An Improved Protocol for Efficient Engraftment in NOD/ LTSZ-SCIDIL-2RcNULL Mice Allows HIV Replication and Development of Anti-HIV Immune Responses

in PLoS ONE (2012), 7(6), 38491

Cord blood hematopoietic progenitor cells (CB-HPCs) transplanted immunodeficient NOD/LtsZ-scidIL2Rcnull (NSG) and NOD/SCID/IL2Rcnull (NOG) mice need efficient human cell engraftment for long-term HIV-1 ... [more ▼]

Cord blood hematopoietic progenitor cells (CB-HPCs) transplanted immunodeficient NOD/LtsZ-scidIL2Rcnull (NSG) and NOD/SCID/IL2Rcnull (NOG) mice need efficient human cell engraftment for long-term HIV-1 replication studies. Total body irradiation (TBI) is a classical myeloablation regimen used to improve engraftment levels of human cells in these humanized mice. Some recent reports suggest the use of busulfan as a myeloablation regimen to transplant HPCs in neonatal and adult NSG mice. In the present study, we further ameliorated the busulfan myeloablation regimen with fresh CB-CD34+cell transplantation in 3–4 week old NSG mice. In this CB-CD34+transplanted NSG mice engraftment efficiency of human CD45+cell is over 90% in peripheral blood. Optimal engraftment promoted early and increased CD3+T cell levels, with better lymphoid tissue development and prolonged human cell chimerism over 300 days. These humanized NSG mice have shown long-lasting viremia after HIV-1JRCSF and HIV-1Bal inoculation through intravenous and rectal routes. We also saw a gradual decline of the CD4+T cell count, widespread immune activation, up-regulation of inflammation marker and microbial translocation after HIV-1 infection. Humanized NSG mice reconstituted according to our new protocol produced, moderate cellular and humoral immune responses to HIV-1 postinfection. We believe that NSG mice reconstituted according to our easy to use protocol will provide a better in vivo model for HIV-1 replication and anti-HIV-1 therapy trials. [less ▲]

CHIC cells: a novel ALK+ cell line derived from a relapsed anaplastic large cell lymphoma

in British Journal of Haematology (2011), 152

Since the initial description of anaplastic large cell lymphoma (ALCL) as a proliferation of large CD30+ lymphoid cells, the morphological spectrum of ALCL positive for anaplastic lymphoma kinase (ALCL ... [more ▼]

Since the initial description of anaplastic large cell lymphoma (ALCL) as a proliferation of large CD30+ lymphoid cells, the morphological spectrum of ALCL positive for anaplastic lymphoma kinase (ALCL, ALK+) has expanded, and beyond the common pattern most frequently encountered, several variants have been identified, including the lymphohistiocytic and the small cell patterns (Swerdlow et al, 2008). Only ten ALK+ ALCL cell lines are currently available, and most were derived from tumours demonstrating the common type morphology (Drexler & MacLeod, 2004). We have established a novel cell line (CHIC) from the cerebrospinal fluid of a 32-year-old man with relapsing/refractory ALK+ ALCL with a t(2;5)(p23;q35) translocation whose initial tumour exhibited lymphohistiocytic features. This cell line is now made available to the scientific community. In addition to multiple in vitro applications, the tumourigenic capacity of these cells represents a useful property for in vivo drug testing. [less ▲]

Lung interstitial macrophages alter dendritic cell functions to prevent airway allergy in mice

in Journal of Clinical Investigation (2009), 119(12), 3723-38

The respiratory tract is continuously exposed to both innocuous airborne antigens and immunostimulatory molecules of microbial origin, such as LPS. At low concentrations, airborne LPS can induce a lung DC ... [more ▼]

The respiratory tract is continuously exposed to both innocuous airborne antigens and immunostimulatory molecules of microbial origin, such as LPS. At low concentrations, airborne LPS can induce a lung DC-driven Th2 cell response to harmless inhaled antigens, thereby promoting allergic asthma. However, only a small fraction of people exposed to environmental LPS develop allergic asthma. What prevents most people from mounting a lung DC-driven Th2 response upon exposure to LPS is not understood. Here we have shown that lung interstitial macrophages (IMs), a cell population with no previously described in vivo function, prevent induction of a Th2 response in mice challenged with LPS and an experimental harmless airborne antigen. IMs, but not alveolar macrophages, were found to produce high levels of IL-10 and to inhibit LPS-induced maturation and migration of DCs loaded with the experimental harmless airborne antigen in an IL-10-dependent manner. We further demonstrated that specific in vivo elimination of IMs led to overt asthmatic reactions to innocuous airborne antigens inhaled with low doses of LPS. This study has revealed a crucial role for IMs in maintaining immune homeostasis in the respiratory tract and provides an explanation for the paradox that although airborne LPS has the ability to promote the induction of Th2 responses by lung DCs, it does not provoke airway allergy under normal conditions. [less ▲]

Molecular classification of T-cell lymphomas.

in Critical Reviews in Oncology/Hematology (2009)

T-cell neoplasms encompass a heterogeneous group of relatively rare disease entities. This review, focused on lymphoblastic tumors (T-ALL/LBL) and nodal-based peripheral T-cell lymphomas (PTCL ... [more ▼]

T-cell neoplasms encompass a heterogeneous group of relatively rare disease entities. This review, focused on lymphoblastic tumors (T-ALL/LBL) and nodal-based peripheral T-cell lymphomas (PTCL), summarizes recent advances in the molecular characterization of these diseases. In T-ALL/LBL, molecular subgroups delineated by gene expression profiling correlate with leukemic arrest at specific stages of normal thymocyte development and different oncogenic pathways, and seem to be of interest for prognosis prediction. Angioimmunoblastic T-cell lymphoma (AITL), one of the most common PTCL entities, comprises neoplastic cells with a molecular signature similar to normal follicular helper T cells, and this cellular derivation might account for several of the peculiar aspects of this disease. Except in ALK-positive anaplastic large cell lymphoma, defined by ALK gene fusions, chromosomal translocations are otherwise rare in PTCLs, but some recurrent rearrangements might be associated with distinct lymphoma subtypes. In PTCL, not otherwise specified (PTCL, NOS), novel molecular biomarkers of potential therapeutic interest have been recently identified. [less ▲]

The prevention of spontaneous apoptosis of follicular lymphoma B cells by a follicular dendritic cell line: involvement of caspase-3, caspase-8 and c-FLIP.

in Haematologica (2008), 93(8), 1169-77

BACKGROUND: Follicular lymphoma, the neoplastic counterpart of germinal center B cells, typically recapitulates a follicular architecture. Several observations point to the crucial role of the cellular ... [more ▼]

BACKGROUND: Follicular lymphoma, the neoplastic counterpart of germinal center B cells, typically recapitulates a follicular architecture. Several observations point to the crucial role of the cellular microenvironment in the development and/or progression of follicular lymphoma cells in vivo. The aim of our study was to characterize the spontaneous apoptosis of follicular lymphoma cells in vitro, and the modulation of this apoptosis by follicular dendritic cells. DESIGN AND METHODS: We used a cell line derived from follicular dendritic cells to model the functional interactions of these cells and lymphoma cells in co-culture. Follicular lymphoma cells were isolated from tissue biopsies. Apoptosis was quantified by flow cytometry and apoptotic pathways were investigated by western blotting. RESULTS: The spontaneous apoptosis of follicular lymphoma cells in vitro involves the activation of caspases-3 and -8 but not of caspase-9, occurs despite persistent high levels of BCL-2 and MCL-1, and is associated with down-regulation of c-FLIP(L). Spontaneous apoptosis of follicular lymphoma cells is partially prevented by co-culture with the follicular dendritic cells, which prevents activation of caspase-8, caspase-3 and induces an upregulation of c-FLIP(L). Using neutralizing antibodies, we demonstrated that interactions involving CD54 (ICAM-1), CD106 (VCAM-1) and CD40 are implicated in this biological process. CONCLUSIONS: Follicular dendritic cells constitute a useful tool to study the functional interactions between follicular lymphoma cells and follicular dendritic cells in vitro. Understanding the molecular mechanisms involved in these protective interactions may lead to the identification of therapeutic agents that might suppress the survival and growth of follicular lymphoma cells. [less ▲]

The gene expression profile of nodal peripheral T-cell lymphoma demonstrates a molecular link between angioimmunoblastic T-cell lymphoma (AITL) and follicular helper T (T-FH) cells

in Blood (2007), 109(11), 4952-4963

The molecular alterations underlying the pathogenesis of angioimmunoblastic T-cell lymphoma (AITL) and peripheral T-cell lymphoma, unspecified (PTCL-u) are largely unknown. In order to characterize the ... [more ▼]

The molecular alterations underlying the pathogenesis of angioimmunoblastic T-cell lymphoma (AITL) and peripheral T-cell lymphoma, unspecified (PTCL-u) are largely unknown. In order to characterize the ontogeny and molecular differences between both entities, a series of AITLs (n = 18) and PTCLs-u (n = 16) was analyzed using gene expression profiling. Unsupervised clustering correlated with the pathological classification and with CD30 expression in PTCL-u. The molecular profile of AITLs was characterized by a strong microenvironment imprint (overexpression of B-cell- and follicular dendritic cell-related genes, chemokines, and genes related to extracellular matrix and vascular biology), and overexpression of several genes characteristic of normal follicular helper T (T-FH) cells (CXCL13, BCL6, PDCD1, CD40L, NFATC1). By gene set enrichment analysis, the AITL molecular signature was significantly enriched in published T-FH-specific genes. The enrichment was higher for sorted AITL cells than for tissue samples. Overexpression of several T-FH genes was validated by immunohistochemistry in AITLs. A few cases with molecular T-FH-like features were identified among CD30(-) PTCLs-u. Our findings strongly support that TFH cells represent the normal counterpart of AITL, and suggest that the AITL spectrum may be wider than suspected, as a subset of CD30(-) PTCLs-u may derive from or be related to AITL. [less ▲]

Lymphotoxin-beta receptor-dependent genes in lymph node and follicular dendritic cell transcriptomes

in Journal of Immunology (2005), 174(9), 5526-5536

Affinity-maturation and Ab class switches occur in lymphoid germinal centers (GCs), in which differentiation and maintenance depend on lymphotoxin (LT) signaling and include differentiation of follicular ... [more ▼]

Affinity-maturation and Ab class switches occur in lymphoid germinal centers (GCs), in which differentiation and maintenance depend on lymphotoxin (LT) signaling and include differentiation of follicular dendritic cells (FDCs). The events leading to FDC and GC maturation are poorly defined. Using several approaches of functional genomics, we enumerated transcripts affected in mice by suppressing LT beta receptor (LT beta R) signaling and/or overrepresented in FDC-enriched GC isolates. Protein expression analysis of 3 of 12 genes both enriched in FDCs and down-regulated by LT beta R signaling suppression validated them as FDC markers. Functional analysis of one of these three, clusterin, suggests a role as an FDC-derived trophic factor for GC B cells. Hence, the set of genes presented in this study includes markers emanating from LT beta R signaling and transcripts relevant to GC and FDC function. [less ▲]

Interfaces between dendritic cells, other immune cells, and nerve fibres in mouse Peyer’s patches : potential site for neuroinvasions in prion diseases.

Poster (2004, July)

Levels and profiles of PCDDs, PCDFs and cPCBs in Belgian breast milk. Estimation of infant intake

in Chemosphere (2002), 48(8), 763-770

Congener-specific analyses of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and non-ortho (coplanar) polychlorinated biphenyls (cPCBs) were performed on 20 non-pooled ... [more ▼]

Congener-specific analyses of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and non-ortho (coplanar) polychlorinated biphenyls (cPCBs) were performed on 20 non-pooled breast milk samples collected in or close to an industrial area of Wallonia (Belgium). PCDD/F concentrations ranged between 16.0 and 52.1 pg TEQ/g fat, with a mean value of 29.4 pg TEQ/g fat. If coplanar PCBs (77, 126, 169) are included in TEQ calculations, levels ranged between 22.2 and 100.2 pg TEQ/g fat, with a mean value of 40.8 pg TEQ/g fat. It appears that 2,3,7,8-TCDD, 1,2,3,7,8-PeCDD, 2,3,4,7,8-PeCDF and PCB-126 account for more than 90% of the TEQ. Estimated PCDD/F dietary intake is 76 pg TEQ/kg body weight (bw)/day. This value is almost 20 times higher than the World Health Organization tolerable daily intake. A value of 103 pg TEQ/kg bw/day represents the intake of PCDDs, PCDFs and cPCBs (no mono-ortho PCBs included). (C) 2002 Published by Elsevier Science Ltd. [less ▲]

New Histochemical and Ultrastructural Observations on Normal Bovine Tonsils

in Veterinary Record : Journal of the British Veterinary Association (2001), 149(20), 613-7

Samples of normal bovine palatine tonsils were examined by light and electron microscopy. Like human tonsils, they were composed of crypts, subepithelial areas, follicles, and T-dependent zones, but their ... [more ▼]

Samples of normal bovine palatine tonsils were examined by light and electron microscopy. Like human tonsils, they were composed of crypts, subepithelial areas, follicles, and T-dependent zones, but their well-developed capsule subdivided the lymphoid tissue by connective septa. B cells formed the major lymphoid component. The follicles and T-dependent zones had morphological and histochemical features typical of peripheral lymph organs. Follicular dendritic cells were isolated and shown to be similar to human follicular dendritic cells. [less ▲]