Activity Of Spleen Cells Research Articles

Immunostimulatory Effects of Red Beet Ferment Extract on Cyclophosphamide-Induced Immunosuppression in Wistar Rats

Red beet extract contains a variety of bioactive compounds, including antioxidant and immune-stimulating properties. Red beets are rich in nutrients and have been reported to help mitigate cardiovascular disease, while also possessing potent antioxidant capacity. In this study, we sought to determine the immune-enhancing effects of red beet fermented extract. The immunosuppressive drug cyclophosphamide (Cy) and red beet fermented extract were orally administered to Wistar rats once daily for four weeks. Blood analysis was performed to measure the expression of immune cytokines. We also examined the immunostimulatory effects of red beet fermented extract by measuring the activity and viability of spleen cells and the expression of immune cytokines. The expression of immune cytokines in the blood and spleen cells was increased in the red beet fermented extract treatment group compared to that in the negative control group, which induced immunosuppression of cytokines. It also increased the activity of NK cells and improved the viability of spleen cells. In conclusion, red beet fermented extract increased the expression of immune cytokines and increased the activity of adipocytes and NK cells, confirming its immunostimulatory effect. Therefore, red beet fermented extract has the potential to be utilized as a nutraceutical ingredient to enhance immunity.

Macrophage population state and proliferative activity of spleen cells under liver regeneration conditions

Relevance. Currently, the participation of immune system cells in the regulation of reparative processes is attracting more and more attention of researchers. There is an anatomical connection between the liver and spleen by means of portal vein. Thus, cytokines and other biologically active substances can enter the liver from the spleen through the portal vein, as well as cells can migrate to the liver. However, the specific mechanisms of mutual influence of the mentioned organs, including in reparative processes, remain poorly studied. The aim of our work was to study the state of spleen monocyte-macrophage population after liver resection, as well as the proliferative activity of spleen cells during liver regeneration . Materials and Methods . The model of liver regeneration after 70 % resection in mouse was reproduced in this work. The animals were taken out of the experiment after 1, 3 and 7 days. The marker of cell proliferation Ki67 was immunohistochemically detected, the state of spleen monocyte-macrophage population was evaluated by markers CD68, CD115, CD206, F4/80 by methods of immunohistochemistry and flow cytometry. Results and Discussion . The liver regeneration had a pronounced effect on the cytoarchitectonics of the spleen. In 1 day after liver resection in the spleen there was observed a decrease in the share of Ki67+cells, according to the flow cytometry data there was a decrease in the number of CD115+cells, in 3 and 7 days there was a decrease in the number of F4/80+ macrophages. Conclusion . Liver resection causes changes in the state of cell populations of the spleen as well. First of all, to the decrease in the activity of proliferative processes in it, as well as to the changes in the state of the monocyte-macrophage system. A decrease in the content of CD115+ and F4/80+ cells in the spleen was found, which indirectly indicates the migration of monocytes/macrophages after liver resection, which can also influence the course of reparative processes in the liver.

Oral administration of procyanidin B2 3,3"-di-O-gallate ameliorates experimental autoimmune encephalomyelitis through immunosuppressive effects on CD4+ T cells by regulating glycolysis

Multiple Sclerosis (MS) is a chronic autoimmune disease of the central nervous system caused by the excessive activation of T cells. Procyanidins are polyphenols that exhibit anti-inflammatory activity. Procyanidin B2 (PCB2) gallate [specifically, PCB2 3,3″-di-O-gallate (PCB2DG)] inhibits cytokine production in T cells by suppressing the acceleration of glycolysis. In this study, we determined the effect of PCB2DG on T cell-mediated autoimmune disease in vivo. We examined the immunosuppressive effects of PCB2DG using an experimental autoimmune encephalomyelitis (EAE) model, which is a classic animal model for MS. Our results indicated that the clinical score for EAE symptoms improved significantly following the oral administration of PCB2DG. This effect was associated with the suppression of T cell-mediated cytokines (e.g., IFN-γ, TNF-α, and IL-17) and infiltrating T cells into the spinal cord, which ameliorated spinal cord injury. In addition, spleen cell culture experiments revealed that the increase of T cell-mediated pro-inflammatory cytokines in EAE mice was significantly decreased following PCB2DG treatment. We further analyzed the glycolytic activity of spleen cells to identify the mechanism of the immunosuppressive effects of PCB2DG. The production of lactate and the expression of glycolytic enzymes and transporters were increased following EAE induction, but not in PCB2DG-treated EAE mice. Collectively, our results indicate that a dietary polyphenol, which has a unique structure, improves the onset of EAE symptoms and inhibits the excessive activation of T cells by influencing glycolysis.

Combined therapy with methotrexate nanoconjugate and dendritic cells with downregulated IL-10R expression modulates the tumor microenvironment and enhances the systemic anti-tumor immune response in MC38 murine colon carcinoma.

Understanding the negative impact of the tumor microenvironment on the creation of an effective immune response has contributed to the development of new therapeutic anti-cancer strategies. One such solution is combined therapy consisting of chemotherapeutic administration followed by dendritic cell (DC)-based vaccines. The use of cytostatic leads to the elimination of cancer cells, but can also modulate the tumor milieu. Moreover, great efforts are being made to increase the therapeutic outcome of immunotherapy, e.g. by enhancing the ability of DCs to generate an efficient immune response, even in the presence of immunosuppressive cytokines such as IL-10. The study aimed to determine the effectiveness of combined therapy with chemotherapeutic with immunomodulatory potential - HES-MTX nanoconjugate (composed of methotrexate (MTX) and hydroxyethyl starch (HES)) and DCs with downregulated expression of IL-10 receptor stimulated with tumor antigens (DC/shIL-10R/TAg) applied in MC38 murine colon carcinoma model. With the use of lentiviral vectors the DCs with decreased expression of IL-10R were obtained and characterized. During in vivo studies MC38-tumor bearing mice received MTX or HES-MTX nanoconjugate as a sole treatment or combined with DC-based immunotherapy containing unmodified DCs or DCs transduced with shRNA against IL-10R (or control shRNA sequence). Tumor volume was monitored during the experiment. One week after the last injection of DC-based vaccines, tumor nodules and spleens were dissected for ex vivo analysis. The changes in the local and systemic anti-tumor immune response were estimated with the use of flow cytometry and ELISA methods. In vitro studies showed that the downregulation of IL-10R expression in DCs enhances their ability to activate the specific anti-tumor immune response. The use of HES-MTX nanoconjugate and DC/shIL-10R/TAg in the therapy of MC38-tumor bearing mice resulted in the greatest tumor growth inhibition. At the local anti-tumor immune response level a decrease in the infiltration of cells with suppressor activity and an increase in the influx of effector cells into MC38 tumor tissue was observed. These changes were crucial to enhance the effective specific immune response at the systemic level, which was revealed in the greatest cytotoxic activity of spleen cells against MC38 cells.

ИЗМЕНЕНИЯ ПЛАЗМАТИЧЕСКИХ КЛЕТОК КРЫС ПРИ ЭКСПЕРИМЕНТАЛЬНОМ ЗАРАЖЕНИИ ТРИХИНЕЛЛАМИ

For experimentally infected rats with Trichinella spiralis (Owen, 1835) Railliet, 1895, spleen and bone marrow are shown to play an important role in the host immune responses. We have studied a role of plasma cells in formation of protective responses for experimental Trichinella infection of white rats. It's been established that a degree of immunological transformation directly depended on a stage of Trichinella spiralis in the host. A stimulating effect of Trichinella has been shown at early intestinal and early muscular stages of the parasite's development. In these periods, high levels of blast cells with mitoses and high number of plasma cells were noticed. A suppressive effect of Trichinella at migration stage was accompanied by decrease of proliferation level and numbers of plasma cells, leading to suppression of the host immune response. Also, a sinusoid-like flow of plasmacytic reaction and mitotic activity of spleen cells had been noted. During studies of morphological composition of peripheral blood increase in eosinophils' numbers was noted. This fact may be explained by the migration of Trichinella larvae, which may cause defensive reactions in the host (eosinophils are excreted into blood). Key words: Trichinella spiralis, white rats, bone marrow, tear, defense reactions of the organism.

The protective effects of sonicated Bordetella bronchiseptica bacterin on the immunosuppression of spleen cells induced by anti-cancer drugs (5-fluorouracil, doxorubicin, and vincristine)

5-Fluorouracil, doxorubicin, and vincristine are chemotherapy agents used to treat various cancers, such as breast cancer and lymphoma for decades, and their effects on cancer have been proven. On the other hand, these anti-cancer drugs cause fatal side effects, including immunosuppression. This study investigated whether sonicated Bordetella bronchiseptica bacterin can attenuate the immunosuppression of spleen cells induced by these chemotherapy agents and which subsets of spleen cells were affected. B. bronchiseptica increased the metabolic activity of spleen cells treated with 3 anti-cancer drugs. Cell death analysis using Annexin V/propidium iodide showed that B. bronchiseptica markedly decreased the death of spleen cells. The subsets of spleen cells were analyzed by flow cytometry using a surface marker-specific antibody. B. bronchiseptica increased nitric oxide production in the spleen cells treated with anti-cancer drugs (p < 0.0001). Despite the pharmacological effects of anti-cancer drugs, many patients suffer from the fatal side effects of immunosuppression. This study provides valuable information on how to overcome chemotherapy-induced immunosuppression.

Enhanced production of IL-2 from anti-CD3 antibody-stimulated mouse spleen cells by artepillin C, a major component of Brazilian green propolis

ObjectivesIn this report, we attempt to clarify the immune modulatory effects of Brazilian green propolis (BGP) and its major component, artepillin C, on the cytokine production of anti-CD3 antibody-stimulated mouse spleen cells. We also estimate the physiological mechanism affecting artepillin C's upon the cells. MethodsMale C3H/HeN mouse spleen cells stimulated by antiCD3 monoclonal antibody were co-cultured with BGP, artepillin C, and HC030031, a transient receptor potential ankyrin 1 (TRPA1) Ca2+ channel antagonist. The synthesis of interferon (IFN)-γ, interleukin (IL)-6, IL-17, IL-4, IL-10, and IL-2 was assayed by enzyme-linked immunoassay. The expression of IL-2 mRNA and the protein product were examined by reverse transcription-quantitative polymerase chain reaction and Western blot analyses, respectively. ResultsThe production of IL-2 was markedly enhanced, while that of IL-4 and IL-10 was not significantly affected; by contrast, the production of IFN-γ, IL-6, and IL-17 was significantly reduced in the antibody-stimulated spleen cells treated with BGP at a non-cytostatic concentration. These effects were reproduced in the cells treated with artepillin C. The expression of IL-2 mRNA was unaffected; however, that of the protein was significantly enhanced in the artepillin C-treated cells compared to untreated control cells. The enhancement of protein expression and the production of IL-2 by artepillin C was significantly alleviated by adding HC030031. ConclusionsArtepillin C is an important regulator of cytokine synthesis from activated spleen cells. The agent specifically augmented the expression of IL-2 via the Ca2+-permeable cation channel, TRPA1, at least in part, at the translational or secretion levels.

Identification of EPZ004777 and FG2216 as inhibitors of TGF-β1 induced Treg cells by screening a library of epigenetic compounds

AimsRegulatory T cells play an essential role in immune tolerance and homeostasis. Their long-term stability depends on epigenetic modifications and identification of small molecule modulators of Treg differentiation therefore has many applications. In this study, we performed a novel functional screen of an epigenetic compound library to identify compounds that can modulate generation of TGF-β1 induced T regulatory cells. Main methodsA screening strategy based on IFN-γ ELISA was designed to screen epigenetic compound library. Effect of hit compounds on Treg phenotype and function was assessed by RT-PCR, flow cytometry and suppression assays. TGF-β signalling proteins were assayed by western blotting. Chromatin Immunoprecipitation (ChIP) assay was used to assess epigenetic modifications at Foxp3 gene locus. Key findingsWe screened 160 compounds to identify hits capable of reversing TGF-β induced inhibition of IFN-γ production in activated spleen cells and CD4+ T cells. Two compounds EPZ004777 and FG-2216 consistently reversed TGF-β1 iTregs in terms of (a) differentiation of naïve T cells into CD4+CD25+Foxp3+Treg cells, (b) Foxp3 target gene expression and (c) Treg suppressive function without affecting TGF-β downstream signalling. ChIP assay revealed that the compounds were able to reverse – TGF- β mediated decrease in epigenetic marks H3K27me3 and 5-mC and an increase in epigenetic marks H3K4me3 and H3K27Ac in the promoter and conserved non coding sequence (CNS1) regions of the Foxp3 gene. SignificanceEPZ004777 and FG-2216 have been identified as potent epigenetic modulators that can reverse TGF-β1 induced T regulatory cells and may be used to treat diverse immune disorders.

Study of the haematopoietic and immune effect of microalgae extracts

Microalgae, as a source of numerous biologically active substances, are promising candidates for the development of novel biologically active supplements. An important aspect determining the possibility of using microalgae involves the absence of adverse effects on the organs and systems of the human and animal body. At the development stage, special attention should be paid to the safety of microalgae for biomedical use in terms of the absence of significant negative effects on the haematopoiesis and the functional status of immune cells. In this regard, the present study investigates the effect of oil extracts obtained from five microalgae species on haematopoietic parameters, the number and functional activity of spleen and thymus cells, as well as on immunoglobulin levels in the blood serum of laboratory animals. According to the obtained results, Chlorella vulgaris (C. vulgaris) and Cylindrotheca closterium (C. closterium) extracts decrease the number of leukocytes in the peripheral blood. Coelastrella sp., C. closterium, and Porphyridium purpureum (P. purpureum) increase the proportion of neutrophils. P. purpureum was found to initiate an increase in the proportion of eosinophils. Arthrospira (Spirulina) platensis (A. platensis) and C. closterium produce a decrease in the proportion of monocytes. C. closterium and P. purpureum induce a reduction in the proportion of lymphocytes in the peripheral blood of laboratory mice. All microalgae extracts had no effect on erythropoiesis and haemoglobin. In addition, all microalgae extracts were found to reduce splenocyte proliferation, while their effect on thymocyte proliferation depended on the microalgae type. In the mice serum, Coelastrella sp. microalgae extract increases IgG levels, while P. purpureum and C. vulgaris decrease IgM and IgA levels, respectively.

Cytotoxic Activity and Lymphocyte Subtypes in Mice Selected for Maximal and Minimal Inflammatory Response after Transplantation of B16F10 and S91 Melanoma Cells.

AIRmax and AIRmin mice strains were selected according to the intensity of their acute inflammatory responsiveness. Previous studies have shown that AIR mice differ in their resistance to chemically induced skin tumors and in the development of melanoma metastases, in addition to differences in neutrophil and NK cells activity. In the present work, we aimed to evaluate whether the difference of susceptibility to murine melanoma is associated with NK cytotoxic activity against Yac.1 cells and lymphocyte subsets. Mice were subcutaneously inoculated with B16F10 or S91 melanoma cells. After 7, 14, or 30 days, the animals were euthanized to analyze the number of lymphocyte subsets, cytotoxic activity, and number of cytokine-producing spleen cells. AIRmax mice presented a higher number of CD4+/CD25+ cells than that of AIRmin mice following inoculation of B16F10 cells, whereas inoculation of S91 cells reduced CD4+/CD25+ and increased TCD8+ cell subsets in the AIRmax mice. AIRmax mice had a higher number of interleukin (IL)-10- and IL-12-producing cells and a lower number of interferon-γ–producing cells than those of AIRmin mice at 30 days. The cytotoxic activity of nonadherent spleen cells was similar in both the AIR strains. These results suggest that melanoma cells can induce different responses in AIR mice, possibly owing to alterations in regulatory mechanisms, such as the action of CD4+/CD25+ regulatory T cells and IL-10, in AIRmax mice.

Discovery of Eucalyptin C, derived from the fruits of Eucalyptus globulus Labill., as a novel selective PI3Kγ inhibitor for immunosuppressive treatment

The fruits of Eucalyptus globulus Labill. are known to have a plenty of medicinal properties, such as anti-tumor, anti-inflammatory, and immunosuppressive activity. Our previous study found that the phloroglucinol-sesquiterpene adducts in the fruits of E. globulus were immunosuppressive active constituents, especially Eucalyptin C (EuC). Phosphoinositide 3-kinases-γ (PI3Kγ) plays a pivotal role in T cell mediated excessive immune responses. In this study, EuC was first discovered to be a novel selective PI3Kγ inhibitor with an IC50 value of 0.9 μmol·L-1 and selectivity over 40-fold towards the other PI3K isoforms. Molecular docking, molecular dynamics simulation, and cellular thermal shift assay showed that EuC bound to PI3Kγ. Furthermore, EuC suppressed the downstream of PI3Kγ to induce the apoptosis and inhibit the activation of primary spleen cells derived from allergic contact dermatitis mice. This work highlights the role of the fruits of E. globulus as a source of bioactive plant with immunosuppressive activity.

Evaluation of the New Outer Membrane Protein A Epitope-based Vaccines for Mice Model of Acinetobacter baumannii Associated Pneumonia and Sepsis Infection

Nosocomial infections caused by Acinetobacter baumannii (A. baumannii) are considered as a global serious problem in hospitalized patients because of emerging antibiotic resistance. Immunotherapy approaches are promising to prevent such infections. In our previous study, five antigenic epitopes of outer membrane protein A (OmpA), as the most dangerous virulence molecule in A. baumanii, were predicted in silico. In this study, the investigators evaluated some immunological aspects of the peptides.Five peptides were separately injected into C5BL/6 mice; then the cytokine production (interleukin-4 and interferon-gamma) of splenocytes and opsonophagocytic activity of immunized serum were assessed. To identify the protective function of the peptides, animal models of sepsis and pneumonia infections were actively and passively immunized with selected peptides and pooled sera of immunized mice, respectively. Then, their survival rates were compared with the non-infected controls.Based on the results, activated spleen cells in P127 peptide-immunized mice exhibited an increased level of IFN-γ compared with the other experimental groups, but not about the IL-4 concentration. The results of the opsonophagocytic assay revealed an appropriate killing the activity of produced antibodies against A. baumannii in a dose-dependent manner. Further, the survival rates of the mice under passive immunization with the immunized sera or active immunization with P127 peptide were significantly more than those in the control group. Moreover, the survival rate of the P127 peptide immunized group was considerably higher than that of the other peptide-immunized group.In conclusion, findings indicated that peptides derived from OmpA can be used as a promising tool for designing the epitope-based vaccines against infections caused by A. baumannii.

Corrective effects of original bioflavonoid complex in the cyclophosphamide-induced immunity disorders

Our aim was to evaluate immunomodulatory properties of an original bioflavonoid complex in experimental immune disturbances induced by cyclophosphamide (Cy). We have studied morphometric indexes of thymus and spleen, as well as blood leukocyte counts, cell proliferative activity in lymphoid organs, delayed hypersensitivity responses to T cell-dependent antigen, along with differentiation activity of bone marrow stem cells in experimental animals during Cy-induced immune suppression after a course of bioflavonoid treatment. Suspension of the bioflafonoid complex was introduced to the male mice (СВАхC57Bl/6)F1 aged 12- 14 weeks at a daily dose of 2 mg/animal (80 mg/kg), per os, using gastric catheter, over 14 days. Cytostatic immunosuppression was produced by a single intraperitoneal Cy injection. Proliferative activity of spleen and thymic cells was determined by standard method with Н3 -thymidine incorporation in the 72-h cell culture. Cellular immune response was assayed by the degree of delayed-type hypersensitivity development in response to sheep erythrocytes. The number of hematopoietic progenitors was evaluated by culturing bone marrow cells in methylcellulose-based medium. The experiments have shown mitigation of immunosuppressive effects induced by Cy, in the course of bioflavonoid complex treatment, with respect to absolute and relative mass of lymphoid organs and leukocyte numbers in peripheral blood. Moreover, we have demonstrated decreased effects of Cy treatment upon the spontaneous activity of spleen cells, mitogen-induced thymocyte and splenocyte proliferation, intensivity of delayed-type hypersensitivity response that reached the values of intact animals. Following the course of bioflavonoids, we have revealed an increase in early hematopoietic progenitors. Alleviation of Cy-induced suppressive effects upon cellular immune response, proliferation rates of immune cells, as well as stimulation of hematopoietic stem cell functions suggest a sufficient capacity of the original bioflavonoid complex for modulation of immunity and hematopoiesis, thus presenting experimental proofs for its potential usage as an adjuvant treatment of the patients with malignant diseases.

Immunomodulatory activity of biosilica water on mouse dendritic cells

Biosilica is a material extracted from the shell (cell wall) of Melosira nummuloides, a type of sea diatom, and is one of the widely distributed biominerals. Recently, some studies have revealed that biosilica has a characteristic bio-modulatory activity compared to synthetic silica. However, there has been little research on the effects and action mechanisms of biosilica in immune cells. In this study, we investigated the effect of biosilica water on mouse dendritic cells (DCs), the most potent antigen-presenting cells in immunity, and whether it may alter the function of DCs. Biosilica water decreased the metabolic activity of DCs at 20% concentration (v/v) and the production of IL-1 beta in a concentration-dependent manner. And also, more cells with fragmented nuclei were observed in the DCs treated with 20% biosilica water compared to other treatment groups. The mixed leukocyte response experiment showed the biosilica water-treated DCs significantly modulated the metabolic activity and proliferation of allogeneic spleen cells compared to control DCs. This result suggests that biosilica water may modulate the antigen-presenting capability of DCs. Taken together, this study shows the immunomodulatory activity of biosilica on DCs and may affect immune responses. Further research is needed to investigate the immunological activity of biosilica water.

Pharmacological activation of protein tyrosine phosphatase SHP-1 ameliorates autoimmune arthritis in mice

Abstract Background The Src homology region 2 domain-containing phosphatase-1 (SHP-1) is known to exert negative regulatory effects on immune cell signaling. We observed previously that mice overexpressing an SHP-1 transgene were resistant to the development of autoimmune arthritis and showed decreased immune responses in the cartilage proteoglycan (PG)-induced (PGIA) model of rheumatoid arthritis (RA). We sought to explore if pharmacological activation of SHP-1 in wildtype (WT) mice prevents or ameliorates arthritis. Methods To induce PGIA, mice were immunized with human (PG) in adjuvant. For in vivo SHP-1 activation, mice were treated with regorafenib (BAY 73-4506) per os either before arthritis symptoms developed (preventive treatment) or shortly after the initial signs of arthritis (therapeutic treatment). Regorafenib administration was continued for at least 21 days while arthritis incidence and severity were monitored. Results Preventive regorafenib treatment of WT mice significantly decreased arthritis severity (10 or 20 mg/kg) and incidence compared to vehicle treatment. Preventive treatment (10 mg/kg) increased tyrosine phosphatase activity of spleen cells and decreased IFNγ secretion by splenic T cells in vitro. Therapeutic treatment with 15 mg/kg decreased the severity of arthritis and lowered IFNγ production. Conclusion Our studies are the first to investigate the role of SHP-1 in autoimmune arthritis. We found that pharmacological activation of SHP-1 in vivo prevented the development of autoimmune arthritis or ameliorated arthritis severity when applied after the disease onset in the PGIA model of RA. Activation of SHP-1 might open a new therapeutic perspective in RA treatment.

Abdominal surgery prior to chronic psychosocial stress promotes spleen cell (re)activity and glucocorticoid resistance

There is convincing evidence from different mouse models that chronic psychosocial stress promotes splenomegaly, basal and lipopolysaccharide (LPS)-induced in vitro splenocyte activation and insensitivity towards glucocorticoids (GC) in in vitro LPS-treated splenocytes. However, we just recently showed, employing the chronic subordinate colony housing (CSC) paradigm, that bite wounds received during stressor exposure drive these stress-induced spleen changes. As skin wounds induced by planned surgery or physical trauma are more adequately reflecting what chronically stressed humans are likely to experience, it was the objective of the present study to investigate whether abdominal surgery prior to stressor exposure also promotes respective stress-induced spleen effects in the absence of any bite wounds. In line with our hypothesis, abdominal surgery prior to CSC induced splenomegaly, increased in vitro cell viability under basal and LPS conditions as well as the delta response to LPS (LPS – basal), and promoted the inability of isolated splenocytes to respond with a decreased cell viability to increasing concentrations of corticosterone following LPS-stimulation in vitro. Together with previous data, these findings demonstrate that physical injury, either in form of received bite wounds during stressor exposure or in form of abdominal surgery prior to stressor exposure, promotes the development of splenic immune activation and GC resistance.

Connexin43 Is Required for the Effective Activation of Spleen Cells and Immunoglobulin Production.

Gap junctions (Gjs), formed by specific protein termed connexins (Cxs), regulate many important cellular processes in cellular immunity. However, little is known about their effects on humoral immunity. Here we tested whether and how Gj protein connexin43 (Cx43) affected antibody production in spleen cells. Detection of IgG in mouse tissues and serum revealed that wild-type (Cx43+/+) mouse had a significantly higher level of IgG than Cx43 heterozygous (Cx43+/−) mouse. Consistently, spleen cells from Cx43+/+ mouse produced more IgG under both basal and lipopolysaccharide (LPS)-stimulated conditions. Further analysis showed that LPS induced a more dramatic activation of ERK and cell proliferation in Cx43+/+ spleen cells, which was associated with a higher pro-oxidative state, as indicated by the increased NADPH oxidase 2 (NOX2), TXNIP, p38 activation and protein carbonylation. In support of a role of the oxidative state in the control of lymphocyte activation, exposure of spleen cells to exogenous superoxide induced Cx43 expression, p38 activation and IgG production. On the contrary, inhibition of NOX attenuated the effects of LPS. Collectively, our study characterized Cx43 as a novel molecule involved in the control of spleen cell activation and IgG production. Targeting Cx43 could be developed to treat certain antibody-related immune diseases.

Selective Histone Deacetylase 6 Inhibition Normalizes B Cell Activation and Germinal Center Formation in a Model of Systemic Lupus Erythematosus.

Autoantibody production by plasma cells (PCs) plays a pivotal role in the pathogenesis of systemic lupus erythematosus (SLE). The molecular pathways by which B cells become pathogenic PC secreting autoantibodies in SLE are incompletely characterized. Histone deactylase 6 (HDAC6) is a unique cytoplasmic HDAC that modifies the interaction of a number of tubulin- associated proteins; inhibition of HDAC6 has been shown to be beneficial in murine models of SLE, but the downstream pathways accounting for the therapeutic benefit have not been clearly delineated. In the current study, we sought to determine whether selective HDAC6 inhibition would abrogate abnormal B cell activation in SLE. We treated NZB/W lupus mice with the selective HDAC6 inhibitor, ACY-738, for 4 weeks beginning at 20 weeks-of age. After only 4 weeks of treatment, manifestation of lupus nephritis (LN) were greatly reduced in these animals. We then used RNAseq to determine the genomic signatures of splenocytes from treated and untreated mice and applied computational cellular and pathway analysis to reveal multiple signaling events associated with B cell activation and differentiation in SLE that were modulated by HDAC6 inhibition. PC development was abrogated and germinal center (GC) formation was greatly reduced. When the HDAC6 inhibitor-treated lupus mouse gene signatures were compared to human lupus patient gene signatures, the results showed numerous immune, and inflammatory pathways increased in active human lupus were significantly decreased in the HDAC6 inhibitor treated animals. Pathway analysis suggested alterations in cellular metabolism might contribute to the normalization of lupus mouse spleen genomic signatures, and this was confirmed by direct measurement of the impact of the HDAC6 inhibitor on metabolic activities of murine spleen cells. Taken together, these studies show HDAC6 inhibition decreases B cell activation signaling pathways and reduces PC differentiation in SLE and suggest that a critical event might be modulation of cellular metabolism.

Grouper (Epinephelus coioides) MyD88 adaptor-like (Mal): Molecular cloning, expression, and functionality

Initiation of the innate immune response requires recognition of pathogen-associated molecular patterns by pathogen recognition receptors such as Toll-like receptors (TLRs). MyD88 adaptor-like (Mal) is an adaptor that responds to TLR activation and acts as a bridging adaptor for MyD88. In the present study, the open reading frame of Mal was identified in orange-spotted grouper (Epinephelus coioides), and named EcMal. It contained 831 bp encoding 276 aa, and was encoded by a 1299 bp DNA sequence with three exons and two introns. EcMal and the Mal sequence of other species shared different degrees of sequence identity, and clustered into the same group. EcMal was distributed in all tissues tested in healthy grouper, with the highest expression level in the head kidney. After infection with Cryptocaryon irritans, the expression level of EcMal was up-regulated in the gill and spleen. In addition, EcMal exhibited global cytosolic and nucleus localization, and could significantly activate NF-κB activity in grouper spleen cells.

Effect of Welsh onion (Allium fistulosum L.) green leaf extract on immune response in healthy subjects: a randomized, double-blind, placebo-controlled study

Background: Welsh onion belongs to genus allium. Although its medicinal benefit such as cold prevention is well known by tradition, the underlying mechanism and active components have never been elucidated. The recent study revealed that Welsh onion mucus enhances tumor necrosis factor-α and monocyte chemotactic protein-1 production from RAW 264 cells and natural killer (NK) cell activity in murine spleen cells. This mucilage was abundant in the leaf blade of Welsh onion. Thus, we investigated the effect of Welsh onion green leaf extract (GLE) on immune competence in the human clinical trial. Methods: A randomized, double-blind, placebo-controlled trial was conducted. Fifty-five healthy subjects were enrolled after the screening based on NK cell activity, and each sample (placebo, low-dose GLE or high-dose GLE) was supplemented for four weeks. The immune competence activity was evaluated through the primary endpoints that were NK cell activity and the score of immunological vigor (SIV). The SIV was calculated from lymphocyte subset analysis by flow cytometry method.Results: NK cell activity was enhanced in all supplemented groups including placebo, especially, it was significant in both GLE groups. The result of immune score showed that the immunity of high-dose GLE group did not change although it was significantly lowered in placebo group (p<0.01), suggesting that GLE ameliorated the immunity suppression. In addition, when SIV was compared between pre- and post-intake, the ratios of the improved subjects in two GLE groups were higher than that of placebo group while those of the aggravated subjects showed the opposite result. In particular, they were remarkable in high-dose GLE group.Conclusion: These results suggest that the intake of low- or high-dose GLE might positively regulate immune competence.Keywords: welsh onion, immunity, natural killer cell, clinical trial