Laboratoire HLA

Berre-les-Alpes, France

Laboratoire HLA

Berre-les-Alpes, France
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PubMed | CEA DAM Ile-de-France, laboratoire HLA, laboratoire dimmunologie, laboratoire Jean Dausset and 6 more.
Type: Journal Article | Journal: Bulletin du cancer | Year: 2016

In an attempt to harmonize clinical practices among French hematopoietic stem cell transplantation centers, the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) held its sixth annual workshop series in September 2015 in Lille. This event brought together practitioners from across the country with the purpose of offering careful analysis of published studies on clinical practice issues that remain to be disputed. This article addresses the impact of HLA and KIR gene polymorphism on the outcome of the transplantation in order to optimize unrelated donor selection.

PubMed | Laboratoire HLA EFS, Laboratoire HLA, British Petroleum, Histocompatibilite et immunogenetique and 8 more.
Type: Journal Article | Journal: Pathologie-biologie | Year: 2014

The role of anti-HLA antibodies in allogeneic stem cell transplantation setting is still unclear. In the attempt to harmonize clinical practices between different French transplantation centers, the French Society of Bone Marrow Transplantation and Cell Therapies (SFGM-TC) set up its fourth annual series of workshops which brought together practitioners from all of its member centers. These workshops took place in September 2013 in Lille. This article offers the recommendations of the group that considered the impact that have anti-HLA antibodies on outcomes in allogeneic stem cell transplantation.

Braza F.,French Institute of Health and Medical Research | Braza F.,French National Center for Scientific Research | Braza F.,University of Nantes | Chesne J.,French Institute of Health and Medical Research | And 9 more authors.
Allergy: European Journal of Allergy and Clinical Immunology | Year: 2014

B cells are essentially described for their capacity to produce antibodies ensuring anti-infectious immunity or deleterious responses in the case of autoimmunity or allergy. However, abundant data described their ability to restrain inflammation by diverse mechanisms. In allergy, some regulatory B-cell subsets producing IL-10 have been recently described as potent suppressive cells able to restrain inflammatory responses both in vitro and in vivo by regulatory T-cell differentiation or directly inhibiting T-cell-mediated inflammation. A specific deficit in regulatory B cells participates to more severe allergic inflammation. Induction of allergen tolerance through specific immunotherapy induces a specific expansion of these cells supporting their role in establishment of allergen tolerance. However, the regulatory functions carried out by B cells are not exclusively IL-10 dependent. Indeed, other regulatory mechanisms mediated by B cells are (i) the production of TGF-β, (ii) the promotion of T-cell apoptosis by Fas-Fas ligand or granzyme-B pathways, and (iii) their capacity to produce inhibitory IgG4 and sialylated IgG able to mediate anti-inflammatory mechanisms. This points to Bregs as interesting targets for the development of new therapies to induce allergen tolerance. In this review, we highlight advances in the study of regulatory mechanisms mediated by B cells and outline what is known about their phenotype as well as their suppressive role in allergy from studies in both mice and humans. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Tonnerre P.,French Institute of Health and Medical Research | Tonnerre P.,Nantes University Hospital Center | Tonnerre P.,University of Nantes | Gerard N.,French Institute of Health and Medical Research | And 13 more authors.
Journal of the American Society of Nephrology | Year: 2013

MHC class I-related chain A (MICA) antigens are surface glycoproteins strongly implicated in innate immunity, and the MICA gene is highly polymorphic. Clinical observations suggest a role for donor MICA antigens expressed on transplant endothelial cells in the alloimmune response, but the effect of MICA genotype is not well understood. Here, we investigated the immunologic effect of the A5.1 mutation, related to the common MICA*008 allele. Compared with wild-type endothelial cells (ECs), homozygosity for MICA A5.1 associated with an endothelial phenotype characterized by 7- to 10-fold higher levels of MICA mRNA and MICA proteins at the cell surface, as well as exclusive release in exosomes instead of enzymatic cleavage. Mechanistically, we did not detect quantitative changes in regulatory microRNAs. Functionally, A5.1 ECs enhanced NKG2D interaction and natural killer cell activation, promoting NKG2Ddependent lysis of ECs. In kidney transplant recipients, polyreactive anti-MICA sera bound preferentially to ECs from MICA A5.1 donors, suggesting thatMICA*008(A5.1) molecules are the preferential antigenic determinants on ECs of grafts. Furthermore, the incidence of MICA A5.1mismatch revealed a statistically significant association between donor MICA A5.1 and both anti-MICA sensitization and increased proteinuria in kidney recipients. Taken together, these results identify the A5.1 mutation as an immunodominant factor and a potential risk factor for transplant survival. Copyright © 2013 by the American Society of Nephrology.

Touzeau C.,Nantes University Hospital Center | Touzeau C.,French Institute of Health and Medical Research | Gagne K.,Laboratoire HLA | Gagne K.,Laboratoire EA4271 | And 12 more authors.
Human Immunology | Year: 2012

The impact of HLA-DPB1 mismatches after unrelated hematopoietic stem cell transplantation (HSCT) remains controversial. We retrospectively analyzed the impact of permissive/non-permissive HLA-DPB1 mismatches on the outcome of 141 patients who underwent 10/10 HLA allelic-matched unrelated HSCT. Each pair was classified according to the 3 (TCE3) and 4-group (TCE4) algorithm based on DPB1 alleles immunogenicity. Outcome analysis revealed that TCE3 and TCE4 non-permissive HLA-DPB1 disparities were not associated with worsened overall survival, relapse risk neither risk of acute GvHD. Overall, this single center retrospective study does not confirm the adverse prognostic of non-permissive HLA-DPB1 mismatches. © 2012 American Society for Histocompatibility and Immunogenetics.

PubMed | University of Nantes, Laboratoire HLA and Nantes University Hospital Center
Type: Journal Article | Journal: The Journal of infectious diseases | Year: 2016

BK polyomavirus (BKPyV) frequently reactivates in kidney transplant recipients during immunosuppressive therapy and triggers BKPyV-associated nephropathy and graft rejection. Determining effective risk factors for BKPyV reactivation is required to achieve efficient prevention.This study investigated the role of major histocompatibility complex (MHC) class I-related chain A (MICA) in BKPyV reactivation in a cohort of 144 transplant donor/recipient pairs, including recipients with no reactivation (controllers) and those with mild (virurics) or severe (viremics) BKPyV reactivation after graft receipt.We show that, in the kidney, MICA is predominantly expressed in tubule epithelial cells, the natural targets of BKPyV, questioning a role for MICA in the immune control of BKPyV infection. Focusing on MICA genotype, we found a lower incidence of BKPyV reactivation in recipients of a renal graft from a donor carrying the MICA A5.1 mutant, which encodes a truncated nonconventional MICA. We established that a mismatch for MICA A5.1 between transplant donor and recipient is critical for BKPyV reactivation and BKPyV-associated nephropathy. Functionally, we found that a low prevalence of BKPyV reactivation was associated with elevated anti-MICA sensitization and reduced plasma level of soluble MICA in recipients, 2 potential effector mechanisms.These findings identify the MHC-related MICA as an immunogenetic factor that may functionally influence anti-BKPyV immune responses and infection outcomes.

PubMed | University of Nantes, Laboratoire HLA, French Institute of Health and Medical Research and Nantes University Hospital Center
Type: Journal Article | Journal: PloS one | Year: 2014

In order to characterize the reactivity of B cells against nominal antigens, a method based on the coupling of antigens onto the surface of fluorescent core polystyrene beads was developed. We first demonstrate that murine B cells with a human MOG-specific BCR are able to interact with MOG-coated beads and do not recognize beads coated with human albumin or pp65. B cells purified from human healthy volunteer blood or immunized individuals were tested for their ability to interact with various nominal antigens, including viral, vaccine, self and alloantigens, chosen for their usefulness in studying a variety of pathological processes. A substantial amount of B cells binding self-antigen MOG-coated beads can be detected in normal blood. Furthermore, greater frequencies of B cell against anti-Tetanic Toxin or anti-EBNA1 were observed in primed individuals. This method can reveal increased frequencies of anti-HLA committed B cells in patients with circulating anti-HLA antibodies compared to unsensitized patients and normal individuals. Of interest, those specific CD19 cells were preferentially identified within CD27(-)IgD(+) (i-e nave) subset. These observations suggest that a broad range of medical situations could benefit from a tool that allows the detection, the quantification and the characterization of antigen-specific blood B cells.

Amoura S.,Center Hospitalo University Mustapha Bacha | Dubois V.,Laboratoire HLA | Bouali-Benhalima M.,Center Hospitalo University Mustapha Bacha
Revue Francophone des Laboratoires | Year: 2012

The introduction of solid phase assays for the detection of HLA antibodies in routine led to the application of new algorithms for the immunological monitoring of patients for renal transplantation and has prevented many cases of rejection, which would have been impossible to detect using complement dependent serological techniques In this work, we made a comparative study between two techniques of HLA antibody testing, ELISA and Luminex®. Luminex®'s data were analyzed in two ways, firstly with the cut-off of the supplier and then with the new thresholds established after analysis of discrepancies and identification of antibodies. Following this study, we can argue that both techniques are sensitive. However, the Luminex® technology is more specific and faster. © 2012 - Elsevier Masson SAS - Tous droits réservés.

Fromont P.,Laboratoire HLA | Prie N.,Laboratoire HLA | Simon P.,Laboratoire HLA | Cesbron-Gautier A.,Laboratoire HLA | And 4 more authors.
Transfusion | Year: 2010

BACKGROUND: Granulocyte antibodies have been implicated in allo- and autoimmune neutropenia and in transfusion reactions. STUDY DESIGN AND METHODS: Fifty-one sera from suspected alloimmune neutropenia or transfusion-related acute lung injury (TRALI) and 40 sera from suspected autoimmune neutropenia were tested for granulocyte antibodies using LABScreen MULTI (One Lambda, Inc.), compared with classical tests (flow cytometry [FC] and granulocyte agglutination [GAT] followed by monoclonal antibody-specific immobilization of granulocyte antigens [MAIGA]). RESULTS: In alloimmune situations, 48 sera were concordant (94%), two sera positive for HNA with LABScreen MULTI were negative by FC/GAT and/or MAIGA, and one serum sample negative for HNA with LABScreen MULTI was positive by classical tests. In autoimmune neutropenia, 30 sera were concordant (75%), four sera positive for HNA with LABScreen MULTI were negative by FC/GAT and/or MAIGA, and six sera negative for HNA with LABScreen MULTI were positive by FC/GAT and/or MAIGA. For detection of autoantibodies, the LABScreen MULTI was less concordant. However, with the exception of one case, the discrepancies were observed in sera that did not show a clear specificity. CONCLUSIONS: LABScreen MULTI correlated well with our classical methods for HNA-1 and HNA-2a antibody screening. It can be used for screening blood donors or patients suspected of TRALI, but GAT is still needed for HNA-3a antibody screening. © 2010 American Association of Blood Banks.

Ducreux S.,Laboratoire HLA | Favre-Victoire I.,Laboratoire HLA | Giannoli C.,Laboratoire HLA | Moskovtchenko P.,Laboratoire HLA | Dubois V.,Laboratoire HLA
Tissue Antigens | Year: 2014

We characterized three new HLA class I alleles: B*15:222, B*15:247 and B*27:92 found by routine typing. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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