test_moissonnage_selune
type: Agent

Memory B cells in anti-HLA humoral response in organ transplantation
type: Dataset
contact point: Organization
  fn: CCSD
keyword: hla
keyword: organ-transplantation
keyword: lymphocytes-b
keyword: theses
keyword: transplantation-dorgane
keyword: infoeu-reposemanticsdoctoralthesis
keyword: b-cells
keyword: lymphocytes-b-memoire
keyword: transplantation-renale
keyword: renal-transplantation
keyword: sdvmheplife-sciences-q-biohuman-health-and-pathology
keyword: anti-hla-antibodies
keyword: memory-b-cells
keyword: anticorps-anti-hla
keyword: baff
landing page: https://theses.hal.science/tel-00919770
description: Anti-HLA antibodies are directed against various epitopes of HLA molecules. They develop during organ transplantations, red cell transfusions or pregnancies. But anti-HLA antibodies are also detected with sensitive assays in the absence of any sensitizing event. In renal transplantation, anti-HLA antibodies, through the development of antibody-mediated rejection, represent the first cause of late allograft loss. Nevertheless, the mechanisms and the exact nature of B cells involved in anti-HLA antibodies synthesis are poorly understood.In a first part, we studied by flow cytometry in patients awaiting kidney transplantation the distribution of the different peripheral B cell subsets in relation with immunizing events, titer and diversity of anti-HLA antibodies. We also studied the serum levels of BAFF ("B cell activating factor belonging to the TNF family"), the main factor involved in survival and differentiation of mature B cells. We found an association between the presence and the diversity of anti-HLA antibodies, and the proportion of activated naive Bm2 B cells, at the expense of other subsets, independently of immunizing events. BAFF serum levels were also positively associated with the presence and the diversity of anti-HLA antibodies. These data suggest that the increase in activated naive B cells and in BAFF levels facilitate the development of anti-HLA antibodies, following an immunizing event. Similarly to what is observed in autoimmunity, BAFF could help to the positive selection of alloreactive B cell clones, in the presence of alloantigen.In a second part, we focused on the role of circulating alloreactive memory B cells in anti-HLA humoral response. To detect those alloreactive memory B cells, we used a polyclonal stimulation assay allowing the differentiation of memory B cells into plasmablasts and we studied the specificity of anti-HLA antibodies recovered from culture supernatant. A first important result was the detection, decades after an imunizi…
identifier: NNT: 2013PA05T039
issued: 2026-05-07T18:46:44.158931
language: fr
modified: 2026-05-07T18:46:44.158937

Memory B cells in anti-HLA humoral response in organ transplantation
type: Distribution
access URL: https://theses.hal.science/tel-00919770
format: HTML
issued: 2026-05-07T18:46:44.166105
modified: 2026-05-07T18:46:44.141445