IL-6 and G-CSF levels in amniotic fluid during the second trimester in normal and abnormal pregnancies

Regulation of maternal serum and amniotic fluid cytokine profiles in the mouse: Possible roles in the onset of labour

Murine pregnancy is characterised by marked increases in serum cytokine profiles with advancing gestation, but whether these changes reflect concentrations in amniotic fluid is unknown. This study therefore profiled 23 cytokines by fluid-phase multiplex immunoassay of amniotic fluid and serum collected from naturally mated mice during mid- and late pregnancy (days 11 and 18, respectively). The marked increase in serum profile of many cytokines from days 11 to 18 was not reflected in amniotic fluid, wherein most cytokine concentrations were lower on day 18. Serum and amniotic fluid cytokine concentrations were largely inversely related, indicating separate, localised regulatory mechanisms geared towards the maintenance of pregnancy, modulation of immune effector cell function and optimisation of fetal development. We suggest that, while maternal systemic inflammatory priming prepares the mother for birth, the amniotic compartment exhibits a tightly regulated inflammatory quiescence. These findings are discussed in relation to the onset of labour, which ultimately results in the elevated cytokine amniotic levels traditionally associated with the final stages of pregnancy.

Inducing proliferation of human amniotic epithelial (HAE) cells for cell therapy

Probably because amnion is derived from the fetus and is exposed to the maternal immune system, human amniotic epithelial (HAE) cells do not express the HLA-A, -B, -C, or -DR antigens on their surfaces, suggesting that HAE cells do not induce rejection (immune reaction) after allotransplantation. And the amnion, like the placenta, is useless to the mother and child after birth. Therefore, HAE cells or tissues were expected to be suitable for allotransplantation. Because HAE cells produce large amounts of enzymes, amnion transplantation has been carried out in order to correct inborn errors of metabolism by supplementing lysosomal enzyme deficiencies. However, several problems remain before amnion allotransplantation can be accepted as effective. The HAE cell population is limited, because the maximum number of HAE cells obtainable from one donor is about 2 x 10(8) cells, and HAE cells proliferate poorly in in vitro culture. In this study, we aimed at increasing the HAE cell population in vitro. First, we investigated the effect of several cytokines on HAE cell proliferation and found that hepatocyte growth factor (HGF), epidermal growth factor (EGF), and transforming growth factor-beta stimulated it, whereas IL-6 and LIF inhibited it. Second, we investigated the effects of amniotic fluid on HAE cell proliferation and observed that IL-6 in amniotic fluid inhibits it. Then, to inhibit the dying of cells, we attempted to inhibit apoptosis (one mode of cell death). Treatment with caspase III inhibitor increased the cell viability of HAE cells by 20%.

Concentrations of serum granulocyte-colony-stimulating factor in normal pregnancy and preeclampsia

OBJECTIVE

In order to elucidate the potential role of granulocyte-colony-stimulating factor (G-CSF) during the course of normal pregnancy and preeclampsia, we measured the serum concentrations of G-CSF in both normal pregnant women and preeclamptic patients.

METHODS

Sera of 10 nonpregnant women, 34 normal pregnant women (n = 10, first trimester; n = 10, second trimester; n = 14, third trimester), 10 postpartum women, 10 mild preeclamptic patients, and 10 severe preeclamptic patients were collected. The serum concentrations of G-CSF were measured by enzyme immunoassay.

RESULTS

The serum level of G-CSF in normal pregnant women (third trimester: 38.3 +/- 15.3 pg/mL; mean +/- SD) was significantly increased when compared with the levels observed in nonpregnant women (20.3 +/- 10.1 pg/mL, p < 0.05), which was similar to the G-CSF concentrations in postpartum subjects (20.7 +/- 9.1 pg/mL). The mild and severe preeclamptic patients showed significantly higher levels of G-CSF (56.9 +/- 18.8 pg/mL, p < 0.05; 73.2 +/- 30.4 pg/mL, p < 0.0001, respectively) than those noted in the third trimester women. The preeclamptic patients who presented with edema had greater (p < 0.01) serum levels of G-CSF (75.5 +/- 25.0 pg/mL) compared with nonedematous patients (44.7 +/- 14.9 pg/mL). The serum levels of G-CSF significantly correlated with both weight gain (p < 0.05), diastolic blood pressure (p < 0.01), and systolic blood pressure (p < 0.01), but not with white blood cell counts.

CONCLUSION

Serum concentrations of G-CSF are increased in normal and, even more so, in preeclamptic pregnancies. Because there was no relationship between serum G-CSF concentration and the number of leukocytes, G-CSF might act not to promote the physiological leukocytosis of pregnancy, but to stimulate the function of leukocytes such as phagocytosis. Moreover, it might be that G-CSF plays important roles in the activation of granulocytes or vascular endothelial injury, which are considered to be important pathological conditions in the development of preeclampsia.

Human amniotic fluid lacks interleukin-2 and interleukin-15 but can interact with the beta-chain of the interleukin-2 receptor

The present study investigated whether an explanation for the conflicting reports on the interleukin-2 (IL-2) status of amniotic fluid is due to the presence of IL-15 which shares biological activities with IL-2 and utilizes the IL-2 receptor beta-chain. Amniotic fluids from 45 normally progressing pregnancies between 14 and 16 weeks after the last menstrual period were assayed for IL-2 and IL-15 by bioassay and enzyme-linked immunosorbent assay (ELISA). The ability of amniotic fluids to induce cytotoxic T lymphoblastoid line-2 (CTLL-2) cell proliferation was demonstrated to be dependent upon bioassay culture conditions. In serum-free medium each amniotic fluid stimulated CTLL-2 proliferation with a mean level of IL-2-like bioactivity of 14.7 +/- 2.3 ng/ml but amniotic fluids failed to induce CTLL-2 proliferation in serum-supplemented medium. Treatment with neutralizing anti-IL-2 or anti-IL-15 antibodies failed to inhibit amniotic fluid-induced CTLL cell proliferation in serum-free medium, indicating a lack of IL-2 and IL-15 bioactivity. In contrast, treatment with anti-IL-2 receptor beta-chain antibody significantly reduced amniotic fluid-induced proliferation. The lack of IL-2 and IL-15 activity in amniotic fluids was confirmed using ELISA. Although high levels of IL-15 immunoactivity were detected in all samples, specificity controls showed a lack of specific IL-15 immunoactivity in amniotic fluid. Pretreatment of amniotic fluids with 100-500 ng/ml mouse immunoglobulin G abrogated IL-15 immunoactivity, indicating that amniotic fluid contains molecules binding to Fc regions of immunoglobulins and responsible for false ELISA positivity. These studies unequivocally show that amniotic fluid lacks IL-2 and IL-15 but can stimulate CTLL-2 cell proliferation via the IL-2 receptor beta-chain. The absence of IL-2 and IL-15 in normal mid-trimester amniotic fluid suggests that the cytokine profile of human pregnancy appears to be associated with a bias against type 1 cytokines within the feto-placental unit.

G-CSF, GM-CSF and IL-6 levels in cord blood: diminished increase of G-CSF and IL-6 in preterms with perinatal infection compared to term neonates

AIM

The objectives of this study were 1) to clarify the physiologic regulation of cytokines such as IL-6, G-CSF and GM-CSF in preterm and term neonates and 2) to evaluate the influence of perinatal stress and infection on endogenous cytokine levels.

METHOD

We examined cord blood levels of G-CSF, GM-CSF and IL-6 using a bioassay in 43 term and 44 preterm neonates.

RESULTS

Compared to normal neonates (G-CSF: mean (m) = 97.6 +/- 16.3 pg/ml; IL-6: m = 20.2 +/- 4.6 pg/ml), we found elevated G-CSF levels in newborns with perinatal stress (m = 247.1 +/- 72.1 pg/ml; p = 0.003) and increased levels for G-CSF (m = 8980.9 +/- 4388 pg/ml; p = 0.0003) and IL-6 (m = 705 +/- 322.3 pg/ml; p = 0.025) in neonates with infection. Term newborns with infection had higher G-CSF levels than preterms (m = 15575 +/- 9374 pg/ml versus m = 5384.1 +/- 4470.9 pg/ml; p = 0.024). G-CSF levels of newborns with infection were correlated with birth weight (r = 0.50; p = 0.024) but not with gestational age (r = 0.40; p = 0.057). GM-CSF was only detectable in cord blood in 4 cases of normal healthy neonates.

CONCLUSIONS

The response of G-CSF levels in preterms to infection is diminished. Body cell mass is more important than gestational age to provide high G-CSF levels during states of infection.

Interleukin-6, interferon-gamma, interleukin-8, and granulocyte-macrophage colony stimulating factor levels in human amniotic fluid at term

Cytokines contribute to the maintenance of successful pregnancy and have also been implicated in the initiation of labour. This study has examined those cytokines which may be involved in normal term parturition. IL-6, IFN-gamma, IL-8 and GM-CSF levels were measured by ELISA in samples of amniotic fluid, peripheral and uterine venous blood plasma, and umbilical artery blood plasma from non-labouring women undergoing elective caesarean section at term and from women in spontaneous labour. IFN-gamma and IL-6 were detected only in amniotic fluid and not in blood plasma samples, unlike IL-8 which was found in all amniotic fluid and plasma samples from both labouring and non-labouring women; GM-CSF was undetectable in all samples examined. Levels of IL-6 were significantly raised in the amniotic fluid of women in labour compared with the control group (P = 0.008). IFN-gamma was detected in the amniotic fluid of both labouring women and the control group, and there was also a significant correlation (P = 0.003) between IFN-gamma and IL-6 levels in individual amniotic fluid samples. The presence of both IFN-gamma and IL-8 in amniotic fluid, as well as IL-6, suggests these cytokines are involved in important immunobiological events relevant to the latter half of gestation.

Characterization of the growth factor activity of amniotic fluid on cells from hematopoietic and lymphoid organs of different life stages

We investigated the proliferation-promoting effects of murine amniotic fluid (MAF) on in vitro cultured cells originally obtained from murine hematopoietic and lymphoid organs at different life stages. MAF promoted proliferation of the fetal liver cells (FLC), newborn spleen cells and adult bone marrow cells. The proliferation-promoting activity of MAF was extended to liver cells and spleen cells from mice younger than 2 weeks old. MAF did not, however, promote the proliferation of newborn or adult thymocytes, or of spleen cells, liver cells or peritoneal cells, liver cells or peritoneal cells from 2-week-old or older mice. Rather, it partially inhibited the proliferation of spleen cells, thymocytes and peritoneal cells from 1-year-old mice. These results suggest that MAF contains growth factors for hematopoietic stem cells but not for either mature or immature T lymphocytes. Supporting this view, the MAF activity was partially neutralized by a polyclonal anti-mouse stem cell factor (SCF) antibody. Moreover, the immunoblotting of MAF against anti-mouse SCF antibody revealed a band at 30-32 kDa corresponding to the previously reported SCF. Interestingly, MAF was able to maintain FLC and adult bone marrow cells alive in culture for a relatively long time (2 weeks). The MAF activity was further shown to be partially and cell type-dependently antagonized by TNF-alpha and TGF-beta. These results provided evidence that MAF contains potentially multiple growth factors preferentially affecting the early stage of hematopoiesis, one of which is SCF.