Jean-Louis Beaumont

Etablissement Français du Sang (EFS), Lutetia Parisorum, Île-de-France, France

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Publications (4)34.49 Total impact

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    Blood 10/2014; 124(16):2613-4. DOI:10.1182/blood-2014-06-582122 · 10.45 Impact Factor
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    ABSTRACT: Donor T cells play a pivotal role in the graft-versus-tumor effect after allogeneic hematopoietic stem cell transplantation. Regulatory T cells (T(reg)s) may reduce alloreactivity, the major component of the graft-versus-tumor effect. In the setting of donor lymphocyte infusion after hematopoietic stem cell transplantation, we postulated that T(reg) depletion could improve alloreactivity and likewise the graft-versus-tumor effect of donor T cells. The safety and efficacy of T(reg)-depleted donor lymphocyte infusion was studied in 17 adult patients with malignancy relapse after hematopoietic stem cell transplantation. All but one had previously failed to respond to at least one standard donor lymphocyte infusion, and none had experienced graft-versus-host disease. Two of the 17 patients developed graft-versus-host disease after their first T(reg)-depleted donor lymphocyte infusion and experienced a long-term remission of their malignancy. Four of the 15 patients who did not respond after a first T(reg)-depleted donor lymphocyte infusion received a second T(reg)-depleted donor lymphocyte infusion combined with lymphodepleting chemotherapy aimed to also eliminate recipient T(reg)s. All four developed acute-like graft-versus-host disease that was associated with a partial or complete and durable remission. In the whole cohort, graft-versus-host disease induction through T(reg) depletion was associated with improved survival. These results suggest that T(reg)-depleted donor lymphocyte infusion is a safe, feasible approach that induces graft-versus-host or graft-versus-tumor effects in alloreactivity-resistant patients. In patients not responding to this approach, the combination of chemotherapy-induced lymphodepletion of the recipient synergizes with the effect of T(reg)-depleted donor lymphocyte infusion. These findings offer a rational therapeutic approach for cancer cellular immunotherapy.
    Science translational medicine 07/2010; 2(41):41ra52. DOI:10.1126/scitranslmed.3001302 · 15.84 Impact Factor
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    ABSTRACT: Regulatory T cells (Treg) play a pivotal role in the control of graft-versus-host disease (GVHD) and might also influence the graft-versus-tumor effect after allogeneic stem cell transplantation. We assessed this role after donor lymphocyte infusions (DLIs) by quantifying Treg in DLI products, using the CD25, Foxp3 but also the recently identified CD127 Treg markers. Compared with others, patients in durable complete remission of their malignancy after DLI had received a lower number of FoxP3CD25, FoxP3CD127, or CD4CD127 Treg cells (P=0.04). The CD4CD127 Treg content of DLI remained significantly correlated with the hematologic response in multivariate analysis (P=0.05). Treg may thus inhibit graft-versus-tumor effect after DLI, a setting where the antitumoral effect observed is only driven by T-cell-mediated cytotoxicity, independently of any other associated treatment. In comparison with the intracytoplasmic Foxp3 marker, the membranous CD4CD127 phenotype of Treg could be particularly relevant to manipulate this cell-population, to increase the antitumoral response in strategies of allogeneic or autologous immunotherapy.
    Journal of immunotherapy (Hagerstown, Md.: 1997) 11/2008; 31(9):806-11. DOI:10.1097/CJI.0b013e318184908d · 4.01 Impact Factor
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    ABSTRACT: An excess of mixed-handedness has been repeatedly reported in schizophrenia and schizotypy. Handedness is a measure of atypical cerebral lateralization, which is considered as a risk factor for schizophrenia. Several studies have attempted to identify correlations between handedness and dimensions of psychosis but the results obtained so far remain inconclusive. To explore a possible link between mixed-handedness and the three classical dimensions of psychosis. As speech and language disorders may be associated with cerebral lateralization, we predicted a correlation between mixed-handedness and disorganized dimension. We used the Schizotypal Personality Questionnaire (SPQ) and the Edinburgh Handedness Inventory (EHI) to study the correlation between mixed-handedness scores and positive, negative or disorganized dimensions in a sample of 62 healthy subjects. We found a negative correlation between mixed-handedness and the disorganized dimension of schizotypy, as individuals with prominent mixed-handedness showed more severe disorganization. We have identified a link between mixed-handedness and the disorganized dimension that may help to identify genetic vulnerability factors involved in psychosis.
    The World Journal of Biological Psychiatry 04/2007; 9(2):121-5. DOI:10.1080/15622970701218679 · 4.18 Impact Factor