Levels Of LIF Research Articles

Regulatory T cells in pregnancy

Tolerance mechanisms are responsible for the survival of the fetus within the maternal uterus without being attacked by the cells of the maternal immune system despite their direct contact. Regulatory T cells (Treg) were claimed to be important players in the tolerance towards the fetus bearing alloantigens. Recent evidence confirmed an augmentation in the number of Treg during pregnancy and, most importantly, diminished numbers of Treg were associated with immunological rejection of the fetus. This could be prevented by adoptively transferring CD4(+)/CD25(+) Treg cells from normal pregnant mice into abortion-prone animals. Treg prevented abortion while creating a transient tolerant microenvironment characterized by high levels of TGF-beta, LIF, and HO-1. Downregulated levels of Treg were accordingly also reported during human miscarriage. Furthermore, we have evidence suggesting that, to be protective, Treg need to be activated by male antigens during pregnancy.

124 THE MAJOR GENE EXPRESSION PATTERNS IN ENDOMETRIAL TISSUE OF PIGS DURING EARLY GESTATION

Although the expression of important genes in the embryo at pre-implantation stage, which encompasses the period from fertilization to implantation, have been reported for mice and cows, little information relevant to this subject is known in pigs. The objective of this study was to investigate the changes of importantly expressed genes and proteins in endometrial tissue of pigs from fertilization to implantation. Six genes, including estrogen receptor-α, estrogen receptor-β, LIF, LR (LIF receptor), TGFβ1, and TGFβ2, that may play important roles in regulating uterine receptivity and successful implantation and that show different expression patterns by the stages of pregnancy were selected. As a step toward understanding the role of gene and protein expression changes in endometrial tissue of pigs during the preimplantation stage (Day 2, Day 6, Day 8, Day 12, and Day 17, n = 3/group) and the post-implantation stage (Day 21 and Day 33, n = 3/group) and Day 0 (estrous), real-time PCR methods for quantitative analysis of genes and immunohistochemistry methods to localize protein expression were utilized. Data from quantitative real-time PCR were analyzed by ANOVA. The results of this experiment indicated that estrogen receptor-β mRNA level was sharply increased to Day 12 of pregnancy, while estrogen receptor-α mRNA did not change drastically during early pregnancy stage. In contrast, levels of LIF and LR mRNA were increased from Day 2 to Day 33. Although TGFβ1 mRNA reached peak on Day 17 and TGFβ2 mRNA showed the highest level on Day 17, TGFβ2 did not appear to change drastically. For the protein expression patterns, estrogen receptor-α and estrogen receptor-β proteins were expressed in both luminal epithelium and glandular epithelium, but they were only partially expressed in some tissues of stroma cells. LIF protein was expressed in all cell types, while TGF β1 protein was high expressed in glandular epithelium. Also, ERs, LIF, and TGF β1 mRNA and protein expression showed stage- and cell-specific expression patterns. We also investigated the gene expression of TGF β1 mRNA and TGF β2 mRNA in early conceptus (Day 12 and Day 17). TGF β1 mRNA expression was low in Day 12 embryos, and increased progressively to Day 17. This indicated that both the maternal uterus and the conceptus represent the same gene expression pattern. These results suggest that estrogen receptor-β could be an important factor in estrogen action in endometrial tissue during early gestation in pigs, and TGF βs function in both autocrine and paracrine interactions. Progressive increase in TGF β1 mRNA expression in conceptus and uterine tissues suggest important roles of TGF β1 in conceptus development and establishment of the uterine receptivity during the peri-implantation period.

Evaluation of the placental environment with a new in vitro model of histocultures of early and term placentae: determination of cytokine and chemokine expression profiles

We aimed to set up and validate a new in vitro model of placental histocultures, for the evaluation of cytokine and chemokine profiles of the placental environment, over a long culture period. Micro-explant cultures from 6 early and 6 term placentae were set up on collagen sponge gel supports at a liquid/air interface. At various times during culture, we analyzed tissue morphology and cell death by microscopy and quantified beta-hCG production and mRNA levels for beta-hCG and insulin-like 4 (INSL4). Levels of IL-6, LIF, TNF alpha, IL-10, IFN-gamma, IL-16 and RANTES in the medium were measured by ELISA on days 1, 4 and 7 of culture. SDF-1 mRNA expression was determined by real-time PCR at the same time points. Histocultures from early and term placentae remained viable until day 10. High levels of IL-6 and LIF production, low levels of TNF alpha, IL-10 and IFN-gamma production and significant SDF-1 expression were observed. These data indicate that placental histoculture is a suitable and reliable in vitro model for studying the placental environment.

POTENTIAL CONTRIBUTION OF IL-17- PRODUCING TH1CELLS TO DEFECTIVE REPAIR ACTIVITY IN JOINT INFLAMMATION: PARTIAL CORRECTION WITH Th2-PROMOTING CONDITIONS

To assess the contribution of cell interactions to the production of cytokines and type I collagen, fixed synovium T cell clones were cocultured on synoviocytes and levels of IL-6, LIF and PICP, a marker of type I collagen synthesis measured. Levels of IL-6 and LIF were higher with Th1than with Th0and Th2clones. Levels of PICP were decreased with Th1clones and increased with Th2clones. IL-17-producing T cells, all Th1, were among the highest inducers of cytokine and inhibitors of collagen synthesis. Preincubation of clones in Th1conditions (IL-12 plus anti-IL-4) increased IL-6 production, whereas Th2conditions (IL-4 plus anti-IL-12) strongly inhibited IL-6 production and restored repair activity. As rheumatoid synovium is infiltrated by Th1cells, local cell interactions result in a pro-inflammatory pattern with defective repair, which can be reversed at least in part, by a Th2pattern.

Direct contact between CD34 +lin − cells and stroma induces a soluble activity that specifically increases primitive hematopoietic cell production

Perfused human bone marrow (BM) mononuclear cell (MNC) cultures result in a greater long-term culture-initiating cell (LTC-IC) output than parallel CD34 + lin − cell cultures, even when CD34 + lin − cells are placed on irradiated preformed stroma (IPFS). This difference has been attributed to accessory cell effects that are potentiated by medium perfusion. The present study investigated the relative contributions of direct contact- and soluble-mediated mechanisms of accessory cells in this culture system. CD34 + lin − cells within (i.e., in contact with) the MNC accessory cell mixture generated greater LTC-IC output than CD34 + lin − cells in contact with IPFS. Incubation of CD34 + lin − cells with MNC conditioned medium (CM) resulted in partial restoration of MNC accessory activity, while CM from IPFS had no activity on LTC-IC output. Interestingly, the level of LTC-IC output supported by MNC CM was equivalent to that supported by direct contact with IPFS. CD34 + lin − cells were then cultured in Transwell™ inserts either alone, with IPFS (direct contact), or with IPFS below the insert. Direct contact with IPFS significantly increased the output of cells, CFU-GM, and LTC-IC from CD34 + lin − cells. IPFS below the insert also resulted in significantly increased cell and CFU-GM output, but did not significantly affect LTC-IC output. Further experiments using CM from CD34 + lin − cells and IPFS cultures showed that LTC-IC supportive activity was present only when direct contact was allowed between CD34 + lin − cells and IPFS. ELISA and RT-PCR experiments showed that contact did not induce changes in the levels of several known growth factors, including GM-CSF, IL-1β, IL-3, IL-6, IL-11, LIF, KL, FL, Tpo, TGF-β, and MIP-1α. These results indicate that direct contact between CD34 + lin − cells and IPFS induces soluble activity, which specifically increases LTC-IC output from CD34 + lin − cell cultures, providing evidence for a novel direct contact-mediated two-way mechanism of communication between primitive hematopoietic cells and stroma.

ELISA detection of circulating levels of LIF, OSM, and CNTF in septic shock.

ELISA detection of circulating levels of LIF, OSM, and CNTF in septic shock.

Autologous stem cell transplantation: release of early and late acting growth factors relates with hematopoietic ablation and recovery

We have monitored the serum concentrations of hematopoietic growth factors (HGFs; ie, stem cell factor [SCF], leukemia inhibitory factor [LIF], interleukin-3 [IL-3], IL-6, IL-8, and granulocyte colony- stimulating factor [G-CSF]) in 15 lymphoma/leukemia and 6 ovarian cancer patients undergoing autologous bone marrow (BM) or peripheral blood (PB) stem cell transplantation (SCT). Thus, the analysis was performed during and after high-dose chemotherapy (from day -6 to day - 1), at the time of SCT (day 0), and thereafter (through day +17). Despite the heterogeneity of these patients and their conditioning regimens, a consistent kinetic pattern was observed for all analyzed cytokines. Particularly, (1) SCF serum concentration did not significantly fluctuate. (2) High levels of LIF (approximately 250 to 450 pg/mL) before chemotherapy rapidly declined to markedly lower concentrations (approximately 10 ng/mL) starting from day -1 through day +17; (3) conversely, IL-3 level was low before treatment, sharply increased during chemotherapy, and rapidly returned to base-line level after SCT. Hypothetically, the sharp LIF decrease and IL-3 increase during chemotherapy may underlie the induction of stem cell cycling and differentiation caused by hematopoietic ablation. Furthermore, (4) IL-6 concentration was low before and immediately after chemotherapy, but increased starting from day +5, peaked at day +6 through 9 and then declined to baseline level from day +10 onward; (5) a strictly similar pattern was consistently observed for both G-CSF and IL-8 levels, in agreement with our previous studies. It is relevant that peak IL-6, G- CSF, and IL-8 concentrations were directly correlated to peak neutrophil numbers in the recovery phase, thus suggesting an important role for these cytokines in granulocyte rescue; in line with this interpretation, hematologic patients undergoing PBSCT (10 of 15) exhibited higher peaks of IL-6, G-CSF, and IL-8 and a more pronounced increase of neutrophil/platelet number than did hematologic cases undergoing BMSCT (5 of 15). Altogether, these studies indicate a coordinate pattern of cytokine release during hematopoietic ablation/recovery after chemotherapy and autologous SCT, the fluctuations of LIF and IL-3 levels during chemotherapy are seemingly related to stem cell recruitment, whereas the post-SCT increase of IL- 6, G-CSF, and IL-8 may underlie the neutrophil recovery.

Autologous Stem Cell Transplantation: Release of Early and Late Acting Growth Factors Relates With Hematopoietic Ablation and Recovery

We have monitored the serum concentrations of hematopoietic growth factors (HGFs; ie, stem cell factor [SCF], leukemia inhibitory factor [LIF], interleukin-3 [IL-3], IL-6, IL-8, and granulocyte colony-stimulating factor [G-CSF]) in 15 lymphoma/leukemia and 6 ovarian cancer patients undergoing autologous bone marrow (BM) or peripheral blood (PB) stem cell transplantation (SCT). Thus, the analysis was performed during and after high-dose chemotherapy (from day -6 to day -1), at the time of SCT (day 0), and thereafter (through day +17). Despite the heterogeneity of these patients and their conditioning regimens, a consistent kinetic pattern was observed for all analyzed cytokines. Particularly, (1) SCF serum concentration did not significantly fluctuate. (2) High levels of LIF (approximately 250 to 450 pg/mL) before chemotherapy rapidly declined to markedly lower concentrations (approximately 10 ng/mL) starting from day -1 through day +17; (3) conversely, IL-3 level was low before treatment, sharply increased during chemotherapy, and rapidly returned to base-line level after SCT. Hypothetically, the sharp LIF decrease and IL-3 increase during chemotherapy may underlie the induction of stem cell cycling and differentiation caused by hematopoietic ablation. Furthermore, (4) IL-6 concentration was low before and immediately after chemotherapy, but increased starting from day +5, peaked at day +6 through 9 and then declined to baseline level from day +10 onward; (5) a strictly similar pattern was consistently observed for both G-CSF and IL-8 levels, in agreement with our previous studies. It is relevant that peak IL-6, G-CSF, and IL-8 concentrations were directly correlated to peak neutrophil numbers in the recovery phase, thus suggesting an important role for these cytokines in granulocyte rescue; in line with this interpretation, hematologic patients undergoing PBSCT (10 of 15) exhibited higher peaks of IL-6, G-CSF, and IL-8 and a more pronounced increase of neutrophil/platelet number than did hematologic cases undergoing BMSCT (5 of 15). Altogether, these studies indicate a coordinate pattern of cytokine release during hematopoietic ablation/recovery after chemotherapy and autologous SCT, the fluctuations of LIF and IL-3 levels during chemotherapy are seemingly related to stem cell recruitment, whereas the post-SCT increase of IL-6, G-CSF, and IL-8 may underlie the neutrophil recovery.

A study of the variational convergence of theFcentre energy levels of LiF

SCFMO calculations have been made on the F centre states of LiF using a crystal fragment whose potential closely approximates that of the full crystal. The effect of including electrons of up to third neighbours has been studied. The most extensive calculation gives a binding energy for the 2 S state in the unrelaxed lattice of 5·25 eV and a 2 S→2 P transition energy of 4·6 eV. Lattice relaxation has been calculated in a model appropriate to all lithium halides in which only nearest neighbour electrons are considered. For LiF an outward displacement of nearest neighbour ions by 2·5 per cent of the lattice parameter has been calculated. For the other halides the predicted displacements are smaller.

Valence Bands and Core Levels of the Isoelectronic Series LiF, BeO, BN, and Graphite Studied by ESCA

The core lines and valence bands of LiF, BeO, BN and graphite have been studied by the ESCA technique. The energy differences between inner levels and valence bands are compared with X-ray transition energies. The changes in binding energy for the Bels level when going from metal to oxide and fluoride are compared with X-ray spectroscopic data and with a study of the disintegration constant in electron capture of 7Be in the same compounds.