Joyeux anniversaire, CD34 !

Vingt ans après la première description de l’antigène CD34, cette molécule continue de susciter la curiosité des scientifiques, qui cherchent toujours à élucider la fonction exacte de ce qui est rapidement apparu comme un « marqueur de la cellule souche hématopoïétique » dans différentes espèces incluant l’homme, les primates et la souris. Parallèlement, de nombreux outils ont été développés pour faire de CD34 un outil médical, essentiellement utilisé dans le diagnostic des hémopathies malignes et dans l’évaluation des greffons de cellules hématopoïétiques. Cet article présente les principales connaissances qui se sont accumulées au cours de vingt années d’études scientifiques et médicales.Twenty years after the initial description of the CD34 antigen, scientists are still interested in elucidating the exact function of a prototypic « stem cell antigen » in human, primate and mouse models. While this question remains largely unresolved, this has not precluded the development of medical tools using the detection of CD34 in several applications that range from diagnosis of malignant blood diseases through the biological monitoring of haematopoietic cell collection for autologous or allogeneic transplantation. This review focuses on major aspects of CD34 biology

Ten years after the first inspection of a candidate European centre, an EBMT registry analysis suggests that clinical is improved when hematopoietic SCT is performed in a Jacie accredited program

In 2010, JACIE, the Joint Accreditation Committee of ISCT (International Society for Cell Therapy) Europe and EBMT (European group for Blood and Marrow Transplantation) celebrated the tenth anniversary of the first inspection of a European hematopoietic SCT program. JACIE standards establish the criteria for a comprehensive quality management program that covers all three major domains of activity that are necessary for the delivery of HSCT: clinical, collection and processing, as well as their interactions with ancillary and supportive activities. Although more than 200 European programs have applied for JACIE accreditation, and more than 100 have been granted accreditation, a recent retrospective analysis of the large-size EBMT registry of autologous and allogenic hematopoietic HSCT demonstrates that one of the factors affecting the overall survival of recipients of allogenic transplantation is the status of the transplant program regarding JACIE accreditation. This provides one of the first demonstrations that introduction of a quality management system contributes to the overall survival of patients treated with a highly specific medical procedure, and represents a milestone in the implementation of JACIE

Structure of and Signalling Through Chimeric Antigen Receptor

AbstractChimeric antigen receptor (CAR) is a synthetic transmembrane protein expressed at the surface of immune effector cells (IECs) that are reprogrammed either in vitro or in vivo (June et al. 2018; June and Sadelain 2018). Techniques for genetic engineering of autologous or allogeneic IECs are described in the next chapter. The synthetic CAR incorporates several functional domains. The extracellular domain is composed of a single chain variable fragment (ScFV) of immunoglobulin and recognizes the "tumour" antigen. The clinical relevance of the selected tumour antigen—with a view to minimize "on-target/off-tumour" side effects—is discussed in the third chapter of this section. Bispecific and trispecific CARs are currently being evaluated in preclinical and early clinical trials (Bielamowicz et al. 2018; Shah et al. 2020). The use of an immunoglobulin domain as the ligand of the target antigen means that recognition is not restricted to HLA antigens and that CAR-T cells are universally applicable as opposed to T cell receptor (TCR) transgenic T cells that recognize antigenic peptides presented in the context of a defined major histocompatibility complex (MHC), limiting clinical applications to subsets of patients with defined HLA typing. The intracellular domain is composed of the intracellular domain of the zeta chain of the CD3 component of the TCR, which will trigger signalling when the CAR engages the targeted ligand. The transmembrane region links the two extracellular and intracellular domains through the cell membrane and plays an important role in determining the conformation and flexibility of the CAR and its ability to efficiently bind the targeted antigen/epitope. Association of only these three functional domains characterized first generation CARs, as described in the original publications (Kuwana et al. 1987; Eshhar et al. 1993). However, full activation of T cells requires the addition of one (second generation CARs) or two (third generation CARs) domains from costimulatory molecules, such as CD28, 4-1BB/CD137, or OX40/CD134, that provide the T cell costimulatory signal. Currently approved CAR-T cells are second generation CAR-T cells; as an illustration, the CAR in tisagenlecleucel contains a 4-1BB domain, while the CAR in axicabtagene ciloleucel contains a CD28 domain. The nature of the costimulatory domain influences the ability of CAR-T cells to expand or persist (limit T cell exhaustion) in vivo after infusion into the patient, although it is unclear how this translates clinically and affects disease control, occurrence of adverse events, and overall survival due to the lack of head-to-head comparison between approved products. Finally, fourth generation CAR-T cells have been developed for preclinical projects. These cells, named armoured CAR cells or T cells redirected for universal cytokine-mediated killing (TRUCKS), encode not only a CAR (usually with one costimulatory domain, such as in second generation CARs) but also a cytokine, interleukin, pro-inflammatory ligand, or chemokine that will counteract the immune suppressive microenvironment that prevails in most solid tumours (Eshhar et al. 1993; Chmielewski and Abken 2015)

La valorisation du bois dans le cadre de la restauration et de l'entretien de ripisylve : Le Tech dans les Pyrénées Orientales.

Cet article présente le « Contrat Rivière du Tech » (33 communes, 83 km, 20 millions d'euros sur 5 ans) signé en janvier 2001 et la mise en uvre du programme de travaux issu du schéma d'entretien. La prise en compte, sous réserve de conditions favorables de la valorisation des bois de la ripisylve, permet une économie parfois des coûts et le maintien d'une activité dans la vallée. Le partenariat établi entre les différentes structures de la forêt privée, le SIVU du Tech, les propriétaires et les élus, donne plus de poids aux actions engagées et une meilleure appréhension des enjeux économiques, sociaux et environnementaux du Tech et de ses bassins versants (750 km2)

Essential requirements for setting up a stem cell processing laboratory

The Graft Processing subcommittee of the Worldwide Network for Blood and Marrow Transplantation wrote this guideline to assist physicians and laboratory technologists with the setting up of a cell processing laboratory (CPL) to support a hematopoietic stem cell transplant program, thereby facilitating the start-up of a transplant program in a new location and improving patient access to transplantation worldwide. This guideline describes the minimal essential features of designing such a laboratory and provides a list of equipment and supply needs and staffing recommendations. It describes the typical scope of services that a CPL is expected to perform, including product testing services, and discusses the basic principles behind the most frequent procedures. Quality management (QM) principles specific to a CPL are also discussed. References to additional guidance documents that are available worldwide to assist with QM and regulatory compliance are also provided. © 2014 Macmillan Publishers Limited All rights reserved

DNAM-1 and PVR Regulate Monocyte Migration through Endothelial Junctions

DNAX accessory molecule 1 (DNAM-1; CD226) is a transmembrane glycoprotein involved in T cell and natural killer (NK) cell cytotoxicity. We demonstrated recently that DNAM-1 triggers NK cell–mediated killing of tumor cells upon engagement by its two ligands, poliovirus receptor (PVR; CD155) and Nectin-2 (CD112). In the present paper, we show that PVR and Nectin-2 are expressed at cell junctions on primary vascular endothelial cells. Moreover, the specific binding of a soluble DNAM-1–Fc molecule was detected at endothelial junctions. This binding was almost completely abrogated by anti-PVR monoclonal antibodies (mAbs), but not modified by anti–Nectin-2 mAbs, which demonstrates that PVR is the major DNAM-1 ligand on endothelial cells. Because DNAM-1 is highly expressed on leukocytes, we investigated the role of the DNAM-1–PVR interaction during the monocyte transendothelial migration process. In vitro, both anti–DNAM-1 and anti-PVR mAbs strongly blocked the transmigration of monocytes through the endothelium. Moreover, after anti–DNAM-1 or anti-PVR mAb treatment, monocytes were arrested at the apical surface of the endothelium over intercellular junctions, which strongly suggests that the DNAM-1–PVR interaction occurs during the diapedesis step. Altogether, our results demonstrate that DNAM-1 regulates monocyte extravasation via its interaction with PVR expressed at endothelial junctions on normal cells

development of adaptive immune effector therapies in solid tumors

Abstract State-of-the-art treatment strategies have drastically ameliorated the outcome of patients affected by cancer. However, resistant and recurrent solid tumors are generally nonresponsive to conventional therapies. A central factor in the sequence of events that lead to cancer is an alteration in antitumor immune surveillance, which results in failure to recognize and eliminate the transformed tumor cell. A greater understanding of the dysregulation and evasion of the immune system in the evolution and progression of cancer provides the basis for improved therapies. Targeted strategies, such as T-cell therapy, not only generally spare normal tissues, but also use alternative antineoplastic mechanisms that synergize with other therapeutics. Despite encouraging success in hematologic malignancies, adaptive cellular therapies for solid tumors face unique challenges because of the immunosuppressive tumor microenvironment, and the hurdle of T-cell trafficking within scarcely accessible tumor sites. This review provides a brief overview of current cellular therapeutic strategies for solid tumors, research carried out to increase efficacy and safety, and results from ongoing clinical trials

Secondary malignancies after high-dose chemotherapy in germ cell tumor patients: A 34-year retrospective study of the European Society for Blood and Marrow Transplantation (EBMT)

We aimed to assess the incidence and risk factors of secondary malignancy (SM) in the young adult patients who received high-dose chemotherapy (HDCT) for germ cell tumors (GCT). The EBMT database was interrogated. Criteria for patient selection included adult male GCT and HDCT administered in any line of therapy. Cumulative incidence methods were used to estimate the time-to-SM diagnosis. Univariable Fine and Gray proportional hazard regression evaluated risk factors of SM occurrence. From 1981 to 2015, 9153 autografts were identified. Among 5295 patients, 59 cases of SM, developed after a median follow-up of 3.8 years, were registered. Of these patients, 23 (39%) developed hematologic SM, 34 (57.6%) solid SM (two patients had uncoded SM). Twenty-year cumulative incidence of solid versus hematologic SM was 4.17% (95% CI: 1.78-6.57) versus 1.37% (95% CI: 0.47-2.27). Median overall survival after SM was significantly shorter for patients who developed hematologic SM versus solid SM (8.6 versus 34.4 months, p = 0.003). Age older than 40 years at the time of HDCT was significantly associated with hematologic, but not solid, SM development (p = 0.004 versus p = 0.234). SM occurrence post-HDCT showed different patterns of incidence and mortality in GCT. These data may be important to optimize patient selection, counseling and follow-up after HDCT

Response to Immunosuppressive Treatment Predicts Outcome in Patients with Chronic Graft-versus-Host Disease: A Single-Center Analysis of Longitudinal Data

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