isolated cryptococcal osteomyelitis of the scapula at 10 years of age. His previous medical history was remarkable only for prolonged, severe varicella infection at 6 years of age. He had persistent moderate lymphopenia, anergy, and absent lymphocyte blastogenic responses to mitogens, antigens, or monoclonal T cell antibodies. Subnormal blastogenic responses were seen after exposure to high concentrations of phorbol esters. Immunoglobulin levels and specific antibodies were normal. The patient has been in good health since treatment of his osteomyelitis. However, his lymphocyte blastogenic responses to mitogens have remained absent during 4 years of observation; investigation of the cause revealed a specific interleukin-2 deficiency resulting from defective generation of interleukin-2 messenger ribonucleic acid. Secretion of interleukin-1 by monocytes was normal, suggesting that the abnormal blastogenic response and interleukin-2 production were due to a problem intrinsic to T lymphocytes. The generation of messenger ribonucleic acid for interleukin-4 was not affected. Interferon-gamma was produced at subnormal levels. The addition of recombinant interleukin-2 restored lymphocyte blastogenic responses and increased the expression of interleukin-2 receptors. The clinical findings and immunologic abnormalities present in this patient differ from other primary and secondary immunodeficiencies associated with interleukin-2 deficiency. Thus our observations in this patient extend the spectrum of immunodeficiencies associated with abnormalities in the production of this important cytokine.

Loss of tumorigenicity of rat glioblastoma directed by episome-based antisense cDNA transcription of insulin-like growth factor I

Malignant glioma is the most common brain tumor. The molecular basis of glioma tumorigenicity has not been defined. Cultured glioma cells accumulate high levels of insulin-like growth factor I (IGF-I) transcripts. We asked whether IGF-I expression is coupled to tumorigenicity, using a combined in vivo/in vitro system employing antisense RNA for IGF-I. An antisense IGF-I expression construct in an expression vector that incorporates Epstein-Barr virus replicative signals and the ZnSO4-inducible metallothionein I transcriptional promoter was assembled. Stable glioma transfectants were derived from C6 glioma cells, which constitutively express IGF-I. B-104 neuroblastoma cells, derived originally from the same tumor but not expressing IGF-I, were also transfected as controls. In the absence of ZnSO4, the C6 transfectants expressed high levels of IGF-I mRNA and protein as detected by in situ hybridization and immunocytochemistry, respectively. Addition of ZnSO4 in the culture medium resulted in high levels of antisense transcript accumulation and dramatically decreased levels of endogenous IGF-I mRNA and IGF-I protein. Subcutaneous injection of either nontransfected C6 parental cells or C6 cells transfected with vector without IGF-I sequences into rats resulted in large tumors after 2 weeks, as did transfected and nontransfected B-104 cells. However, the rats injected with transfected C6 cells yielded no tumors after 40 weeks of observation. Two weeks after injection of the transfected C6 cells a small cyst was apparent in six rats. Histologic sections revealed a few glioma cells infiltrated by a large number of mononuclear cells. No infiltration of mononuclear cells was apparent in the glioma tumors resulting from injection of parental (nontransfected) cells, suggesting that the parental cells, but not the antisense IGF-I transfectants, escape the host immune response.

Interleukin-2 receptor positive cells in human decidua during the first trimester of pregnancy and their association with macrophages

Maternal immune rejection of the fetus could sometimes be the cause of unexplained recurrent spontaneous abortion. Components of the T cell-mediated immunity were investigated in the first trimester of pregnancy in women having spontaneous abortion and compared to those with normal pregnancy having a termination on social grounds. Interleukin 2 (IL-2) had no proliferative effect on the trophoblasts of chorionic villi and there were also no IL-2 receptors in these cells. However IL-2 receptor positive cells were found in the decidua in 7 out of 24 women with normal pregnancy and in 12 out of 18 with spontaneous abortion. A high density of macrophages showed an association with IL-2 receptors in both groups. There were no differences with respect to T-cytotoxic cells and T-helper cells in cases of normal pregnancy (with and without IL-2 receptor positive cells), whereas in women having spontaneous abortion we found lower densities of T-helper and T-cytotoxic cells in those without IL-2 receptors than in those with IL-2 receptors.

Expression of activation antigens CD69, HLA-DR, interleukin-2 receptor-alpha (IL-2R alpha) and IL-2R beta on T cells of human decidua at an early stage of pregnancy

T cells of human decidua at an early stage of pregnancy were examined by flow cytometry for the expression of the T-cell-activation antigens CD69, HLA-DR, interleukin-2 receptor-alpha (IL-2R alpha) and IL-2R beta. The decidua contained a small number of T cells and both CD4+ and CD8+ subsets expressed CD69, HLA-DR, IL-2R alpha and IL-2R beta antigens significantly whereas, in peripheral blood, only a small number of T cells expressed these activation antigens. These findings indicate that T cells in the decidua in the first trimester of pregnancy are regionally activated.

Growth factors in the uterus: steroidal regulation and biological actions

Rapid progress has been made within the last 5-6 years in characterizing polypeptide growth factors in uterine tissues and fluids. There is convincing evidence that their synthesis and/or secretion is regulated by steroid hormones. The possibility that these growth factors play a central role in growth and development of the uterus or placenta is suggested by the presence of their receptors on uterine or placental cells and their stimulatory effects on these cells in vitro. Since growth factors interact synergistically and also have non-mitogenic functions, the presence of a variety of these factors in the uterus suggests that they probably regulate various aspects of uterine function through complex autocrine and paracine pathways. However, experimental models need to be designed that will permit a more detailed analysis of the actual role of these factors in utero. Fruitful approaches may be to administer neutralizing antibodies or blocking peptides so as to antagonize uterine growth factor action, or to develop appropriate transgenic animals. These and other lines of study should help us to understand the role of growth factors in development of the immature uterus, growth of the placenta or gravid uterus, repair and angiogenesis of the endometrium, and uterine pathology.

Tumor necrosis factor alpha mRNA and protein are present in human placental and uterine cells at early and late stages of gestation

Tumor necrosis factor alpha (TNF-alpha), a polypeptide that regulates cellular growth and modulates the synthesis of various cell surface and secreted molecules, has been identified in the pregnant uterus. To determine which specific cells transcribed and translated this gene, extraembryonic fetal tissues (placenta and membranes) and uterine tissue from early and late stages of gestation were analyzed for TNF-alpha mRNA by in situ hybridization using biotinylated antisense and sense TNF-alpha probes, and for immunoreactive TNF-alpha using two monoclonal antibodies. Tumor necrosis factor-alpha transcripts and protein were identified in both extraembryonic and maternal cells. In first-trimester placental villi, TNF-alpha mRNA was present in syncytiotrophoblast but was low to absent in cytotrophoblast and villous stromal cells. Decidual and epithelial cells in maternal tissues contained TNF-alpha transcripts. In term placentas, both syncytiotrophoblast and villous stromal cells contained TNF-alpha mRNA, and transcripts were present in maternal cells in the decidua adjacent to the extraplacental membranes. In both first-trimester and term tissues, coincident expression of TNF-alpha mRNA and immunoreactive TNF-alpha was demonstrated. The results of this study show that TNF-alpha is synthesized by cells in both extraembryonic membranes and maternal tissues during human gestation and that transcription in specific types of cells is influenced by gestational age. These observations are consistent with a major role for TNF-alpha in the dynamic developmental events of human pregnancy.

Hepatocyte growth factor in human placenta and trophoblastic disease

The hepatocyte growth factor (HGF) is an acidic protein with a strong mitogenic effect on hepatocytes. Hepatocyte growth factor mRNA recently was cloned from a placental cDNA library. Here we demonstrate the purification of HGF from human placenta with heparin-agarose chromatography and TSK-heparin high-pressure liquid chromatography and describe the distribution of placental HGF by immunohistochemistry using a polyclonal antibody to HGF. The yield of HGF from the placenta was approximately 100 to 200 times greater than that previously obtained from human plasma. Placental HGF was expressed strongly in the villous syncytium, extravillous trophoblast, and amnionic epithelium, and, to a lesser degree in endothelial cells and villous mesenchyme. Hepatocyte growth factor also was identified in the trophoblast of complete hydatidiform moles, choriocarcinomas, and a case of blighted ovum. The presence of HGF in an organ characterized by rapid cell proliferation during gestation and in trophoblastic tumors strongly suggests that the growth-regulating effect of HGF is not limited to hepatocytes.