Plaque-forming Cells Research Articles

Hepatotoxicity and Nephrotoxicity in Mice Induced by Abamectin and Ameliorating Effect of Quercetin

Abamectin is a natural fermentation product and widely used as insecticide, acaricide and anthelmintic drug. This study was conducted to investigate the acute toxicity of abamectin toward male mice and evaluate the impact effect of repeated sublethal dose (1/10 LD 50 for 14 days) on some hematological, immunological and biochemical parameters as well as histopathological changes. Also, the effectiveness of quercetin in alleviating the toxicity of abamectin was investigated. The data indicated that, there was significant decrease in the body weight gain and increase in the relative weights of liver and kidney of animals treated with abamectin compared with control. Also, a significant decline in hemoglobin content (Hb), packed cell volume (PCV) and red blood cells (RBC), while the white blood cells (WBC), mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) increased. Abamectin reduced the cellular immunity; active and total rosette-forming cells (RFC) and humoral immunity; plaque forming cells (PFC) and serum immunoglobulins; total Ig, IgG and IgM levels. Oxidative stress of abamectin was assessed by significant increase of lipid peroxidation (LPO), glutathione peroxidase (GPx) activity and decrease of glutathione content (GSH). Also, the function parameters of liver; aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and Alkaline phosphatase (ALP) activities and kidney; creatinine and urea concentrations were significantly increased by abamectin treatment. The above findings were confirmed by histopathological examination of liver and kidney. In addition, the results showed that quercetin supplementation significantly protected the adverse effects of abamectin.

Investigations into the Immunotoxicity and Allergic Potential Induced by Topical Application of N-Butylbenzenesulfonamide (NBBS) in a Murine Model

N-Butylbenzene sulfonamide (NBBS) is a commonly used plasticizer found in numerous products. Due to its extensive use, lack of adequate toxicological data, and suspicion of toxicity based on the presence of structural alerts, it was nominated to the National Toxicology Program for comprehensive toxicological testing. The purpose of this study was to evaluate the potential for hypersensitivity and immune suppression following dermal exposure to NBBS using a murine model. NBBS tested negative in a combined irritancy/local lymph node assay (LLNA), classifying it as nonirritating and nonsensitizing. To estimate the immunosuppressive potential of NBBS, assays that assessed immunotoxicity were performed, including the immumnoglobulin (Ig) M response to T-cell-dependent antigen sheep red blood cells (SRBC), using the plaque-forming cell (PFC) assay and immune cell phenotyping. After a 28-d treatment with NBBS, mice exposed to the lowest concentration (25% NBBS) showed a significant increase in IgM-producing B cells in the spleen. No marked changes were identified in immune cell markers in the lymph node. In contrast to body weight, a significant elevation in kidney and liver weight was observed following dermal exposure to all concentrations of NBBS. These results demonstrate that dermal exposure to NBBS, other than liver and kidney toxicity, did not apparently induce immunotoxicity in a murine model.

Immune response modulatory effect of Emilia sonchifolia (L.) DC: an in vivo experimental study.

This study was performed in order to provide a scientific basis for the conventional use of Emilia sonchifolia in the traditional Indian Ayurvedic medicine possibly through modulation of the host immune defense. Emilia sonchifolia methanolic extract (25 mg/kg body weight) was administered intraperitoneally in mice, and hematological parameters, relative organ weights, bone marrow cellularity, and α-esterase activity were assessed. Humoral immune response was evaluated by hemagglutinating antibody (HA) titer and plaque forming cell (PFC) assay. Blastogenesis assays of lymphoid organs were done in the presence and absence of various mitogens such as phytohemagglutinin, concanavalin A, pokeweed mitogen, and lipopolysaccharide. Cytotoxic T lymphocyte (CTL) production was assessed by Winn's neutralization test. The levels of cytokines interleukin-2 (IL-2) and interferon-γ (IFN-γ) were evaluated by ELISA. Emilia sonchifolia significantly enhanced the total white blood cell count (9995±535 cells/mm3), bone marrow cellularity, α-esterase activity, and weight of lymphoid organs (p<0.001). The effect on humoral immune response was evident from the enhanced HA titer and increased number of PFCs (p<0.001). The blastogenic effects of mitogens were also stimulated to significant levels by E. sonchifolia treatment. Emilia sonchifolia treatment augmented cell-mediated immune response by enhancing the killing activity of CTLs and by enhanced production of IL-2 and IFN-γ. From these results, it was very evident that E. sonchifolia, an indigenous medicinal plant, is a potent immune response modulator, and the present report is so far the first study to demonstrate the immunoregulatory activity of E. sonchifolia.

Dried fruit extract of Terminalia chebula modulates the immune response in mice

Terminalia chebula, traditionally regarded as universal panacea, is known for its pleiotropic effects, including the effects on oxidative stress, malignant tumor growth, wound healing, and insulin sensitivity in Type 2 diabetes. This study reports the effect of dry fruit extract of T. chebula (TCE) on Th1/Th2-mediated immune responses in mice. TCE was administered orally for 10 consecutive days, after which mice were immunized with goat RBC (gRBC) or ovalbumin. TCE enhanced the expression of Th1 cytokine, interferon γ, decreased interleukin 4, and increased the number of plaque-forming cells in gRBC-immunized mice. The percentage of CD4+ cells and delayed-type hypersensitivity response also increased in these mice. Treatment is reported to increase lymphocyte proliferation and macrophage phagocyte response, but decrease nitrite production. The bone marrow cellularity and WBC count also increased in the treated mice. None of the group showed any sign of toxicity. The data indicate that TCE elicits a significant dose-dependent Th1 response.

Effect of Kalpaamruthaa on immunosuppression of both humoral and cell-mediated immunity in DMBA-induced mammary tumours of rats

The present study was carried out to elucidate the protective effect of Kalpaamruthaa on improving 7,12-dimethylbenz(a)anthracene (DMBA)-induced immunosuppression of both humoral and cell-mediated immunity in mammary carcinoma-induced rats. Breast cancer was induced in rats by administering DMBA orally (25 mg/rat) as a single dose. After 90 days of induction, SA (200 mg/kg body weight) and KA (300 mg/kg body weight) were administered for 14 days, by gastric intubation. Several immunotoxicological assays such as T cell rosette delayed type hypersensitivity (DTH) response, migration inhibition factor (MIF) assay, lymphocyte proliferation assay, plaque forming cell (PFC) assay and haemagglutination assay, plaque forming cell (PFC) assay, serum soluble immune complex and cytokine production, T and B cell mitogenesis induced by Con A and nonspecific cell-mediated immunity were evaluated using phagocytosis activity and NBT reduction. In cancer-induced animals (group II), the leukocyte migration inhibition declined markedly (p < 0.001), the levels of cytokines IFN-γ and IL-2 were significantly decreased (p < 0.001) and also the antibody titre level (p < 0.001) was significantly reduced when compared with control rats. A marked decline in PFC (p < 0.001) and serum soluble immune complex (PEG) formation (p < 0.001) was also observed. Hence, the present study clearly demonstrates the immunoprotective effect of KA.

Homeopathic remedies with antineoplastic properties have immunomodulatory effects in experimental animals

Our previous work suggests that Thuja occidentalis, Carcinosinum and Ruta graveolens have antineoplastic properties. The mechanism of this action has not previously been studied. We studied the hypothesis that the mechanism of action is through the immune modulation. We evaluated the effects of Thuja occidentalis, Carcinosinum and Ruta graveolens 1M, 200c and 30c on the immune system of Balb/c mice. The homeopathic preparations were administered orally for ten consecutive days. Haematological parameters (Total White Blood Cell (WBC) Count, Differential Count and Haemoglobin content), haematopoietic parameters (bone marrow cellularity and α-esterase positive cells) and immune parameters for antibody response and lymphoid cell proliferation were assessed using standard methods. Results were analysed by statistical comparison with the control. We observed significant enhancement of haematological parameters including total WBC count, haematopoietic parameters such as bone marrow cellularity and the number of α-esterase positive cells, other parameters of immune response such as circulating antibody titre and the number of plaque forming cells (PFC), particularly with higher dilutions of Thuja and Ruta. Enhanced proliferation of B and T lymphoid cells was also observed. No toxic effects were observed. The results suggest immunomodulatory activity of homeopathic preparations in high dilution. This may be a mechanism through which homeopathic preparations act.

Effects of selenium-chitosan on blood selenium concentration, antioxidation status, and cellular and humoral immunity in mice.

One hundred and eighty Kunming mice were allotted to three groups in a randomized complete block design, including two treatments and one control. Mice in group 1 were fed a basal diet as control, while mice in groups 2 and 3 were fed the basal diet supplemented with 0.2mg/kg selenium as sodium selenite (SS) or selenium-chitosan (SC), respectively. On day 28 of the experiment, blood selenium concentration, glutathione peroxidase (GPx) activity, plasma superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, and Con A-induced splenocyte proliferation were determined, and plasma interleukin-2 (IL-2) and interferon-γ (IFN-γ) concentrations, splenic plaque-forming cell (PFC) responses, serum hemolysis level (HC50), and delayed-type hypersensitivity (DTH) responses were determined on day 15 of the experiment. The results showed that blood selenium concentration, GPx activity, splenic PFC response, and plasma IL-2 and IFN-γ concentrations in SC group were higher than those in the control and SS groups (P < 0.01 or P < 0.05), respectively. Plasma SOD activity, Serum hemolysis level, DTH responses, and Con A-induced splenocyte proliferation in SC group were higher than those in control (P < 0.01 or P < 0.05). Plasma SOD activity, serum hemolysis level, DTH responses, and Con A-induced splenocyte proliferation in SC group were also higher than those in SS group, while there was no significant difference between SC and SS groups (P > 0.05). Plasma MDA content in SC group was lower than those in the control and SS groups (P < 0.01 or P < 0.05). It is concluded that SC supplement can increase blood selenium concentration, antioxidation status, and cellular and humoral immunity, and SC has better biological activity than SS in mice.

The effect of 5-amino-3-methyl-4-isoxazolecarboxylic acid hydrazide on lymphocyte subsets and humoral immune response in SRBC-immunized mice

5-Amino-3-methyl-4-isoxazolecarboxylic acid hydrazide is a non-cytotoxic synthetic isoxazole derivative with considerable immunomodulatory properties demonstrated in in vitro experiments. The aim of this study was to investigate the influence of this compound, depending on the dosage and schedule of treatment, on lymphocyte subsets in non-immunized mice and humoral immune response in SRBC (sheep red blood cells)-immunized mice. An analysis of lymphocyte subsets was carried out by flow cytometry, using specific monoclonal antibodies stained with fluorescein isothiocyanate (FITC) or phycoerythrin (PE). In the SRBC-immunized mice, the influence of the compound on the humoral response was determined, depending on the time of administration relative to the antigen. The number of plaque forming cells (PFC) was determined by a local hemolysis technique in an agar gel. Total and 2-mercaptoethanol resistant serum agglutination titers were defined by active hemagglutination test carried out on microplates. The investigated hydrazide was able to modulate the percentage and absolute number of T lymphocyte subsets in the thymus, and T and B lymphocytes in the peripheral lymphatic organs. It also enhanced humoral immune response in SRBC-immunized mice by increasing the number of cells producing hemolytic anti-SRBC antibodies (PFC) and by augmenting the level of total and 2-mercaptoethanol resistant hemagglutinin. The present study showed modulatory effects of 5-amino-3-methyl-4-isoxazolecarboxylic acid hydrazide on lymphocyte subsets and humoral immune response in mice. This compound could be potentially useful for the treatment of autoimmune diseases, infections or as an adjuvant for boosting the efficacy of vaccines.

A New Activated Water Charged by Electrophoresis, Effect on the Experimentally Immuno-Suppressed Animal and Their Anti-Oxidative Activity

Every individuals expose to the lisk of conventional immunodeficiency in daily life with both internal and externals. In a series of investigation, we have been assessed the various health promoting menu such as hot spring hydrotherapy, acupuncture & moxibution, light excurse, evidenced Control water western medicine technique. In this report, we try to investigate the regulatory effect of hydrotherapy by activated water molecule as our representative menu under the influence of hypothalamus system. We set up both animal and human model for assessment of hydrotherapy. Before starting experimental assessment, six males and females seven-week-old ddY mice, are used for the acute oral toxicity study. There is no sign for toxicity as judged by body weight, organ inspection by veterinary doctor. Next, young ddY mice are experimentally induced diabetes and immune-deficient status by administrating cancer chemotherapeutic agent, Streptzotosin. Charged Water was evident to control the blood sugar level compared to the Control Water group together with conventional control group. Both experimental group of mice wear statistically significant for recovery from blood sugar level and antibody secreting cell both IgM and IgG plaque-forming cell. We confirm also activated water group delivered the granulocyte that slow down the oxidative stress by super oxide.

The effect of Aloe vera extraction on immunity

Aloe vera aqueous extraction was examined for its immunomodulatory effect. Concentrated aqueous extraction was administrated orally 2ml/day for 30 days to the white mice, immunomodulatory effect was studied on total white blood cells (WBCs)count, phagocytosis, antibody titer and plaque forming cell (PFC). There is a significant increase in total count of WBC, reach 11300cell/ml3 at the day 28 after administration. Increase in phagocytosis activity was observed clearly after three and four week compared with control. Remarkable increase in the antibody titer against SRBCs for primary and secondary immune response (10.4±022, 14.2±2) respectively, and finally apparent effect on plaque forming cell (PFC) and maximum value was found after 5 days after immunization with SRBCs. It was 1200 PFC/106 of spleen cell.

In vivo and in vitro immunomodulatory potential of swertiamarin isolated from Enicostema axillare (Lam.) A. Raynal that acts as an anti-inflammatory agent.

Swertiamarin is a secoiridoid glycoside found in Enicostema axillare (Lam) A. Raynal, a medicinal plant used as a depurative in the Indian system of traditional medicine. The present study evaluated the immunomodulatory activity of isolated swertiamarin. In vivo immunomodulatory activity of swertiamarin (2, 5, and 10 mg/kg b.w.) was evaluated in a model of sheep red blood cells (SRBC) by assessing its effect on organ weight, hemagglutinating antibody titer (HA), plaque-forming cells (PFC), quantitative hemolysis of SRBC, and delayed type hypersensitivity (DTH). In vitro immunomodulatory potential was studied on isolated splenocytes, neutrophils, and peritoneal macrophages. In silico immunomodulatory effects were evaluated by docking of swertiamarin on proinflammatory cytokines to confirm its potential. In in vivo studies, the animals treated with swertiamarin showed a significant (P ≤ 0.05) increase in antibody titer, plaque-forming cells, and also in weight of the thymus and spleen. A decreased response to DTH reaction was recorded with the treatment of swertiamarin. In in vitro studies, treatment with swertiamarin modulated the messenger RNA (mRNA) and protein expression of IFN-γ, IL-10, and IL-4 significantly (P ≤ 0.05) and also favored Th2-mediated response on concanavalin A (Con A)-induced splenocytes. The compound inhibited the release of free radicals significantly (P ≤ 0.05) in phytohemagglutinin (PHA)-induced neutrophils and also ameliorated the mRNA and protein expression of proinflammatory cytokines (TNF-α, IL-1β, and IL-6) in lipopolysaccharide (LPS)-induced macrophages. In in silico, the best docked pose of swertiamarin with the target proteins (TNF-α, IL-1β, and IL-6) was confirmed that swertiamarin acted as an anti-inflammatory mediator.

Immunotoxicological Evaluation of Corn Genetically Modified with Bacillus thuringiensis Cry1Ah Gene by a 30-Day Feeding Study in BALB/c Mice

This study was to investigate the immunotoxicological potential of corn genetically modified (GM) with Bacillus thuringiensis (Bt) Cry1Ah gene in BALB/c mice. Female BALB/c mice were randomly assigned to one of the four groups: the negative control group, the parental corn group, the GM corn group and the positive control group with 10 mice per group. Mice in the GM corn group and the parental corn group were fed with diets containing 70% corresponding corn for 30 days. Mice in the negative control group and the positive control group were fed with AIN93G diet, administered with saline or 200 mg/kg of cyclophosphamide (CY) via intraperitoneal injection 24 h before the termination of the study, respectively. At the end of the study, the immunotoxicological effects of the GM corn were evaluated through immunopathology parameters including body and organ weights, hematology and clinical chemistry parameters, histological examination, peripheral blood lymphocytes phenotype; humoral immunity including antibody plaque-forming cell, serum immunoglobulin, cytokine and half hemolysis value; cellular immunity such as mitogen-induced splenocyte proliferation, cytotoxic T-lymphocyte reaction, delayed-type hypersensitivity reaction; non-specific immunity including phagocytic activities of phagocytes, natural killer cell activity. A single dose of cyclophosphamide (200 mg/kg bw) was found to have significant adverse effects on immunopathology, cellular immunity, and humoral immunity in mice. The corn genetically modified with Bt Cry1Ah gene is considered consistent with the parental corn in terms of immunopathology, humoral immunity, cellular immunity and non-specific immunity. No adverse immunotoxicological effects of GM corn with Bt Cry1Ah gene were found when feeding mice for 30 days.

Effects of short-term oral combined exposure to environmental immunotoxic chemicals in mice

People are constantly exposed to environmental chemicals through contact with the atmosphere or by ingestion of food. Therefore, when conducting safety assessments, the immunotoxic effects of combinations of chemicals in addition to toxicities produced by each chemical alone should be considered. The objective of the studies reported here were to demonstrate the combined effects of three well-known environmental immunotoxic chemicals -- methoxychlor (MXC), an organochlorine compound; parathion (PARA), an organophosphate compound; and piperonyl butoxide (PBO), an agricultural insecticide synergist -- by using a short-term oral exposure method. Seven-week-old Balb/cAnN mice received daily oral exposure to either one or two of the environmental immunotoxic chemicals for 5 consecutive days. On Day 2, all mice in each group were immunized with sheep red blood cells (SRBC), and their SRBC-specific IgM responses were analyzed by using an enzyme-linked immunosorbent assay and plaque-forming cell assay. T- and B-cell counts in the mouse spleens were also assessed via surface antigen expression. Mice that received MXC + PARA and PBO + MXC treatment showed marked decreases in SRBC-specific IgM production and T- and B-cell counts compared with those in mice that received vehicle control or the corresponding individual test substance. This suggests that simultaneous exposure to multiple environmental chemicals increases the immunotoxic effects of the chemicals compared to individual exposure.

Immunotoxicological Evaluation of Wheat Genetically Modified with TaDREB4 Gene on BALB/c Mice

ObjectiveTo evaluate the immunotoxicological effects of genetically modified wheat with TaDREB4 gene in female BALB/c mice. MethodsFemale mice weighing 18-22 g were divided into five groups (10 mice/group), which were set as negative control group, common wheat group, parental wheat group, genetically modified wheat group and cyclophosphamide positive control group, respectively. Mice in negative control group and positive control group were fed with AIN93G diet, mice in common wheat group, non-genetically modified parental wheat group and genetically modified wheat group were fed with feedstuffs added corresponding wheat (the proportion is 76%) for 30 days, then body weight, absolute and relative weight of spleen and thymus, white blood cell count, histological examination of immune organ, peripheral blood lymphocytes phenotyping, serum cytokine, serum immunoglobulin, antibody plaque-forming cell, serum half hemolysis value, mitogen-induced splenocyte proliferation, delayed-type hypersensitivity reaction and phagocytic activities of phagocytes were detected. ResultsNo immunotoxicological effects related to the consumption of the genetically modified wheat were observed in BALB/c mice when compared with parental wheat group, common wheat group and negative control group. ConclusionFrom the immunotoxicological point of view, results from this study demonstrate that genetically modified wheat with TaDREB4 gene is as safe as the parental wheat.

Mineral pitch stimulates humoral, cellular and innate immune responses in mice

Context: Mineral pitch (MP), a traditional medicine, is proposed to boost immunity in conditions that suppress Th1 cytokines such as AIDS/HIV, tuberculosis, leishmaniasis and cancer.Objective: This study investigates the immunoregulatory mechanisms of MP in innate, humoral and cell-mediated immunity.Materials and methods: Mice given MP (100, 200, 300 or 400 mg/kg, orally) for 10 consecutive days were immunized intravenously with goat RBC or ovalbumin, and investigated for plaque-forming cells (PFC), hemagglutination titer, hypersensitivity response, lymphocyte proliferation and macrophage function.Results: MP increased PFC (330.2 versus 182.2/106 splenocytes) in mice immunized with goat RBC and elicited ovalbumin-specific IgG titer at 400 mg/kg. Increase in Th1 immunity was correlated with the increased level of IFN-γ (724 versus 470 pg/ml) and decreased IL-4 (96 versus 178 pg/ml). CD4+/CD3+ ratio and delayed-type hypersensitivity response also increased to, respectively, 20.62 ± 0.59 (versus 16.47 ± 0.72) and 1.59 ± 0.12 (versus 0.87 ± 0.10 mm) in MP-treated mice. MP increased lymphocyte proliferation (11.14 ± 0.60 versus 5.81 ± 0.40 SI) and macrophage phagocyte response (0.24 ± 0.02 versus 0.15 ± 0.009), expressed as absorbance at 570 nm, but decreased nitrite production (17.4 ± 1.10 versus 24.3 ± 1.30 µM/106 cells). We also observed an increased bone marrow cellularity (24.5 ± 1.10 versus 17.10 ± 0.70 cells/femur) and WBC count (12 667 ± 377 versus 9178 ± 213 cells/mm3) following MP treatment. There was no sign of toxicity at 400 mg/kg, 1/12th of reported LD50.Conclusion: MP elicits a dose-dependent Th1 immune response.

Involvement of (IgG and IgM)-secreting B lymphocytes in severity of autoimmune hepatitis type 1

Autoimmune hepatitis type 1 (AIH1) is an autoimmune disease attacks the liver and characterized by periportal inflammation, elevated immunoglobulins, and autoantibodies. The central role of B lymphocyte in pathogenicity of AIH1 is unclear. Here, the effect of antibody-secreting cells activity in terms of number of plaque-forming cells (PFC) on severity of AIH1 was evaluated. The high number of PFC-(IgG and IgM) in peripheral blood of patients with AIH1 was observed and this was concomitant with increase in the number of CD4+ T lymphocyte, immunoglobulin (Ig) (IgG and IgM) concentrations, and levels of liver function tests (LFTs). However, the negative correlation (r < -0.5, P < 0.05) between the numbers of PFC-(IgG and IgM) and CD8+ T lymphocytes was reported here. The present study showed the positive relationship between the concentrations of Ig (IgG and IgM) and levels of LFTs (r > +0.5, P < 0.05). The high expression of IL-10 mRNA was found in the tissue culture of peripheral blood lymphocytes obtained from patients with AIH1 as compared with that isolated from control group (P < 0.05). The current study proved the direct role of (IgG and IgM)-secreting cells in severity of AIH1. This was associated with CD4+ cell numbers and IL-10 mRNA expression, and mediated by IgG and IgM.

Immunomodulatory Effect of Ganoderma Lucidum Polysaccharides (GLP) on Long-Term Heavy-Load Exercising Mice

Long-term heavy-load exercise can lead to a decrease in the organism's immune response. In this study, we used 100 Kunming (KM) mice to investigate the immune-regulatory effects of Ganoderma lucidum polysaccharides (GLP) on long-term heavy-load exercising mice. Peripheral white blood cells (WBC), the absolute value of neutrophils (NEUT), the phagocytic function of macrophages, serum agglutination valence, and the number of plaque-forming cells (PFC) were evaluated 4 weeks after gavaging long-term heavy-load exercising mice with GLP. After exercise, the WBC count in peripheral blood, absolute neutrophil count, macrophage phagocytic index, serum agglutination valence, and the number of plaque-forming cells were significantly reduced in the mice not fed GLP. Both medium and high doses of GLP drastically increased peripheral WBC, absolute neutrophil count, macrophage phagocytic index, serum agglutination valence, and the number of plaque-forming cells in long-term heavy-load exercising mice. High doses of GLP increased peritoneal macrophage phagocytic rate considerably. With this study, we demonstrate that 4 weeks of heavy-load exercise can lead to exercise-induced immunosuppression in mice. A supplement of GLP fed to these mice improves both non-specific and specific immune responses among these mice. The effect for the high-dose GLP treatment is especially significant.

Immunotoxicity Induced by Acute Subtoxic Doses of Paraquat Herbicide: Implication of Shifting Cytokine Gene Expression toward T-Helper (TH)-17 Phenotype

Paraquat (PQ) is a free radical-inducing agent commonly used as an herbicide. This study assesses the acute immunotoxicity of PQ in BALB/c mice and examines its effect on cytokine gene expression profile. It was found that single subtoxic oral doses of 2, 4, and 20 mg/kg significantly inhibited the in vitro mitogen-induced proliferation in both T and B cells. Also, such acute doses have resulted in significant reduction of the IgM plaque-forming cells counts. The impact of PQ on the cytokine gene expression of in vitro PHA-activated splenocytes was assessed at 2.0 and 0.006 μg/mL. The concentrations used in vitro represent the lowest in vivo dose given in this study and FAO-WHO set PQ acceptable daily intake (ADI) dose, respectively. Interestingly, the RT²-PCR array for common cytokines' expression demonstrated that PQ had markedly elevated the mRNA expression of several proinflammatory cytokines at both concentrations. More importantly, at concentrations equivalent to ADI, PQ had caused a marked up-regulation of IL-17 cytokine family including IL-17B, C, E, and F. Also, PQ has up-regulated mRNA expression of the T(H)-17-promoting cytokines IL-9 and -21. Together, these results show that PQ at higher concentrations can deplete immune functions, but at lower concentrations, it has potential to alter immune responses toward the proinflammatory profiles as that of T(H)-17. Such a T cell helper profile has been implicated in the development and the pathophysiology of several autoimmune and allergic diseases. Thus, considering that maximum residue levels (MRLs) of PQ set by FAO and WHO for certain food and animal feed crops range between 0.005 and 10.0 mg/kg, our findings stress the importance of applying strict regulation on the use of PQ as an herbicide.

Immunotoxicity of the organochlorine pesticide methoxychlor in female ICR, BALB/c, and C3H/He mice

Several types of pesticides, including organochlorines, are known to suppress or modulate immune responses. The present study evaluated the immunotoxicity of the organochlorine pesticide methoxychlor (MXC) in female BALB/c, C3H/He, and ICR mice. Mice were given oral MXC doses of 0, 30, 100, and 300 mg/kg each day for 7 consecutive days. On day 4, the mice also received an intravenous injection of sheep red blood cells (SRBC). The splenic plaque-forming cell (PFC) IgM response and the serum anti-SRBC IgM antibody titer were evaluated while splenic lymphocytes were counted by flow cytometry and the spleen underwent histopathological analysis. Significant decreases in IgM PFC responses were seen in BALB/c, C3H/He, and ICR mice that received MXC doses of 100 and 300 mg/kg. Similar changes in serum anti-SRBC IgM antibody titers occurred in three strain mice. Flow cytometric analysis revealed significantly decreased splenic T-cell (CD3+) populations in a dose dependent manner in BALB/c mice, and in the 300 mg/kg of MXC-treated group of C3H/He mice. Germinal center (GC) B-cell (CD19+PNA+) populations were significantly decreased in the 300 mg/kg of MXC-treated groups of all three mouse strains and in the 30 and 100 mg/kg of MXC-treated groups of BALB/c and C3H/He strain mice. Histopathological analysis revealed decreased cellularity of the periarteriolar lymphoid sheath (PALS; T-cell area) and decreased GC development in all three strains of mice treated with 300 mg/kg MXC. These results suggest that MXC has an immune-suppressive effect in mice, and that our protocol may be useful for rapidly detecting immunosuppression induced by environmental chemicals.

The effects of bestatin on humoral response to sheep erythrocytes in non-treated and cyclophosphamide-immunocompromised mice

The effects of bestatin on humoral immune response to sheep erythrocytes (SRBC) and restoration of the response impaired by a single cyclophosphamide dose (350 mg/kg) were tested on mice. Bestatin (at doses of 10, 1, and 0.1 mg/kg) was administered intraperitoneally (i.p.) 5 or 10 times. The pharmacological immunosuppression was induced by a single i.p. injection of cyclophosphamide (350 mg/kg) administered 24 h before the first bestatin dose. The mice were immunized i.p. with SRBC 24 h after the last dose of bestatin. It was found that multiple administration of bestatin at all three doses potentiated the humoral response to SRBC in non-treated mice, resulting in an increased number of plaque-forming cells (PFC) and 2-mercaptoethanol (2-ME)–resistant anti-SRBC antibodies. However, five times administration of bestatin at the doses under investigation caused further decreases in total anti-SRBC hemagglutinins. A single injection of cyclophosphamide (350 mg/kg) suppressed humoral response of mice to the antigen. Administration of bestatin after pharmacological immunosuppression partially prevented the suppressive action of cyclophosphamide in the in vivo model of the humoral immune response to SRBC. The protective action of bestatin was both dose- and schedule-dependent. Ten times’ exposure to a bestatin dose of 0.1 mg/kg after a high cyclophosphamide dose partially reduced the suppressive effect of this drug on humoral response of SRBC-immunized mice, increasing PFC on days 4 and 7 after immunization, which coincided with restored ability of the lymphocytes to produce the 2-ME–resistant hemagglutinins on day 7 and the total anti-SRBC hemagglutinins on day 14 after priming.