BackgroundResponses to influenza vaccines are poorly characterized in immunocompromised patients. The goal of this study was to assess the efficacy of the AS03-adjuvanted influenza H1N1/A/09 vaccine in allogeneic hematopoietic stem cell transplant recipients. Design and MethodsWe enrolled 65 patients and 138 controls in an open prospective study. Controls received one dose and patients 2 doses of the AS03-adjuvanted influenza H1N1/A/09 vaccine at a 3-week interval. Geometric mean titers and seroprotection/seroconversion rates were determined by hemagglutination inhibition before and four weeks after the last immunization. Clinical and biological markers, including immunoglobulins, CD3 + , CD4 + , CD8+ and naïve CD4 + T-cell counts were assessed in all patients. ResultsBaseline seroprotection rates were low in patients (6.6%) and controls (14.8%). After 2 doses, patients (n=57, 92.3%) achieved similar seroprotection rates (84% vs. 87%, P=0.65) and antibody titers (305 vs. 340, P=0.88) as controls (n=131, 93.9%) after one dose. In univariate analysis, transplant-to-vaccination interval less than 12 months, active graft-versus-host disease, immunosuppressive drugs, hemoglobin less than 12g/L, lymphopenia less than1G/L, IgG less than 4g/L, IgA less than 0.5g/L, IgM less than 0.5g/L and naive CD4 + T cells less than 150/mL were significantly associated with weaker responses. Multivariate analysis identified transplant-to-vaccination interval and active graft-versus-host disease as the most powerful negative predictors of antibody responses (P=0.04 and P=0.002, respectively). Vaccination was well tolerated in both cohorts. ConclusionsIn allogeneic hematopoietic stem cell transplant recipients, 2 doses of an adjuvanted influenza vaccine elicited comparable responses to a single dose in healthy individuals. However, vaccine responses remained poor in patients with ongoing graft-versus-host disease, supporting the need for additional strategies in this high-risk patient population. Graft-versus-host disease is the major determinant of humoral responses to the AS03-adjuvanted influenza A/09/H1N1 vaccine in allogeneic hematopoietic stem cell transplant recipients

It is critical to quantitatively analyse the developing human fetal brain in order to fully understand neurodevelopment in both normal fetuses and those with congenital disorders. To facilitate this analysis, automatic multi-tissue fetal brain segmentation algorithms are needed, which in turn requires open datasets of segmented fetal brains. Here we introduce a publicly available dataset of 50 manually segmented pathological and non-pathological fetal magnetic resonance brain volume reconstructions across a range of gestational ages (20 to 33 weeks) into 7 different tissue categories (external cerebrospinal fluid, grey matter, white matter, ventricles, cerebellum, deep grey matter, brainstem/spinal cord). In addition, we quantitatively evaluate the accuracy of several automatic multi-tissue segmentation algorithms of the developing human fetal brain. Four research groups participated, submitting a total of 10 algorithms, demonstrating the benefits the dataset for the development of automatic algorithms.

IntroductionEfficient delivery of genes into primary human B lymphocytes would allow the investigation of gene functions in these cells for the purposes of research and the development of gene therapies. One could then test in mature B cells the promoters/genes potentially suitable for stem cell-based therapies for immunodeficiencies. 1 Vectors achieving the efficient transfection of primary B cells would most likely also be suitable for the delivery of genes into freshly collected B tumor cells-for example, for the development of immune-based anti-B-tumor therapies. 2 Various viral vectors are currently being studied for their ability to transduce hematopoietic cells. [3][4][5] Retroviral vectors derived from murine leukemia virus (MLV) 6,7 can transfer genes into immortal human B-cell lines, such as lymphoblastoid cells, 8 and primary B precursors, 9 but they are inefficient for mature human B cells. 10,11 These simple retroviruses can transduce genes only into actively dividing cells, 12 but a potent T-independent mitogen for human B cells in vitro, such as lipopolysaccharide (LPS) for murine B cells, has not been found. 13 In addition, MLV vectors might not be well adapted for human B cells because of the host species difference. HIV-1 and HIV-derived pseudotyped lentiviral vectors efficiently integrate into human cells, irrespective of cell division. 14-22 High transgene expression from such vectors in human T cells or total lymphocytes has been reported. [23][24][25] Generally, productive HIV infection or lentivectormediated transduction of truly quiescent lymphocytes has not been observed; activation, at least from G 0 to G 1 , seems to be required. 23,[25][26][27][28] Efficient transduction of primary acute lymphoblastic leukemia cells with a bicistronic HIV vector, leading to the expression of a cytokine (granulocyte macrophage-colonystimulating factor [GM-CSF]) and an immunostimulatory molecule (CD80), has also been achieved, 29 indicating a potential use of such vectors in novel anti-B-tumor therapies.In this study we investigated the transduction of peripheral blood B cells with multiply attenuated HIV vectors pseudotyped with vesicular stomatitis virus (VSV) G glycoprotein. 21 Efficient transduction of such B cells occurred after their activation in a culture system using murine EL-4 B5 thymoma cells as helper T cells in conjunction with human cytokines. [30][31][32][33] This system leads to proliferation and subsequent plasmocytic differentiation of all naive and memory human B subsets. 33 Nondividing, freshly isolated multiple myeloma cells were also efficiently transduced by HIV vector. By contrast, an MLV vector pseudotyped with VSV G protein was inefficient even in dividing B cells. F.B. and P.S. contributed equally to this work. D.T. has declared a financial interest as consultant to Cell Genesis, a company whose potential product is related to the HIV-1 vectors used in this study.Reprints: R. Zubler, Division of Hematology, University Hospital, 1211 Geneva-14, Switzerland; e-mail: rudolf.zubl...

Summary. Differentiation of B lymphocytes into plasma cells is regulated by the interaction of distinct transcription factors (TFs) which activate gene expression in a lineage‐ and stage‐specific pattern. Using reverse transcription polymerase chain reaction, we studied the expression of five TFs (octamer binding factor oct‐2, ets family members PU.1 and Spi‐B, pax gene family member BSAP, and Blimp‐1) in (1) human cell lines with a plasma cell phenotype, (2) primary malignant plasma cells [obtained from patients with plasma cell leukaemia (PCL) and multiple myeloma], and (3) normal human plasma cells generated in vitro or isolated from normal bone marrows. The expression pattern was compared with TFs expressed by normal CD19+ B lymphocytes and by B cells from chronic lymphocytic leukaemia patients. Our results showed that plasma cells expressed a restricted set of TFs compared with CD19+ B lymphocytes, with continued expression of Spi‐B and oct‐2, increased Blimp‐1 expression, and downregulation of BSAP and PU.1. Cells from PCL lost Spi‐B and PU.1 expression completely and expressed only oct‐2 and Blimp‐1, and thus resembled plasma cell lines. Human plasma cell differentiation therefore seems to be positively regulated by Blimp‐1; whether this TF has any oncogenic potential will have to be analysed in future studies.

Follicle center lymphoma (FCL) is an indolent B cell non-Hodgkin's lymphoma (NHL) characterized genetically by the t(14;18) translocation. Histological transformation and clinical progression of FCLs are frequently associated with secondary genetic alterations at both nucleic acid and chromosomal levels. To determine the type and pattern of genomic instability occurring in histological transformation of FCLs and the role of DNA mismatch repair defects in this procedure, we have performed microsatellite analysis, comparative genomic hybridization (CGH) and mutational analysis of hMLH1 and hMSH2 genes on serial biopsy specimens from patients with FCL transformed to diffuse large cell lymphoma (DLCL). Paired biopsy samples of eight patients were analyzed for microsatellite instability and structural alterations for hMLH1 and hMSH2 genes, and tumor samples of five patients were subjected to CGH analysis. A high level of microsatellite instability was associated with histological transformation of two cases of FCL, but no mutations of the hMLH1 and hMSH2 genes were detected in any of the lymphoma samples. In the five cases subjected to CGH analysis, the histological transformation of FCLs was associated with genomic imbalances at 21 chromosomal regions. The genomic abnormalities found were rather heterogeneous and none of the genetic changes were overrepresented in the transformed DLCLs. These data suggest that histological transformation of FCLs to DLCL is frequently associated with genome wide instability at both nucleic acid and chromosomal levels, although mutations of the hMSH1 and hMLH2 genes are not involved in this process. Leukemia (2000) 14, 2142-2148.