Publications by authors named "Jean Yves Cesbron"

31 Publications

The Immunopathology of Complement Proteins and Innate Immunity in Autoimmune Disease.

Clin Rev Allergy Immunol 2020 Apr;58(2):229-251

Laboratoire d'Immunologie, Pôle de Biologie, CHU Grenoble Alpes, 10217, Cedex 9, 38043, Grenoble, CS, France.

The complement is a powerful cascade of the innate immunity and also acts as a bridge between innate and acquired immune defence. Complement activation can occur via three distinct pathways, the classical, alternative and lectin pathways, each resulting in the common terminal pathway. Complement activation results in the release of a range of biologically active molecules that significantly contribute to immune surveillance and tissue homeostasis. Several soluble and membrane-bound regulatory proteins restrict complement activation in order to prevent complement-mediated autologous damage, consumption and exacerbated inflammation. The crucial role of complement in the host homeostasis is illustrated by association of both complement deficiency and overactivation with severe and life-threatening diseases. Autoantibodies targeting complement components have been described to alter expression and/or function of target protein resulting in a dysregulation of the delicate equilibrium between activation and inhibition of complement. The spectrum of diseases associated with complement autoantibodies depends on which complement protein and activation pathway are targeted, ranging from autoimmune disorders to kidney and vascular diseases. Nevertheless, these autoantibodies have been identified as differential biomarkers for diagnosis or follow-up of disease only in a small number of clinical conditions. For some autoantibodies, a clear relationship with clinical manifestations has been identified, such as anti-C1q, anti-Factor H, anti-C1 Inhibitor antibodies and C3 nephritic factor. For other autoantibodies, the origin and the functional consequences still remain to be elucidated, questioning about the pathophysiological significance of these autoantibodies, such as anti-mannose binding lectin, anti-Factor I, anti-Factor B and anti-C3b antibodies. The detection of autoantibodies targeting complement components is performed in specialized laboratories; however, there is no consensus on detection methods and standardization of the assays is a real challenge. This review summarizes the current panorama of autoantibodies targeting complement recognition proteins of the classical and lectin pathways, associated proteases, convertases, regulators and terminal components, with an emphasis on autoantibodies clearly involved in clinical conditions.
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http://dx.doi.org/10.1007/s12016-019-08774-5DOI Listing
April 2020

The Innate Part of the Adaptive Immune System.

Clin Rev Allergy Immunol 2020 Apr;58(2):151-154

UMR1227, Lymphocytes B et Autoimmunité, Univ Brest, Brest, France.

The innate immune response provides a first line of defense against common microorganisms and, for more complex and/or recurring situations where pathogens must be eliminated, an adaptive immune response has emerged and evolved to provide better protection against subsequent infections. However, such dichotomy has to be reevaluated because innate B cells (e.g., B1 and marginal zone B cells) and the newly described innate lymphoid cells (iLC) have been found to exhibit innate-like properties, such as antigen internalization, regulatory B cell functions, and helper T cell activities. In addition, the production and function of natural antibodies (nAbs) by innate B cells and their capacity to activate the classical complement pathway constitute additional important mechanisms at the junction of innate and adaptive immunity as well as the recent integration of platelets into the innate immune spectrum. There is no doubt that these mechanisms present an advantage in immunity and homeostasis particularly during the first years of life, but arguments are arising to consider that these precursors may have detrimental effects in a variety of autoimmune/inflammatory diseases, allergies and cancers, as well as in response to immunotherapy. Accordingly, and as presented in this special issue of Clinical Reviews in Allergy and Immunology, a better comprehension of the key molecular and cellular actors implicated at the crossroads of the innate and adaptive immune response represents a new challenge in our understanding of the immunological and immunopathological responses.
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http://dx.doi.org/10.1007/s12016-019-08740-1DOI Listing
April 2020

Flow cytometric analysis of neutrophil myeloperoxidase expression in peripheral blood for ruling out myelodysplastic syndromes: a diagnostic accuracy study.

Haematologica 2019 12 19;104(12):2382-2390. Epub 2019 Apr 19.

Service d'Hématologie Biologique, Hopital Estaing, Centre Hospitalier Universitaire de Clermont-Ferrand, F-63003 Clermont-Ferrand.

Suspicion of myelodysplastic syndromes (MDS) is one of the commonest reasons for bone marrow aspirate in elderly patients presenting with persistent peripheral blood (PB) cytopenia of unclear etiology. A PB assay that accurately rules out MDS would have major benefits. The diagnostic accuracy of the intra-individual robust coefficient of variation (RCV) for neutrophil myeloperoxidase (MPO) expression measured by flow cytometric analysis in PB was evaluated in a retrospective derivation study (44 MDS cases and 44 controls) and a prospective validation study (68 consecutive patients with suspected MDS). Compared with controls, MDS cases had higher median RCV values for neutrophil MPO expression (40.2% 30.9%; <0.001). The area under the receiver operating characteristic curve estimates were 0.94 [95% confidence interval (CI): 0.86-0.97] and 0.87 (95%CI: 0.76-0.94) in the derivation and validation studies, respectively. A RCV lower than 30% ruled out MDS with 100% sensitivity (95%CI: 78-100%) and 100% negative predictive value (95%CI: 83-100%) in the prospective validation study. Neutrophil MPO expression measured by flow cytometric analysis in PB might obviate the need for invasive bone marrow aspirate and biopsy for up to 29% of patients with suspected MDS.
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http://dx.doi.org/10.3324/haematol.2018.202275DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6959174PMC
December 2019

Effects of immunoadsorption combined with membrane filtration on complement markers - results of a randomized, controlled, crossover study.

Transpl Int 2019 Aug 5;32(8):876-883. Epub 2019 Apr 5.

Laboratoire d'Immunologie, Centre Hospitalier Universitaire (CHU) Grenoble-Alpes, Grenoble, France.

The complement system has been implicated in several kidney diseases, such as antibody-mediated rejection after kidney transplantation. Antibody-depletion techniques allow successful ABO- and/or HLA-incompatible transplantation. Considering the IgG removal, the use of semi-selective immunoadsorption (IA) has been advocated. However, because of results on incomplete IgM depletion, the adjunctive use of membrane filtration (MF) has been proposed to enhance the removal of macromolecules and to interfere with complement activation. This secondary endpoint analysis of a recently published randomized, controlled, cross-over trial was designed to investigate the effect of combined treatment IA + MF compared to IA alone on complement depletion. Two treatment sequences, a single session of IA + MF followed by IA (and vice versa), were analyzed with regard to C5b-9, properdin, and mannose-binding lectin (MBL) levels. Neither IA alone nor IA + MF provoked complement activation as demonstrated by stable low levels of C5b-9 after the procedure as compared to the previous. The combined treatment substantially lowered properdin (77% vs. 26% reduction, P < 0.0001) as well as MBL concentrations (81% vs. 11% reduction, P < 0.0001). Recovery of properdin and MBL levels appears to be longer after IA alone compared to IA + MF. Depletion of properdin and MBL levels may have potential clinical implications in the setting of kidney transplantation.
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http://dx.doi.org/10.1111/tri.13431DOI Listing
August 2019

Letter to the Editor: Protein phosphatase 1 subunit Ppp1r15a/GADD34 is overexpressed in systemic lupus erythematosus and related to the expression of type I interferon response genes.

Autoimmun Rev 2019 02 19;18(2):211-213. Epub 2018 Dec 19.

Laboratoire d'Immunologie, Pôle de Biologie, Centre Hospitalier Universitaire Grenoble Alpes, CS 10217, 38043 Grenoble, Cedex 9, France; BNI Team, TIMC-IMAG UMR5525, Université Grenoble Alpes, CNRS, BP170, 38042 Grenoble, Cedex 9, France. Electronic address:

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http://dx.doi.org/10.1016/j.autrev.2018.09.007DOI Listing
February 2019

Diagnostic biologique des angioedèmes bradykiniques : les recommandations du CREAK.

Presse Med 2019 Jan 8;48(1 Pt 1):55-62. Epub 2018 Nov 8.

Centre de référence national des angioedèmes (CREAK), 38043 Grenoble, France; Service d'immunologie, CHUGA, 38043 Grenoble, France.

Bradykinin mediated angioedema (BK-AE) can be associated either with C1Inhibitor deficiency (hereditary and acquired forms), either with normal C1Inh (hereditary form and drug induced AE as angiotensin converting enzyme inhibitors…). In case of high clinical suspicion of BK-AE, C1Inh exploration must be done at first: C1Inh function and antigenemy as well as C4 concentration. C1Inh deficiency is significant if the tests are below 50 % of the normal values and controlled a second time. In case of C1Inh deficiency, you have to identify hereditary from acquired forms. C1q and anti-C1Inh antibody tests are useful for acquired BK-AE. SERPING1 gene screening must be done if a hereditary angioedema is suspected, even if there is no family context (de novo mutation 15 %). If a hereditary BK-AE with normal C1Inh is suspected, F12 and PLG gene screening is suitable.
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http://dx.doi.org/10.1016/j.lpm.2018.06.015DOI Listing
January 2019

Accurate quantification of fourteen normal bone marrow cell subsets in infants to the elderly by flow cytometry.

Cytometry B Clin Cytom 2018 09;94(5):627-636

Department of Immunology, Grenoble-Alpes University Hospital (CHUGA), Grenoble, F-38700, France.

Background: Studies of normal bone marrow (BM) cell composition by flow cytometry are scarce. Presently, we aimed to quantify 14 cell subsets from infants to elderly patients.

Methods: Cell subsets in BM samples from 180 individuals without morphologically abnormal leukocytes were analyzed using a single combination of eight antibodies: CD3/CD10/CD38/CD19/CD36/CD16/CD34/CD45.

Results: By comparison with the Holdrinet score, we first validated the immature granulocyte/neutrophil (IGRA/N) ratio as a readily obtainable criterion of BM sample purity in 145 cases. Then, the 115 highly pure samples were selected (IGRA/N ≥ 1.2) and analyzed according to age group. CD34+ myeloblasts became progressively more infrequent with age: median 1.4% in infancy to 0.5% in the elderly. Neutrophils increased: 10.7% to 22.8%; all other myeloid subsets, IGRA, eosinophils, basophils and monocytes remained stable: respectively 40.3% to 46.7%, 2.0% to 2.8%, 0.2% to 0.3%, and 4.4% to 5.0% throughout life. Erythroblasts were lower in children (8.4% to 10.3%) than in adults (12.5% to 15.1%). For lymphoid cells, hematogones and transitional B-cells decreased: 15.5% to 0.6% and 3.6% to 0.1%, respectively; mature lymphocytes remained stable: B-cells: 1.4% to 2.8%, T-cells: 5.8% to 8.7%, and NK-cells: 0.7% to 1.4%. Plasma cells varied slightly: 0.1% to 0.5%. Differences of about 40% were seen in moderately pure (IGRA/N: 0.5 to 1.2) BM samples.

Conclusion: We thus provide the first values for 14 myeloid and lymphoid subsets characterizing BM cell composition in 5 age ranges. They should provide important information when screening patients for hematological disorders or abnormal bone marrow development. © 2018 International Clinical Cytometry Society.
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http://dx.doi.org/10.1002/cyto.b.21643DOI Listing
September 2018

Antibodies targeting circulating protective molecules in lupus nephritis: Interest as serological biomarkers.

Autoimmun Rev 2018 Sep 29;17(9):890-899. Epub 2018 Jul 29.

Univ. Grenoble Alpes, CNRS, CEA, IBS, F-38000 Grenoble, France.

Lupus nephritis (LN) is one of the most frequent and severe manifestations of systemic lupus erythematosus (SLE), considered as the major predictor of poor prognosis. An early diagnosis of LN is a real challenge in the management of SLE and has an important implication in guiding treatments. In clinical practice, conventional parameters still lack sensitivity and specificity for detecting ongoing disease activity in lupus kidneys and early relapse of nephritis. LN is characterized by glomerular kidney injury, essentially due to deposition of immune complexes involving autoantibodies against cellular components and circulating proteins. One of the possible mechanisms of induction of autoantibodies in SLE is a defect in apoptotic cells clearance and subsequent release of intracellular autoantigens. Autoantibodies against soluble protective molecules involved in the uptake of dying cells, including complement proteins and pentraxins, have been described. In this review, we present the main autoantibodies found in LN, with a focus on the antibodies against these protective molecules. We also discuss their pathogenic role and conclude with their potential interest as serological biomarkers in LN.
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http://dx.doi.org/10.1016/j.autrev.2018.03.013DOI Listing
September 2018

Routinely used immunoassays do not detect circulating anti-GBM antibodies against native NC1 hexamer and EA epitope of the α3 chain of type IV collagen.

Eur J Immunol 2018 06 2;48(6):1082-1084. Epub 2018 May 2.

Laboratoire d'Immunologie, Pôle de Biologie, Centre Hospitalier Universitaire Grenoble Alpes, Grenoble, Cedex 9, France.

Detection of circulating anti-GBM antibodies has a key role for the diagnosis of Goodpasture syndrome but immunoassays using purified or recombinant alpha3(IV)NC1 as antigen do not recognize all anti-GBM antibodies. We show that anti-GBM antibodies directed against epitopes in their native conformation or cryptic epitopes are detected by indirect immunofluorescence.
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http://dx.doi.org/10.1002/eji.201747324DOI Listing
June 2018

Autoantibodies Targeting Ficolin-2 in Systemic Lupus Erythematosus Patients With Active Nephritis.

Arthritis Care Res (Hoboken) 2018 08 21;70(8):1263-1268. Epub 2018 Jun 21.

Laboratoire d'Immunologie, Pôle de Biologie, Centre Hospitalier Universitaire Grenoble Alpes and CNRS-Université Grenoble Alpes, Grenoble Cedex 9, France.

Objective: Systemic lupus erythematosus (SLE) is a multisystem inflammatory disease characterized by the production of various autoantibodies. The aim of this study was to investigate the presence of anti-ficolin-2 antibodies in SLE patients and to evaluate the association between the levels of these autoantibodies, clinical manifestations, and disease activity.

Methods: This is a comparative study using a cohort of 165 SLE patients and 48 healthy subjects. SLE patients were further divided into 2 groups (low disease activity [SLE Disease Activity Index (SLEDAI) score ≤4, n = 88] and high disease activity [SLEDAI score >4, n = 77]). Clinical manifestations were defined according to the physician in charge. Active lupus nephritis (LN) was documented by kidney biopsy. Detection of anti-ficolin-2 antibodies was performed by enzyme-linked immunosorbent assay.

Results: Levels of anti-ficolin-2 autoantibodies were significantly higher in SLE patients as compared to healthy subjects and associated with SLEDAI score. They were found to be positive in 61 of 165 SLE patients (37%). The presence of anti-ficolin-2 antibodies was significantly related only to renal involvement, with a very high prevalence (86%) of anti-ficolin-2 antibodies in SLE patients with active LN. Patients with active proliferative LN had significantly more positive anti-ficolin-2 antibodies than those with nonproliferative LN. The combination of anti-ficolin-2, anti-ficolin-3, and anti-C1q demonstrated a very high specificity (98%) for the diagnosis of active LN.

Conclusion: Our results support the usefulness of anti-ficolin-2 as a complementary serologic biomarker for the diagnosis of active lupus with renal manifestations.
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http://dx.doi.org/10.1002/acr.23449DOI Listing
August 2018

Novel Strategy for Phenotypic Characterization of Human B Lymphocytes from Precursors to Effector Cells by Flow Cytometry.

PLoS One 2016;11(9):e0162209. Epub 2016 Sep 22.

Laboratoire d'Immunologie, Département d'Hématologie, Oncogénétique et Immunologie, Pôle de Biologie, Grenoble University Hospital, Grenoble, France.

A precise identification and phenotypic characterization of human B-cell subsets is of crucial importance in both basic research and medicine. In the literature, flow cytometry studies for the phenotypic characterization of B-lymphocytes are mainly focused on the description of a particular cell stage, or of specific cell stages observed in a single type of sample. In the present work, we propose a backbone of 6 antibodies (CD38, CD27, CD10, CD19, CD5 and CD45) and an efficient gating strategy to identify, in a single analysis tube, a large number of B-cell subsets covering the whole B-cell differentiation from precursors to memory and plasma cells. Furthermore, by adding two antibodies in an 8-color combination, our approach allows the analysis of the modulation of any cell surface marker of interest along B-cell differentiation. We thus developed a panel of seven 8-colour antibody combinations to phenotypically characterize B-cell subpopulations in bone marrow, peripheral blood, lymph node and cord blood samples. Beyond qualitative information provided by biparametric representations, we also quantified antigen expression on each of the identified B-cell subsets and we proposed a series of informative curves showing the modulation of seventeen cell surface markers along B-cell differentiation. Our approach by flow cytometry provides an efficient tool to obtain quantitative data on B-cell surface markers expression with a relative easy-to-handle technique that can be applied in routine explorations.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5033467PMC
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0162209PLOS
September 2016

Association between the Presence of Autoantibodies Targeting Ficolin-3 and Active Nephritis in Patients with Systemic Lupus Erythematosus.

PLoS One 2016 15;11(9):e0160879. Epub 2016 Sep 15.

Laboratoire d'Immunologie, pôle de Biologie, CHU Grenoble Alpes, Grenoble, France.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by the production of multiple autoantibodies. Antibodies against Ficolin-3 were previously identified in the sera of some SLE patients, but their prevalence and significance have not been yet investigated. The aims of this study were to determine the prevalence of anti-ficolin-3 antibodies among SLE patients and to investigate their potential as diagnostic and/or prognostic biomarkers in SLE. In this retrospective study, sera from SLE patients (n = 165) were selected from a preexisting declared biological collection. Samples from healthy controls (n = 48) were matched with SLE sera. Disease activity was determined according to the SLEDAI score. Anti-ficolin-3, anti-dsDNA and anti-C1q antibodies levels were measured in sera by ELISA. First, a highly significant difference was found in the anti-ficolin-3 levels between SLE patients and healthy subjects. Anti-ficolin-3 antibodies were detected as positive in 56 of 165 (34%) SLE patients. The titer of anti-ficolin-3 antibodies was correlated with the SLEDAI score (r = 0.38, p<0.0001). The presence of anti-ficolin-3 antibodies was associated with anti-C1q and anti-dsDNA antibodies. Regarding associations with clinical manifestations, the presence of active lupus nephritis was significantly associated with the presence of anti-ficolin-3 antibodies (p≤0.001). This association with renal involvement was higher with anti-ficolin-3 or anti-C1q antibodies than with other auto-antibodies. Interestingly, the combination of anti-ficolin-3 and anti-C1q antibodies demonstrated higher specificity than any other serological biomarker. These results suggest that anti-ficolin-3 antibodies could be useful for the diagnosis of active nephritis in SLE patients.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0160879PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5025237PMC
August 2017

One tube with eight antibodies for 14-part bone marrow leukocyte differential using flow cytometry.

Cytometry B Clin Cytom 2017 07 6;92(4):299-309. Epub 2016 May 6.

Department of Immunology CHU Grenoble, La Tronche, F-38700, France.

Background: Bone marrow analysis by flow cytometry is part of the routine diagnosis of hematological disorders in medical laboratories. Differential leukocyte count and identification of abnormal cell subsets is currently performed through morphological examination on bone marrow smears by skilled cytologists. In this work, we propose a single 8-color tube for providing equivalent information, using flow cytometry.

Methods: 99 bone marrow samples were classified into 2 groups, (i) 51 samples, obtained from either healthy donors (n = 4) or patients with various diseases at diagnosis or during remission that did not present a hematological malignancy (n = 47), and (ii) 48 pathological samples with quantitative and/or qualitative abnormalities. A panel of eight antibodies-CD3-FITC/CD10-PE/CD38-PerCP-Cy5.5/CD19-PECy7/CD36-APC/CD16-APC-H7/CD34-BV421/CD45-V500-was tested to identify the main cell subsets at different stages of maturation using a FACSCanto-II analyzer.

Results: We first proposed a strategy of sequential gating leading to the identification of 14 leukocyte subsets, that is, erythroblasts, monocytes, B-lymphoid cells from hematogones to plasma-cells (5 subsets), T- and NK-cells, polymorphonuclear cells (neutrophils, eosinophils, and basophils), myeloblasts and other immature granular cells. This approach was validated by comparing flow cytometry and microscopic morphological examination, both in cases of normal and abnormal samples. Interestingly, cell identification, and numeration by flow cytometry was easy to perform and highly reproducible.

Conclusion: A very simple, rapid, and reproducible flow cytometric approach, using a combination of eight antibodies allows determination of the cellular composition of bone marrow with high precision. © 2016 International Clinical Cytometry Society.
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http://dx.doi.org/10.1002/cyto.b.21369DOI Listing
July 2017

Unfolded protein response gene GADD34 is overexpressed in rheumatoid arthritis and related to the presence of circulating anti-citrullinated protein antibodies.

Autoimmunity 2016 1;49(3):172-8. Epub 2016 Feb 1.

a Laboratoire d'Immunologie , Pôle de Biologie, Grenoble University Hospital , Grenoble , France .

Growth arrest and DNA damage-inducible gene 34 (GADD34) is an inducible cofactor of protein phosphatase 1, which has an important role in the unfolded protein response. GADD34 has been shown to be necessary for type I interferon and proinflammatory cytokine production in response to viral infection in murine models. We investigate the expression of GADD34 in rheumatoid arthritis (RA), in which proinflammatory cytokines have an important pathogenic role. The objective of this study was to evaluate the potential of GADD34 expression as a biomarker in RA patients. We report a case-control study on GADD34 gene expression in peripheral blood mononuclear cells of patients (n = 75) with RA and age- and sex-matched healthy controls (n = 25). The study was approved by the relevant local ethics committees. GADD34 gene expression level in peripheral blood mononuclear cells was measured by quantitative PCR and analyzed with Mann-Whitney test. The relation between GADD34 gene overexpression and clinical or biological characteristics was analyzed with univariate and multivariate analysis. GADD34 gene expression was significantly higher in RA patients compared with healthy controls (p ≤ 0.001). Interestingly, GADD34 overexpression in PBMC of patients was related to the presence of circulating anti-citrullinated protein antibodies (p = 0.030). Data of this study strengthen the evidence of an unfolded protein response during the course of RA and provide an insight of the potential interest in GADD34 as a relevant marker for RA.
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http://dx.doi.org/10.3109/08916934.2016.1138220DOI Listing
December 2016

Ataxia with cerebellar lesions in mice expressing chimeric PrP-Dpl protein.

J Neurosci 2013 Jan;33(4):1391-9

Laboratoire Adaptation et Pathogénie des Microorganismes, CNRS UMR 5163-UJF, 38042 Grenoble, France.

Mutations within the central region of prion protein (PrP) have been shown to be associated with severe neurotoxic activity similar to that observed with Dpl, a PrP-like protein. To further investigate this neurotoxic effect, we generated lines of transgenic (Tg) mice expressing three different chimeric PrP-Dpl proteins. Chi1 (amino acids 1-57 of Dpl replaced by amino acids 1-125 of PrP) and Chi2 (amino acids 1-66 of Dpl replaced by amino acids 1-134 of PrP) abrogated the pathogenicity of Dpl indicating that the presence of a N-terminal domain of PrP (23-134) reduced the toxicity of Dpl, as reported. However, when the amino acids 1-24 of Dpl were replaced by amino acids 1-124 of PrP, Chi3 Tg mice, which express the chimeric protein at a very low level, start developing ataxia at the age of 5-7 weeks. This phenotype was not counteracted by a single copy of full-length-PrP(c) but rather by its overexpression, indicating the strong toxicity of the chimeric protein Chi3. Chi3 Tg mice exhibit severe cerebellar atrophy with a significant loss of granule cells. We concluded that aa25 to aa57 of Dpl, which are not present in Chi1 and Chi2 constructs, confer toxicity to the protein. We tested this possibility by using the 25-57 Dpl peptide in primary culture of mouse embryo cortical neurons and found a significant neurotoxic effect. This finding identifies a protein domain that plays a role in mediating Dpl-related toxicity.
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http://dx.doi.org/10.1523/JNEUROSCI.2231-12.2013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6618747PMC
January 2013

Prion replication in the hematopoietic compartment is not required for neuroinvasion in scrapie mouse model.

PLoS One 2010 Oct 5;5(10). Epub 2010 Oct 5.

Laboratoire Adaptation et Pathogénie des Micro-organismes, Centre National Recherche Scientifique UMR 5163, Université Joseph Fourier, Grenoble, France.

Fatal neurodegenerative prion diseases are caused by the transmissible PrP(Sc) prion agent whose initial replication after peripheral inoculation takes place in follicular dendritic cells present in germinal centers of lymphoid organs. However, prion replication also occurs in lymphoid cells. To assess the role of the hematopoietic compartment in neuroinvasion and prion replication, we generated chimeric mice, on a uniform congenic C57/BL6J background, by bone marrow replacement with hematopoietic cells expressing different levels of PrP protein. Nine different types of chimeric mice were inoculated intraperitoneally either with the lymphotropic Rocky Mountain Laboratory (RML) strain or the non lymphotropic ME-7 scrapie strain, at different doses. Here, we clearly demonstrate that overexpression of PrP by the hematopoietic system, or the lack of PrP expression by the bone marrow derived cells, does not change the incubation time period of the disease, even when the mice are infected at limiting doses. We conclude that the hematopoietic compartment is more or less permissive to prion replication, both for RML and ME-7, but does not play a role in neuroinvasion.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0013166PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2950141PMC
October 2010

Sex effect in mouse and human prion disease.

J Infect Dis 2010 Aug;202(4):648-54

Laboratoire Adaptation et Pathogénie des Micro-organismes, Centre National de la Recherche Scientifique (CNRS) Unité Mixte de Recherche (UMR) 5163-Université Joseph Fourier, Grenoble, France.

Sex effect on the incubation period of variant Creutzfeldt-Jakob disease (vCJD) disease in human and ME-7 murine models was investigated. In the 167 vCJD cases reported in the United Kingdom as of January 2009, age at onset was significantly lower in female patients (by 2 years) than in male patients after stratification on birth cohort. In C57/Bl6N mice infected with ME-7 scrapie strain, incubation was shorter in female than in male mice. The incubation period increased in castrated male mice after intraperitoneal infection but not after intracerebral inoculation. In the absence of androgen receptors, the incubation period for prion disease increased after intraperitoneal inoculation. In ovariectomized or estrogen receptor alpha-defective female mice, no effect was observed on the incubation period of mouse prion disease. These results show that androgens influence the prion diseases incubation period after inoculation at a peripheral site.
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http://dx.doi.org/10.1086/654818DOI Listing
August 2010

Complement protein C1q forms a complex with cytotoxic prion protein oligomers.

J Biol Chem 2010 Jun 21;285(25):19267-76. Epub 2010 Apr 21.

Laboratoire Adaptation et Pathogénie des Micro-organismes, Université Joseph Fourier, 38042 Grenoble cedex 9, France.

A growing number of studies have investigated the interaction between C1q and PrP, but the oligomeric form of PrP involved in this interaction remains to be determined. Aggregation of recombinant full-length murine PrP in the presence of 100 mm NaCl allowed us to isolate three different types of oligomers by size-exclusion chromatography. In contrast to PrP monomers and fibrils, these oligomers activate the classical complement pathway, the smallest species containing 8-15 PrP protomers being the most efficient. We used Thioflavine T fluorescence to monitor PrP aggregation and showed that, when added to the reaction, C1q has a cooperative effect on PrP aggregation and leads to the formation of C1q-PrP complexes. In these complexes, C1q interacts through its globular domains preferentially with the smallest oligomers, as shown by electron microscopy, and retains the ability to activate the classical complement pathway. Using two cell lines, we also provide evidence that C1q inhibits the cytotoxicity induced by the smallest PrP oligomers. The cooperative interaction between C1q and PrP could represent an early step in the disease, where it prevents elimination of the prion seed, leading to further aggregation.
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http://dx.doi.org/10.1074/jbc.M109.071860DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2885205PMC
June 2010

Carbohydrate recognition properties of human ficolins: glycan array screening reveals the sialic acid binding specificity of M-ficolin.

J Biol Chem 2010 Feb 23;285(9):6612-22. Epub 2009 Dec 23.

Laboratoire d'Enzymologie Moléculaire, Institut de Biologie Structurale Jean-Pierre Ebel, Commissariat à l'Energie Atomique, CNRS UMR 5075, Université Joseph Fourier, 41 rue Jules Horowitz, Grenoble 38027 Cedex 1, France.

Ficolins are oligomeric innate immune recognition proteins consisting of a collagen-like region and a fibrinogen-like recognition domain that bind to pathogen- and apoptotic cell-associated molecular patterns. To investigate their carbohydrate binding specificities, serum-derived L-ficolin and recombinant H- and M-ficolins were fluorescently labeled, and their carbohydrate binding ability was analyzed by glycan array screening. L-ficolin preferentially recognized disulfated N-acetyllactosamine and tri- and tetrasaccharides containing terminal galactose or N-acetylglucosamine. Binding was sensitive to the position and orientation of the bond between N-acetyllactosamine and the adjacent carbohydrate. No significant binding of H-ficolin to any of the 377 glycans probed could be detected, providing further evidence for its poor lectin activity. M-ficolin bound preferentially to 9-O-acetylated 2-6-linked sialic acid derivatives and to various glycans containing sialic acid engaged in a 2-3 linkage. To further investigate the structural basis of sialic acid recognition by M-ficolin, point mutants were produced in which three residues of the fibrinogen domain were replaced by their counterparts in L-ficolin. Mutations G221F and A256V inhibited binding to the 9-O-acetylated sialic acid derivatives, whereas Y271F abolished interaction with all sialic acid-containing glycans. The crystal structure of the Y271F mutant fibrinogen domain was solved, showing that the mutation does not alter the structure of the ligand binding pocket. These analyses reveal novel ficolin ligands such as sulfated N-acetyllactosamine (L-ficolin) and gangliosides (M-ficolin) and provide precise insights into the sialic acid binding specificity of M-ficolin, emphasizing the essential role of Tyr(271) in this respect.
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http://dx.doi.org/10.1074/jbc.M109.065854DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2825457PMC
February 2010

[Care networks, mobile palliative and supportive teams. What benefits are there for patients, natural caregivers and general practitioners in patient homes?].

Rev Prat 2009 Jun;59(6):813-9

Médecin responsable de l'équipe mobile d'accompagnement en soins de support et palliatifs, CHU, Angers Cedex.

Civil society at large and all caregivers, whether at home or within institutions, are involved in palliative care However, procedures may vary considerably, excluding a single approach. So as to best adapt their responses, the authors recorded everyone's expectations. Such a participatory methodology is, sine 1990, behind the establishment of local networks providing assistance, support and training to physicians non-specialized in palliative care (general practitioners, specialists, students or residents facing specific aspects of this medical management, as well as other health and social workers).
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June 2009

Residue Lys57 in the collagen-like region of human L-ficolin and its counterpart Lys47 in H-ficolin play a key role in the interaction with the mannan-binding lectin-associated serine proteases and the collectin receptor calreticulin.

J Immunol 2009 Jan;182(1):456-65

Institut de Biologie Structurale Jean-Pierre Ebel, Unité Mixte de Recherche 5075, Centre National de la Recherche Scientifique-Commissariat à l'Energie Atomique, Université Joseph Fourier, Grenoble, France.

L- and H-ficolins are serum oligomeric defense proteins consisting of a collagen-like region and a fibrinogen-like recognition domain that bind to pathogen- and apoptotic cell-associated molecular patterns. They share with mannan-binding lectin (MBL) the ability to associate with MBL-associated serine proteases (MASP)-1, -2, -3, and protein MAp19 and to trigger the lectin complement pathway through MASP-2 activation. Recent studies have revealed the essential role of Lys(55) in the collagenous region of MBL in the interaction with the MASPs and calreticulin (CRT). To test the possible involvement of the homologous residues Lys(57) of L-ficolin and Lys(47) of H-ficolin, point mutants of both proteins were produced in which these residues were mutated to Ala, Glu, or Arg. The resulting mutants exhibited oligomerization patterns and ligand binding properties similar to those of their wild-type counterparts. In contrast, all three mutations strongly inhibited the interaction of L- and H-ficolins with MAp19 and MASP-2 and impaired the ability of each ficolin to trigger the lectin pathway. In the case of MASP-1 and MASP-3, replacement of the target Lys residues by Ala or Glu abolished interaction, whereas the Lys to Arg mutations had only slight inhibitory effects. Likewise, binding of each ficolin to CRT was inhibited by mutation of Lys to Ala or Glu, but not to Arg. In conclusion, residues Lys(57) of L-ficolin and Lys(47) of H-ficolin are key components of the interaction with the MASPs and CRT, providing strong indication that MBL and the ficolins share homologous binding sites for both types of proteins.
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http://dx.doi.org/10.4049/jimmunol.182.1.456DOI Listing
January 2009

Aspergillus conidia activate the complement by the mannan-binding lectin C2 bypass mechanism.

J Immunol 2008 Nov;181(10):7100-5

Laboratoire Adaptation et Pathogénie des Micro-organismes, Université Joseph Fourier, Grenoble 1, BP 170, Grenoble, France.

Innate immunity is the major host defense against invasive aspergillosis. To determine whether the collectin mannan-binding lectin (MBL) is involved in the initial protective immunity through complement activation against opportunistic fungal infections caused by Aspergillus, we performed in vitro studies on 29 different strains of Aspergillus conidia from five different species. Incubation of Aspergillus conidia in human normal serum leads to activation of the alternative pathway, whereas neither the classical nor the lectin pathways through C4 and C2 cleavage are activated. Complement response to conidia was investigated using a MBL-deficient serum and reconstitution experiments were conducted with MBL/MASPs complexes. We found that MBL can directly support C3 activation by a C2 bypass mechanism. Finally, a stronger activation of the alternative pathway was observed for the clinical strains isolated from patients with invasive aspergillosis, compared with the environmental strains.
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http://dx.doi.org/10.4049/jimmunol.181.10.7100DOI Listing
November 2008

Risk assessment of transmission of sporadic Creutzfeldt-Jakob disease in endodontic practice in absence of adequate prion inactivation.

PLoS One 2007 Dec 26;2(12):e1330. Epub 2007 Dec 26.

Université Pierre et Marie Curie-Paris6, Unité de Recherche Epidémiologie-Systèmes d'information-Modélisation, UMR S 707, Paris, France.

Background: Experimental results evidenced the infectious potential of the dental pulp of animals infected with transmissible spongiform encephalopathies (TSE). This route of iatrogenic transmission of sporadic Creutzfeldt-Jakob disease (sCJD) may exist in humans via reused endodontic instruments if inadequate prion decontamination procedures are used.

Methodology/principal Findings: To assess this risk, 10 critical parameters in the transmission process were identified, starting with contamination of an endodontic file during treatment of an infectious sCJD patient and ending with possible infection of a subsequent susceptible patient. It was assumed that a dose-risk response existed, with no-risk below threshold values. Plausible ranges of those parameters were obtained through literature search and expert opinions, and a sensitivity analysis was conducted. Without effective prion-deactivation procedures, the risk of being infected during endodontic treatment ranged between 3.4 and 13 per million procedures. The probability that more than one case was infected secondary to endodontic treatment of an infected sCJD patient ranged from 47% to 77% depending on the assumed quantity of infective material necessary for disease transmission. If current official recommendations on endodontic instrument decontamination were strictly followed, the risk of secondary infection would become quasi-null.

Conclusion: The risk of sCJD transmission through endodontic procedure compares with other health care risks of current concern such as death after liver biopsy or during general anaesthesia. These results show that single instrument use or adequate prion-decontamination procedures like those recently implemented in dental practice must be rigorously enforced.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0001330PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2129113PMC
December 2007

PrP N-terminal domain triggers PrP(Sc)-like aggregation of Dpl.

Biochem Biophys Res Commun 2008 Jan 13;365(3):478-83. Epub 2007 Nov 13.

Laboratoire Adaptation et Pathogénie des Micro-organismes, Université Joseph Fourier, BP 170, 38042 Grenoble Cedex 9, France.

Transmissible spongiform encephalopathies are fatal neurodegenerative disorders thought to be transmitted by self-perpetuating conformational conversion of a neuronal membrane glycoprotein (PrP(C), for "cellular prion protein") into an abnormal state (PrP(Sc), for "scrapie prion protein"). Doppel (Dpl) is a protein that shares significant biochemical and structural homology with PrP(C). In contrast to its homologue PrP(C), Dpl is unable to participate in prion disease progression or to achieve an abnormal PrP(Sc)-like state. We have constructed a chimeric mouse protein, composed of the N-terminal domain of PrP(C) (residues 23-125) and the C-terminal part of Dpl (residues 58-157). This chimeric protein displays PrP-like biochemical and structural features; when incubated in presence of NaCl, the alpha-helical monomer forms soluble beta-sheet-rich oligomers which acquire partial resistance to pepsin proteolysis in vitro, as do PrP oligomers. Moreover, the presence of aggregates akin to protofibrils is observed in soluble oligomeric species by electron microscopy.
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http://dx.doi.org/10.1016/j.bbrc.2007.10.202DOI Listing
January 2008

Activation of classical pathway of complement cascade by soluble oligomers of prion.

Cell Microbiol 2007 Dec;9(12):2870-9

Laboratoire d'Adaptation et Pathogenèse des Microorganismes, UMR5163 CNRS-UJF, Institut Jean Roget, BP170, 38042 Grenoble cedex 9, France.

Mice defective for C1q complement factor show enhanced resistance to peripheral prion inoculation, and previous work demonstrated a direct interaction between C1q and conformationally modified PrP. However, the nature and physiological consequences of this interaction remain uncharacterized. PrP amino acids 141-159 has been identified as a potential C1q binding site; we show, by both surface plasmon resonance (SPR) spectroscopy and ELISA, that C1q and its globular region bind to PrP mutagenized in the region of interest with comparable efficiency to that of wild-type protein. To test PrP's ability to activate complement, soluble oligomers of the PrP constructs were made. Only PrP and mutagenized PrP oligomers activate the classical complement cascade while PrP monomer and the C-terminal domain, both in oligomeric and in monomeric form, failed to induce activation. This suggests that a conformational change in PrP, which occurs both when PrP is bound to an SPR sensor chip and when it undergoes oligomerization, is requisite for PrP/C1q interaction and activation of the complement cascade. We propose that C1q may act as a natural sensor for prions, leading to activation of the classical complement cascade, which could result in local inflammation and subsequent recruitment of the immune cells that prions initially infect.
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http://dx.doi.org/10.1111/j.1462-5822.2007.01002.xDOI Listing
December 2007

Overexpression of cellular prion protein induces an antioxidant environment altering T cell development in the thymus.

J Immunol 2006 Mar;176(6):3490-7

Laboratoire d'Immunochimie, Commissariat à l'Energie Atomique, Institut National de la Santé et de la Recherche Médicale Unité 548, Université J. Fourier, 17 Rue des Martyrs, 38054 Grenoble, France.

Cellular prion protein (PrP(C)) is an ubiquitously expressed glycoprotein whose roles are still widely discussed, particularly in the field of immunology. Using TgA20- and Tg33-transgenic mice overexpressing PrP(C), we investigated the consequences of this overexpression on T cell development. In both models, overexpression of PrP(C) induces strong alterations at different steps of T cell maturation. On TgA20 mice, we observed that these alterations are cell autonomous and lead to a decrease of alphabeta T cells and a concomitant increase of gammadelta T cell numbers. PrP(C) has been shown to bind and chelate copper and, interestingly, under a copper supplementation diet, TgA20 mice presented a partial restoration of the alphabeta T cell development, suggesting that PrP(C) overexpression, by chelating copper, generates an antioxidant context differentially impacting on alphabeta and gammadelta T cell lineage.
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http://dx.doi.org/10.4049/jimmunol.176.6.3490DOI Listing
March 2006

Epidemiological evidence of higher susceptibility to vCJD in the young.

BMC Infect Dis 2004 Aug 10;4:26. Epub 2004 Aug 10.

INSERM U444, Assistance Publique Hôpitaux de Paris, Université Pierre et Marie Curie, Paris, France.

Background: The strikingly young age of new variant Creutzfeldt-Jacob disease (vCJD) cases remains unexplained. Age dependent susceptibility to infection has been put forward, but differential dietary exposure to contaminated food products in the UK population according to age and sex during the bovine spongiform encephalopathy (BSE) epidemic may provide a simpler explanation.

Methods: Using recently published estimates of dietary exposure in mathematical models of the epidemiology of the new variant Creutzfeldt Jacob disease (vCJD), we examine whether the age characteristics of vCJD cases may be reproduced.

Results: The susceptibility/exposure risk function has likely peaked in adolescents and was followed by a sharp decrease with age, evocative of the profile of exposure to bovine material consumption according to age. However, assuming that the risk of contamination was proportional to exposure, with no age dependent susceptibility, the model failed to reproduce the observed age characteristics of the vCJD cases: The predicted cumulated proportion of cases over 40 years was 48%, in strong disagreement with the observed 10%. Incorporating age dependent susceptibility led to a cumulated proportion of cases over 40 years old of 12%.

Conclusions: This analysis provides evidence that differential dietary exposure alone fails to explain the pattern of age in vCJD cases. Decreasing age related susceptibility is required to reproduce the characteristics of the age distribution of vCJD cases.
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http://dx.doi.org/10.1186/1471-2334-4-26DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC514608PMC
August 2004

Prion protein (PrPc) immunocytochemistry and expression of the green fluorescent protein reporter gene under control of the bovine PrP gene promoter in the mouse brain.

J Comp Neurol 2004 May;473(2):244-69

Neurotransmission et Sécrétion Neuroendocrine UPR 2356 Centre National de la Recherche Scientifique, IFR37 des Neurosciences, 67084 Strasbourg, France.

Expression of the cellular prion protein (PrP(c)) by host cells is required for prion replication and neuroinvasion in transmissible spongiform encephalopathies. As a consequence, identification of the cell types expressing PrP(c) is necessary to determine the target cells involved in the cerebral propagation of prion diseases. To identify the cells expressing PrP(c) in the mouse brain, the immunocytochemical localization of PrP(c) was investigated at the cellular and ultrastructural levels in several brain regions. In addition, we analyzed the expression pattern of a green fluorescent protein reporter gene under the control of regulatory sequences of the bovine prion protein gene in the brain of transgenic mice. By using a preembedding immunogold technique, neuronal PrP(c) was observed mainly bound to the cell surface and presynaptic sites. Dictyosomes and recycling organelles in most of the major neuron types also exhibited PrP(c) antigen. In the olfactory bulb, neocortex, putamen, hippocampus, thalamus, and cerebellum, the distribution pattern of both green fluorescent protein and PrP(c) immunoreactivity suggested that the transgenic regulatory sequences of the bovine PrP gene were sufficient to promote expression of the reporter gene in neurons that express immunodetectable endogenous PrP(c). Transgenic mice expressing PrP-GFP may thus provide attractive murine models for analyzing the transcriptional activity of the Prnp gene during prion infections as well as the anatomopathological kinetics of prion diseases.
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http://dx.doi.org/10.1002/cne.20117DOI Listing
May 2004

Modelling the epidemic of variant Creutzfeldt-Jakob disease in the UK based on age characteristics: updated, detailed analysis.

Stat Methods Med Res 2003 Jun;12(3):221-33

Epidémiologie et Sciences de l'Information, INSERM U444, Assistance Publique, Hôpitaux de Paris, Université Pierre et Marie Curie, Paris, France.

Incubation period of the new variant Creutzfeldt-Jakob disease (vCJD) from infection to clinical onset and the eventual impact of the disease remain major concerns. Based on i) epidemiological conceptualization of human exposure to BSE contaminated material, ii) exponentially decreasing susceptibility after 15 years of age, and iii) typical incubation period (IP) distributions for time from infection to onset, we have previously estimated mean incubation period and projected number of vCJD cases. In this paper, we investigate the robustness of these estimates with respect to i-iii using the UK's 113 vCJD cases with clinical onset before December 2000. Mean incubation period was estimated at 16.4 years (95% CI 11.4-24.8), 15.9 years (95% CI 11.4-22.0), 14.1 years (95% CI 10.4-24.2) with the log-normal, Gamma and Weibull distributions respectively. Corresponding predictions for the total size of the epidemic ranged from 183 to 304. Maximal susceptibility to infection between 1.3 and 15.9 years and decreasing by 15% per year of age thereafter yielded the best fit. The shape of the IP distribution did not affect the predictions. In summary, within a set of reasonable assumptions, mean incubation period for vCJD ranged from 15 to 20 years, and the eventual impact of vCJD was a few hundred patients.
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http://dx.doi.org/10.1191/0962280203sm329raDOI Listing
June 2003