Signal Transducer and Activator of Transcription 3 (STAT3) and Suppressor of Cytokine Signaling (SOCS3) Balance Controls Cytotoxicity and IL-10 Expression in Decidual-Like Natural Killer Cell Line NK-92

Metabolomics of human umbilical vein endothelial cell-based analysis of the relationship between hyperuricemia and dyslipidemia

BACKGROUND AND AIMS

Hyperuricemia frequently accompanies dyslipidemia, yet the precise mechanism remains elusive. Leveraging cellular metabolomics analyses, this research probes the potential mechanisms wherein hyperuricemia provokes endothelial cell abnormalities, inducing disordered bile metabolism and resultant lipid anomalies.

METHODS AND RESULTS

We aimed to identify the differential metabolite associated with lipid metabolism through adopting metabolomics approach, and thereafter adequately validating its protective function on HUVECs by using diverse assays to measure cellular viability, reactive oxygen species, migration potential, apoptosis and gene and protein levels of inflammatory factors. Taurochenodeoxycholic acid (TCDCA) (the differential metabolite of HUVECs) and the TCDCA-involved primary bile acid synthesis pathway were found to be negatively correlated with high UA levels based on the results of metabolomics analysis. It was noted that compared to the outcomes observed in UA-treated HUVECs, TCDCA could protect against UA-induced cellular damage and oxidative stress, increase proliferation as well as migration, and decreases apoptosis. In addition, it was observed that TCDCA might protect HUVECs by inhibiting UA-induced p38 mitogen-activated protein kinase/nuclear factor kappa-B p65 (p38MAPK/NF-κB p65) pathway gene and protein levels, as well as the levels of downstream inflammatory factors.

CONCLUSION

The pathogenesis of hyperuricemia accompanying dyslipidemia may involve high uric acid levels eliciting inflammatory reactions and cellular damage in human umbilical vein endothelial cells (HUVECs), mediated through the p38MAPK/NF-κB signaling pathway, subsequently impinging on cellular bile acid synthesis and reducing bile acid production.

Natural Killer Cell Derived Microvesicles Affect the Function of Trophoblast Cells

The interaction of natural killer (NK) and trophoblast cells underlies the formation of immune tolerance in the mother-fetus system and the maintenance of the physiological course of pregnancy. In addition, NK cells affect the function of trophoblast cells, interacting with them via the receptor apparatus and through the production of cytokines. Microvesicles (MVs) derived from NK cells are able to change the function of target cells. However, in the overall pattern of interactions between NK cells and trophoblasts, the possibility that both can transmit signals to each other via MVs has not been taken into account. Therefore, the aim of this study was to assess the effect of NK cell-derived MVs on the phenotype, proliferation, and migration of trophoblast cells and their expression of intracellular messengers. We carried out assays for the detection of content transferred from MV to trophoblasts. We found that NK cell-derived MVs did not affect the expression of CD54, CD105, CD126, CD130, CD181, CD119, and CD120a receptors in trophoblast cells or lead to the appearance of CD45 and CD56 receptors in the trophoblast membrane. Further, the MVs reduced the proliferation but increased the migration of trophoblasts with no changes to their viability. Incubation of trophoblast cells in the presence of MVs resulted in the activation of STAT3 via pSTAT3(Ser727) but not via pSTAT3(Tyr705). The treatment of trophoblasts with MVs did not result in the phosphorylation of STAT1 and ERK1/2. The obtained data indicate that NK cell-derived MVs influence the function of trophoblast cells, which is accompanied by the activation of STAT3 signaling.

The hydrophobic tail of a pH-sensitive cationic lipid influences siRNA transfection activity and toxicity in human NK cell lines

The use of natural killer (NK) cells in cell therapy is an attractive next generation strategy for cancer immunotherapy. NK-92 cells (a human NK cell line) have been tested in clinical trial stages, making them an off-the-shelf medicine. Controlling gene expression in NK-92 cells by an artificial delivery system is an available for enhancing NK-92 cell therapy. We report here on the development of a siRNA-loaded lipid nanoparticle (LNP) composed of CL1H6 (CL1H6-LNP), an optimized, pH-sensitive cationic lipid, with efficient gene silencing and low cytotoxicity in NK-92 cells. The hydrophilic head group of the lipid molecule used in preparing these particles largely influences the pK_a of the final LNP, and lipids with an amino moiety substituted with a methyl group showed a high gene silencing activity. Compared with myristate and palmitate, the hydrophobic tail of oleate had a high gene silencing activity and cell viability. Analyses of intracellular trafficking indicated that the CL1H6-LNP appeared to escape from the endosomes via membrane fusion, without disrupting the membrane. The mechanism of endosomal escape should contribute to our understanding of efficient gene silencing with a low degree of cytotoxicity. These results therefore suggest that a CL1H6-LNP has promise for delivering siRNA to NK-92 cells.

SOCS Proteins in Immunity, Inflammatory Diseases, and Immune-Related Cancer

Cytokine signaling represents one of the cornerstones of the immune system, mediating the complex responses required to facilitate appropriate immune cell development and function that supports robust immunity. It is crucial that these signals be tightly regulated, with dysregulation underpinning immune defects, including excessive inflammation, as well as contributing to various immune-related malignancies. A specialized family of proteins called suppressors of cytokine signaling (SOCS) participate in negative feedback regulation of cytokine signaling, ensuring it is appropriately restrained. The eight SOCS proteins identified regulate cytokine and other signaling pathways in unique ways. SOCS1–3 and CISH are most closely involved in the regulation of immune-related signaling, influencing processes such polarization of lymphocytes and the activation of myeloid cells by controlling signaling downstream of essential cytokines such as IL-4, IL-6, and IFN-γ. SOCS protein perturbation disrupts these processes resulting in the development of inflammatory and autoimmune conditions as well as malignancies. As a consequence, SOCS proteins are garnering increased interest as a unique avenue to treat these disorders.

A Brief Analysis of Tissue-Resident NK Cells in Pregnancy and Endometrial Diseases: The Importance of Pharmacologic Modulation

NK cells are lymphocytes involved in the innate and adaptative immune response. These cells are located in peripheral blood and tissues with ample functions, from immune vigilant to tolerogenic reactions. In the endometrium, NK cell populations vary depending on age, hormones, and inflammation. When pregnancy occurs, tissue-resident NK cells and conventional NK cells are recruited to protect the fetus, a tolerogenic response. On the contrary, in the inflamed endometrium, various inflammatory cells down-regulate NK tolerance and impair embryo implantation. Therefore, NK cells’ pharmacological modulation is difficult to achieve. Several strategies have been used, from progesterone, lipid emulsions to steroids; the success has not been as expected. However, new therapeutic approaches have been proposed to decrease the endometrial inflammatory burden and increase pregnancy success based on understanding NK cell physiology.

The Role of Tim-3 on dNK Cells Dysfunction During Abnormal Pregnancy With Toxoplasma gondii Infection

Vertical transmission of Toxoplasma gondii (T. gondii) infection during gestation can result in severe complications such as abortion, congenital malformation, fetal teratogenesis, etc. Immune inhibitory molecule Tim-3 was discovered to be expressed on some decidual immune cells and participates in the maintenance of maternal-fetal tolerance. Dysregulation of Tim-3 expression on decidual NK (dNK) cells was observed in several cases of pregnancy complications, whereas the role of Tim-3 on dNK cells during T. gondii infection remains unclear. In the present study, T. gondii infected Tim-3^-/- pregnant mice, and anti-Tim-3 neutralizing antibody treated and infected human dNK cells were successfully established to explore the role of Tim-3 in dysfunction of dNK cells during abnormal pregnancy. Our results illustrated that Tim-3^-/- pregnant mice displayed more worse pregnancy outcomes with T. gondii infection compared to infected WT pregnant mice. Also, it demonstrated that Tim-3 expression on dNK cells was significantly down-regulated following T. gondii infection. Data suggested a remarkable activation of dNK cells in Tim-3^-/- mice and anti-Tim-3 neutralizing antibody treated and infected groups, with higher ratios of activating receptor NKG2D to inhibitory receptor NKG2A or KIR2DL4, IFN-γ/IL-10, and increased granule production compared with that of the infected group. Mechanism analysis proved that T. gondii-induced Tim-3 down-regulation significantly activated the phosphatidylinositol-3-kinase (PI3K)-AKT and JAK-STAT signaling pathway, by which the GranzymeB, Perforin, IFN-γ, and IL-10 production were further up-regulated. Our research demonstrated that the decrease of Tim-3 on dNK cells caused by T. gondii infection further led to dNK cells function disorder, which finally contributed to the development of abnormal pregnancy outcomes.

Genetic and epigenetic modification of human primary NK cells for enhanced antitumor activity

Cancer immunotherapy using genetically modified immune cells such as those expressing chimeric antigen receptors has shown dramatic outcomes in patients with refractory and relapsed malignancies. Natural killer (NK) cells as a member of the innate immune system, possessing both anticancer (cytotoxic) and proinflammatory (cytokine) responses to cancers and rare off-target toxicities have great potential for a wide range of cancer therapeutic settings. Therefore, improving NK cell antitumor activity through genetic modification is of high interest in the field of cancer immunotherapy. However, gene manipulation in primary NK cells has been challenging because of broad resistance to many genetic modification methods that work well in T cells. Here we review recent successful approaches for genetic and epigenetic modification of NK cells including epigenetic remodeling, transposons, mRNA-mediated gene delivery, lentiviruses, and CRISPR gene targeting.

Determining the Molecular Background of Endometrial Receptivity in Adenomyosis

Background: Adenomyosis is a gynaecological condition with limited evidence of negative impact to endometrial receptivity. It is commonly associated with endometriosis, which has been shown to alter endometrial expression patterns. Therefore, the candidate genes identified in endometriosis could serve as a source to study endometrial function in adenomyosis. Methods: Transcripts/proteins associated with endometrial receptivity in women with adenomyosis or endometriosis and healthy women were obtained from publications and their nomenclature was adopted according to the HUGO Gene Nomenclature Committee (HGNC). Retrieved genes were analysed for enriched pathways using Cytoscape/Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) and Reactome tools to prioritise candidates for endometrial receptivity. These were used for validation on women with (n = 9) and without (n = 13) adenomyosis. Results: Functional enrichment analysis of 173, 42 and 151 genes associated with endometriosis, adenomyosis and healthy women, respectively, revealed signalling by interleukins and interleukin-4 and interleukin-13 signalling pathways, from which annotated LIF, JUNB, IL6, FOS, IL10 and SOCS3 were prioritised. Selected genes showed downregulated expression levels in adenomyosis compared to the control group, but without statistical significance. Conclusion: This is the first integrative study providing putative candidate genes and pathways characterising endometrial receptivity in women with adenomyosis in comparison to healthy women and women with endometriosis.

LETMD1 Regulates Phagocytosis and Inflammatory Responses to Lipopolysaccharide via Reactive Oxygen Species Generation and NF-κB Activation in Macrophages

LETM1 domain-containing protein 1 (LETMD1), also known as HCCR-1, is a mitochondrial protein and is known to regulate p53 and STAT3 activities in cancer cells. In this study, we present, for the first time (to our knowledge), data indicating that LETMD1 suppresses multiple immune responses in monocyte/macrophage lineage cells and mouse primary macrophages. Attenuation of LETMD1 expression with specific small interfering RNA and short hairpin RNA constructs enhanced LPS-induced expressions of inflammatory mediators in macrophages. In addition, LETMD1 attenuation caused potentiation of phagocytosis as well as migration in a macrophage-like cell line, U937. These enhancing effects were associated with altered activation of signaling adaptors (such as NF-κB, MAPKs, p53, and JAK-STAT) involved in TLR4 signaling. Especially, LETMD1 selectively regulated TLR4-induced NF-κB activation via MyD88 but not via TIR-domain-containing adapter-inducing IFN-β (TRIF). Attenuation of LETMD1 expression caused mitochondrial hyperpolarization and subsequent decrease in ATP production and increase in mitochondrial/cellular reactive oxygen species (ROS) and intracellular calcium levels. LETMD1 attenuation also enhanced LPS-induced expression of NADPH oxidase (NOX) 2, the main producer of cellular ROS in phagocytes, through augmenting IFN regulatory factor 1. Accordingly, treatment with ROS scavenger, NOX2 suppressing agents, or calcium chelators resulted in suppression of LPS-induced cytokine production as well as NF-κB activation in cells with LETMD1 attenuation. These findings reveal a previously unknown function of LETMD1 and provide evidences showing LETMD1 negatively regulates macrophage functions by modulating mitochondrial function, subsequent ROS generation, and NF-κB activation.

Discovery of a novel natural killer cell line with distinct immunostimulatory and proliferative potential as an alternative platform for cancer immunotherapy

BACKGROUND

Human natural killer (NK) cell lines serve as an attractive source for adoptive immunotherapy, but NK-92 remains the only cell line being assessed in the clinic. Here, we established a novel NK cell line, NK101, from a patient with extra-nodal natural killer/T-cell lymphoma and examined its phenotypic, genomic and functional characteristics.

METHODS

Single cell suspensions from lymphoma tissue were expanded with anti-NKp46/anti-CD2-coated beads in the presence of IL-2. A continuously growing CD56⁺ cell clone was selected and designated as NK101. Flow cytometry and RNA sequencing were used to characterize phenotypic and genomic features of NK101. In vitro cytotoxicity and IFN-γ/TNF-α secretion were measured by flow cytometry-based cytotoxicity assay and enzyme-linked immunosorbent assay, respectively, after direct co-culture with tumor cells. Immunomodulatory potential of NK101 was assessed in an indirect co-culture system using conditioned medium. Finally, in vivo antitumor efficacy was evaluated in an immunocompetent, syngeneic 4T1 mammary tumor model.

RESULTS

NK101 displayed features of CD56^dimCD62L⁺ intermediate stage NK subset with the potential to simultaneously act as a cytokine producer and a cytotoxic effector. Comparative analysis of NK101 and NK-92 revealed that NK101 expressed lower levels of perforin and granzyme B that correlated with weaker cytotoxicity, but produced higher levels of pro-inflammatory cytokines including IFN-γ and TNF-α. Contrarily, NK-92 produced greater amounts of anti-inflammatory cytokines, IL-1 receptor antagonist and IL-10. Genome-wide analysis revealed that genes associated with positive regulation of leukocyte proliferation were overexpressed in NK101, while those with opposite function were highly enriched in NK-92. The consequence of such expressional and functional discrepancies was well-represented in (i) indirect co-culture system where conditioned medium derived from NK101 induced greater proliferation of human peripheral blood mononuclear cells and (ii) immunocompetent 4T1 tumor model where peritumoral injections of NK101 displayed stronger anti-tumor activities by inducing higher tumor-specific immune responses. In a manufacturing context, NK101 not only required shorter recovery time after thawing, but also exhibited faster growth profile than NK-92, yielding more than 200-fold higher cell numbers after 20-day culture.

CONCLUSION

NK101 is a unique NK cell line bearing strong immunostimulatory potential and substantial scalability, providing an attractive source for adoptive cancer immunotherapy.

Pregnancy and the apoptotic pathway in experimental melanoma

Pregnancy-associated melanoma is defined as melanoma diagnosed during pregnancy or within 1 year of delivery. The association of pregnancy with melanoma is well known, but its underlying molecular mechanisms of association are poorly understood. The aim was to assess the expression of apoptosis-related genes in melanoma tumors during pregnancy in an attempt to elucidate the molecular mechanisms underlying apoptosis-driven activation of melanoma cells in this period. Mice were allocated across two experimental groups (nonpregnant and pregnant) and implanted with the melanoma cell line BF16-F10. Tumor tissue was collected for RNA extraction and purification, and gene expression was quantified using the mouse apoptosis RT2ProfilerTM PCR array. Different intracellular apoptotic pathways were activated (positively or negatively) by pregnancy in tumor cells: intrinsic (21.5%), extrinsic (32%), caspase (14%), apoptosis (21.5%), and caspase-activated DNase (11%). The proportion of upregulated genes for each of these pathways was 100, 30, 50, 17, and 0%, respectively. MetaCore software was then used to analyze gene ontology processes and pathways by building networks. Among the gene ontology processes, the majority of differentiated genes were related to the apoptotic process. The main pathway activated by pregnancy was the intrinsic one (genes Api-5, Bcl2-L1, Birc-2, Birc-3, Bok, and Trp53bp2). Pregnancy activates the intrinsic apoptosis pathway to stimulate caspases 7 and 9, but the final balance is inhibition of apoptosis mechanisms. In mice, pregnancy cannot promote or worsen melanoma.

Mapping out p38MAPK

To generate new hypotheses, sometimes a "systems" approach is needed. In this review, I focus on the mitogen-activated kinase p38 because it has been recently shown to play an important role in the developmental programing and senescence of normal and stressed reproductive tissues. What follows is an overview of (i) pathways of p38 activation and their involvement in basic biological processes, (ii) evidence that p38 is involved in the homeostasis of reproductive tissues, (iii) how focus on p38 can be incorporated into investigation of normal and stressed pregnancies. Existence of excellent reviews will be mentioned as well as relevant animal models.

Extracellular vesicles in blood, milk and body fluids of the female and male urogenital tract and with special regard to reproduction

Extracellular vesicles (EVs) are released from almost all cells and tissues. They are able to transport substances (e.g. proteins, RNA or DNA) at higher concentrations than in their environment and may adhere in a receptor-controlled manner to specific cells or tissues in order to release their content into the respective target structure. Blood contains high concentrations of EVs mainly derived from platelets, and, at a smaller amount, from erythrocytes. The female and male reproductive tracts produce EVs which may be associated with fertility or infertility and are released into body fluids and mucosas of the urogenital organs. In this review, the currently relevant detection methods are presented and critically compared. During pregnancy, placenta-derived EVs are dynamically detectable in peripheral blood with changing profiles depending upon progress of pregnancy and different pregnancy-associated pathologies, such as preeclampsia. EVs offer novel non-invasive diagnostic tools which may reflect the situation of the placenta and the foetus. EVs in urine have the potential of reflecting urogenital diseases including cancers of the neighbouring organs. Several methods for detection, quantification and phenotyping of EVs have been established, which include electron microscopy, flow cytometry, ELISA-like methods, Western blotting and analyses based on Brownian motion. This review article summarises the current knowledge about EVs in blood and cord blood, in the different compartments of the male and female reproductive tracts, in trophoblast cells from normal and pre-eclamptic pregnancies, in placenta ex vivo perfusate, in the amniotic fluid, and in breast milk, as well as their potential effects on natural killer cells as possible targets.

Regulation of Natural Killer Cell Function by STAT3

Natural killer (NK) cells, key members of a distinct hematopoietic lineage, innate lymphoid cells, are not only critical effectors that mediate cytotoxicity toward tumor and virally infected cells but also regulate inflammation, antigen presentation, and the adaptive immune response. It has been shown that NK cells can regulate the development and activation of many other components of the immune response, such as dendritic cells, which in turn, modulate the function of NK cells in multiple synergistic feed back loops driven by cell–cell contact, and the secretion of cytokines and chemokines that control effector function and migration of cells to sites of immune activation. The signal transducer and activator of transcription (STAT)-3 is involved in driving almost all of the pathways that control NK cytolytic activity as well as the reciprocal regulatory interactions between NK cells and other components of the immune system. In the context of tumor immunology, NK cells are a first line of defense that eliminates pre-cancerous and transformed cells early in the process of carcinogenesis, through a mechanism of “immune surveillance.” Even after tumors become established, NK cells are critical components of anticancer immunity: dysfunctional NK cells are often found in the peripheral blood of cancer patients, and the lack of NK cells in the tumor microenvironment often correlates to poor prognosis. The pathways and soluble factors activated in tumor-associated NK cells, cancer cells, and regulatory myeloid cells, which determine the outcome of cancer immunity, are all critically regulated by STAT3. Using the tumor microenvironment as a paradigm, we present here an overview of the research that has revealed fundamental mechanisms through which STAT3 regulates all aspects of NK cell biology, including NK development, activation, target cell killing, and fine tuning of the innate and adaptive immune responses.

Transcription of the activating receptor NKG2D in natural killer cells is regulated by STAT3 tyrosine phosphorylation

Signal transducer and activator of transcription 3 (STAT3) is considered a negative regulator of inflammation, as inhibition of STAT3 signaling enhances antitumor immunity. However, STAT3 activation is a key oncogenic pathway in natural killer (NK)-lineage large granular lymphomas, and we recently reported enhanced proliferation and function of human NK cells activated with IL-21, which signals primarily through STAT3. These IL-21-expanded NK cells also have increased NKG2D expression, which led us to focus our investigation on whether STAT3 regulates NKG2D. In this study, we show that modulation of STAT3 phosphorylation with cytokines and small-molecule inhibitors correlates with NKG2D expression on human NK cells, leading to altered NK-cell degranulation. Moreover, NKG2D expression on murine NK cells having conditional STAT3 ablation is lower than on NK cells from wild-type mice, and human NK cells carrying dominant-negative STAT3 mutations have decreased baseline NKG2D expression and blunted responses to IL-10 and IL-21. Lastly, we show binding of STAT3 to a predicted STAT3 binding site upstream of the NKG2D gene, which is enhanced by IL-10 and IL-21 and decreased by STAT3 inhibition. Taken together, these data show that NKG2D expression in NK cells is regulated at the transcriptional level by STAT3, resulting in a functional NK cell defect in patients with STAT3 mutations.

What is the impact of SOCS3, IL-35 and IL17 in immune pathogenesis of recurrent pregnancy loss?

OBJECTIVE

To investigate the plasma levels of interleukin-4 (IL-4), IL-6, IL-10, tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), transforming growth factor-beta (TGF-beta), IL-17, IL-35 and suppressor of cytokine signaling 3 (SOCS3) in the women with history of idiopathic recurrent pregnancy loss (RPL) and in the fertile controls.

METHODS

This study was conducted with 60 idiopathic RPL cases and 40 age-matched fertile controls. Mid-follicular plasma levels of IL-17, IFN-gamma, TNF-alpha, TGF-beta, IL-6, IL-4, IL-10, SOCS3 and IL-35 were assayed by an enzyme linked immunosorbent assay.

RESULTS

The mean age of RPL and control cases were 31.6 ± 0.6 and 32.1 ± 0.7 years, respectively. While plasma IL-35 and SOCS3 levels of RPL group were significantly lower than that of the control group; IFN-gamma, TNF-alpha, IL-4, IL-6, IL-10, IL-17 and TGF-beta levels of RPL group were significantly higher than that of the control group. The comparison of cytokine ratios between RPL and control groups indicated significantly high TNF-alpha/IL-10, TNF-alpha/IL-4, IFN-gamma/IL-10, IFN-gamma/IL-6 and IFN-gamma/IL-4 ratios in the RPL group. IL-35/IL-17 ratio was significantly low in the RPL group compared to that in the control group. Overstimulation of TNF-alpha presented moderate influence on recurrent miscarriage risk.

CONCLUSION

Decreased SOCS3 and IL-35 plasma levels and increased Th1/Th2 cytokine ratios in RPL cases pointed out the supression of anti-inflammatory process and this supression might play an important role in the pathogenesis of idiopathic RPL.

NK cells in hepatitis B virus infection: a potent target for immunotherapy

Viruses, including hepatitis B virus (HBV), are the most prevalent and infectious agents that lead to liver disease in humans. Hepatocellular carcinoma (HCC) and cirrhosis of the liver are the most serious complications arising from prolonged forms of hepatitis B. Previous studies demonstrated that patients suffering from long-term HBV infections are unable to eradicate HBV from hepatocytes completely. The mechanisms responsible for progression of these forms of infection have not yet been clarified. However, it seems that there are differences in genetic and immunological parameters when comparing patients to subjects who successfully clear HBV infections, and these may represent the causes of long-term infection. Natural killer (NK) cells, the main innate immune cells that target viral infections, play important roles in the eradication of HBV from hepatocytes. NK cells carry several stimulatory and inhibitor receptors, and binding of receptors with their ligands results in activation and suppression of NK cells, respectively. The aim of this review is to address the recent information regarding NK cell phenotype, functions and modifications in hepatitis B. This review addresses the recent data regarding the roles of NK cells as novel targets for immunotherapies that target hepatitis B infection. It also discusses the potential to reduce the risk of HCC or cirrhosis of the liver by targeting NK cells.

Monocyte chemoattractant protein-1 secreted by decidual stromal cells inhibits NK cells cytotoxicity by up-regulating expression of SOCS3

BACKGROUND

Decidual stromal cells (DSCs) are of particular importance due to their pleiotropic functions during pregnancy. Although previous research has demonstrated that DSCs participated in the regulation of immune cells during pregnancy, the crosstalk between DSCs and NK cells has not been fully elucidated. To address this issue, we investigated the effect of DSCs on perforin expression in CD56(+) NK cells and explored the underlying mechanism.

METHODOLOGY/PRINCIPAL FINDINGS

Flow cytometry analysis showed perforin production in NK cells was attenuated by DSC media, and it was further suppressed by media from DSCs pretreated with lipopolysaccharide (LPS). However, the expression of granzyme A and apoptosis of NK cells were not influenced by DSC media. ELISA assays to detect cytokine production indicated that monocyte chemoattractant protein-1 (MCP-1) in the supernatant of DSCs conditioned culture significantly increased after LPS stimulation. The inhibitory effect of DSC media on perforin was abolished by the administration of anti-MCP-1 neutralizing antibody. Notably, reduced perforin expression attenuated the cytotoxic potential of CD56(+) NK cells to K562 cells. Moreover, Suppressor of cytokine signaling 3 (SOCS3) expression in NK cells was enhanced by treatment with MCP-1, as measured by RT-PCR and western blot. Interestingly, MCP-1-induced perforin expression was partly abolished by the siRNA induced SOCS3 knockdown. Western blot analysis suggested that both NF-κB and ERK/MAPKs pathway were involved in the LPS-induced upregulation of MCP-1 in DSCs.

CONCLUSIONS/SIGNIFICANCE

Our results demonstrate that LPS induces upregulation of MCP-1 in DSCs, which may play a critical role in inhibiting the cytotoxicity of NK cells partly by promoting SOCS3 expression. These findings suggest that the crosstalk between DSCs and NK cells may be crucial to maintain pregnancy homeostasis.

Early postnatal hyperalimentation impairs renal function via SOCS-3 mediated renal postreceptor leptin resistance

Early postnatal hyperalimentation has long-term implications for obesity and developing renal disease. Suppressor of cytokine signaling (SOCS) 3 inhibits phosphorylation of signal transducer and activator of transcription (STAT) 3 and ERK1/2 and thereby plays a pivotal role in mediating leptin resistance. In addition, SOCS-3 is induced by both leptin and inflammatory cytokines. However, little is known about the intrinsic-renal leptin synthesis and function. Therefore, this study aimed to elucidate the implications of early postnatal hyperalimentation on renal function and on the intrinsic-renal leptin signaling. Early postnatal hyperalimentation in Wistar rats during lactation was induced by litter size reduction at birth (LSR) either to LSR10 or LSR6, compared with home cage control male rats. Assessment of renal function at postnatal day 70 revealed decreased glomerular filtration rate and proteinuria after LSR6. In line with this impairment of renal function, renal inflammation and expression as well as deposition of extracellular matrix molecules, such as collagen I, were increased. Furthermore, renal expression of leptin and IL-6 was up-regulated subsequent to LSR6. Interestingly, the phosphorylation of Stat3 and ERK1/2 in the kidney, however, was decreased after LSR6, indicating postreceptor leptin resistance. In accordance, neuropeptide Y (NPY) gene expression was down-regulated; moreover, SOCS-3 protein expression, a mediator of postreceptor leptin resistance, was strongly elevated and colocalized with NPY. Thus, our findings not only demonstrate impaired renal function and profibrotic processes but also provide compelling evidence of a SOCS-3-mediated intrinsic renal leptin resistance and concomitant up-regulated NPY expression as an underlying mechanism.

Role of interleukin-10 in breast cancer

Cytokines are low molecular weight regulatory proteins or glycoprotein that modulates the intensity and duration of immune response by stimulating or inhibiting the activation, proliferation, and/or differentiation of target cells. Different cytokines are known to have diverse role in breast cancer initiation and progression. Interleukin-10 (IL-10), a pleiotropic anti-inflammatory cytokine, induces immunosuppression and assists in escape from tumor immune surveillance. Like several other cytokines, IL-10 also can exert dual proliferative and inhibitory effect on breast tumor cells indicating a complex role of IL-10 in breast cancer initiation and progression. In this review, we tried to put together a comprehensive current view on significance of IL-10 in promotion, inhibition, and importance as prognosticator in breast cancer based on in vitro, in vivo, and clinical evidences. For literature collection, we conducted PubMed search with keywords "IL-10" and "breast cancer".