Zhang and colleagues explored the immunomodulatory activity of the cholesterol-lowering agent simvastatin. Their pharmaco-dynamic studies indicated that the immuno-modulatory activity of statins may involve two basic mechanisms. First, it may involve an increase in SOCS-3 and SOCS -7, i.e. members of the molecular family of “Suppressors of Cytokine Secretion”. And second, it may involve the inhibition of Interleukin-17 (IL-17), a central pro-inflammatory mediator.
The members of the SOCS family of molecules are important negative feedback regulators in adaptive and innate immune responses, while IL-17 producing CD4+ cells, the so-called “Th17 cells”, play a central role in the development of autoimmune diseases.
From their findings the authors conclude as follows: “Based on the described immunomodulatory mechanisms, good safety profile and oral biovailabalility, statins represent a promising therapeutic approach for multiple sclerosis and other chronic inflammatory diseases.”
Along the lines of this study by Zhang and colleagues, FOCUS Immunology is prepared to provide state-of-the-art services for pharmacodynamic (PD) analyses of immuno-modulatory compounds under GLP conditions.
If you are interested in learning more or in discussing your specific experimental needs, please feel free to contact Dr. Eddy Bruyns, Head of FOCUS Immunology Laboratory via e-mail eddy.bruyns@focus-cdd.com or via telephone +49 6221 64935124.
Source
Zhang et al.
Simvastatin Inhibits IL-17 Secretion by Targeting Multiple IL-17-Regulatory Cytokines and by Inhibiting the Expression of IL-17 Transcription Factor RORC in CD4+ Lymphocytes
The Journal of Immunology 2008; 180; 6988-6996
Hyperactivation of the immune system can lead to tissue destruction and auto-immunity. Therefore, the amplitude and duration of immune responses after antigenic and cytokine signaling are regulated in a feedback manner.
So-called “Suppressors of Cytokine Signaling (SOCS)” are important molecular players in this negative feedback regulation. 7 members of the SOCS molecular family have been described so-far. The SOCS family members 1 and 3 are of particular importance, since they are involved in adaptive and innate immune responses.
SOCS-1 and -3 are induced by LPS stimulation via the Toll-like Receptor-4 (TLR-4). While SOCS-1 directly targets the downstream signaling molecules of TLR4, SOCS-3 regulates the secondary effects of many LPS-induced cytokines. E.g. IL-1R signalling pathways are negatively regulated by SOCS-3.
In adaptive immune responses SOCS-1 and -3 play a role in the regulation of T cell activation, proliferation and diferentiation.
Recently, SOCS molecules were found to be central elements in the pharmacodynamics of the immuno-modulatory compound simvastatin and probiotic lactobacilli.
FOCUS Immunology is prepared to provide state-of-the-art services for pharmacodynamic (PD) studies for immunomodulatory compounds under GLP conditions. This includes studies on the regulation of intra- and extracellular mediators of inflammationand immunity.
If you are interested in learning more about FOCUS Immunology’s experience and offers or if you want to discuss your specific experimental needs, please feel free to contact Dr. Eddy Bruyns, Head of FOCUS Immunology Laboratory via e-mail eddy.bruyns@focus-cdd.com or via telephone +49 6221 64935124.
Source
Dimitriou et al.
Putting out the fire: coordinated suppression of the innate and adaptive immune systems by SOCS1 and SOCS3 proteins
Immunological reviews 2008, Vol. 224: 265-283
More information on SOCS1: Wikipedia on SOCS1
More information on SOCS3: Wikipedia on SOCS3
Suppressors of Cytokine Signaling (SOCS) are a group of proteins that play an important role in attenuating immune responses. These molecules may thus be important players in the pharmacodynamics (PD) of immuno-modulatory therapies.
In a recent publication Lee and colleagues explored whether probiotics induced anti-inflammatory properties through induction of SOCS.
Helicobacter pylori (H. pylori) or lipopolysaccharides derived thereof were found to increase the expression of pro-inflammatory cytokines in a human gastric cell line. Pre-treatment of the cells with probiotic bacteria of the Lactobacillus group reduced the H.Pylori-induced expression of these cytokines.
When the underlying molecular mechanisms were explored in more detail, the administration of probiotics was found to increase the expression of SOCS-2 and SOCS-3.
The authors conclude that the “Anti-inflammatory signals of SOCS … might be a key anti-inflammatory mechanism of probiotics …”
FOCUS Immunology is prepared to provide state-of-the-art servcies for pharmacodynamic (PD) studies for immunomodulatory compounds under GLP conditions.
If you are interested in learning more about FOCUS Immunology’s experience and offers or if you want to discuss your specific experimental needs, please feel free to contact Dr. Eddy Bruyns, Head of FOCUS Immunology Laboratory via e-mail eddy.bruyns@focus-cdd.com or via telephone +49 6221 64935124.
Source
Jeong Sang Lee et al.
Anti-inflammatory actions of probiotics through activating suppressor of cytokine signaling (SOCS) expression and signaling in Helicobacter pylori infection: A novel mechanism
Journal of Gastroenterology and Hepatology 25 (2010) 194-202
T lymphocytes (T cells) play a central role in the initiation and propagation of physiological and pathological immune responses. To exert their functions, resting T cells are activated, whereby the activation signals and pathways can be manifold and the resulting cellular functions are diverse.
Modern cell biological techniques allow to distinctively address the different activation pathways by specific stimulators and inhibitors, be it by specific antibodies against cell surface receptors (e.g. anti-CD3, or anti-CD28) or be it by chemical reagents (e.g. phorbol myristate acetate or ionomycin).
These sophisticated stimulation protocols can then be combined with appropriate analytical technologies to assess the phenotype and function of the activated cell populations, like expression of cell surface activation markers, secretion of cytokines, or proliferation.
FOCUS Immunology operates these technologies and tailors their use to the specific needs of a study protocol.
To learn more about FOCUS Immunology’s expertise and service offer in T cell biology contact us at immunology@focus-cdd.com or contact directly our Head of FOCUS Immunology Dr. Eddy Bruyns at eddy.bruyns@focus-cdd.com.
FOCUS Immunology laboratory is part of the Clinical Research Organisation (CRO) FOCUS-CDD GmbH. FOCUS Immunology provides immunological biomarker services under GLP and non-GLP conditions for the development of novel medicines.
Lamina Propria Lymphocytes (LPL) are a dominant cell population in the gut-associated lymphoid system. Apparently, LPL play an important role in keeping the immunological homeostasis at the large resorptive interface between the gut lumen and the interior of the body. LPL dysfunctions are thought to contribute to the pathology of chronic inflammatory bowel diseases.
Together with clinical institutions of the Heidelberg Medical Centre FOCUS Immunology has established processes that allow to use purified LPL for cell biological and mode-of-action studies.
For further information on our expertise and service offer in LPL biology please us at immunology@focus-cdd.com or contact directly our Head of FOCUS Immunology Dr. Eddy Bruyns at eddy.bruyns@focus-cdd.com.
FOCUS Immunology laboratory is part of the Clinical Research Organisation (CRO) FOCUS-CDD GmbH. FOCUS Immunology provides immunological biomarker services under GLP and non-GLP conditions for the development of novel medicines.
The specific or adaptive immune system comprises T and B lymphocytes. FOCUS Immunology provides assays to analyze the activity of these cells.
Cytokine secretion or proliferation is assessed in bulk cultures, or alternatively at the single cell level by single cell analysis techniques. The latter techniques offered by FOCUS Immunology are EliSpot or ICS (Intracellular Cytokine Staining) to analyze cytokine secretion on the single cell level or the flow cytometry-based CFSE assay to determine proliferation of individual T or B cells.
Prior to analysis the cells may be stimulated polyclonally by using PHA, PMA + Ionomycin, or antibodies directed against CD3 and CD28. Or the cells may be stimulated in an antigen-specific manner by using CMV (Cytomegalovirus) antigens and Tetanus Toxoid.
For many of the assays it is possible to select different cell populations to start with such as whole blood, purified peripheral blood mononuclear cells (PBMC), or selected lymphoid subpopulations such as B cells, T cells, CD4+cells or regulatory T cells and so on.
Specifically, FOCUS Immunology performs the following tests to determine effects of compounds on cells of the specific immune system:
(i) Proliferation assays to determine the proliferation rate of T or B lymphocytes. Upon antigen-specific or non-specific stimulation, cell proliferation will be determined either in bulk cultures by metabolic assays (MTS or ATP-dependent) or by measuring DNA synthesis (BrdU incorporation).
Alternatively, cell proliferation may be determined on the single cell level using the CFSE assay. Hereby, cells are labelled with CFDA-SE (carboxyfluorescein diacetate succinimidyl ester), a cell-permeable, non-fluorescent compound, which is converted by intracellular esterases to the fluorescent and non-membran-permeable CFSE (carboxyfluorescein succinimidyl ester). This molecule is highly stable and is distributed during cell division evenly to the daughter generations. Thus, flow cytometry allows to track proliferation of stimulated lymphocytes through consecutive generations.
(ii) Flow cytometry assays to analyze functional states of lymphocytes. T and B lymphocytes are not only characterized by lineage-specific markers such as CD3 for T cells and CD19 or CD20 for B cells but also by a continuously growing panel to distinguish subpopulations. CD4 and CD8 for helper and cytotoxic T cells and CD4,CD25 for regulatory T cells are just a few examples.
Additionally, cells of the lymphoid lineage acquire specific activation markers upon stimulation, which are not expressed on resting cells. Among these are CD69, CD25 and CD86.
A combination of lineage and activation markers allows analyzing the functional states of lymphoid cells on the single cell level, which thus allows analyzing the effects test-compounds on the functionality of lymphoid subpopulation.
FOCUS Immunology uses a dual-laser FACSCalibur from BD Biosciences to analyze up to four different markers in parallel allowing a detailed analysis of cell surface and/or intracellular markers.
(iii) Analysis of cytokine induction. Upon antigen-specific or non-specific stimulation cytokine production will be measured using either of three assays:
(a) ELISA, to determine the total amount of cytokine(s) secreted into the cell culture medium,
(b) EliSpot, to determine the frequency of cells secreting (a) particular cytokine(s), and
(c) Intracellular Cytokine Staining (ICS), to measure multiple cytokines and correlate their expression on the single cell level with lineage markers.
Friday, July 2, 2010
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