concanavalin-a and resazurin

Depression is a serious psychiatric disorder affecting not only the monaminergic, glutamatergic, and GABAergic neurosystems, but also the immune system. Patients suffering from depression show disturbance in the immune parameters as well as increased susceptibility to infections. Zinc is well known as an anti-inflammatory agent, and its link with depression has been proved, zinc deficiency causing depression- and anxiety-like behavior with immune malfunction. It has been discovered that trace-element zinc acts as a neurotransmitter in the central nervous system via zinc receptor GPR39. In this study we investigated whether GPR39 knockout would cause depressive-like behavior as measured by the forced swim test, and whether these changes would coexist with immune malfunction. In GPR39 knockout mice versus a wild-type control we found: i) depressive-like behavior; ii) significantly reduced thymus weight; (iii) reduced cell viability of splenocytes; iv) reduced proliferative response of splenocytes; and v) increased IL-6 production of splenocytes after ConA stimulation and decreased IL-1b and IL-6 release after LPS stimulation. The results indicate depressive-like behavior in GPR39 KO animals with an immune response similar to that observed in depressive disorder. Here for the first time we show immunological changes under GPR39-deficient conditions.

Topics: Animals; Cell Proliferation; Cell Survival; Concanavalin A; Cytokines; Depressive Disorder; Disease Models, Animal; Female; Gene Expression Regulation; Lipopolysaccharides; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitogens; Motor Activity; Organ Size; Oxazines; Receptors, G-Protein-Coupled; Spleen; Swimming; Thymocytes; Xanthenes

An increasing aim in safety assessment of chemicals and drugs is to reduce, refine and replace animal testing, especially in the context of the new system for the registration, evaluation and authorisation of chemicals (REACH). Regarding immunosuppression, most methods are based on mitogen stimulation assays. To our knowledge the in vitro antibody response (Mishell-Dutton culture) has never been considered as an alternative to the existing animal tests nor has its potential of correctly predicting different immunosuppressant compounds been analyzed. Therefore, we designed a study comprising seven immunosuppressant and four negative compounds and compared the results to data obtained from rat mitogen stimulation experiments (analysis of proliferation, TNFalpha and IFNgamma release). The in vitro antibody response showed a high sensitivity and specificity. It is a promising assay for the prediction of immunosuppressive properties of chemicals and drugs, whereas the results from rat spleen cell mitogen stimulation assays were rather poor in respect thereof. Mitogen stimulation assays are restricted to certain cell types and the chosen endpoints, while any compound-induced alteration is likely to be detected in a functional assay like the in vitro antibody response, when several immunocompetent cells have to cooperate to result in the humoral response analyzed.

Topics: Animal Testing Alternatives; Animals; Antibodies; Cell Proliferation; Cell Survival; Cells, Cultured; Concanavalin A; Female; Immunosuppressive Agents; Interferons; L-Lactate Dehydrogenase; Lipopolysaccharides; Male; Mice; Oxazines; Rats; Spleen; Tumor Necrosis Factor-alpha; Xanthenes

Proliferation of human lymphocytes in response to various stimuli has traditionally been assessed by measuring uptake of radiolabeled nucleotides such as 3H-thymidine. We have evaluated a fluorometric assay, which uses the commercially available reagent, alamarBlue, as a potential substitute for the 3H-thymidine assay in measuring proliferation of human lymphocytes. In this assay, alamarBlue is added to a population of cells where it is reduced by mitochondrial enzyme activity. The reduced form of the reagent is fluorescent and can be quantitatively detected. The safety and convenience of the alamarBlue assay make it very attractive for use in the clinical laboratory. In this study peripheral blood mononuclear cells (PBMC) from healthy donors were stimulated using the mitogen Concanavalin A, and proliferation was assessed using either the 3H-thymidine or the alamarBlue assay. The alamarBlue assay reliably detects human PBMC and we found that the linear range of detection was 10(4) cells/well (96-well plate) to 5 x 10(5) cells/well. Detection of human PBMC is highly reproducible and the alamarBlue assay may be suitable in a number of applications where detection or relative quantitation of human PBMC is required. The alamarBlue assay also detected mitogen induced proliferation of PBMC although with a significantly lower level of sensitivity than the standard 3H-thymidine assay.

Topics: Cell Count; Coloring Agents; Concanavalin A; Evaluation Studies as Topic; Fluorescent Dyes; Humans; Leukocytes, Mononuclear; Lymphocyte Activation; Methods; Oxazines; Reagent Kits, Diagnostic; Sensitivity and Specificity; Thymidine; Tritium; Xanthenes

A one-step non-radioactive assay to determine the proliferation of murine lymphocytes, lymphoid tumor cells and hybridoma cells is described. This assay requires the addition of Alamar Blue dye to cell cultures and the degree of change in its color, which is reflective of the extent of cellular proliferation, can be determined by an ELISA plate reader. Alamar Blue must be added during the initial phase of cell culture. The pattern of concanavalin A (ConA) or anti-CD3 antibody-induced proliferative response of murine lymphocytes as assessed by Alamar Blue was similar to that of a [3H]thymidine assay. Similarly, the spontaneous proliferation curve of anti-CD3 antibody secreting cell line (YCD3-1), monocytic macrophage cell lines (PU5-1.8, P388D1, J774.1) and myeloma cells (Sp2/0) as determined by Alamar Blue closely resembled that of the [3H]thymidine assay. The minimum detectable number of proliferating cells was comparable in Alamar Blue and [3H]thymidine assays. Since cell lysis/extraction and washing procedures are not involved in the Alamar Blue assay, this approach has several distinct advantages over currently available assays (eg. [3H]thymidine). First, it allows daily monitoring of proliferation without compromising the sterility of cultures. An indication of proliferation can be evaluated (spectrophotometrically or visually) as early as 24 h after ConA stimulation. Second, unlike previously reported assays, Alamar Blue permits further analysis of proliferating cells by other methods. Analysis of cells in culture with Alamar Blue for various surface antigens (CD44, CD45RB, CD4, heat stable antigen) by flow cytometry revealed that the fluorescent profile and relative percentage of cells in cultures with the Alamar Blue were comparable to those without this reagent. The salient advantages of Alamar Blue assay over the [3H]thymidine assay include: (i) non-radioactivity; (ii) simplicity; (iii) less costly; (iv) non-labor intensive; (v) rapidity of assessment of proliferation of large number of samples; (vi) non-toxicity; (vii) usefulness in determining the kinetics of cell growth of hybridomas; and (viii) non-interference of secretion of antibodies by a hybridoma cell line.

Topics: Animals; Antibody Formation; CD3 Complex; Cell Line; Cell Survival; Cells, Cultured; Coloring Agents; Concanavalin A; Flow Cytometry; Hybridomas; Kinetics; Lymphocyte Activation; Macrophages; Mice; Mice, Inbred C57BL; Monocytes; Multiple Myeloma; Oxazines; Spleen; T-Lymphocytes; Thymidine; Thymus Gland; Tumor Cells, Cultured; Xanthenes