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Archive | Immunology Studies

Various T helper cell sub-populations in the control of adaptive immune responses – implications for pharmacodynamic studies on immuno-modulatory compounds

Tuesday, August 10, 2010

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T lymphocytes mature into CD4- or CD8-expressing single positive cells in the thymus from where they become “peripheral T lymphocytes” which populate the secondary lymphoid organs. Upon interaction with antigen-presenting cells, peripheral T lymphocytes become activated, proliferate and expand to differentiate into effector and memory cells.

Until some years ago two functionally different CD4+ T helper (Th) cell types were known, i.e. “Th1 cells” which are induced by the action of IFN-gamma and IL-12 to protect against specific intracellular pathogens, and “Th2 cells” which are induced by IL-4 to encounter parasitic infections and also to participate in allergic reactions.
Additional CD4+ Th subtypes have been described meanwhile.

First the “Th17 effector T cell”, which produces IL-17 and IL-6 and which is generated by the action of IL-23. Th17 cells function to clear a range of pathogens distinct from Th1 and under pathologiocal conditions they are involved in autoimmune responses. The latter has sparked general interest for these cells as targets for immuno-modulatory and anti-inflammatory therapies.

“Treg cells” (CD4+, CD25+, FoxP3+) represent another variant of CD4+ effector T-cells with a pivotal role in the regulation of immune responses.

FOCUS Immunology provides state-of-the-art scientific support and services to study these cell types 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.

Bettelli et al Nat Immunol 2007 8:345-350
Shevach Immunol Rev 2006 212: 60-73
Murphy Nat Rev Immunol 2002 2: 933-944

“Multiple cytokine secreting cells”: central players in pharmaco-dynamics of immuno-modulatory therapies?

Tuesday, August 10, 2010

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In a workshop hosted by the European Medicine Agency the possible role of in vitro cytokine release assays for prediction of unwanted side effects of novel (immuno-) therapeutics has been discussed. With respect to the latter the “cytokine release syndrome” and “cytokine storm” are severe and sometimes fatal adverse clinico-pathological events for which predictive assay systems are urgently needed.

In the workshop the central role of so-called “multiple cytokine secreting cells” in the pharmaco-dynamics of immuno-modulatory compounds and associated adverse events was pointed out.

As the name implies, these cells are characterized by the production of several cytokines in any single cell and thus contrast cells in which only one or two cytokines may be detected. In other words: “Multiple Cytokine Secretion” is a functional characteristic of a given cell and pretty much every T cell may become such a multiple cytokine secreting cell upon activation. Multiple cytokine secretion is a temporary state, only as long as the cell is being activated.

Physiological stimulation of T cells to multiple cytokine secretion is required for host defense and tissue remodeling. However, aberrant or un-intentional stimulation under pathological conditions or by (over-dosing of) immuno-modulatory compounds may result in severe pathologies, such as the above-mentioned “Cytokine Release Syndrome“.

The analysis of multiple cytokine secreting cells requires sophisticated multi-parameter assays, like multiplex immunological assays for measuring cytokine profiles in cellular secretions under various stimulation conditions. Ultimately, it requires multi-color intracellular cytokine staining by flow cytometry, which allows multiple cytokine determinations at the single level.

FOCUS Immunology is experienced in providing state-of-the-science analyses for multiple cytokine secreting cells 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.

EMEA workshop: “In vitro cytokine release assays to predict Cytokine Release Syndrome: the current-state-of-the science”

Elucidating the immuno-modulatory activities of statins (simvastatin)

Friday, July 2, 2010

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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

SOCS proteins (“Suppressors of Cytokine Signaling”): regulators for innate and adaptive immune responses with relevance for the pharmacodynamics of immuno-modulatory compounds

Friday, July 2, 2010

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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

Multicolor flow cytometry for immunological biomarker determination on a single cell level

Tuesday, March 23, 2010

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Modern flow cytometric methods allow the simultaneous detection of more than one fluorescent dye, this is termed “Multicolor flow cytometry”.

Thus, multicolor flow cytometry is a technology platform to gather detailed information on specific cells within a mixed population or on different parameters at the single cell level. This is especially relevant to maximize data generation from small or limited samples.

FOCUS Biomarker offers Multicolor Flow Cytometry to analyse immune cell parameters in clinical trials under GLP conditions. Together with our expertise in standardized cell sample generation and transportation as well as GLP-compliant assay development we offer this interesting technology for biomarker determination. This will enhance the assessment of PD aspects in early and late clinical trials with immuno-modulatory or anti-inflammatory drugs.

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.

Video presentation on immune monitoring in clinical trials

Monday, January 25, 2010

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One of FOCUS Immunology’s key services is immune-monitoring in clinical trials.
In the presentation basic options of this service are outlined.
Please note that this is not a standard procedure, but that the actual procedures and parameters will be tailored to the specific needs of a given clinical trial.

FOCUS Immunology’s experts are looking forward to discuss this in detail with you.

Contact:
Dr. Eddy Bruyns, Ph.D.
Telephone: +49 6221 649 350
Email:eddy.bruyns@focus-cdd.com

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FOCUS Immunology on Pre-Analytical Services

Wednesday, October 21, 2009

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Dr. Eddy Bruyns, FOCUS Immunology, has provided a white paper on FOCUS Immunologies‘ pre-analytical services. He addresses aspects of sample collection, processing and shipment in clinical trials.

He points out procedures that allow cell preparation and transportation for functional analysis in international multi-center trials as well as procedures for collection, transportation and central testing of whole blood sample for flow cytometry.
You may download the white paper here.

Immune monitoring in clinical multicenter trials

Thursday, July 9, 2009

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FOCUS Immunology has developed methods for on-site isolation of immune cells from peripheral blood, their transportation to Heidelberg, and subsequent functional testing under conditions of international multicenter clinical trials.

In a recent project patients were recruited at medical centers in several countries. At these sites FOCUS implemented its robust and simple protocol for on-site cell preparation. Then FOCUS organised the controlled transportation of the cells to the central testing laboratory in Heidelberg, Germany.

Incoming samples were QC-ed, and cytokine production as well as proliferation was determined in cultures of the isolated immune cells together with various defined stimuli of immune functions.

It took FOCUS only 6 weeks to implement standardized sample generation, sample logistics and testing.

The studies led to further understanding of the compound’s mode-of-action.

FOCUS Immunology offers immune monitoring tailored to the needs of given clinical trial protocols. For further information please contact immunology@focus-cdd.com or contact directly FOCUS’ Head of the Immunology Laboratory Dr. Eddy Bruyns at eddy.bruyns@focus-cdd.com, Tel.: +49 (0) 6221 649 35 124.

Immunogenicity testing of new biologicals as part of safety studies

Monday, May 18, 2009

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Biologicals used as therapeutics may induce unwanted immune responses in treated patients. Thus, the EMEA has recently issued a guideline for immunogenicity assessment. Immunogenicity testing should be part of clinical efficacy and safety studies.

Key elements of the EMEA recommendations in brief: Immunogenicity should be evaluated in all study participants and not only in symptomatic individuals. Bioassays for neutralizing antibodies need to be designed in a product-dependent manner. Clear criteria have to be defined to distinguish positive from negative findings and to confirm positive results.

FOCUS Immunology supports its clients to integrate these recommendations into their repsective clinical trial protocols. FOCUS’ services comprise assay development and validation for preclinical and clinical studies, testing under GLP conditions, implementation of confirmatory assays, development of bioassays for testing of neutralising antibodies and sample logistics in international multicenter trials.

If you have questions or want to discuss immunogenicity testing in your specific development project, please do not hesitate to contact our Head of the Immunology Laboratory Dr. Eddy Bruyns via email (eddy.bruyns@focus-cdd.com) or via telephone (+49 6221 649 35 124).

The current EMEA guideline on immunogenicity testing can be found here.

Central testing of immune cell functions in an international multi-center trial

Monday, May 11, 2009

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FOCUS used the expertise of its Heidelberg-based subsidiary FOCUS Immunology in an international multi-center clinical trial that required the isolation of immune cells from peripheral blood, their transportation and subsequent testing for cellular functions.

Patients were recruited at medical centers in different countries. FOCUS established a robust and simple protocol for standardized on-site cell preparation and organised the controlled transportation of the cells to the central testing laboratory in Heidelberg.

After appropriate quality control of in-coming samples, isolated immune cells were cultured and tested for various functions including cytokine production and proliferation.

The preparation and implementation of standardized sample generation, sample logistics and testing was completed within 6 weeks.

The studies led to further understanding of patient characteristics and the compound’s mode-of-action.

For further information contact FOCUS’ Head of Immmunology laboratory Dr. Eddy Bruyns via eddy.bruyns@focus-cdd.com or +49 (0) 649 35 124.