EFS Auvergne Loire

Clermont-Ferrand, France

EFS Auvergne Loire

Clermont-Ferrand, France
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Damien P.,Jean Monnet University | Cognasse F.,Jean Monnet University | Eyraud M.-A.,EFS Auvergne Loire | Arthaud C.-A.,EFS Auvergne Loire | And 4 more authors.
BMC Immunology | Year: 2015

Background: Platelets are instrumental to primary haemostasis; in addition, as they are central to endothelium vascular repair, they play a role in physiological inflammation. Platelets have also been demonstrated to be key players in innate immunity and inflammation, expressing Toll-like receptors (TLRs) to sense microbial infection and initiate inflammatory responses. They are equipped to decipher distinct signals, to use alternate pathways of signalling through a complete signalosome, despite their lack of a nucleus, and to adjust the innate immune response appropriately for pathogens exhibiting different types of 'danger' signals. Previous work has described the two main LPS isoforms-TLR4 activation pathways in purified platelets. However, the precise mechanism of TLR4 signalling in platelets is not completely unravelled, especially how this signalling may occur since platelets do not express CD14, the TLR4 pathophysiological companion for LPS sensing. Thus, we investigated from what source the CD14 molecules required for TLR4 signalling in platelets could come. Results: Here we show that CD14, required for optimal response to LPS stimulation, is obtained from plasma, but used with restrictive regulation. These data add to the body of evidence that platelets are closer to regulatory cells than to first line defenders. The readout of our experiments is the canonical secreted cytokine-like protein, soluble (s)CD40L, a molecule that is central in physiology and pathology and that is abundantly secreted by platelets from the alpha-granules upon stimulation. Conclusions: We show that sCD14 from plasma contributes to LPS/TLR4 signalling in platelets to allow significant release of soluble CD40L, thereby elucidating the mechanism of LPS-induced platelet responses and providing new insights for reducing LPS toxicity in the circulation. © Damien et al.; licensee BioMed Central.


Chavarin P.,EFS Auvergne Loire | Cognasse F.,EFS Auvergne Loire | Argaud C.,EFS Auvergne Loire | Vidal M.,EFS Auvergne Loire | And 6 more authors.
Vox Sanguinis | Year: 2011

Background and Objectives INTERCEPT Blood System™ is a pathogen inactivation system for blood components. The initial approval required a platelet component to be suspended in a combination of plasma and Platelet additive Solution/PAS-III. Improved platelet storage has been reported with Mg++ and K+ supplementation (PAS-IIIM). This study validated the use of INTERCEPT™/PAS-IIIM for apheresis and pooled buffy-coat platelet components.Materials and Methods The platelet dose and pH throughout 5 days of storage met the European and French requirements for quality standards.Results and Conclusion Additional metabolic and activation assessments of the treated platelets confirmed the previously reported superiority of PAS-IIIM over PAS-III, but extended it to the INTERCEPT™ process. © 2010 The Author(s). Vox Sanguinis © 2010 International Society of Blood Transfusion.


Berthet J.,Jean Monnet University | Damien P.,Jean Monnet University | Hamzeh-Cognasse H.,Jean Monnet University | Arthaud C.-A.,EFS Auvergne Loire | And 7 more authors.
Clinical Immunology | Year: 2012

Platelets are currently acknowledged as cells of innate immunity and inflammation and play a complex role in sepsis. We examined whether different types of LPS have different effects on the release of soluble signaling/effective molecules from platelets. We used platelet-rich plasma from healthy volunteers and LPS from two strains of gram-negative bacteria with disparate LPS structures. We combined LPS-stimulated platelet supernatants with reporter cells and measured the PBMC cytokine secretion profiles. Upon stimulation of platelets with both Escherichia coli O111 and Salmonella minnesota LPS, the platelet LPS::TLR4 interaction activated pathways to trigger the production of a large number of molecules. The different platelet supernatants caused differential PBMC secretion of IL-6, TNFα, and IL-8. Our data demonstrate that platelets have the capacity to sense external signals differentially through a single type of pathogen recognition receptor and adjust the innate immune response appropriately for pathogens exhibiting different types of 'danger' signals. © 2012 Elsevier Inc.


Lafarge S.,EFS Auvergne Loire | Lafarge S.,Jean Monnet University | Hamzeh-Cognasse H.,Jean Monnet University | Richard Y.,French Institute of Health and Medical Research | And 6 more authors.
Clinical and Experimental Immunology | Year: 2011

The signal transducer and activator of transcription 3 (STAT3) transcription factor pathway plays an important role in many biological phenomena. STAT3 transcription is triggered by cytokine-associated signals. Here, we use isolated human B cells to analyse the role of STAT3 in interleukin (IL)-10 induced terminal B cell differentiation and in immunoglobulin (Ig)A production as a characteristic readout of IL-10 signalling. We identified optimal conditions for inducing in-vitro IgA production by purified blood naive B cells using IL-10 and soluble CD40L. We show that soluble CD40L consistently induces the phosphorylation of nuclear factor (NF)-κB p65 but not of STAT3, while IL-10 induces the phosphorylation of STAT3 but not of NF-κB p65. Interestingly, while soluble CD40L and IL-10 were synergistic in driving the terminal maturation of B cells into IgA-producing plasma cells, they did not co-operate earlier in the pathway with regard to the transcription factors NF-κB p65 or STAT3. Blocking either NF-κB p65 or STAT3 profoundly altered the production of IgA and mRNA for activation-induced cytidine deaminase (AID), an enzyme strictly necessary for Ig heavy chain recombination. Finally, the STAT3 pathway was directly activated by IL-10, while IL-6, the main cytokine otherwise known for activating the STAT3 pathway, did not appear to be involved in IL-10-induced-STAT3 activation. Our results suggest that STAT3 and NF-κB pathways co-operate in IgA production, with soluble CD40L rapidly activating the NF-κB pathway, probably rendering STAT3 probably more reactive to IL-10 signalling. This novel role for STAT3 in B cell development reveals a potential therapeutic or vaccine target for eliciting IgA humoral responses at mucosal interfaces. © 2011 The Authors. Clinical and Experimental Immunology © 2011 British Society for Immunology.


Nguyen K.A.,Jean Monnet University | Hamzeh-Cognasse H.,Jean Monnet University | Palle S.,CNRS Hubert Curien Laboratory | Anselme-Bertrand I.,Jean Monnet University | And 5 more authors.
PLoS ONE | Year: 2014

Background: Platelets participate in tissue repair and innate immune responses. Sialic acid-binding immunoglobulin-like lectins (Siglecs) are well-characterized I-type lectins, which control apoptosis.Methodology/Principal Findings: We characterized the expression of Siglec-7 in human platelets isolated from healthy volunteers using flow cytometry and confocal microscopy. Siglec-7 is primarily expressed on a granular membranes and colocalized with CD62P. Siglec-7 expression was increased upon platelet activation and correlated closely with CD62P expression. Cross-linking Siglec-7 with its ligand, ganglioside, resulted in platelet apoptosis without any significant effects on activation, aggregation, cell morphology by electron microscopy analysis or secretion. We show that ganglioside triggered four key pathways leading to apoptosis in human platelets: (i) mitochondrial inner transmembrane potential (ΔΨm) depolarization; (ii) elevated expression of pro-apoptotic Bax and Bak proteins with reduced expression of antiapoptotic Bcl-2 protein; (iii) phosphatidylserine exposure and (iv), microparticle formation. Inhibition of NAPDH oxidase, PI3K, or PKC rescued platelets from apoptosis induced by Siglec-7 recruitment, suggesting that the platelet receptors P2Y1 and GPIIbIIIa are essential for ganglioside-induced platelet apoptosis.Conclusions/Significance: The present work characterizes the role of Siglec-7 and platelet receptors in regulating apoptosis and death. Because some platelet pathology involves apoptosis (idiopathic thrombocytopenic purpura and possibly storage lesions), Siglec-7 might be a molecular target for therapeutic intervention/prevention. © 2014 PLOS ONE.


Nguyen K.A.,Jean Monnet University | Hamzeh-Cognasse H.,Jean Monnet University | Sebban M.,CNRS Hubert Curien Laboratory | Fromont E.,CNRS Hubert Curien Laboratory | And 5 more authors.
PLoS ONE | Year: 2014

Background: Platelet component (PC) transfusion leads occasionally to inflammatory hazards. Certain BRMs that are secreted by the platelets themselves during storage may have some responsibility. Methodology/Principal Findings: First, we identified non-stochastic arrangements of platelet-secreted BRMs in platelet components that led to acute transfusion reactions (ATRs). These data provide formal clinical evidence that platelets generate secretion profiles under both sterile activation and pathological conditions. We next aimed to predict the risk of hazardous outcomes by establishing statistical models based on the associations of BRMs within the incriminated platelet components and using decision trees. We investigated a large (n = 65) series of ATRs after platelet component transfusions reported through a very homogenous system at one university hospital. Herein, we used a combination of clinical observations, ex vivo and in vitro investigations, and mathematical modeling systems. We calculated the statistical association of a large variety (n = 17) of cytokines, chemokines, and physiologically likely factors with acute inflammatory potential in patients presenting with severe hazards. We then generated an accident prediction model that proved to be dependent on the level (amount) of a given cytokine-like platelet product within the indicated component, e.g., soluble CD40-ligand (>289.5 pg/109 platelets), or the presence of another secreted factor (IL-13, >0). We further modeled the risk of the patient presenting either a febrile non-hemolytic transfusion reaction or an atypical allergic transfusion reaction, depending on the amount of the chemokine MIP-1α (<20.4 or >20.4 pg/109 platelets, respectively). Conclusions/Significance: This allows the modeling of a policy of risk prevention for severe inflammatory outcomes in PC transfusion. © 2014 Nguyen et al.


PubMed | CNRS Hubert Curien Laboratory, EFS Auvergne Loire and Jean Monnet University
Type: Journal Article | Journal: PloS one | Year: 2014

Platelets participate in tissue repair and innate immune responses. Sialic acid-binding immunoglobulin-like lectins (Siglecs) are well-characterized I-type lectins, which control apoptosis.We characterized the expression of Siglec-7 in human platelets isolated from healthy volunteers using flow cytometry and confocal microscopy. Siglec-7 is primarily expressed on granular membranes and colocalized with CD62P. Siglec-7 expression was increased upon platelet activation and correlated closely with CD62P expression. Cross-linking Siglec-7 with its ligand, ganglioside, resulted in platelet apoptosis without any significant effects on activation, aggregation, cell morphology by electron microscopy analysis or secretion. We show that ganglioside triggered four key pathways leading to apoptosis in human platelets: (i) mitochondrial inner transmembrane potential (m) depolarization; (ii) elevated expression of pro-apoptotic Bax and Bak proteins with reduced expression of anti-apoptotic Bcl-2 protein; (iii) phosphatidylserine exposure and (iv), microparticle formation. Inhibition of NAPDH oxidase, PI3K, or PKC rescued platelets from apoptosis induced by Siglec-7 recruitment, suggesting that the platelet receptors P2Y1 and GPIIbIIIa are essential for ganglioside-induced platelet apoptosis.The present work characterizes the role of Siglec-7 and platelet receptors in regulating apoptosis and death. Because some platelet pathology involves apoptosis (idiopathic thrombocytopenic purpura and possibly storage lesions), Siglec-7 might be a molecular target for therapeutic intervention/prevention.


PubMed | EFS Auvergne Loire
Type: Evaluation Studies | Journal: Transfusion clinique et biologique : journal de la Societe francaise de transfusion sanguine | Year: 2011

Like every actor in transfusion, staff members practising within blood banks of healthcare establishments have to follow a specific initial training and must frequently update their knowledge in blood transfusion.To address this need from these professionals, the tablissement franais du sang Auvergne-Loire set up training sessions which content regularly evolved according to regulation recommendations. Every cycle consists in a total of 35hours of training, divided in five one-day modules. The comparison of the evaluation questionnaires offered at the beginning and at the end of each day allowed to measure the benefits provided by every module and to compare progress according to the number of modules previously followed. The analysis of satisfaction surveys contributed to improving the education towards a high level of satisfaction of every participant.At the end of its third year of existence, the 35hours education programme permitted to achieve a better level of training for all the staffs and the evolution towards an on-site continuing education format seems to better correspond to the personnels expectations.


INTERCEPT Blood System is a pathogen inactivation system for blood components. The initial approval required a platelet component to be suspended in a combination of plasma and Platelet additive Solution/PAS-III. Improved platelet storage has been reported with Mg++ and K+ supplementation (PAS-IIIM). This study validated the use of INTERCEPT/PAS-IIIM for apheresis and pooled buffy-coat platelet components.The platelet dose and pH throughout 5 days of storage met the European and French requirements for quality standards.Additional metabolic and activation assessments of the treated platelets confirmed the previously reported superiority of PAS-IIIM over PAS-III, but extended it to the INTERCEPT process.


The signal transducer and activator of transcription 3 (STAT3) transcription factor pathway plays an important role in many biological phenomena. STAT3 transcription is triggered by cytokine-associated signals. Here, we use isolated human B cells to analyse the role of STAT3 in interleukin (IL)-10 induced terminal B cell differentiation and in immunoglobulin (Ig)A production as a characteristic readout of IL-10 signalling. We identified optimal conditions for inducing in-vitro IgA production by purified blood naive B cells using IL-10 and soluble CD40L. We show that soluble CD40L consistently induces the phosphorylation of nuclear factor (NF)-B p65 but not of STAT3, while IL-10 induces the phosphorylation of STAT3 but not of NF-B p65. Interestingly, while soluble CD40L and IL-10 were synergistic in driving the terminal maturation of B cells into IgA-producing plasma cells, they did not co-operate earlier in the pathway with regard to the transcription factors NF-B p65 or STAT3. Blocking either NF-B p65 or STAT3 profoundly altered the production of IgA and mRNA for activation-induced cytidine deaminase (AID), an enzyme strictly necessary for Ig heavy chain recombination. Finally, the STAT3 pathway was directly activated by IL-10, while IL-6, the main cytokine otherwise known for activating the STAT3 pathway, did not appear to be involved in IL-10-induced-STAT3 activation. Our results suggest that STAT3 and NF-B pathways co-operate in IgA production, with soluble CD40L rapidly activating the NF-B pathway, probably rendering STAT3 probably more reactive to IL-10 signalling. This novel role for STAT3 in B cell development reveals a potential therapeutic or vaccine target for eliciting IgA humoral responses at mucosal interfaces.

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