PEGylated siRNA lipoplexes for silencing of BLIMP-1 in Primary Effusion Lymphoma: In vitro evidences of antitumoral activity

Silencing of the B lymphocyte-induced maturation protein 1 (Blimp-1), a pivotal transcriptional regulator during terminal differentiation of B cells into plasma cells with siRNAs is under investigation as novel therapeutic approach in Primary Effusion Lymphoma (PEL), a HHV-8 related and aggressive B cell Lymphoma currently lacking of an efficacious therapeutic approach. The clinical application of small interfering RNA (siRNA) in cancer therapy is limited by the lack of an efficient systemic siRNA delivery system. In this study we aim to develop pegylated siRNA lipoplexes formed using the cationic lipid DOTAP and DSPE-PEG2000, capable to effectively stabilize anti-Blimp-1 siRNA and suitable for systemic administration. Two types of pegylated lipoplexes using a classic (C-PEG Lipoplexes) or a post-pegylation method (P-PEG-Lipoplexes) were formulated and compared in their physicochemical properties (size, zeta potential, morphology and structure) and efficiency on PEL cell lines. A stable siRNAs protection was obtained with post pegylation approach (2% molar of DSPE-PEG2000 with respect to lipid) resulting in structures with diameters of 300 nm and a complexation efficiency higher that 80% (0.08 nmol/10 nmol of lipid). In vitro studies on PEL cell lines suggested that empty liposomes were characterized by a low cell toxicity also after PEG modification (cell viability and cell density over 85% after treatment with 10 μM of lipid). We demonstrated that P-PEG-Lipoplexes were able to significantly reduce the levels of BLIMP-1 protein leading to reduction of viability (less that 15% after transfection with 100 nM of complexed siRNAs) and activation of apoptosis. In vitro efficiency encourages us to further test the in vivo potential of P-PEG-Lipoplexes in PEL therapy

Circulating functional T cells specific to human herpes virus 6 (HHV6) antigens in individuals with chromosomally integrated HHV6

Circulating functional T cells specific to human herpes virus 6 (HHV6) antigens in individuals with chromosomally integrated HHV

All-trans retinoic acid (ATRA) in non-promyelocytic acute myeloid leukemia (AML): results of combination of ATRA with low-dose Ara-C in three elderly patients with NPM1-mutated AML unfit for intensive chemotherapy and review of the literature

Based upon the clinical behavior of three patients, we suggest that the combination of low-dose Ara-C and all-trans retinoic acid may potentially be effective in some elderly patients, unfit for intensive chemotherapy, affected with NPM1-mutated acute myeloid leukemia without FLT3 mutations, warranting perspective clinical studies in these selected patients

The bone marrow represents an enrichment site of specific T lymphocytes against filamentous fungi

Bone marrow has already been described as an enrichment site for several antigen-specific T lymphocytes, but the presence of mould-specific T cells has never been investigated in the bone marrow. We have previously demonstrated that mould-specific T cells emerge in the peripheral blood of patients with invasive fungal infections (IFI) but tend to become undetectable after disease resolution. In seven patients with a history of IFI, we investigated the presence of mould-specific T cells secreting different cytokines in bone marrow and peripheral blood paired samples. The results showed that the frequencies of mould-specific T cells secreting the protective cytokine IFNI3 are significantly higher in bone marrow (BM) and are mainly represented by CD8+ T lymphocytes with effector phenotype. A putative disappearance of such protective BM responses after myeloablative therapy could contribute to the increased risk of IFI in hematologic patients

Characterization and dynamics of specific T cells against nucleophosmin-1 (NPM1)-mutated peptides in patients with NPM1-mutated acute myeloid leukemia

Nucleophosmin(NPM1)-mutated protein, a leukemia-specific antigen, represents an ideal target for AML immunotherapy. We investigated the dynamics of NPM1-mutated-specific T cells on PB and BM samples, collected from 31 adult NPM1-mutated AML patients throughout the disease course, and stimulated with mixtures of 18 short and long peptides (9-18mers), deriving from the complete C-terminal of the NPM1-mutated protein. Two 9-mer peptides, namely LAVEEVSLR and AVEEVSLRK (13.9-14.9), were identified as the most immunogenic epitopes. IFNγ-producing NPM1-mutated-specific T cells were observed by ELISPOT assay after stimulation with peptides 13.9-14.9 in 43/85 (50.6%) PB and 34/80 (42.5%) BM samples. An inverse correlation between MRD kinetics and anti-leukemic specific T cells was observed. Cytokine Secretion Assays allowed to predominantly and respectively identify Effector Memory and Central Memory T cells among IFNγ-producing and IL2-producing T cells. Moreover, NPM1-mutated-specific CTLs against primary leukemic blasts or PHA-blasts pulsed with different peptide pools could be expanded ex vivo from NPM1-mutated AML patients or primed in healthy donors. We describe the spontaneous appearance and persistence of NPM1-mutated-specific T cells, which may contribute to the maintenance of long-lasting remissions. Future studies are warranted to investigate the potential role of both autologous and allogeneic adoptive immunotherapy in NPM1-mutated AML patients

Prognostic Relevance of Multi-Antigenic Myeloma-Specific T-Cell Assay in Patients with Monoclonal Gammopathies

: Multiple Myeloma (MM) typically originates from underlying precursor conditions, known as Monoclonal Gammopathy of Undetermined Significance (MGUS) and Smoldering Multiple Myeloma (SMM). Validated risk factors, related to the main features of the clonal plasma cells, are employed in the current prognostic models to assess long-term probabilities of progression to MM. In addition, new prognostic immunologic parameters, measuring protective MM-specific T-cell responses, could help to identify patients with shorter time-to-progression. In this report, we described a novel Multi-antigenic Myeloma-specific (MaMs) T-cell assay, based on ELISpot technology, providing simultaneous evaluation of T-cell responses towards ten different MM-associated antigens. When performed during long-term follow-up (mean 28 months) of 33 patients with either MGUS or SMM, such deca-antigenic myeloma-specific immunoassay allowed to significantly distinguish between stable vs. progressive disease (p < 0.001), independently from the Mayo Clinic risk category. Here, we report the first clinical experience showing that a wide (multi-antigen), standardized (irrespective to patients' HLA), MM-specific T-cell assay may routinely be applied, as a promising prognostic tool, during the follow-up of MGUS/SMM patients. Larger studies are needed to improve the antigenic panel and further explore the prognostic value of MaMs test in the risk assessment of patients with monoclonal gammopathies

Nutlin-3 loaded nanocarriers: Preparation, characterization and in vitro antineoplastic effect against primary effusion lymphoma

In this investigation, Nutlin-3 (Nut3), a novel antitumor drug with low water solubility (<0.1mg/L at 25°C), was loaded into liposomes (Lipo-Nut3), polymeric nanoparticles (NPs-Nut3) and nanoparticles engineered with an antibody direct against Syndecan-1/CD 138 (Syn-NPs-Nut3) to obtain carriers targeted to PEL (primary effusion lymphoma). The physicochemical properties of these carriers were determined. Atomic force microscopy showed that all the particles were well formed and spherical in shape. The presence of the antibody on surface led to a significant increase of mean diameter (280 ± 63 nm), PDI (0.3) and the shift of zeta potential towards neutrality (-1 mV). The entrapment efficiency of Lipo-Nut3, NPs-Nut3 and Syn-NPs-Nut3 was 30, 52 and 29%, and drug loading was 1.4, 4.5 and 2.6%, respectively. By performing cytofluorimetric analyses and bromodeoxyuridine (BrdU) assay, the efficacy of nanocarriers to deliver the antineoplastic drug into a PEL cell line namely BCBL-1 (immortalized body cavity B-cell lymphoma) was investigated. Two days after the treatment with 20 μM of Syn-NPs-Nut3, the cell density decreased at about 60% while the cell viability decreased at 56% only 5 days after transfection, when compared with untreated cells. A cell cycle arrest was observed with a significant decrease of cells in S-phase and increasing of apoptotic cell, if compared with untreated control. These results confirms the potential of nanocarriers approaches to deliver antitumor drug with unfavorable chemico-physical properties. Moreover, this study strongly suggests that Syn-NPs-Nut3 can be a valuable drug carrier system for the treatment of PEL lymphoma

BCR-ABL-specific T-cell therapy in Ph+ ALL patients on tyrosine-kinase inhibitors

Although the emergence of bone marrow (BM)-resident p190BCR-ABL-specific T lymphocytes has been correlated with hematologic and cytogenetic remissions in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) undergoing maintenance tyrosine-kinase inhibitor treatment, little is known about the possibility of culturing these cells ex vivo and using them in T-cell therapy strategies. We investigated the feasibility of expanding/priming p190BCR-ABL-specific T cells in vitro by stimulation with dendritic cells pulsed with p190BCR-ABL peptides derived from the BCR-ABL junctional region and alternative splicing, and of adoptively administering them patients with relapsed disease. We report on the feasibility of producing clinical-grade BCR-ABL-specific cytotoxic T lymphocytes (CTLs), endowed with antileukemia activity, from Ph+ ALL patients and healthy donors. We treated 3 patients with Ph+ ALL with autologous or allogeneic p190BCR-ABL-specific CTLs. No postinfusion toxicity was observed, except for a grade II skin graft-versus-host disease in the patient treated for hematologic relapse. All patients achieved a molecular or hematologic complete remission (CR) after T-cell therapy, upon emergence of p190BCR-ABL-specific T cells in the BM. Our results show that p190BCR-ABL-specific CTLs are capable of controlling treatment-refractory Ph+ ALL in vivo, and support the development of adoptive immunotherapeutic approaches with BCR-ABL CTLs in Ph+ ALL