1,720,986 research outputs found
High frequency of CD8+/CD28- cells expressing CD30, CD70 and KIR antigens in chronic lymphocytic leukemia may reflect expansion of chronically activated memory cells impaired in immune recognition.
No full textSurvival and Immunosuppression Induced by Hepatocyte Growth Factor in Chronic Lymphocytic Leukemia
No full textChronic lymphocytic leukemia (CLL), the most common leukemia among adults in the western world, is characterized by a progressive accumulation of relatively mature CD5+ B cells in peripheral blood, lymph nodes and bone marrow. Despite much recent advancement in therapy, CLL is still incurable. Lymph nodes and bone marrow represent sanctuary sites preserving leukemic cells from spontaneous or drug-induced apoptosis, and infiltration of leukemic cells in these districts correlates with clinical stages and prognosis. The central role played by the microenvironment in the disease has become increasingly clear. Different chemokines (CXCL12, CXCL13, CCL19, CCL21) may in fact participate in attracting CLL cells into bone marrow and lymph nodes, where various factors, such as IL-15 and CXCL12, enhance leukemic cells survival. Recently, we have suggested that hepatocyte growth factor (HGF), produced by microenviromental stromal cells, can contribute to CLL pathogenesis. We have demonstrated that HGF exerts a double effect on CLL B cells through the interaction with its receptor c-MET; HGF, infact, protects CLL B cells, which are c-MET+, from apoptosis, and also polarizes mono/macrophages towards the M2 phenotype, thus facilitating the evasion of the CLL clone from immune control. This double effect, appears mediated by the activation of two major signaling pathways: STAT3TYR705 and AKT. The aim of this review is to summarize data on HGF and c-MET expression in normal B cells and in B cell malignancies, with a particular emphasis on our results obtained in the CLL. Altogether, the observations described here suggest that the HGF/c-MET axis may have a prominent role in malignancy progression further indicating novel potential therapeutic options aimed to block HGF-induced signaling pathways in B lymphoproliferative disorders
The administration of demethylfruticulin A from Salvia corrugata to mammalian cells lines induces‘‘anoikis’’, a special form of apoptosis
No full textRecently demethyl fruticulin A was identified as the major diterpenoid component of the exudates produced by the trichomes of Salvia corrugata leafs. Given the documented apoptotic effects of some of the other known components of the exudates from Salvia species, we assessed if demethyl fruticulin A, once administered to mammalian cells, was involved in the onset of apoptosis and if its biological effects were exerted through the participation of a scavenger membrane receptor, CD36. Three model cell lines were chosen, one of which lacking CD36 expression. Functional availability of the receptor, or its transcriptional rate, were blocked/reduced with a specific antibody or by the administration of vitamin E. Immunodetection of cell cytoskeletal components and tunel analysis revealed that demethyl fruticulin A triggers the onset of anoikis, a special form of apoptosis induced by cell detachment from the substrate. Impairment of CD36 availability/transcription confirmed the receptor partial involvement in the intake of the substance and in anoikis, as also sustained by FACS analysis and by the downregulation of p95, a marker of anoikis, upon blockade of CD36 transcription. However, experiments with CD36-deficient cells suggested that alternate pathways, still to be determined, may take part in the biological effects exerted by demethyl fruticulin A
Resistence to CD95-mediated apoptosis of CD40-activated chronic lymphocytic leukemia B cells is not related to lack of DISC molecules expression.
No full textIn chronic lymphocytic leukemia nurse-like cells are targeted by Hepatocyte Growth Factor produced by bone mesenchymal stromal cells
No full textMagnetic resonance imaging at 1.5 T with immunospecific contrast agent in vitro and in vivo in a xenotransplant model.
No full textOBJECT:
Demonstrating the feasibility of magnetic resonance imaging (MRI) at 1.5 T of ultrasmall particle iron oxide (USPIO)-antibody bound to tumor cells in vitro and in a murine xenotransplant model.
METHODS:
Human D430B cells or Raji Burkitt lymphoma cells were incubated in vitro with different amounts of commercially available USPIO-anti-CD20 antibodies and cell pellets were stratified in a test tube. For in vivo studies, D430B cells and Raji lymphoma cells were inoculated subcutaneously in immunodeficient mice. MRI at 1.5 T was performed with T1-weighted three-dimensional fast field echo sequences (17/4.6/13 degrees ) and T2-weighted three-dimensional fast-field echo sequences (50/12/7 degrees ). For in vivo studies MRI was performed before and 24 h after USPIO-anti-CD20 administration.
RESULTS:
USPIO-anti-CD20-treated D430B cells, showed a dose-dependent decrease in signal intensity (SI) on T2*-weighted images and SI enhancement on T1-weighted images in vitro. Raji cells showed lower SI changes, in accordance to the fivefold lower expression of CD20 on Raji with respect to D430B cells. In vivo 24 h after USPIO-anti-CD20 administration, both tumors showed an inhomogeneous decrease of SI on T2*-weighted images and SI enhancement on T1-weighted images.
CONCLUSIONS:
MRI at 1.5 T is able to detect USPIO-antibody conjugates targeting a tumor-associated antigen in vitro and in vivo
IL4 production and increased CD30 expression by a unique CD8+ T-cell subset in B-cell chronic lymphocytic leukaemia
No full text
Phenotypic analysis of hairy cell leukemia: "Variant" cases express the interleukin 2 receptor b chain, but not the a chain (CD25).
No full textImmunotoxins containing saporin linked to different CD2 monoclonal antibodies: in vitro evaluation.
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