Suppressed Splenocyte Proliferation Research Articles

The mechanisms underlying alcohol-induced decreased splenic size: A network meta-analysis study.

Organ weight change is widely accepted as a measure of toxicologic pathology. We and other groups have shown that excessive alcohol exposure leads to decreased spleen weight in rodents. This study explores the mechanisms underlying alcohol-induced splenic injury through a network meta-analysis. QIAGEN Ingenuity Pathway Analysis (IPA) and Mammalian Phenotype (MP) Ontology were used to identify alcohol-related molecules associated with the small spleen phenotype. Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) and IPA bioinformatics tools were then used to analyze the biologic processes and enriched signaling pathways engaging these molecules. In addition, the "downstream effects analysis" algorithm was used to quantify alcohol's effects. IPA identified 623 molecules affected by alcohol and a Venn diagram revealed that 26 of these molecules overlapped with those associated with the MP Ontology of small spleen. The 26 molecules are TGFB1, CASP8, MTOR, ESR1, CXCR4, CAMK4, NFKBIA, DRD2, BCL2, FAS, PEBP1, TRAF2, ATM, IGHM, EDNRB, MDM2, GLRA1, PRF1, TLR7, IFNG, ALOX5, FOXO1, IL15, APOE, IKBKG, and RORA. Some of the 26 molecules were also associated with the MP Ontology of abnormal white pulp and red pulp morphology of the spleen, abnormal splenic cell ratio, decreased splenocyte number, abnormal spleen physiology, increased splenocyte apoptosis, and reduced splenocyte proliferation. STRING and IPA "Core Analysis" showed that these molecules were mainly involved in pathways related to cell apoptosis, proliferation, migration, and immune responses. IPA's "Molecular Activity Predictor" tool showed that concurrent effects of activation and inhibition of these molecules led to decreased spleen size by modulating apoptosis, proliferation, and migration of splenocytes. Our network meta-analysis revealed that excessive alcohol exposure can damage the spleen through a variety of molecular mechanisms, thereby affecting immune function and human health. We found that alcohol-mediated splenic atrophy is largely mediated by increased apoptosis signaling, migration of cells, and inhibition of splenocyte proliferation.

Silk Sericin Activates Mild Immune Response and Increases Antibody Production.

To clarify whether nanoparticles of silk sericin (SS) and silk fibroin (SF) can induce inflammation and immune responses, we analyzed splenocyte proliferation, apoptosis and cytokine release to identify the effects of SS and SF on mouse splenocytes in vitro. We implanted mice with SS and SF through intraperitoneal, intramuscular, and subcutaneous routes to evaluate the innate and adaptive immune response to SS and SF in vivo. Cytokines in the serum and spleen were analyzed by Luminex and antibody array. Antigen-specific antibodies were evaluated by enzyme-linked immunosorbent assay (ELISA) at week 1 and 5 after implantation. Distinct cell populations in the spleen and bone marrow were analyzed by flow cytometry. SS suppressed the proliferation of splenocytes and CD11b+CD27- NK cells, induced splenocyte apoptosis, and increased interleukin-1 β (IL-1 β) and tumor necrosis factor-α (TNF-α) in the culture supernatant. SF suppressed splenocyte proliferation, induced splenocyte apoptosis, and increased the titer of TNF-α in culture supernatants. At both week 1 and 5 after implantation with SS, mouse serum interleukin-1 α (IL-1 α) and keratinocyte chemoattractant (KC) were decreased, SS-specific antibody was increased, the proportion of bone marrow CD4+ T cells was increased, and the proportion of splenic neutrophils was decreased. At week 5 after subcutaneous implantation with SF, mouse serum IL-1α, and splenic IL-6, TIMP-1, IL-4, MCP-1, IFN-γ, TCA-3, TNF-α, and IL-17 were decreased. SS was able to induce a mild immune response, as evidenced by CD4+ T cell activation, splenocyte apoptosis, and antigen-specific antibody secretion. Comparatively, SF had low immunogenicity and anti-inflammatory properties.

Oxymatrine protects cardiac allografts by regulating immunotolerant cells

Organ transplantation is an effective treatment strategy for patients with irreversible organ failure or congenital organ dysfunction. Oxymatrine (OMT) is a quinolizidine alkaloid with protective and anti-inflammatory effects on tissues and organs. The objective of this study was to investigate whether OMT could exert protective effects in cardiac allografts by regulating immune cells. In vitro cell proliferation and co-culture experiments were used to measure the effects of OMT on splenocyte proliferation and differentiation. In the in vivo study, C57BL/6 mice transplanted with BALB/c cardiac grafts were randomly divided into untreated, low-dose OMT treated, middle-dose OMT treated, high-dose OMT treated, and rapamycin-treated groups. Haematoxylin and eosin and immunohistochemical staining were used to assess pathological changes in the grafts, and fluorescence-activated cell sorting analysis was performed to measure the percentages of immune cells. The results showed that, in the in vitro study, OMT inhibited splenocyte proliferation, decreased the percentage of mature dendritic cells (DCs), and increased the percentage of regulatory T cells (Tregs) and regulatory B cells (Bregs). In the in vivo study, OMT exerted allograft protective effects by prolonging survival time, alleviating pathological damages to the cardiac allograft, decreasing intragraft CD3+ cell and increasing intragraft Foxp3+ cell infiltration, decreasing the percentages of mature DCs, increasing the percentages of Tregs and Bregs, and inhibiting the function of DCs. In conclusion, our study demonstrates that OMT exerted a protective effect on cardiac allografts by regulating immunotolerant cells. More in-depth studies of OMT may provide additional insight into the use of immunosuppressive drugs as a post-transplantation treatment strategy.

Tofacitinib treatment aggravates Staphylococcus aureus septic arthritis, but attenuates sepsis and enterotoxin induced shock in mice

Tofacitinib, a janus kinase inhibitor, is a novel immunosuppressive drug for treatment of rheumatoid arthritis (RA). Septic arthritis (SA) and sepsis caused by Staphylococcus aureus (S. aureus), for which RA patients are at risk, are infections with high mortality. The aim of this study was to investigate the effect of tofacitinib on S. aureus infections using mouse models. In vitro tofacitinib treated mouse splenocytes were stimulated with S. aureus derived stimuli. Mice pre-treated with tofacitinib were inoculated intravenously with either arthritogenic- or septic doses of S. aureus. Arthritis severity and mortality were compared between groups. Additionally, pre-treated mice were challenged with staphylococcal toxin TSST-1 to induce shock. Tofacitinib inhibited splenocyte proliferation and IFN-γ production in response to TSST-1 and dead S. aureus. In SA, tofacitinib treatment aggravated arthritis with more severe bone erosions. However, in sepsis, treated mice displayed significantly prolonged survival compared to controls. Similarly, in staphylococcal enterotoxin-induced shock tofacitinib pre-treatment, but not late treatment dramatically reduced mortality, which was accompanied by decreased levels of TNF-α and IFN-γ. Our findings show that tofacitinib treatment increase susceptibility of SA in mice, but has a positive effect on survival in S. aureus-induced sepsis and a strong protective effect in toxin-induced shock.

Melatonin attenuates diabetes-induced oxidative stress in spleen and suppression of splenocyte proliferation in laboratory mice

Hyperglycaemic condition induced oxidative stress in diabetic individuals caused oxidative damages of internal organs, including immune organ spleen. We studied the effects of low doses of melatonin (25, 50, and 100 µg/100g. B.wt./day) on histoarchitecture, oxidative stress, and splenocyte proliferation in streptozotocin-induced diabetic mice. Melatonin significantly resisted the increase in blood glucose levels and showed a dose-dependent effect on circulatory melatonin, body weight, and relative spleen weight in diabetic mice. Exogenous melatonin suppressed the diabetes-induced lipid peroxidation and increased the activity of the antioxidant enzymes and antioxidant GSH in the spleen tissue of diabetic mice in a dose-dependent manner. Melatonin improved the reactivity of Nrf-2 and HO-1 in the spleen of diabetic mice. Melatonin treatment normalised the splenic cellularity and increased the splenocyte proliferation in a dose-dependent manner. The present study may suggest the dose-dependent effect of melatonin in attenuation of oxidative stress and suppression of splenocyte proliferation in diabetic mice.

Immunomodulatory Effects of Tigecycline in Balb/C Mice.

Tigecycline is a glycylcycline antibiotic approved by the FDA for the treatment of complicated infections. Despite its effectiveness, the FDA announced a warning of increasing mortality associated with its use. There is, however, no clear explanation for this side effect. Previous reports found a possible effect of tigecycline on leukocyte proliferation and proinflammatory cytokine release. We t herefore i nvestigated the effect of tigecycline on the immune components and response in Balb/c mice in vivo and in vitro. It was found that tigecycline enhanced lymphocyte proliferation and significantly increased cellular infiltration within the footpad, as based on DTH testing, but reduced the hemagglutination titer. In splenocyte cultures, tigecycline suppressed splenocyte proliferation with IC50 3-5 mmol L-1, significantly increased IL-2 secretion and reduced IL-17 secretion in a dose dependent mode. In conclusion, tigecycline is safe at therapeutic and sub-therapeutic doses, but it could still have an immunomodulatory effect at higher doses. Use of higher doses of tigecycline requires further investigation.

Selective effects of fenitrothion on murine splenic T-lymphocyte populations and cytokine/granzyme production

ABSTRACTThe aim of this study was to investigate in vitro effects of fenitrothion (FNT) on mouse splenic lymphocytes. Here, naïve mice had their spleens harvested and splenocytes isolated. After exposure to FNT for 48 hr: splenocyte viability was measured using a tetrazolium dye assay; cell phenotypes, i.e., B-cells (CD19+), T-cells (CD3+), and T-cell subsets (CD4+ and CD8+), were quantified by flow cytometry; and, production of cytokines/granzyme-B was assessed via enzyme-linked immunosorbent assay. The ability for FNT to induce oxidative stress in the cells was evaluated by measuring hydroxyl radical (·OH) and malondialdehyde (MDA) production and changes in glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activity. The results showed that FNT significantly inhibited splenocyte proliferation, and decreased production of interleukin (IL)-2, interferon gamma, IL-4, and granzyme B, but had no impact on IL-6 production. FNT also selectively decreased splenic T-cell levels but did not induce changes in CD19+ B-cells. Further, within the T-cell populations, percentages of CD3+, CD4+, and CD8+ T-cells (particularly CD8+ T-cells) were reduced. Lastly, FNT selectively increased MDA and ·OH production and inhibited SOD and GSH-Px activities in the splenic lymphocytes. These findings suggest that, due to oxidative damage, FNT selectively inhibits splenic T-lymphocyte survival and cytokine/granzyme production in vitro.

Critical disease windows shaped by stress exposure alter allocation trade-offs between development and immunity.

Ubiquitous environmental stressors are often thought to alter animal susceptibility to pathogens and contribute to disease emergence. However, duration of exposure to a stressor is likely critical, because while chronic stress is often immunosuppressive, acute stress can temporarily enhance immune function. Furthermore, host susceptibility to stress and disease often varies with ontogeny; increasing during critical developmental windows. How the duration and timing of exposure to stressors interact to shape critical windows and influence disease processes is not well tested. We used ranavirus and larval amphibians as a model system to investigate how physiological stress and pathogenic infection shape development and disease dynamics in vertebrates. Based on a resource allocation model, we designed experiments to test how exposure to stressors may induce resource trade-offs that shape critical windows and disease processes because the neuroendocrine stress axis coordinates developmental remodelling, immune function and energy allocation in larval amphibians. We used wood frog larvae (Lithobates sylvaticus) to investigate how chronic and acute exposure to corticosterone, the dominant amphibian glucocorticoid hormone, mediates development and immune function via splenocyte immunohistochemistry analysis in association with ranavirus infection. Corticosterone treatments affected immune function, as both chronic and acute exposure suppressed splenocyte proliferation, although viral replication rate increased only in the chronic corticosterone treatment. Time to metamorphosis and survival depended on both corticosterone treatment and infection status. In the control and chronic corticosterone treatments, ranavirus infection decreased survival and delayed metamorphosis, although chronic corticosterone exposure accelerated rate of metamorphosis in uninfected larvae. Acute corticosterone exposure accelerated metamorphosis increased survival in infected larvae. Interactions between stress exposure (via glucocorticoid actions) and infection impose resource trade-offs that shape optimal allocation between development and somatic function. As a result, critical disease windows are likely shaped by stress exposure because any conditions that induce changes in differentiation rates will alter the duration and susceptibility of organisms to stressors or disease.

Cis-bifenthrin induces immunotoxicity in adolescent male C57BL/6 mice.

Bifenthrin (BF) is an important synthetic pyrethroid. Previous studies have demonstrated that cis-BF exhibits toxic effects on development, the neurological, reproductive and endocrine system. In this study, we evaluated the immunotoxicity caused by cis-BF in adolescent male C57BL/6 mice. Mice were exposed orally to 0, 5, 10, and 20 mg/kg/d for 3 weeks. The results showed that body weight, spleen weight, and splenic cellularity decreased in mice exposed to 20 mg/kg/d cis-BF. Additionally, we found that the mRNA levels of the pro-inflammatory factors IL-1β, IL-6, CXCL-1, and TNF-α, in peritoneal macrophages, the spleen, and the thymus were inhibited in the cis-BF-treated groups. Moreover, MTT assays demonstrated that cis-BF inhibited splenocyte proliferation stimulated by LPS or Con A, as well as the secretion of IFN-γ on Con A stimulation. Collectively, the results of this study suggest that exposure to cis-BF has the potential to induce immunotoxicity in adolescent male C57BL/6 mice.

A herbal formula comprising Rosae Multiflorae Fructus and Lonicerae Japonicae Flos, attenuates collagen-induced arthritis and inhibits TLR4 signalling in rats

RL, a traditional remedy for Rheumatoid arthritis (RA), comprises two edible herbs, Rosae Multiflorae Fructus and Lonicerae Japonicae Flos. We have reported that RL could inhibit the production of inflammatory mediators in immune cells. Here we investigated the effects and the mechanism of action of RL in collagen-induced arthritis (CIA) rats. RL significantly increased food intake and weight gain of CIA rats without any observable adverse effect; ameliorated joint erythema and swelling; inhibited immune cell infiltration, bone erosion and osteophyte formation in joints; reduced joint protein expression levels of TLR4, phospho-TAK1, phospho-NF-κB p65, phospho-c-Jun and phospho-IRF3; lowered levels of inflammatory factors (TNF-α, IL-6, IL-1β, IL-17A and MCP-1 in sera and TNF-α, IL-6, IL-1β and IL-17A in joints); elevated serum IL-10 level; reinvigorated activities of antioxidant SOD, CAT and GSH-Px in the liver and serum; reduced Th17 cell proportions in splenocytes; inhibited splenocyte proliferation and activation; and lowered serum IgG level. In conclusion, RL at nontoxic doses inhibited TLR4 signaling and potently improved clinical conditions of CIA rats. These findings provide further pharmacological justifications for the traditional use of RL in RA management.

Effect of 6'-acetylpaeoniflorin on dinitrochlorobenzene-induced allergic contact dermatitis in BALB/c mice.

Allergic contact dermatitis (ACD) is a classical experimental model of allergic inflammatory skin disease, which is a delayed-type hypersensitivity reaction that is mediated by hapten-specific T lymphocytes. The goal of this study was to investigate the pharmacokinetic profiles of 6'-acetylpaeoniflorin (6-AP) and the effect of 6-AP on the ACD model. 6-AP was synthesized from paeoniflorin (Pae) via acetylation, and the structure was confirmed. There were statistically significant differences in the pharmacokinetic parameters including t 1/2α , t 1/2β , AUC, MRT and C max among the animals that were orally administered Pae and 6-AP. An ACD model was induced using immunization with dinitrochlorobenzene (DNCB) in BALB/c mice. The mice were orally administered 6-AP (35, 70 and 140mg/kg/d), Pae (70mg/kg/d) and prednisone (Pre, 5mg/kg/d) from day 1 to day 7 after immunization. The results indicated that the topical application of DNCB to the skin provoked obvious inflammatory responses. 6-AP significantly inhibited ear swelling and decreased inflammatory cell infiltration and epidermal keratinization. Additionally, 6-AP observably alleviated the hyperplasia of red pulp and germinal center appearance, decreased the spleen index and inhibited splenocyte proliferation in the ACD model compared to that of Pae. Furthermore, the study indicated that 6-AP could increase the IL-10 level, while simultaneously reducing the IL-17 level in splenocytes. In summary, these results suggest that 6-AP has a significantly higher anti-inflammatory effect than Pae and that 6-AP might be a candidate for the treatment of allergic skin diseases.

Immunologic characterization of 3 murine regimens of allergen-specific immunotherapy

Allergen-specific immunotherapy (ASIT) is used to treat the symptoms of immediate type I hypersensitivity. The mechanisms driving establishment of allergen tolerance are not yet fully understood. The goal of this study was to develop and immunologically characterize 3 murine models of ASIT to simulate protocols currently used to treat patients with type I hypersensitivities. Ovalbumin (OVA)-sensitized mice were desensitized to OVA by means of repeated injections of OVA with a rapid, intermediate, or gradual protocol. After desensitization, mice were assessed for clinical sensitivity to OVA, and immunologic parameters were assessed. Mice in all treatment protocols displayed decreased vascular permeability in response to OVA challenge after desensitization. Circulating OVA-specific IgE levels, as well as basophil activation in response to OVA stimulation and IgE cross-linking, were significantly decreased in all treatment groups. Intermediate and gradual protocols, but not rapid desensitization, suppressed splenocyte proliferation and production of IL-4, IL-5, and IFN-γ in response to OVA and polyclonal activation. Similarly, significant increases in IL-10 production, numbers of CD4(+)CD25(+) forkhead box protein 3-positive regulatory T cells, and OVA-specific IgG1 antibody levels were only observed in mice undergoing prolonged ASIT regimens. Suppression of IgE-mediated activation is a common feature of all desensitization schedules. Induction of immunoregulatory networks requires prolonged desensitization schedules.

Assessment of the immunosuppressive and hemolytic activities of an edible fern, Diplazium esculentum

Context: Diplazium esculentum is the most commonly consumed fern throughout Asia and Oceania. Systemic toxicity and pathological effects on its consumption have already been demonstrated. But, the immunosuppressive and hemolytic activities of the boiled Diplazium esculentum (BDE), the form in which human consumes it, have not yet been studied.Objective: To investigate the immunosuppressive as well as hemolytic activities, if any, of BDE in Swiss albino mice.Materials and methods: Body weight, relative spleen weight, plaque forming cell assay, hemaggutination antibody (HA) titer assay and macrophage counting were performed in BDE treated mice and respective control groups within a span of 180 days, and in vitro assays such as counting of cultured splenocytes, splenocytes proliferation assay and hemolytic assay were performed to justify the immunomodulatory as well as hemolytic activities of D. esculentum.Results: Body weight and relative spleen weight were significantly decreased in BDE fed mice. Significant decreases were observed in the number of plaques formed, HA titer value and in the number of peritoneal macrophages within a span of 180 d. Significant dose-dependent decrease was observed in the number of cultured splenocytes. Significant dose-dependent increases in the percentage inhibition of splenocyte proliferation as well as percentage of hemolysis were evident by in vitro assays.Discussion: These results suggest that the intake of D. esculentum may evoke immune dysfunction as well as may cause destruction of erythrocytes even after cooking.Conclusion: Therefore, the consumption of D. esculentum is alarming and may act as immunosuppressive agent.

Maternal exposure to airborne particulate matter causes postnatal immunological dysfunction in mice offspring

Evidence suggests that prenatal exposure to air pollution affects the ontogeny and development of the fetal immune system. The aim of this study was to investigate the effect of maternal exposure to airborne particulate matter (PM) on immune function in postnatal offspring.Pregnant female ICR mice were intralaryngopharyngeally administered with 30μl of phosphate buffered solution (the control group) or resuspended PM of Standard Reference Material 1649a at 0.09 (low), 0.28 (medium), 1.85 (high) or 6.92 (overdose) μg/μl once every three days from day 0 to 18 of pregnancy (n=8–10). Offspring were sacrificed on postnatal day 30. Interleukin-4 and interferon-γ levels in plasma and splenocytes, splenic lymphocyte proliferation, and expressions of GATA-3 and T-bet mRNA in the spleen were tested. The spleen and thymus were histopathologically examined.The offspring of the medium, high and overdose PM-exposed dams showed significantly suppressed splenocyte proliferation. Decreased interferon-γ and increased interleukin-4 levels in the blood and splenocytes, and lowered T-bet and elevated GATA-3 mRNA expressions were found in the spleen in the medium, high and overdose groups when compared with the control or low dose group (P<0.05). Histopathology revealed prominent tissue damage in the spleen and thymus in the overdose group.These results suggest that exposure of pregnant mice to PM modulates the fetal immune system, resulting in postnatal immune dysfunction by exacerbation of Thl/Th2 deviation. This deviation is associated with altered T-bet and GATA-3 gene expressions.

Artemisiae capillaris herba Induces Prolonged Survival of Fully Cardiac Allografts and Generates Regulatory Cells in Mice

Inchingorei-san (TJ-117), a 6-component herbal medicine, is used in Japan for the treatment of vomiting, urticaria, and liver and kidney disorders with few side effects. In this study we investigated the effect of TJ-117 on alloimmune responses in murine cardiac allograft transplantation. CBA (H2k) mice underwent transplantation of a C57BL/6 (B6, H2b) heart with oral administration of TJ-117 (or 1 component of TJ-117) from the day of transplantation for 7 days. CBA recipients given 1 g/kg/d of TJ-117 showed prolonged B6 allograft survival (median survival time [MST], 23 days). Naive CBA mice rejected B6 cardiac grafts acutely (MST, 7 days). Moreover, Artemisiae capillaris herba (ACH; 1g/kg/d) 1 component of TJ-117, significantly prolonged B6 allograft survival (MST, > 100 days). However, the other 5 components of TJ-117 were individually less effective than TJ-117 or ACH. ACH also suppressed splenocyte proliferation and interferon-γ production. Secondary CBA recipient showed prolonged survival of B6 hearts after treatments with whole splenocytes from primary ACH-treated CBA recipients carrying B6 cardiac allografts for 30 days (MST, >50 days). Flow cytometry studies showed increased CD4+CD25+Foxp3+ regulatory cells in transplant recipients given ACH. In conclusion, ACH, 1 component of TJ-117, as well as TJ-117 induced hyporesponsiveness to fully allogeneic cardiac allografts with generation of CD4+CD25+Foxp3+ regulatory cells.

Amniotic Epithelial Cells from the Human Placenta Potently Suppress a Mouse Model of Multiple Sclerosis

Human amniotic epithelial cells (hAEC) have stem cell-like features and immunomodulatory properties. Here we show that hAEC significantly suppressed splenocyte proliferation in vitro and potently attenuated a mouse model of multiple sclerosis (MS). Central nervous system (CNS) CD3+ T cell and F4/80+ monocyte/macrophage infiltration and demyelination were significantly reduced with hAEC treatment. Besides the known secretion of prostaglandin E2 (PGE2), we report the novel finding that hAEC utilize transforming growth factor-β (TGF-β) for immunosuppression. Neutralization of TGF-β or PGE2 in splenocyte proliferation assays significantly reduced hAEC-induced suppression. Splenocytes from hAEC-treated mice showed a Th2 cytokine shift with significantly elevated IL-5 production. While transferred CFSE-labeled hAEC could be detected in the lung, none were identified in the CNS or in lymphoid organs. This is the first report documenting the therapeutic effect of hAEC in a MS-like model and suggest that hAEC may have potential for use as therapy for MS.

Effects of the synthetic pyrethroid insecticide, permethrin, on two estuarine fish species

Limited toxicity data are available for estuarine and marine species and the widely used pyrethroid insecticide, permethrin. This study determined acute effects of permethrin on survival, lipid peroxidation, acetylcholinesterase activity, and splenocyte proliferation for two fish species found in South Carolina estuaries; juvenile red drum (Sciaenops ocellatus) and adult mummichog (Fundulus heteroclitus). Juvenile S. ocellatus were significantly more sensitive than adult F. heteroclitus to permethrin exposure, with a 96-h LC50 value of 8 μg/L determined for red drum compared to 23 μg/L for mummichog. Lipid peroxidation activity of the liver increased in permethrin-treated fish compared to control animals after 24 h and decreased after 96 h. Permethrin had no effect on acetylcholinesterase activity of the brain at the concentrations tested. Permethrin exposure significantly inhibited splenocyte proliferation, indicating an immunosuppressive effect. Most of the effects of permethrin on fish cellular stress enzymes and survival occurred at concentrations much higher than those typically measured in the environment. However, inhibition of splenocyte proliferation in juvenile red drum occurred at approximately twice that of measured permethrin concentrations in surface water. These findings may prove useful to the future management and regulation of pyrethroid insecticide use near estuarine habitats.

A polysaccharide from Strongylocentrotus nudus eggs protects against myelosuppression and immunosuppression in cyclophosphamide-treated mice

To assess the chemoprotective properties of a polysaccharide from Strongylocentrotus nudus eggs (SEP), myelosuppressed and immunosuppressed mouse models were generated by administration of cyclophosphamide (Cy) and then treated with SEP. SEP (16mg/kg/d) remarkably increased spleen and thymus indices, activated the proliferation of leukocytes and erythrocytes and platelets from peripheral blood, and exhibited co-mitogenic activity on ConA- or LPS-stimulated splenocytes in a dose-dependent manner. An increased percentage of CD34+ cells in bone marrow of Cy-treated mice was also observed. Furthermore, SEP elevated CD4+ T lymphocyte counts as well as the CD4/CD8 ratio dose-dependently, and it increased interleukin-2 (IL-2), IgA, IgM, and IgG levels in the sera of Cy-treated mice. Pre-incubation with TLR2 and TLR4 blocking antibodies inhibited splenocyte proliferation and its IL-2 secretion. Finally, SEP significantly induced Akt phosphorylation in splenocytes from Cy-treated mice, suggesting that chemoprotection by SEP was mediated through the PI3K/Akt signaling pathway. These findings indicate that SEP plays an important role in the protection against myelosuppression and immunosuppression in Cy-treated mice and could be a potential immunomodulatory agent.

Screening of immunomodulatory components in Yu-ping-feng-san using splenocyte binding and HPLC

Yu-ping-feng-san (YPFS) is a widely used immunomodulatory herbal medication used in traditional Chinese medicine, but the active molecules remain obscure. To screen for bioactive components we combined splenocyte binding with high performance liquid chromatography (SB-HPLC). After enrichment by splenocyte binding, two YPFS components (C1 and C2) were analyzed by HPLC. Compound C2 was identified as linoleic acid (LA) based on UV absorption and mass spectrometry. Silica gel chromatography was used to purify compound C1 from Radix Saposhnikoviae, a major constituent of YPFS. This allowed identification of the molecule as panaxynol (PAN) based on EI-MS and NMR spectrometry. Bioassay in vitro demonstrated that PAN significantly inhibited splenocyte proliferation induced by concanavalin A (ConA) in a concentration-dependent manner, whereas LA had no significant effect on splenocyte proliferation. In vivo, PAN was found to attenuate allergic contact dermatitis in a mouse model of delayed-type hypersensitivity (DTH), a pharmacological activity not previously reported for this molecule. It is suggested that PAN contributes to the anti-DTH effects of YPFS. SB-HPLC provides a rapid and efficient method for the identification of potential immunomodulatory components in traditional Chinese medicines.

Effect of Glucocorticoid and Melatonin on Immune Function of an Indian Tropical Bird, Perdicula Asiatica: An in Vivo and in Vitro Study

Inverse relationship between circulatory levels of glucocorticoids and melatonin has been reported for most of the vertebrates including human beings. We report the importance of glucocorticoid along with melatonin in avian immune regulation in an Indian tropical bird, Perdicula asiatica with in vivo and in vitro approach. Dexamethasone (30μg/bird/day) treatment of the male birds suppressed the immune activity as judged by the spleen activity (mass, anatomy), circulating total leukocyte, and lymphocyte count, blastogenic response, increased % apoptosis and cytokine (IL-2) production by splenocytes. Melatonin (25μg/100g B.wt./day) treatment increased the above-mentioned immune parameters whereas melatonin together with dexamethasone restored the suppressed immune parameters by dexamethasone to control level. In vitro melatonin (2.5 pM) supplementation to splenocyte cultures restored the dexamethasone (2 μM) suppressed splenocyte proliferation, % apoptosis and IL-2 production. Therefore, melatonin antagonized the suppressive effect of synthetic glucocorticoid on all immune parameters studied in vivo as well as in vitro. Furthermore, exogenous administration of dexamethasone and melatonin treatment altered the circulatory level of corticosterone and melatonin in an inverse manner. It is therefore, suggested that a hormonal trade-off between glucocorticoid and melatonin exists under in vivo and in vitro conditions, being involved in maintenance of the immune function of P. asiatica probably by involving cytokines i.e. IL-2 mediated pathway.