Human Wharton's jelly-derived mesenchymal stromal cells engineered to secrete Epstein-Barr virus interleukin-10 show enhanced immunosuppressive properties.

BACKGROUND AIMS: Mesenchymal stromal cells (MSCs) modulate the immune response and represent a potential treatment for inflammatory and autoimmune diseases. We hypothesized that this feature could be potentiated by co-administering anti-inflammatory cytokines. In this article, we asked whether engineering of Wharton Jelly-derived human MSCs (WJ-hMSCs) to express an anti-inflammatory cytokine increases cell immunomodulatory properties without altering their native features. METHODS: We used Epstein-Barr virus-derived interleukin-10 (vIL-10), which shares some immunosuppressive properties with human IL-10 but lacks immunostimulatory activity. Engineering was accomplished by transducing WJ-hMSCs with a self-inactivating feline immunodeficiency virus-derived vector co-expressing vIL-10 and herpes simplex virus type-1 thymidine kinase (TK). TK was added to allow future tracking of WJ-hMSC in vivo by positron electron tomography (PET). RESULTS: The results show that (i) expression of TK and/or vIL-10 does not change WJ-hMSC phenotypic and functional properties; (ii) vIL-10 is secreted, biologically active and enhances the immunosuppressing functions of WJ-hMSCs; (iii) v-IL10 and TK can be produced simultaneously by the same cells and do not interfere with each other. DISCUSSION: WJ-hMSCs engineered to secrete vIL-10 could be a powerful tool for adoptive cell therapy of immune-mediated diseases, and therefore, additional studies are warranted to confirm their efficacy in suitable animal disease models.

Characterization of free-standing PEDOT:PSS/iron oxide nanoparticle composite thin films and application as conformable humidity sensors.

In this study, a new simple, fast, and inexpensive technique for the preparation of free-standing nanocomposite ultrathin films based on the conductive polymer poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) and embedding iron oxide nanoparticles (NPs) is presented. These nanofilms were fabricated by a single step of spin-coated assisted deposition in conjunction with a release technique ("supporting layer technique") to detach them from the substrate. Free-standing nanofilms can be easily transferred onto several substrates due to their high conformability, preserving their functionalities. The effect of the addition of iron oxide nanoparticles on the structural and functional properties of the PEDOT:PSS nanofilms is investigated through topography, thickness, magnetic, magneto-optical activity, and conductivity characterizations. PEDOT:PSS and PEDOT:PSS/iron oxide NP nanofilms were tested as resistive humidity sensors. Their sensitivity to humidity was found to increase with increasing nanoparticle concentration. On the basis of these results, it is expected that these composites may furnish inexpensive and reliable means for relative humidity detection.

The role of anti-HLA antibodies in hematopoietic stem cell transplantation.

Donor-specific antihuman leukocyte antigen antibodies (DSHA) have been clearly implicated in graft rejection in solid organ transplantation. Their role in allogeneic hematopoietic stem-cell transplantation (allo-HSCT) remains unclear. We summarize here evidence supporting a role for DSHA in graft failure in animal models of allo-HSCT and in clinical settings whenever no full HLA matching occurs.

Aberrant expression of CD8 in B-cell non-Hodgkin lymphoma: a multicenter study of 951 bone marrow samples with lymphomatous infiltration.

T-cell antigen expression can be observed in B-cell non-Hodgkin lymphoma (B-NHL). Although CD5 is expressed in B-cell chronic lymphocytic leukemia (B-CLL) and mantle cell lymphoma, the presence of other T-cell antigens is less common. This article reports a retrospective multicenter analysis in which flow cytometry was used to evaluate aberrant CD8 expression on the pathologic B cells of 951 bone marrow samples from patients with various types of B-NHL. In a total of 18 patients, CD8 was coexpressed: 10 had B-CLL; 1, small lymphocytic lymphoma (SLL); 1, marginal zone lymphoma; 1, lymphoplasmacytic lymphoma; 2, diffuse large B-cell lymphoma; and 3, follicular lymphoma. There was a 1.89% overall frequency of CD8 coexpression in which B-CLL/SLL had a higher frequency (3.03%) than did the other B-cell neoplasms (1.18%). Most cases were characterized by a favorable outcome.

Meningeal relapse in a case of B acute lymphoblastic leukemia: the role of CD56 expression.

BACKGROUND: Blasts from B acute lymphoblastic leukemia (B-ALL) may express CD56 in about 10% of cases. The presence of this marker at diagnosis is associated with an increased risk of meningeal relapse. A case is described of B-ALL which was CD56 negative at diagnosis, and expressed this marker when isolated meningeal relapse was diagnosed. CASE REPORT: A 53-year-old female patient presented with neurological symptoms during maintenance therapy for B-ALL. Peripheral blood, bone marrow, and cerebrospinal fluid (CSF) were subjected to both morphological and flow cytometric analyses. The latter was carried out by a wide routine panel of MoAbs which was the same as the one at diagnosis and included CD56. Isolated meningeal relapse was diagnosed since blast cell infiltration was detected in the CSF, but not in the peripheral blood and bone marrow samples. Blast cells showed an immunological phenotype similar to that at diagnosis (cyCD79a+, CD79b+, CD19+, CD22+, CD34+, CD10+, CD20+), but characterized by the acquisition of CD56 on the surfaces of more than 90% of cells. CONCLUSIONS: This case shows that CD56 can be expressed at relapse of B-ALL and that its presence likely enables leukemic cell binding to the central nervous system (CNS). This phenomenon may be responsible for the isolated CNS relapse diagnosed in this patient.

CD45 expression in low-grade B-cell non-Hodgkin's lymphomas.

CD45 is a glycoprotein expressed in all lymphohemopoietic cells. Its expression increases during B-lymphocyte ontogeny. Few data are available about CD45 expression in the various types of low-grade B-cell non-Hodgkin's lymphomas (NHL). Low levels of CD45 have been reported in pathologic lymphocytes from typical chronic lymphocytic leukemia (CLL) and higher levels of this antigen have been observed in some cases of atypical CLL and in some cases of other types of NHL. One hundred and seven bone marrow samples of NHL with bone marrow infiltration were investigated: 45 typical CLL, 15 atypical CLL, 9 mantle cell lymphomas (MCL), 1 MCL with CD23 expression, 18 marginal zone lymphomas (MZL), 6 lymphoplasmacytic lymphomas (LPL), 6 follicular lymphomas (FL), and 7 hairy cell leukemias (HCL). CD45 expression was evaluated by flow cytometry: pathologic lymphocytes were identified on the basis of specific immunophenotypic profile, CD19/K or CD19/lambda co-expression. Results were expressed as median fluorescence intensity (MFI) along a 1024 linear scale. CD45 expression was measured also on autologous T-lymphocytes and a "CD45 index" was calculated as the ratio MFI of pathologic B-lymphocytes/MFI of T-lymphocytes, to normalize the results obtained. We found four CD45 expression patterns: very low in typical CLL; relatively low in MCL; intermediate intensity in MZL, LPL, and FL; very high expression in HCL. Among the atypical cases, very high CD45 expression was found in one case of CD23-negative CLL, in CD23-positive MCL, and CLL with atypical morphology. The results indicate different levels of maturation in low-grade NHL and may help to characterize such neoplasias.

Actin polymerization in neutrophils from donors of peripheral blood stem cells: divergent effects of glycosylated and nonglycosylated recombinant human granulocyte colony-stimulating factor.

Neutrophil functions can be modified by Recombinant human G-CSF (rhG-CSF) treatment, with divergent effects on phagocytosis, motility, bactericidal activity, and surface molecule expression. Neutrophil morphology is modified by treatment with filgrastim (the nonglycosylated form of rhG-CSF), while it is not affected by lenograstim (the glycosylated type of rhG-CSF). Little information is available about actin polymerization in neutrophils from subjects treated with the two types of rhG-CSF. In the current paper we evaluated two groups of donors of peripheral blood stem cells (PBSC) for allogeneic transplantation. Ten subjects were treated with filgrastim and 10 with lenograstim to mobilize PBSC; 15 blood donors were evaluated as a control group. Actin polymerization (both spontaneous and fMLP-stimulated) was studied by a flow cytometric assay. A microscopic fluorescent assay was also carried out to evaluate F-actin distribution in neutrophils. We found that filgrastim induced an increased F-actin content in resting neutrophils, along with morphologic evidence for increased actin polymerization distributed principally at the cell membrane and frequently polarized in focal areas; in addition, fMLP was not able to induce further actin polymerization. On the contrary, treatment with lenograstim was associated with F-actin content, distribution, and polymerization kinetics indistinguishable from those displayed by control neutrophils. Such experimental results show that filgrastim and lenograstim display divergent effects also on neutrophil actin polymerization and provide further explanation for previous experimental findings.

[Bone marrow infiltration in B-cell non-Hodgkin's lymphomas: comparison between flow cytometry and bone marrow biopsy]. / Infiltrazione midollare nei linfomi non-Hodgkin a B-cellule: confronto tra citofluorimetria e biopsia osteomidollare.

A comparison of flow cytometry (FC) and bone marrow biopsy (BMB) to evaluate bone marrow infiltration was made in 114 patients suffering from B-cell non-Hodgkin's lymphomas (NHLs; 51 at diagnosis, 63 during post-therapy follow-up). The following parameters were indicative of bone marrow infiltration: altered surface k/l ratio; specific immunophenotypic pattern in particular NHLs (CLL, mantle cell lymphoma, hairy cell leukemia). FC and BMB agreed in 89.5% of cases (i.e. both showed 48 positive and 54 negative cases). In discordant cases (7.9%) and in cases not evaluable by FC (2.6%) IgH rearrangement and bcl-1 gene expression, both evaluated by PCR methods, were used to detect bone marrow infiltration with higher precision. These results show that a more complex analysis of bone marrow is needed to diagnose bone marrow infiltration, particularly in samples with minimal residual disease.