This report describes surface properties of several cell membranes tested by lectininduced agglutination reactions which were quantitated using the microquantitative particle counter agglutination assay of Davis et al. (1976). The quantitative assays of concanavaalin A (con A) induced agglutination were performed for rabbit erythrocyte, rat erythrocyte, human erythrocyte, and sarcoma 180 mouse ascites cells. The percent agglutination versus the con A concentration revealed a sigmoid curve in all cases, but the steepness of the sigmoid curve is variable depending on the cell types. It varies even with the same cell but in different species. Optimum cell concentration was (0.92-0.95) x 10(7) cells/ml final concentration in the hanging drop, for rabbit erythrocytes, (0.77-1.64) x 10(7) cells/ml for rat erythrocytes, (1.59-2.7) x 10(7) cells/ml for human erythrocytes and (0.23-0.39) x 10(7) cells/ml for sarcoma 180 mouse ascites cells. When minimal and maximal agglutination percentages were defined as the concentration of con A/ml/1 x 10(6) cells corresponding to 10% and 95% agglutination, minimal and maximal agglutination occured at 0.56 ug, 19.98 ug for human erythrocytes at 0.56 ug, 224 ug for rat erythrocytes at 0.08 ug, 1.43ug for rabbit erythrocytes at 0.12 ug, 14.8 ug for sarcoma 180-mouse ascites cells respectively. The order of inhibitory activity of alpha-methyl-D-mannopyranoside (alphaMM) for each corresponding cells from the highest inhibition was human erythrocytes, rat erythrocytes, sarcoma 180 mouse ascites cells and rabbit erythrocytes. The concentrations of alphaMM required for 50% inhibition per ml of the final concentration in the hanging drop per 1 x 10(7) cells were 0.565 umoles for rabbit erythrocytes, 0.072 umoles for rat erythrocytes, 0.018 umoles for human erythrocytes and 3.677 umoles for sarcoma 180 mouse ascites cells, respectively. From our experimental results we conclude that the cytoagglutination activity was increased with con A, the inhibitory activity with alphaMM in the presence of con A was decreased, however the sarcoma 180 mouse ascites cells revealed a contradictory result, and might be due to the topological distribution of agglutination site changes to a distribution more favorable for agglutination.
Agglutination ; Agglutination Tests ; Animal ; Cell Membrane/immunology* ; Concanavalin A/pharmacology* ; Erythrocytes/immunology ; Human ; Methylmannosides/pharmacology ; Mice ; Rabbits ; Rats ; Sarcoma 180/immunology ; Surface Properties

Sensitivity of Fas expressing tumor cells (high levels in Hut78 & Jurkat; low levels in P815) toward the cytotoxic Con-A (5 microg/ml) activated spleen cells from young (12 to 16 week old males) and old (2 year old males) mice were studied. The spleen cells from young mice activated for a day showed high levels of cytotoxic activity against Hut78 and Jurkat cell lines but not against P815 cells. The cytotoxic activity against P815 cells were detected in the spleen cells from old but not young mice following a longer period of Con-A activation (three days). Comparable levels of cytotoxic activity against Hut78 and Jurkat cells were observed in the spleen cells from both young and old mice following three days of activation. Treatment of Hut78 cells with anti-Fas antibody affected the tumor cells become resistant against the cytotoxic activity of the spleen cells from young mice in a dose dependent manner however P815 cells were not affect by the anti-Fas antibody treatment. These results show that there are differences in the sensitivity of target tumor cells toward Con-A induced cytotoxic spleen cells from young and old mouse. Mitogen-induced cytotoxic lymphocytes from young mouse spleen appear to kill targets through mechanisms involving Fas antigen, specially, in early stage (1 day) of activation. Old mouse spleen cells generated high levels of cytotoxic cells in later phase (3 days), which appear to kill through Fas-unrelated mechanisms.
Age Factors ; Animal ; Antigens, CD95/immunology* ; Cell Death/immunology ; Cells, Cultured ; Concanavalin A ; Cytotoxicity Tests, Immunologic ; Flow Cytometry ; Gene Expression Regulation/immunology ; Human ; Jurkat Cells ; Mice ; Mice, Inbred Strains ; Mitogens ; Spleen/immunology* ; T-Lymphocytes/immunology*

The studies have provided the first comprehensive comparison of the factors regulating activation and proliferation of WC1+ and WC1- gammadelta T cells. The investigation has shown that accessory molecules essential for activation and function of WC1+ and WC1- gammadelta T cells and the sources and roles of cytokines in activation of gammadelta T cells through the T cell receptor (TCR). The study has also shown that the role of cytokines in activation and function of gammadelta T cells activated indirectly through cytokines secreted by ab T cells, accessory cells and antigen presenting cells (APC). Cytokines were differentially produced by subpopulations of gammadelta T cells under different conditions of activation. The investigation obtained in this study has revealed that factors account for activation and proliferation of gammadelta T cells in cultures designed to study MHC-restricted responses to antigens. Evidence obtained here has shown there is biological relevance to activation under these culture conditions that points to potential regulatory and effector functions of gammadelta T cells. The investigations have also provided the information needed to begin identifying and characterizing antigens recognized by the TCR repertoires of WC1+ and WC1- gammadelta T cells. Finally, the investigations have provided the information needed to begin analysis of the mechanisms by which gammadelta T cells modulate MHC restricted immune responses to pathogens and derived vaccines.
Animals ; Base Sequence ; Cattle ; Concanavalin A ; Cytokines/genetics/immunology ; DNA Primers ; Immunophenotyping ; Lymph Nodes/immunology ; Lymphocyte Activation ; Receptors, Antigen, T-Cell, gamma-delta/*immunology ; Reverse Transcriptase Polymerase Chain Reaction ; T-Lymphocytes/classification/*immunology

OBJECTIVEThis study investigated the immunoregulatory and protective roles of Yinchenhao decoction, a compound of Chinese herbal medicine, in a mouse model of concanavalin A (ConA)-induced chronic liver injury.

METHODSFemale BalB/c mice were randomly divided into 4 groups: normal control, ConA model, ConA model treated with Yinchenhao decoction (400 mg/kg, orally), and ConA model treated with dexamethasone (0.5 mg/kg, orally). All treatments were given once a day for 28 d. Except of the normal control, mice received tail vein injection of ConA (10 mg/kg) on days 7, 14, 21, and 28, at 1 h after treatment with Yinchenhao decoction or dexamethasone or saline to induce chronic liver injury.

RESULTSRepeated ConA injection induced chronic liver injury, which was evidenced by inflammatory cell infiltration and necrosis, increased serum alanine aminotranferease activities, decreased albumin levels, and an imbalanced expression of immunoregulatory genes in the liver tissues including significantly enhanced interferon-γ, interleukin-4, monocyte chemotactic protein-1, and cluster of differentiation 163 mRNA levels, and reduced tumor necrosis factor-α and interleukin-6 mRNA levels. Treatment with Yinchenhao decoction significantly reversed the ConA-induced changes in immunoregulatory gene expression in the liver tissues, reduced serum alanine aminotranferease activity, enhanced serum albumin level, and attenuated the extent of liver inflammation and necrosis. Furthermore, Yinchenhao decoction did not result in hepatocyte degeneration and spleen weight loss that were observed in mice received long-term treatment with dexamethasone.

CONCLUSIONYinchenhao decoction treatment protected liver against the ConA-induced chronic liver damage and improved liver function, which were associated with the modulation of gene expression related to immune/inflammatory response.

Animals ; Chemical and Drug Induced Liver Injury, Chronic ; immunology ; prevention & control ; Concanavalin A ; toxicity ; Disease Models, Animal ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Immunomodulation ; Mice ; Mice, Inbred BALB C

Animals ; Concanavalin A ; adverse effects ; Immunoglobulin G ; blood ; Interleukin-18 ; blood ; immunology ; pharmacology ; Liver Cirrhosis ; blood ; chemically induced ; prevention & control ; Mice ; Mice, Inbred BALB C

Studies were performed to determine the effects of Bcell suppression on the pathogenesis of Subgroup J avian leukosis virus (ALV-J) in broiler chickens. Neonatal chickens were treated with cyclophosphamide (CY) or PBS, and then infected with ALV-J (ADOL-7501) at 2 weeks of age. CY treatment induced B cell specific immunosuppression throughout the experiment confirmed by decreased bursal weight, intact lymphocyte mitogenetic activity stimulated by Con A and increased relative subpopulation of CD3-positive cells as measured by flow cytometry. Chickens in this experiment had Mareks disease virus exposure prior to three weeks of age as determined by the presence of lymphocytic infiltration and antibody. Virus neutralizing antibody against ALV-J was first observed at 6 weeks post-infection in some of the infected chickens in the PBS group. As expected, none of the chickens from the CY group and uninfected chickens developed virus-neutralizing antibody. The viremic status was measured by real time RT-PCR using SYBR green I dye. The percentage of viremic chickens was significantly higher, and more chickens had high titered viremia, in the CY treated group. No neoplastic foci consistent with ALVJ infection were observed in any of the experimental chickens. The frequency and intensity of viral antigen expression determined by immunohistochemistry was significantly higher in tissues from CY treated birds than those of PBS treated chickens at 3 weeks post-infection. This study showed that B cell specific immunosuppression with CY treatment in chickens resulted in increase in viremia and viral antigen load in tissues.
Animals ; Avian Leukosis/*immunology/virology ; Avian leukosis virus/genetics/*immunology ; Body Weight/physiology ; Bursa of Fabricius/immunology ; *Chickens ; Concanavalin A/immunology ; Cyclophosphamide/*pharmacology ; Flow Cytometry/veterinary ; Immunocompromised Host ; Immunohistochemistry/veterinary ; Immunophenotyping/veterinary ; Immunosuppressive Agents/*pharmacology ; Lymphocyte Activation/drug effects/immunology ; Organic Chemicals/chemistry ; Poultry Diseases/immunology/*virology ; RNA, Viral/chemistry/genetics ; Random Allocation ; Reverse Transcriptase Polymerase Chain Reaction/veterinary ; Spleen/immunology/virology ; Statistics, Nonparametric ; Viremia/veterinary

We previously demonstrated that stimulation of bovine peripheral blood mononuclear cells (PBMCs) with staphylococcal enterotoxin C (SEC), led to an inversion of the CD4(+):CD8(+) T cell ratio and generation of an atypical CD8(+) T cell subpopulation expressing CD26. In the present study, we examined T cell apoptosis and proliferation profiles of PBMC subpopulations in cultures stimulated with SEC. Unlike when stimulated with concanavalin A, nucleic acid synthesis in bovine PBMC cultures stimulated with SEC was low during the first four days but increased greatly on day 5. In contrast, nucleic acid synthesis in human PBMC cultures stimulated with SEC increased continuously. To investigate the mechanism of delayed bovine T cell proliferation, various cell phenotypes were monitored. The inversion of the bovine CD4(+):CD8(+) T cell ratio in PBMC cultures stimulated by SEC was associated with higher proliferation and lower apoptosis of CD8(+) T cells compared to CD4(+) T cells. The mRNA levels for interleukin (IL)-4 and IL-13 were sustained over 4 days but IL-12 mRNA levels dropped to background on day 2. These data suggest that SEC induces a prolonged Th-2- biased microenvironment, and together with the inversion of the bovine CD4(+):CD8(+) T cell ratios in bovine PBMC cultures with SEC, may in part explain the inability of the mammary immune system to establish an effective response to Staphylococcus aureus infections.
Animals ; Apoptosis/drug effects/immunology ; CD4-CD8 Ratio/veterinary ; CD4-Positive T-Lymphocytes/drug effects/*immunology/microbiology ; CD8-Positive T-Lymphocytes/drug effects/*immunology/microbiology ; Cattle ; Concanavalin A/pharmacology ; Cytokines/genetics/immunology ; Enterotoxins/*pharmacology ; Female ; Lymphocyte Activation/drug effects ; Mastitis, Bovine/immunology/*microbiology ; Reverse Transcriptase Polymerase Chain Reaction/veterinary ; Staphylococcal Infections/immunology/microbiology/*veterinary ; Staphylococcus aureus/*immunology

OBJECTIVETo explore the effect of Ronggan Mixture (RM) on immunoregulation and hepatocyte apoptosis-related factors in concanavalin A (Con A) induced acute immunological liver injury mice.

METHODSTotally 60 hepatitis B virus (HBV) transgenic mice were randomly divided into 6 groups, i.e., the blank control group, the model group, the RM group, the Herba Artemisiae Scopariae (HAS) group, the Yinchenhao Decoction (YD) group, and the Bifendate group, 10 mice in each group. The acute immunological liver injury model was established by tail vein injection of ConA. Fourteen days before modeling, normal saline was administered to mice in the blank control group and the model group. RM, YD, HAS decoction, and Bifendate solution was respectively given to mice in the RM group, the YD group, the HAS group, and the Bifendate group. The medication was performed once daily. One h after the last gastrogavage, phosphate buffer solution (PBS) was injected to mice in the blank control group from the tail vein. Modeling was conducted by injecting Con A at 3 microg/g body weight from the tail vein. Mice were sacrificed 8 h after modeling. Blood or tissue samples were collected to detect lab indicators such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBil), tumor necrosis factor alpha (TNF-alpha), interferon gamma (INF-gamma), IL-4, IL-10, Fas, FasL, Bax, and bcl-2.

RESULTSThere was significant difference in all lab indicators between the normal group and the blank control group (P < 0.05, P < 0.01). Compared with the model group, ALT and AST levels were significantly lower in the RM group and the Bifendate group (P < 0.01); TBil significantly decreased in the RM group (P < 0.01). The expression level of TNF-alpha decreased in the RM group (P <0.05). The expression level of IFN-gamma decreased in the RM group and the YD group (P < 0.05). The expression level of IL-4 could be elevated in all medicated groups (P < 0.05). RM could elevate the expression level of IL-10 (P < 0.05). The expression level of Fas in the liver tissue decreased in the RM group and the YD group (P < 0.05). The expression level of FasL decreased and the expression of bcl-2 gene increased in the RM group (both P < 0.05). The expression level of Bax was down-regulated in the RM group and the YD group (P < 0.05). The ratio of bcl-2/Bax was up-regulated in the RM group (P < 0.05). Meanwhile, RM showed better effect in decreasing expressions of ALT and AST than HAS (P < 0.05). The effect of increasing IL-10 expression levels was better in the RM group than in the YD group (P < 0.01). The effect of decreasing expressions of Fas and FasL was better in the RM group than in the HAS group, the YD group, and the Bifendate group (P < 0.05). The effect of enhancing the expression of IL-10 in the liver tissue was better in the RM group than in the HAS group (P < 0. 05).

CONCLUSIONRM had protective effect on Con A induced acute immunological liver injury mice, which might be achieved by changing the immunological balance of Thl/Th2 factors (decreasing expressions of TNF-alpha and IFN-gamma, elevating expressions of IL-10 and IL-4) and regulating hepatocyte apoptosis-related factors (down-regulating gene expressions of Fas, FasL, and Bax; up-regulating bcl-2 gene expression, and up-regulating the bcl-2/Bax ratio).

Animals ; Apoptosis ; drug effects ; Chemical and Drug Induced Liver Injury ; immunology ; pathology ; Concanavalin A ; adverse effects ; Cytokines ; immunology ; Drugs, Chinese Herbal ; pharmacology ; Female ; Gene Expression ; Hepatocytes ; cytology ; drug effects ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic

OBJECTIVETo investigate the role played by γδ T cells in acute liver injury using the concanavalin A (ConA)-induced liver injury mouse model.

METHODSAcute liver injury was induced by intravenous injection of 10 mug/g of ConA into male C57BL/6J mice with wild-type or T cell receptor-γ knockout (TCR δ-/-) genetic backgrounds. Mice injected with PBS alone served as negative controls. The degree of liver damage was assessed by measuring serum levels of transaminase and cytokines at post-injection hours 3, 6, 12, 24, 48, and 72. The percentage of γδ T cells and proportions of different subsets in liver lymphocytes were measured by flow cytometry.

RESULTSThe TCR δ-/- mice showed significantly higher levels of the inflammatory cytokines IFN-γ, TNFα and IL-4 than the wild-type mice at post-injection hour 3. The percentage of liver γδ T cells increased with increased injury degree, and the extent of increase was significantly higher in the TCR δ-/- mice than the wild-type mice (post-injection hour 6: 6302.61+/-592.06 vs. 1319.26+/-355.48, 12: 6569.44+/-1060.98 vs. 3415.53+/-343.90, 24: 6514.29+/-757.26 vs. 2062.73+/-365.67, 48: 1262.61+/-558.07 vs. 113.66+/-113.26, and 72: 226.54+/-98.20 vs. 42.35+/-21.51 U/L; all P less than 0.05). In addition, compared to the negative control mice, the ConA-induced mice showed a higher proportions of Vγ4 γδ T cells to total γδ T cells (17.78+/-2.95 vs. 25.26+/-2.43) and to total liver lymphocytes (0.47+/-0.07 vs. 0.66+/-0.05). Similarly, compared to the negative control mice, the ConA-induced mice showed a higher proportion of Vγ1 γδ T cells to total γδ T cells (38.37+/-6.10 vs. 50.19+/-5.52) but the proportion to total liver lymphocytes was not significantly different among the groups (0.76+/-0.18 vs. 0.78+/-0.25). Reinfusion of Vγ4 γδ T lymphocytes into TCR δ-/- mice led to lower serum ALT levels than reinfusion of Vγ1 γδ T lymphocytes (5054.10+/-1748.51 vs. 12333.56+/-663.535 U/L).

CONCLUSIONγδ T cells play a protective role in ConA-induced liver injury and this effect maybe mediated by the Vγ4 γδ T cell subset.

Animals ; Chemical and Drug Induced Liver Injury ; immunology ; pathology ; Concanavalin A ; toxicity ; Interferon-gamma ; immunology ; Interleukin-4 ; immunology ; Liver ; drug effects ; immunology ; pathology ; Male ; Mice ; Mice, Inbred C57BL ; Receptors, Antigen, T-Cell, gamma-delta ; metabolism ; T-Lymphocyte Subsets ; immunology ; Tumor Necrosis Factor-alpha ; immunology

The mechanism underlying T cell-mediated fulminant hepatitis is not fully understood. In this study, we investigated whether myeloid derived suppressor cells (MDSCs) could prevent the concanavalin A (ConA)-induced hepatitis through suppressing T cell proliferation. We observed an increase in the frequencies of MDSCs in mouse spleen and liver at early stage of ConA treatment, implicating that the MDSCs might be involved in the initial resistance of mice against ConA-mediated inflammation. Subpopulation analysis showed that the MDSCs in liver of ConA-induced mice were mainly granulocytic MDSCs. Adoptive transfer of the bone marrow-derived MDSCs into ConA-treated mice showed that the MDSCs migrated into the liver and spleen where they suppressed T cell proliferation through ROS pathway. In addition, the frequencies of MDSCs in mice were also significantly increased by the treatment with immune suppressor glucocorticoids. Transfer of MDSCs into the regulatory T cell (Treg)-depleted mice showed that the protective effect of MDSCs on ConA-induced hepatitis is Treg-independent. In conclusion, our results demonstrate that MDSCs possess a direct protective role in T cell-mediated hepatitis, and increasing the frequency of MDSCs by either adoptive transfer or glucocorticoid treatment represents a potential cell-based therapeutic strategy for the acute inflammatory disease.
Adoptive Transfer ; Animals ; Blotting, Western ; Bone Marrow Cells ; immunology ; CD11b Antigen ; immunology ; metabolism ; Cell Movement ; immunology ; Cell Proliferation ; Chemical and Drug Induced Liver Injury ; etiology ; immunology ; prevention & control ; Concanavalin A ; toxicity ; Dexamethasone ; pharmacology ; Flow Cytometry ; Glucocorticoids ; pharmacology ; Liver ; immunology ; pathology ; Male ; Mice, Inbred C57BL ; Mitogens ; administration & dosage ; toxicity ; Myeloid Cells ; immunology ; metabolism ; transplantation ; Receptors, Chemokine ; immunology ; metabolism ; Spleen ; immunology ; pathology ; T-Lymphocytes ; immunology ; T-Lymphocytes, Regulatory ; immunology