Effect of mTORC1/mTORC2 inhibition on T cell function: potential role in graft-versus-host disease control

Producción CientíficaThe mechanistic target of rapamycin (mTOR) pathway is crucial for the activation and function of T cells, which play an essential role in the development of graft-versus-host disease (GvHD). Despite its partial ability to block mTOR pathway, the mTORC1 inhibitor rapamycin has shown encouraging results in the control of GvHD. Therefore, we considered that simultaneous targeting of both mTORC1 and mTORC2 complexes could exert a more potent inhibition of T cell activation and, thus, could have utility in GvHD control. To assess this assumption, we have used the dual mTORC1/mTORC2 inhibitors CC214-1 and CC214-2. In vitro studies confirmed the superior ability of CC214-1 versus rapamycin to block mTORC1 and mTORC2 activity and to reduce T cell proliferation. Both drugs induced a similar decrease in Th1/Th2 cytokine secretion, but CC214-1 was more efficient in inhibiting na€ıve T cell activation and the expression of Tcell activation markers. In addition, CC214-1 induced specific tolerance against alloantigens, while preserving anti-cytomegalovirus response. Finally, in a mouse model of GvHD, the administration of CC214-2 significantly improved mice survival and decreased GvHD-induced damages. In conclusion, the current study shows, for the first time, the immunosuppressive ability of CC214-1 on T lymphocytes and illustrates the role of CC214-2 in the allogeneic transplantation setting as a possible GvHD prophylaxis agent.Gerencia Regional de Salud de Castilla y León (Proyecto GRS 726/A13

Mesenchymal stromal cells (MSC) from JAK2+ myeloproliferative neoplasms differ from normal MSC and contribute to the maintenance of neoplastic hematopoiesis

[EN]There is evidence of continuous bidirectional cross-talk between malignant cells and bone marrow-derived mesenchymal stromal cells (BM-MSC), which favors the emergence and progression of myeloproliferative neoplastic (MPN) diseases. In the current work we have compared the function and gene expression profile of BM-MSC from healthy donors (HDMSC) and patients with MPN (JAK2V617F), showing no differences in the morphology, proliferation and differentiation capacity between both groups. However, BM-MSC from MPN expressed higher mean fluorescence intensity (MIF) of CD73, CD44 and CD90, whereas CD105 was lower when compared to controls. Gene expression profile of BM-MSC showed a total of 169 genes that were differentially expressed in BM-MSC from MPN patients compared to HD-MSC. In addition, we studied the ability of BM-MSC to support the growth and survival of hematopoietic stem/progenitor cells (HSPC), showing a significant increase in the number of CFU-GM colonies when MPN-HSPC were co-cultured with MPN-MSC. Furthermore, MPN-MSC showed alteration in the expression of genes associated to the maintenance of hematopoiesis, with an overexpression of SPP1 and NF-kB, and a downregulation of ANGPT1 and THPO. Our results suggest that BM-MSC from JAK2+ patients differ from their normal counterparts and favor the maintenance of malignant clonal hematopoietic cell

Historia de la RAMSA. 50º aniversario (1971-2021)

Libro conmemorativo de los 50 años de existencia de la Real Academia de Medicina de Salamanca, donde se recogen todas las actividades llevadas a cabo durante ese tiempo, los premios concedidos, los miembros elegidos, etc., así como se gestó su nacimiento en el contexto de la existencia de otras academias médicas.Universidad de Salamanc

Next Generation Flow for highly sensitive and standardized detection of minimal residual disease in multiple myeloma

[EN]Flow cytometry has become a highly valuable method to monitor minimal residual disease (MRD) and evaluate the depth of complete response (CR) in bone marrow (BM) of multiple myeloma (MM) after therapy. However, current flow-MRD has lower sensitivity than molecular methods and lacks standardization. Here we report on a novel next generation flow (NGF) approach for highly sensitive and standardized MRD detection in MM. An optimized 2-tube 8-color antibody panel was constructed in five cycles of design-evaluation-redesign. In addition, a bulk-lysis procedure was established for acquisition of ⩾107 cells/sample, and novel software tools were constructed for automatic plasma cell gating. Multicenter evaluation of 110 follow-up BM from MM patients in very good partial response (VGPR) or CR showed a higher sensitivity for NGF-MRD vs conventional 8-color flow-MRD -MRD-positive rate of 47 vs 34% (P=0.003)-. Thus, 25% of patients classified as MRD-negative by conventional 8-color flow were MRD-positive by NGF, translating into a significantly longer progression-free survival for MRD-negative vs MRD-positive CR patients by NGF (75% progression-free survival not reached vs 7 months; P=0.02). This study establishes EuroFlow-based NGF as a highly sensitive, fully standardized approach for MRD detection in MM which overcomes the major limitations of conventional flow-MRD methods and is ready for implementation in routine diagnostics.This work has been supported by the International Myeloma Foundation-Black Swan Research Initiative, the Red Temática de Investigación Cooperativa en Cáncer (RTICC); grant SA079U14 from the Consejería de Educación, Junta de Castilla y León, Valladolid, Spain and; grant DTS15/00119 from Instituto de Salud Carlos III, Ministerio de Economía y Competitividad, Madrid, Spain

Minimal residual disease in adolescent (older than 14 years) and adult acute lymphoblastic leukemias: early immunophenotypic evaluation has high clinical value

Se trata de un trabajo que demostró por primera vez que la citometría de flujo es una excelen-te metodología para analizar la enfermedad residual mínima en la leucemia aguda linfoblástica. Hasta entonces sólo se había usado la PCR alelo-específica y a partir de ahí se dio pie a su uso en muchos ensayos, algo que ha ocurrió de forma sistemática en nuestro país desde la publicación este trabajo.[EN]Investigation of minimal residual disease (MRD) in acute leukemias by immunophenotyping and/or molecular techniques is proving to be increasingly valuable for disease monitoring. In acute lymphoblastic leukemia (ALL), most MRD studies have focused on children, whereas in contrast, information on the value of MRD on adult ALL is scanty, and almost exclusively restricted to polymerase chain reaction (PCR) studies. Early response to therapy is one of the most important prognostic factors in acute leukemia, which prompted us to investigate whether or not early immunophenotypic assessment of MRD could also be a valuable tool for predicting relapse in adult patients with ALL. For that purpose we have analyzed the level of MRD during the initial phase of treatment (induction phase) by multiparameter flow cytometry in a series of 102 adolescent (older than 14 years) and adult patients with ALL. Immunophenotypic evaluation of the bone marrow (BM) at day +35 showed that patients with low MRD levels (< 0.05% leukemia-associated phenotype [LAP+] cells) had a significantly longer relapse-free survival (RFS) than patients with high MRD levels, and this prognostic influence was retained when only those patients in morphologic complete remission (mCR) at day +35 were considered (median RFS: 42 months vs 16 months; P =.001). Moreover, immunophenotyping helped to identify a small subset of patients (n = 12) with negative or low MRD levels (< 0.03% LAP+ cells) by day +14, with an excellent prognosis (projected RFS of 90% at 5 years). The contrary is true of patients who achieved late mCR (after day +35), since immunophenotypic investigation of MRD showed that, in spite of the mCR, none of the cases with more than 0.1% LAP+ cells would be relapse-free after 2 years. Multivariate analysis showed that the immunologic evaluation of MRD at day +35 was the most relevant independent prognostic parameter for adult patients with ALL, and together with age, white blood cell (WBC) count at diagnosis, and presence of the Philadelphia (Ph) chromosome, represented the most informative combination of variables for predicting relapse-free survival.Hospital Universitario de Salamanca Universidad de SalamancaHospital Universitario de Salamanc

Mesenchymal Stromal Cell Irradiation Interferes with the Adipogenic/Osteogenic Differentiation Balance and Improves Their Hematopoietic-Supporting Ability

[EN]Bone marrow mesenchymal stromal cells (MSCs) are precursors of adipocytes and osteoblasts and key regulators of hematopoiesis. Irradiation is widely used in conditioning regimens. Although MSCs are radioresistant, the effects of low-dose irradiation on their behavior have not been extensively explored. Our aim was to evaluate the effect of 2.5 Gy on MSCs. Cells from 25 healthy donors were either irradiated or not (the latter were used as controls). Cells were characterized following International Society for Cellular Therapy criteria, including in vitro differentiation assays. Apoptosis was evaluated by annexin V/7-amino-actinomycin staining. Gene expression profiling and reverse transcriptase (RT)-PCR of relevant genes was also performed. Finally, long-term bone marrow cultures were performed to test the hematopoietic-supporting ability. Our results showed that immunophenotypic characterization and viability of irradiated cells was comparable with that of control cells. Gene expression profiling showed 50 genes differentially expressed. By RT-PCR, SDF-1 and ANGPT were overexpressed, whereas COL1A1 was downregulated in irradiated cells (P = .015, P = .007, and P = .031, respectively). Interestingly, differentiation of irradiated cells was skewed toward osteogenesis, whereas adipogenesis was impaired. Higher expression of genes involved in osteogenesis as SPP1 (P = .039) and lower of genes involved in adipogenesis, CEBPA and PPARG (P = .003 and P = .019), together with an increase in the mineralization capacity (Alizarin Red) was observed in irradiated cells. After differentiation, adipocyte counts were decreased in irradiated cells at days 7, 14, and 21 (P = .018 P = .046, and P = .018, respectively). Also, colony-forming unit granulocyte macrophage number in long-term bone marrow cultures was signifi- cantly higher in irradiated cells after 4 and 5 weeks (P = .046 and P = .007). In summary, the irradiation of MSCs with 2.5 Gy improves their hematopoietic-supporting ability by increasing osteogenic differentiation and decreasing adipogenesis