Received: 3 January 2019
Accepted: 30 August 2019
First Online: 7 September 2019
Compliance with ethical standards
: The authors declare no conflict of interest.
: This non-interventional study, which complies with the Declaration of Helsinki, was approved by the appropriate regional ethics committee (“Comités de Protection des Personnes”, Ile-de-France, France) regulated by the government institution “Agence Régionale de Santé” (ARS, Bobigny, France), by the government advisory board for data processing in health care (“Comité Consultatif sur le Traitement de l’Information en matière de Recherche dans le Domaine de la Santé”, Paris, France) (CCTIRS N°14.626), and by the French data protection authority (“Commission Nationale de l’Informatique et des Libertés » , Paris, France) (CNIL N°DR-2015-237). PBMCs from HD were obtained from CTL—Europe or from the EFS. Spleens were obtained from organ transplant donors at the Hôpital Pitié-Salpêtrière (Paris, France), in accordance with national ethics guidelines governing the use of human tissues (Scientific collecting authorization, government institution “Agence de la biomédecine”, Saint Denis, France) (N°PFS14-009). All animal studies were performed in compliance with guidelines from the European Union (EU guideline on animal experiments, European Directive #2010/63/EU) and the national charter on ethics in animal experiments and were approved by the local Charles Darwin Ethics Committee in Animal Experiments, Paris, France (Authorization Number 01530.02).
: All FL patients provided informed written consent to participate in this research study (CCTIRS N°14.626 and CNIL N°DR-2015-237). Written informed consents were obtained by the French state agency EFS (ExternalRef removed) for the use of blood of anonymous healthy donors for research purposes. Human PBMCs from CTL-Europe were collected from sources that have confirmed that they were obtained from healthy donors with informed consent in accordance with applicable laws. Spleens were collected from organ transplant donors at the Hôpital Pitié-Salpétrière (Paris, France) (written protocol N°PFS14-009, Agence de la biomédecine), following national ethical guidelines (L1232-1, L1232-3; ExternalRef removed) regulating the use of human tissues for research purposes.
: HLA-A2.1-/HLA-DR1-transgenic H-2 class I-/class II-KO female C57Bl/6 mice were developed by Dr. Lone at Institut Pasteur—Paris in Dr. F. Lemonnier laboratory. HLA‐A2.1 transgenic H‐2 class I‐KO (β2 m<sup>0</sup>) (obtained at Institut Pasteur—Paris in Dr. F. Lemonnier laboratory) and HLA‐DR1 transgenic H‐2 class II‐KO (IAβ<sup>b°</sup>) (obtained at Institut Pasteur—Lille from Dr. C. Auriault) mice were intercrossed and progenies screened until HLA‐A2.1<sup>+/+</sup>/HLA‐DR1<sup>+/+</sup> double‐transgenic H‐2 class I-/class II-KO animals were obtained [CitationRef removed]. All mice were maintained in pathogen-free facilities.
: C57BL/6 mice-derived EL4 thymoma cells expressing human CD20 (EL4-huCD20) were kindly provided by Pr. Josée Golay from the Center of Cellular Therapy “G. Lanzani”, USC Haematology, Azienda Socio Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy. EL4 cells obtained from the American-Type Culture Collection (ATCC, Manassas, VA) were infected with the Moloney-derived long terminal repeat (LTR)-CD20-LTR vector containing the human CD20 cDNA [CitationRef removed]. The expression of human CD20 on EL4-huCD20 cells was validated before each experiment by flow cytometry using a mouse anti-human CD20 mAb (2H7, BD Biosciences). HLA-DRB1*01:01-expressing AAPCs derived from murine fibroblasts NIH-3T3 cells were developed by Dr. Toutirais and Dr. Latouche. NIH-3T3 cells (obtained from ATCC) were transduced with the common HLA-DRα chain, the specific HLA-DRβ1*01:01 chain, and with the co-stimulatory and adhesion human molecules B7.1, ICAM-1 and LFA-3 [CitationRef removed]. Phenotypic expression of transduced molecules on AAPCs was validated by flow cytometry using anti‐human LFA‐3, B7.1, ICAM‐1 mAbs (BD Biosciences) and an anti‐HLA‐DR complex mAb (Santa Cruz Biotechnology).