Isolation of mesenchymal stem cells with neurogenic potential from the mesoderm of the amniotic membrane

The amniotic membrane has been clinically applied as a therapeutic material in wound covering and corneal surface reconstruction. Recently, mesenchymal stem cells (MSCs) have been isolated from the placenta, specifically from the amniotic membrane. However, the localization of MSCs in the amniotic membrane has not been determined. In this study, term placenta was collected, and we performed immunohistochemical staining techniques to identify and localize MSCs in the mesoderm of the amniotic membrane in situ with MSC antibodies, including CD90 and CD105. We further directly cultured and characterized MSCs from the amniotic membrane mesoderm (AMSCs). The AMSCs were easily isolated and represented a homogenous fibroblastic morphology at early passages. In addition to MSC surface markers, AMSCs expressed Sox2, Oct-4 and Nanog. AMSCs could be induced into osteocytes, adipocytes and chondrocytes in vitro and show immunosuppressive effects on T-cell proliferation. Under appropriate conditions, AMSCs could differentiate into neuronal-like cells, which were identified by neuronal-specific markers and their ability to secrete dopamine. This study reveals that AMSCs provide a promising source for stem cell studies and also extend the clinical potential of the amniotic membrane in the field of regenerative medicine.

Newborn screening for Fabry disease in Taiwan reveals a high incidence of the later-onset GLA mutation c.936+919G>A (IVS4+919G>A)

Fabry disease (alpha-galactosidase A (alpha-Gal A, GLA) deficiency) is a panethnic inborn error of glycosphingolipid metabolism. Because optimal therapeutic outcomes depend on early intervention, a pilot program was designed to assess newborn screening for this disease in 171,977 consecutive Taiwanese newborns by measuring their dry blood spot (DBS) alpha-Gal A activities and beta-galactosidase/alpha-Gal A ratios. Of the 90,288 male screenees, 638 (0.7%) had DBS alpha-Gal A activity <30% of normal mean and/or activity ratios >10. A second DBS assay reduced these to 91 (0.1%). Of these, 11 (including twins) had <5% (Group-A), 64 had 5-30% (Group-B), and 11 had >30% (Group-C) of mean normal leukocyte alpha-Gal A activity. All 11 Group-A, 61 Group-B, and 1 Group-C males had GLA gene mutations. Surprisingly, 86% had the later-onset cryptic splice mutation c.936+919G>A (also called IVS4+919G>A). In contrast, screening 81,689 females detected two heterozygotes. The novel mutations were expressed in vitro, predicting their classical or later-onset phenotypes. Newborn screening identified a surprisingly high frequency of Taiwanese males with Fabry disease (approximately 1 in 1,250), 86% having the IVS4+919G>A mutation previously found in later-onset cardiac phenotype patients. Further studies of the IVS4 later-onset phenotype will determine its natural history and optimal timing for therapeutic intervention.

Immunological aspects and therapeutic significance of an autoantibody against histone H1 in a rat model of concanavalin A-induced hepatitis

We previously demonstrated the immunosuppressive activity of anti-histone H1 autoantibody induced in experimental and clinical liver allograft tolerance. This study aimed to explore the immunological aspects of anti-histone H1 autoantibody in liver injury induced by concanavalin A (Con A). To establish a Con A-hepatitis model, 20 mg/kg Con A was intravenously injected into rats, after which liver function and histopathological analyses were performed. In this model, anti-histone H1 autoantibody was transiently induced in the sera during the natural recovery stage, 3-7 days after Con A injection. To evaluate the therapeutic significance of anti-histone H1 autoantibody, a polyclonal antibody against histone H1 was intraperitoneally injected immediately after Con A injection. We found that injection of anti-histone H1 antibody could reduce Con A-induced liver damage. Further mechanical analyses revealed that anti-histone H1 antibody altered the intracellular activation of mitogen-activated protein kinase, nuclear factor-kappaB and calcineurin via T-cell receptor signalling, suggesting that anti-histone H1 antibody may protect the liver from Con A-induced injury by inhibiting activation of effector T cells. These findings suggest that anti-histone H1 autoantibody may be a natural immune regulatory factor that protects inflamed livers suffering from autoimmune hepatitis and may lead to T-cell unresponsiveness through the selective regulation of mitogen-activated protein kinase/nuclear factor-kappaB and calcineurin signalling.

A novel peptide mimotope identified as a potential immunosuppressive vaccine for organ transplantation

We reported that anti-histone H1 autoantibody is one of the main immunosuppressive factors in serum that is induced after orthotopic liver transplantation in a rat tolerogenic model. We generated a novel anti-histone H1 IgM mAb produced by hybridoma 16G9 (16G9 mAb) that shows MLR-inhibitory activity. Identification of a functional epitope responsible for the immunosuppressive activity of 16G9 mAb may lead to the establishment of a novel therapeutic strategy. We used a combinatorial phage display peptide library to screen for peptides that bind to 16G9 mAb. Consequently, two peptides that bind to 16G9 mAb, SSV and LPQ, were selected from the library. The binding of 16G9 mAb to histone H1 was inhibited by SSV. SSV was recognized by rat tolerogenic post-orthotopic liver transplantation serum and the binding to SSV was inhibited by histone H1. Mice were immunized with keyhole limpet hemocyanin-conjugated SSV and LPQ. Abs induced by SSV immunization inhibited Con A-stimulated splenocyte proliferation, and the inhibition was neutralized by preincubation with SSV. Splenocytes stimulated by anti-CD3 Ab were inhibited by SSV-induced Abs using CFSE labeling. SSV immunization in rats before heterotopic heart transplantation resulted in significant prolonged allograft survival. These findings suggested that SSV is a functional histone H1-binding epitope for 16G9 mAb. SSV is capable of determining serum immunoreactivity against histone H1 as an index marker for tolerance. The inhibitory activity of SSV-induced Abs on blast cell proliferation and the prolonged graft survival that results from SSV immunization imply a potential for the development of an immunosuppressive vaccine.

Induction of indoleamine 2,3-dioxygenase in livers following hepatectomy prolongs survival of allogeneic hepatocytes after transplantation

OBJECTIVES

Indoleamine 2,3-dioxygenase (IDO), which catalyzes the breakdown of tryptophan into kyneurenine, has immunologic significance for the induction of maternal tolerance and liver allograft tolerance by inhibiting T-cell activation. In the present study, we compared survival of syngeneic or allogeneic hepatocytes in livers with or without hepatectomy. Subsequently, we investigated gene expression and localization of IDO in the recipient liver.

METHODS

DA and Fisher 344 rats were used in the following experimental groups: group 1, DA hepatocytes transplanted into hepatectomized Fisher 344 rats; group 2, Fisher 344 hepatocytes transplanted into hepatectomized Fisher 344 rats; group 3, DA hepatocytes transplanted into nonhepatectomized Fisher 344 rats; and group 4, Fisher 344 hepatocytes transplanted into nonhepatectomized Fisher 344 rats. After transplantation, the surviving cells were evaluated on day 5. The IDO signal of the recipient liver was detected by reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry.

RESULTS

In the hepatectomized groups subjected to allogeneic or syngeneic hepatocyte transplantation, the number of surviving hepatocytes was greater than in the nonhepatectomized group after transplantation. The IDO signals (RT-PCR) in the hepatectomized groups were stronger than those in the nonhepatectomized groups. Immunohistochemistry demonstrated that the IDO signal is located in liver antigen-presenting cells, such as Kupffer cells or dendritic cells, and not expressed in hepatocytes.

CONCLUSIONS

Our results demonstrated that IDO is induced in antigen-presenting cells of hepatectomized livers by which subsequently transplanted cells may be protected from rejection by inhibiting indirect or direct recognition of donor antigen and further T-cell activation.

Brain damage by mild metabolic derangements in methylmalonic acidemia

Methylmalonic acidemia caused by an l-methylmalonyl-CoA mutase deficiency. The mut(0) type is associated with significant mortality and morbidity, but tandem mass spectrometry has made early detection possible. Five patients were identified through newborn screening for elevated propionylcarnitine (C3-carnitine) levels. These patients received a positive screening result at a median age of 10 days (range, 5-18 days). When treated at a median age of 11 days (range, 3-50 days), 2 patients were asymptomatic, and only one was significantly acidotic (pH <7.2), but all had various degrees of hyperammonemia (range, 127-1,244 mumol/L). Magnetic resonance imaging of the brain was performed in 4 patients shortly after diagnosis, and the results were all abnormal. Four patients were followed. There was no further metabolic decompensation after the initial episodes, but their mean developmental quotient was only 50. These results suggest that early hyperammonemia can lead to significant brain damage in methylmalonic acidemia. Therefore, treatment of this disease in newborns must be more aggressive.

Immunological role of indoleamine 2,3-dioxygenase in rat liver allograft rejection and tolerance

BACKGROUND AND AIM

Indoleamine 2,3-dioxygenase (IDO) is expressed in the placenta and plays an essential role in maternal tolerance. Recent data showed that giving IDO inhibitor blocked liver allograft tolerance. However, the immunological role of IDO in rat liver allograft models has not been characterized. In the present study, the time-course of IDO expression and the localization of IDO were analyzed to address the role of IDO in the induction of tolerance.

METHODS

Rat orthotopic liver transplantations (OLT) were performed and IDO gene expression of OLT livers was analyzed. Immunohistochemistry was used to evaluate the localization of IDO-expressed cells in the liver.

RESULTS

The IDO gene was detected in the allogeneic liver graft at the acute phase but the signal could not be detected when these OLT rats were treated with cyclosporinee A. The time-course of IDO gene expression in liver grafts of the spontaneous tolerant OLT model revealed that the IDO mRNA was expressed in both the rejection phase and the induction phase of tolerance, but the signal was gradually lowered during the maintenance phase of tolerance. Immunohistochemistry confirmed that the IDO protein was detected in antigen-presenting cells but not in hepatocytes.

CONCLUSION

Our results demonstrated that IDO is induced in antigen-presenting cells of rat liver allografts under drug-free status, suggesting that indirect or direct recognition of donor antigen and further T-cell activation may be inhibited. IDO may act as a local immunosuppressive molecule to protect transplanted cells, tissues and organs from immune attack.

Alloantigen-pulsed host dendritic cells induce T-cell regulation and prolong allograft survival in a rat model of hindlimb allotransplantation

BACKGROUND

Composite tissue allotransplantation is restricted due to the risks presented by long-term therapeutic immunosuppression. This study is conducted to investigate whether treatment with recipient immature dendritic cells (DCs) pulsed with donor alloantigens can prolong allograft survival and induce T-cell regulation in a rodent model.

MATERIALS AND METHODS

Orthotopic hindlimb transplants from Brown-Norway (RT1(n)) to Lewis (RT1(1)) rats were performed (day 0). DCs were propagated from the recipient bone marrow and pulsed with the donor alloantigen lysate. Group 1 (control group) did not receive any treatment. Groups 2 and 3 received cyclosporine A (CsA) at a concentration of 10 and 16 mg.kg(-1).day(-1), respectively, on days 0-20 following composite tissue allotransplantation. Group 4 received antilymphocyte serum (i.p. administered 4 d before and 1 d after transplantation) therapy. Group 5 received combined treatment with CsA (10 mg.kg(-1).day(-1), days 0-20) and donor alloantigen-pulsed recipient DCs (i.v. administered on days 7, 14, and 21). Group 6 received combined treatment with CsA (10 mg.kg(-1).day(-1) on days 0-20), antilymphocyte serum (administered i.p. 4 d before and 1 d after transplantation), and DCs (administered i.v. on days 7, 14, and 21). Graft rejection was defined as epidermolysis/desquamation of the donor skin. The mixed lymphocyte reaction was performed to determine the donor T-cell reactivity. Tissue samples were biopsied to analyze the histological changes, and flow cytometry was performed to quantify the donor T-cells.

RESULTS

Allograft survival was significantly prolonged (>200 d) in Group 6 when compared with the other groups (P < 0.001). The mixed lymphocyte reaction performed for Group 6 revealed hyporesponsiveness of the T-cells to donor alloantigens. Flow cytometric analysis in Group 6 revealed a significant increase in the percentage of CD4(+)/CD25(+) and CD4(+)/foxP3(+) T-cells expression, and significant increase in the percentage of donor cells (RT1(n)) in the recipient peripheral blood. Immunohistochemical staining of allo-skin revealed a significant increase in the proportion of CD25(+) cells in the subcutaneous and dermis layers in Group 6, as compared to other groups.

CONCLUSION

Treatment with donor alloantigen-pulsed recipient immature DCs in combination with transient immunosuppression prolongs allograft survival and induced tolerance by inducing T-cell hyporesponsiveness to donor alloantigens and increasing the CD4(+)/CD25(+) T-cell population.

Involvement of autoimmunity against nuclear histone H1 in liver transplantation tolerance

BACKGROUND

Our recent studies suggested that anti-histone H1 autoantibody (auto-Ab) plays an important role in experimental and clinical liver allograft tolerance as a natural immunosuppressive factor. The present study aimed to explore how the autoimmune response against histone H1 is involved in tolerance induction.

METHODS

The measurement of anti-histone H1 auto-Ab and immunohistochemical analysis were performed in serum and liver allografts after orthotopic liver transplantation (OLT). To compare the auto-Ab response against histone H1 between the recipients of rejector (DA-LEW) and tolerogenic (DA-PVG) OLT models, naïve recipients were immunized with calf thymus histone H1. The immunosuppressive state of histone H1-immunized rats was assayed by mixed lymphocyte reaction (MLR).

RESULTS

Anti-histone H1 Ab titer was transiently increased during the rejection phase after OLT (days 7-21) in the DA-PVG combination, while no such response was confirmed in the DA-LEW acute rejection model. Nuclear histone H1 antigens were found in the cytoplasm and the extracellular environment in liver allografts at the rejection phase in the tolerogenic model but not in the rejector model, resulting from the transient induction of anti-histone H1 auto-Ab in recipient PVG rats after OLT. Low dose and short-term immunization with histone H1 upregulated the anti-histone H1 Ab titer in naïve PVG rats, which exhibited a low allogeneic immune response, while no such response was found in naïve LEW rats.

CONCLUSIONS

These results suggest that the sensitivity to nuclear antigens such as histone H1 may be a key factor determining the acceptance or rejection of donor liver grafts, at least in DA-PVG and DA-LEW combinations.

The role of a nuclear protein, histone H1, on signalling pathways for the maturation of dendritic cells

We have demonstrated previously that liver allograft tolerance is associated with the immunosuppressive activity of anti-histone H1 autoreactive antibodies induced in the serum of liver transplantation. Furthermore, we and others have shown that nuclear proteins such as histone H1 and high mobility group box 1 play an important role in maturation of dendritic cells (DCs), although the precise mechanisms are still unknown. In the present study, we focus upon the significance of histone H1 on DCs in terms of the intracellular signalling pathway of DCs. Our immunostaining and immunoblot studies demonstrated that histone H1 was detected in cytoplasm and culture supernatants upon the activation of DCs. Histone H1 blockage by anti-histone H1 antibody down-regulated the intracellular activation of mitogen-activated protein kinases (MAPKs) (p38) and IkappaBalpha of DCs, and inhibited DC activity in the proliferation of CD4+ T cells. On the other hand, the addition of histone H1 without endotoxin stimulation up-regulated major histocompatibility complex class II, the CD80 and CD86 surface markers of DCs and the activation of MAPKs (p38 and extracellular-regulated kinase 1/2) and IkappaBalpha. These results suggest that the translocation of histone H1 from nuclei to cytoplasm and the release of their own histone H1 are necessary for the maturation of DCs and the activation for T lymphocytes.

Heat preconditioning ameliorates hepatocyte viability after cold preservation and rewarming, and modulates its immunoactivity

BACKGROUND

Heat preconditioning significantly preserved liver graft function after cold preservation in animal experimental model. The elevation of heat shock protein 70 (HSP70) was claimed to play a critical role in protecting grafts against cold preservation-induced hepatocyte apoptosis. However, little is known about whether HSP70 also plays an immunomodulatory role in cold preserved cells. This study aimed at investigating the relationship between HSP70 protein and the immunoactivity in response to lipopolysaccharide (LPS) stimulation.

METHODS AND RESULTS

A normal rat hepatocyte cell line was preserved with University of Wisconsin (UW) solution, Ringer's lactate solution (RL), and phosphate-buffered saline (PBS) at 4 degrees C. No significant morphological alteration was noted in UW-preserved cells after 24 h through phase-contrast microscopic observation and fluorescent viability stain. Western blotting showed a two-fold increase in the ratio of HSP70/Bax proteins in cells after 24 h of UW preservation. Heat preconditioning significantly enhanced the recovery of lactate dehydrogenase (LDH) activity in both RL- and UW-preserved cells that were stored for a period of 12 h or less. Moreover, heat preconditioning promoted HSP70 and NF-kappaB p50 nuclear translocation and suppressed the LPS-induced nuclear p50 accumulation in cells before UW preservation. Immunofluorescent stain revealed that the LPS-induced p50 protein redistribution to nuclear membrane might contribute to NF-kappaB activation, while heat preconditioning and UW cold preservation completely abrogated the p50 intranuclear redistribution. Thus NF-kappaB p50 might be responsible for the endotoxin tolerance induction.

CONCLUSIONS

These findings strongly suggest that heat preconditioning not only preserves hepatocyte viability after cold preservation and rewarming, but also ameliorates its immunoactivity.

Functional network analysis of the transcriptomes of mesenchymal stem cells derived from amniotic fluid, amniotic membrane, cord blood, and bone marrow

Using high-density oligonucleotide microarrays and functional network analyses, we examined whether MSCs derived from four different origins exhibited unique gene expression profiles individually and then compared the gene expression profiles of all MSCs with those of fetal organs. Our results indicated that within each group of MSCs from the same origin, the variability of the gene expression levels was smaller than that between groups of different origins. Functional genomic studies revealed the specific roles of MSCs from different origins. Our results suggest that amniotic fluid MSCs may initiate interactions with the uterus by upregulating oxytocin and thrombin receptors. Amniotic membrane MSCs may play a role in maintaining homeostasis of fluid and electrolytes by regulating the networks of endothelin, neprilysin, bradykinin receptors, and atrial natriuretic peptide. Cord blood MSCs may be involved in innate immune systems as the neonatal defense system against the earliest encountered pathogens. Adult bone marrow MSCs may be an important source not only of all blood lineages but also of bone formation. However, in spite of the different gene expression profiles seen in MSCs derived from different origins, a set of core gene expression profiles was preserved in these four kinds of MSCs. The core signature transcriptomes of all MSCs, when contrasted against those of fetal organs, included genes involved in the regulation of extracellular matrix and adhesion, transforming growth factor-beta receptor signaling, and the Wnt signaling pathways. Disclosure of potential conflicts of interest is found at the end of this article.

Experimental and clinical significance of antinuclear antibodies in liver transplantation

Histone H1 and high-mobility group box 1 (HMGB1) proteins are known to initiate an immune reaction, and the corresponding antibodies (Abs) possess immunosuppressive activity. In the present study, we aimed to evaluate the immunological role of antinuclear Abs in experimental and clinical liver transplantation. In a rat tolerogenic orthotopic liver transplantation (OLT) model, antihistone H1 and HMGB1 titers were induced during the rejection and tolerance induction phases, respectively. Those Ab responses also were confirmed in a drug-induced tolerance model (acute rejection model + cyclosporin A [0 to 14 days after OLT]). We also found a similar tendency in our clinical drug-free patient (who experienced complete cessation of any immunosuppressive treatments) and that antinuclear Abs induced in the serum after cessation of immunosuppressants play a part of immune privilege in this patient. These results suggest that antinuclear Abs are important factors for overcoming rejection and the subsequent tolerance induction in liver transplantation.

The immunological role of lipid transfer/metabolic proteins in liver transplantation tolerance

BACKGROUND

In a rat tolerogenic orthotopic liver transplantation (OLT) model, recipient serum after OLT (post-OLT serum) has been reported to prevent allograft rejection. A previous proteomic study indicated that apolipoprotein E (apo-E), which is an important factor for cholesterol transportation, is expressed at the latter tolerogenic phase after OLT. It has also been known that adipose tissue-derived adipokine, adiponectin, is an essential factor for fatty acid catabolism. This study aimed to characterize the role of lipid transfer/metabolic proteins in liver transplantation tolerance.

METHODS

To identify the apo-E and adiponectin in post-OLT serum, Western analyses and enzyme-linked immunosorbent assay (ELISA) were performed, respectively. The immunosuppressive activities of those factors were evaluated by inhibition of the mixed lymphocyte reaction (MLR).

RESULTS

Western analyses showed that the mobility of apo-E was shifted at the latter tolerogenic phase after OLT in a natural tolerance model, and a similar phenomenon was confirmed in the serum of a drug-induced tolerance model (rejection model+cyclosporin A (CsA); 0 to 14 days) after cessation of CsA. Further study revealed that neutralization of modified apo-E in post-OLT serum reduced the immunosuppressive activity. Additionally, plasma adiponectin was significantly elevated at the latter phase after OLT, and possessed MLR-inhibitory activity.

CONCLUSIONS

These results suggest that the mobility shift of apo-E and/or the up-regulation of adiponectin may be necessary for overcoming the rejection, recovering the liver allograft function, and following tolerance induction in experimental OLT models, and may be useful as one indicator to surmise the prognosis after liver transplantation.

Impact of vaccine therapy using nuclear histone H1 on allograft survival in experimental organ transplantation

BACKGROUND

We recently reported that autoreactive antibody (Ab) against nuclear histone H1 had been identified as an immunosuppressive factor in a rat tolerogenic orthotopic liver transplantation (OLT) model. The present study aimed to determine whether the up-regulation of antihistone H1 Ab by histone H1 vaccination leads to tolerance.

METHODS

Histone H1-immunized rats were established by intraperitoneal vaccination with histone H1 at every two-weekly interval. By using mixed lymphocyte reaction (MLR) and heterotopic heart transplantation (HHT), the alloreactive T cell response and allograft survival of histone H1-immunized rats were compared with those of control rats. Cytokine and cellular profiles in histone H1-immunized rats were determined by reverse transcriptase polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA) and flow cytometry.

RESULTS

Immunization with histone H1 in Freund's adjuvant induced alloreactive T cell unresponsiveness and prolonged heterotopic heart allograft survival. It also down-regulated the expression of major histocompatibility complex (MHC) class II and CD25 on splenic cells, elevated the T helper cell type 2 (Th2) skewing index (Interleukin (IL)-4/interferon (IFN)-gamma ratio or IL-4/IL-2 ratio) and modified the serum cytokine profiles.

CONCLUSIONS

The present results suggest that histone H1 vaccination of transplant recipients, which leads to the production of immunosuppressive factor and the modification of the cytokine/cellular profiles, has great potential as a tolerance therapy for prospective transplantation.

Immunosuppressive activity of serum taken from a liver transplant recipient after withdrawal of immunosuppressants

In orthotopic liver transplantation (OLT), tolerance is induced in a certain combination of donors and a recipient in rats and, in some clinical cases, rejection has not occurred in OLT patients after weaning off immunosuppression. However, this mechanism has not yet been elucidated. Among our cases of liver transplantation (LTx), one OLT patient (Patient A) has not required immunosuppressive drugs for the last 5 years, following post-transplant lymphoproliferative disease (PTLD). This patient's serum interleukin-2 levels were undetectable following withdrawal of immunosuppressants. The same serum taken after discontinuing the immunosuppressants inhibited concanavalin A blast cultured cells and up-regulated the IL-4/IFN-gamma gene expression ratio. These results suggested that other proteins were induced following withdrawal of immunosuppressants. Proteomic assay demonstrated 12 differentiated spots exclusive to this patient where immunosuppressants have been discontinued. Haptoglobin, found to have immunosuppressive activity in vitro, may play an important role in the maintenance of drug-free tolerance as a natural immunological suppressor after cessation of immunosuppression. Proteomic analysis will allow us to develop a novel weaning protocol for patients on long-term immunosuppression to avoid major immunosuppressant-related complications.

The effects of anti-histone H1 antibody on immune cells responsible for rejection reaction

We previously demonstrated the immunosuppressive activity of anti-histone H1 autoreactive antibodies (Ab) transiently induced in serum of a rat tolerogenic orthotopic liver transplantation (OLT) model. In the present study, we investigated the effects of anti-histone H1 Ab on dendritic cells (DCs), T-cells, lymphokine-activated killer (LAK) cells, and human natural killer (NK) cells. The effects of anti-histone H1 Ab on Concanavalin A (ConA) blast, on rat DC cytokine profiles and phenotypes, and on T-cells, LAK cells, and human NK cells were examined by flow cytometry and RT-PCR. The cytotoxicity of LAK and NK cells pretreated with anti-histone H1 Ab was assayed. The addition of anti-histone H1 Ab to ConA blast inhibited the proliferation of 5-(6)-carboxy-fluorescein succinimidyl ester (CFSE)-labeled lymphocytes without toxicity but increased the population of CD4+CD25+ T-cells. DCs treated with anti-histone H1 Ab expressed lower levels of CD80/CD86, IL-1beta, and IL-6. The addition of anti-histone H1 Ab to LAK culture decreased the percentages of NKR-P1 populations and down-regulated levels of inducible nitric oxide synthase (iNOS), IL-2, and INF-gamma in RT-PCR. The cytotoxicity of LAK and NK cells was lower when pretreated with anti-histone H1 Ab than when pretreated with control IgG. We found that the blockade of histone H1 modulated DCs toward tolerogenic status, decreased the cytotoxicity of LAK and NK cells, and induced CD4+CD25+ T-cells. These results suggest that the use of anti-histone H1 Abs might be a useful strategy for the development of a form of immunosuppression.

Roles of ionotropic glutamate receptors in early developing neurons derived from the P19 mouse cell line

We cultured a P19 mouse teratocarcinoma cell line and induced its neuronal differentiation to study the function of ionotropic glutamate receptors (GluRs) in early neuronal development. Immunocytochemical studies showed 85% neuronal population at 5 days in vitro (DIV) with microtubule-associated protein 2-positive staining. Thirty percent and 50% of the cells expressed the alpha-amino-3-hydroxy-5-methyl-4-isopropinonate (AMPA) receptor subunit, GluR2/3, and the kainate (kainic acid; KA) receptor subunit, GluR5/6/7, respectively. In Western blot analysis, the temporal expression of GluR2/3 began to appear at 3 DIV, whereas GluR5/6/7 was already expressed in the undifferentiated cells. P19-derived neurons began to respond to glutamate, AMPA and KA, but not to the metabotropic GluR agonist trans-1-aminocyclopentane-1,3-decarboxylic acid, by 5 DIV in terms of increases in intracellular calcium and phospholipase C-mediated poly-phosphoinositide turnover. Furthermore, KA reduced cell death of P19-derived neurons in both atmospheric and hypobaric conditions in a phospholipase C-dependent manner. The common AMPA/KA receptor antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione, but not the AMPA receptor antagonist, 1,2,3,4-tetrahydro-6-nitro-2,3-dioxo-benzo[f]quinoxaline-7-sulfonamide disodium, profoundly increased hypobaric insult-induced neurotoxicity. In a flow cytometry study, the nerve growth factor-mediated antiapoptotic effect was facilitated by AMPA, with an induction of TrkA, but not p75(NTR) expression. Therefore, AMPA and KA receptors might mediate neurotrophic functions to facilitate neurotrophic factor signaling to protect neurons against hypoxic insult in early neuronal development.

Identification of two down-regulated genes in rat liver allografts by mRNA differential display

Total RNA differential display (DD) using random primers was performed for rat orthotopic liver transplantation (OLT) models. DA (RT1a) donor livers were transplanted into DA, PVG (RT1c), and LEW (RT1l) recipients: (1) syngeneic OLT (DA-DA): no rejection occurs; (2) allogeneic OLT (DA-PVG): rejection occurs, but is naturally overcome without immunosuppression; (3) allogeneic OLT (DA-LEW): animals die of acute rejection within 14 days. cDNA was isolated from selected bands, re-amplified for sequencing, and confirmed by Northern blots. Two down-regulated genes were observed in day-7 allogeneic OLT livers (DA-PVG, DA-LEW), while they were consistently expressed in day-7 syngeneic OLT (DA-DA) livers. These two genes were identified as alpha-glutathione sulfotransferase (alpha-GST) Ya gene and estrogen sulfotransferase (EST), respectively. Northern blots confirmed that their expression was down-regulated in OLT (DA-PVG) livers on days 7-26 and gradually restored. The mRNA expression of GST and EST may be good markers to predict rejection or induction of tolerance.

Effect of different concentrations of recombinant leukemia inhibitory factor on different development stage of mouse embryo in vitro

PURPOSE

To assess the influence of different concentrations of recombinant human leukemia inhibitory factor (LIF) on the in vitro development of mouse embryos.

METHODS

The 2- to 4-cell embryos of CB6F1 mice were cultured in the human tubal fluid (HTF) media containing different concentrations of LIF. Mouse embryos were divided into seven groups: (1) HTF; (2) 1500 IU/ml LIF; (3) 1000 IU/ml LIF; (4) 750 IU/ml LIF; (5) 500 IU/ml LIF; (6) 250 IU/ml LIF; (7) 125 IU/ml LIF. The embryonic numbers of different stages including 5-8 cell, 9-16 cell, morula, blastocyst, and hatching blastocyst were recorded.

RESULTS

The percentage of early embryo stage (2-cell embryos to 6- to 16-cell stages) in all groups were nonsignificantly different. There were higher formation rates of preimplantation embryos (morula to hatching blastocyst) in groups 2, 3, 4, and 5 than in groups 1, 6 and 7.

CONCLUSIONS

LIF has positive effects on preimplantation embryo development and has nonsignificant influence on the early embryo development. The lowest concentration of LIF which could provide the optimal embryo development is 500 IU/ml.

Clusterin may be involved in rat liver allograft tolerance

Little is known about the possible role of complement inhibitors on tolerance induced by liver allografts. Clusterin, which is a plasma glycoprotein, inhibits cytolytic membrane attack complex (MAC) of complement by binding to soluble C5b-7 complex. The role of clusterin in relation to the naturally achieved tolerance in a rat orthotopic liver transplantation (OLT) has not been investigated before. Here we determined the kinetics of clusterin expression at different post-transplantation time points in a tolerogenic model (DA-PVG) where rejection was naturally overcome without any immunosuppressive drugs in comparison with the syngenic OLT model (DA-DA). Peripheral blood and liver tissues were taken from OLT at various post-operative time points. A strong expression of soluble clusterin was observed on post-transplantation day 7, which occurred at the peak of the rejection in this tolerogenic OLT model. The expression of clusterin remained strong even after tolerance was achieved. The intensity of clusterin expression was much stronger when compared with the syngenic OLT (DA-DA) model after OLT. A strong expression of clusterin mRNA was also observed in the tolerogenic model on post-OLT day (POD) 7 and the expression persisted when compared with the syngenic model on post-OLT day 60. Our data have shown that the strongest levels of clusterin during the reaction phase in tolerogenic OLT may be involved in tolerance induction.

Prolonged culture of human cryopreserved embryos with recombinant human leukemia inhibitory factor

PURPOSE

To evaluate the efficiency of recombinant human leukemia inhibitory factor (LIF) in the prolonged culture of human cryopreserved-thawing embryos.

METHODS

After thawing, all embryos were divided into four groups: (1) Human tubal fluid (HTF), (2) HTF + LIF, (3) M3TH medium, and (4) M3TH medium plus LIF. Following prolonged culture, embryo development in each group was compared.

RESULTS

In embryo development from about the 2- to 4-cell to 9- to 16-cell stage, there were nonsignificant differences between each group. There was lower morula formation rate in group 1 (6.9%) than those in other groups (23.2%, 19.7%, 23.1%). The lower blastocyst formation in group 1 and 3 (0%, 0%) than those in group 2 and 4 (11.0%, 12.8%) were noted.

CONCLUSIONS

LIF is beneficial for preimplantation embryos. LIF does not influence the early embryo development. LIF-supplemented HTF provided a similar culture environment for thawing embryos as LIF-supplemented M3TH medium.

Recombinant human leukemia inhibitory factor enhances the development of preimplantation mouse embryo in vitro

OBJECTIVE

To assess the effect of recombinant human leukemia inhibitory factor (rhLIF) on mouse embryos in vitro.

DESIGN

Controlled prospective study.

SETTING

Academic research environment.

ANIMAL(S)

Female CB6F1 mice between 6 and 8 weeks old.

INTERVENTION(S)

Mice were divided randomly into three groups, which included a control group in an in vivo study (group I) and two groups in an in vitro study (groups II and III). Mice were killed at 116-120 hours (group I) and 44-48 hours (groups II and III) after hCG injection. Two-cell embryos (groups II and III) and blastocysts (group I) were obtained. Embryos in group II were cocultured with human tubal fluid (HTF) + 0.5% human serum albumin and in group III with HTF + rhLIF (1,000 U/mL) under paraffin oil.

MAIN OUTCOME MEASURE(S)

The embryonic numbers in different stages were recorded and compared.

RESULT(S)

Similar early embryo development to the four- to eight-cell and morula stages was noted between groups II and III (87.3% versus 91.0% and 74.6% versus 87.1%, respectively). However, further embryo development to the blastocyst, expanded blastocyst, and hatching blastocyst in group II (48.1%, 31.7%, and 18.5%, respectively) was lower than that in group III (83.6%, 53.7%, and 37.8%).

CONCLUSION(S)

RhLIF does not provide obvious stimulation in the early mouse embryo. However, rhLIF has positive effects on preimplantation blastocyst growth, differentiation, and hatching.

Nutritional value for growing turkeys of corn of light test weight

An experiment was conducted to determine the relationship between test weight of corn and growth, efficiency of feed utilization, nutrient retention, and carcass composition of young turkeys. The MEn values of corn were also measured. Two samples of corn differing substantially in test weight were fed to male turkey poults (Nicholas Large White) from 1 to 20 d of age. The test weights of the light-weight corn and the normal-weight corn were 55 kg/hL (43 lb/bu) and 70 kg/hL (54 lb/bu), respectively. The light-weight corn was lower in crude protein concentration (6.63%) than the normal-weight corn (8.53%). The determined MEn of the corn samples did not differ (3.22 vs 3.25 kcal/g). The light-weight corn diet had modest adverse effects on growth and feed efficiency of poults during the 1 to 7 d after hatching. Poult carcass composition and retention of nitrogen and energy were not affected by the test weight of corn.

Identification of two elements involved in regulating expression of the murine leukaemia inhibitory factor gene

Mouse leukaemia inhibitory factor (LIF) is a polyfunctional cytokine which exhibits multiple functions in vitro and in vivo. Two forms of LIF cDNA, differing at their 5' ends, have been described encoding either diffusible (D-LIF) or matrix-associated (M-LIF) forms of the protein [Rathjen, Toth, Willis, Heath and Smith (1990) (Cell 62, 1105-1114]. The present report describes the DNA sequence and functional characterization of the murine LIF gene and its surrounding transcriptional regulatory elements. Transient transfection of constructs containing the LIF gene and various amounts of 5'-non-coding sequence failed to give detectable levels of expression, suggesting the presence of inhibitory sequences within the LIF gene. Stable cell lines were produced by transfection of experimental constructs containing various lengths of 5'-non-coding sequence of the LIF gene, or the heterologous phosphoglycerate kinase promoter, linked to an LIF/neomycin-resistance-hybrid-coding sequence. The frequency of recovery of stable clones indicated that sequences located in the first intron between the transcriptional start sites for D-LIF and M-LIF act to suppress expression of the gene in most genomic locations. This region is rich in GC residues and has been shown to be hypomethylated in vitro [Kaspar, Dvorak and Bartunek (1993) FEBS Lett. 319, 159-162]. Analysis of the LIF/neomycin-resistance transgene expression in these stable cell clones demonstrated that transcripts containing the M-LIF or D-LIF exons required the presence of sequences located between -1200 and -3200 in the LIF gene. In the absence of these sequences, transcription is initiated elsewhere within the first intron. These sequences can be replaced by the heterologous phosphoglycerate kinase promoter. Deletion of the GC-rich region between the D-LIF and M-LIF transcriptional start sites results in the appearance of transcripts that do not splice out the first intron of the LIF gene. These may result from gene or promoter trapping of the LIF gene. Sequence analysis of the region between -1200 and -3200 revealed a number of minimal steroid-response elements, regions of similarity to DNAase I-hypersensitive sites in the uteroglobin gene and a region of alternating purine/pyrimidine sequence. This study therefore defines two important regulatory regions in the LIF gene: a GC-rich region in the first intron and a distal 'enhancer' located between -3200 and -1200.

Growth and differentiation factors of pluripotential stem cells

The mammalian embryo develops as a quasi-stem cell system whose differentiation and pluripotentiality in vitro is controlled by a single regulatory factor, Differentiation Inhibiting Activity/Leukemia Inhibitory Factor (DIA/LIF). DIA/LIF is expressed in two distinct functional forms, derived from the use of alternate transcriptional start sites, one of which is freely diffusible and the other tightly associated with the extracellular matrix. The dissemination of the DIA/LIF signal is therefore under specific molecular control. The expression of DIA/LIF in vitro is both developmentally programmed and controlled by the action of other growth factors, the most notable of which are members of the fibroblast growth factor family expressed by the stem cells themselves. This indicates that differentiation and proliferation in early development of the mouse are controlled, at least in part, by an interactive network of specific growth and differentiation regulatory factors.

Response to and concentration of interleukin-2 in patients with nasopharyngeal carcinoma

To seek beneficial immunomodulation with interleukin-2 (IL-2) for patients with nasopharyngeal carcinoma (NPC), a study was conducted of the response to and concentration of IL-2 by mononuclear cells (MNC) from 45 NPC patients who had been pathologically verified, but pre-treatment, at the time they were studied. Thirty-eight normal healthy controls were studied simultaneously. Lymphocyte subsets did not change much after IL-2 stimulation in either NPC patients or the controls. A decreased IL-2 concentration was found in NPC, and a trend of inverse correlation to clinical staging was detected; the more advanced stage, the less concentration of IL-2. It was concluded that there was a normal response to and decreased concentration of, IL-2 in NPC patients. Whether decreased concentration of IL-2 in NPC patients resulted from decreased production or increased consumption is not clear. A further research of IL-2 immunomodulation in NPC patients should be done before its clinical application.