Antibodies against CD20 or B-Cell Receptor Induce Similar Transcription Patterns in Human Lymphoma Cell Lines

BACKGROUND: CD20 is a cell surface protein exclusively expressed on B cells. It is a clinically validated target for Non-Hodgkin's lymphomas (NHL) and autoimmune diseases. The B cell receptor (BCR) plays an important role for development and proliferation of pre-B and B cells. Physical interaction of CD20 with BCR and components of the BCR signaling cascade has been reported but the consequences are not fully understood. METHODOLOGY: In this study we employed antibodies against CD20 and against the BCR to trigger the respective signaling. These antibodies induced very similar expression patterns of up- and down-regulated genes in NHL cell lines indicating that CD20 may play a role in BCR signaling and vice versa. Two of the genes that were rapidly and transiently induced by both stimuli are CCL3 and CCL4. 4 hours after stimulation the concentration of these chemokines in culture medium reaches a maximum. Spleen tyrosine kinase Syk is a cytoplasmic tyrosine kinase and a key component of BCR signaling. Both siRNA mediated silencing of Syk and inhibition by selective small molecule inhibitors impaired CCL3/CCL4 protein induction after treatment with either anti-CD20 or anti-BCR antibodies. CONCLUSION: Our results suggest that treatment with anti-CD20 antibodies triggers at least partially a BCR activation-like response in NHL cell lines

Growth regulation of simian and human AIDS-related non-Hodgkin's lymphoma cell lines by TGF-β1 and IL-6

BACKGROUND: AIDS-related non-Hodgkin's lymphoma (AIDS-NHL) is the second most frequent cancer associated with AIDS, and is a frequent cause of death in HIV-infected individuals. Experimental analysis of AIDS-NHL has been facilitated by the availability of an excellent animal model, i.e., simian Acquired Immunodeficiency Syndrome (SAIDS) in the rhesus macaque consequent to infection with simian immunodeficiency virus. A recent study of SAIDS-NHL demonstrated a lymphoma-derived cell line to be sensitive to the growth inhibitory effects of the ubiquitous cytokine, transforming growth factor-beta (TGF-beta). The authors concluded that TGF-beta acts as a negative growth regulator of the lymphoma-derived cell line and, potentially, as an inhibitory factor in the regulatory network of AIDS-related lymphomagenesis. The present study was conducted to assess whether other SAIDS-NHL and AIDS-NHL cell lines are similarly sensitive to the growth inhibitory effects of TGF-beta, and to test the hypothesis that interleukin-6 (IL-6) may represent a counteracting positive influence in their growth regulation. METHODS: Growth stimulation or inhibition in response to cytokine treatment was quantified using trypan blue exclusion or colorimetric MTT assay. Intracellular flow cytometry was used to analyze the activation of signaling pathways and to examine the expression of anti-apoptotic proteins and distinguishing hallmarks of AIDS-NHL subclass. Apoptosis was quantified by flow cytometric analysis of cell populations with sub-G1 DNA content and by measuring activated caspase-3. RESULTS: Results confirmed the sensitivity of LCL8664, an immunoblastic SAIDS-NHL cell line, to TGF-beta1-mediated growth inhibition, and further demonstrated the partial rescue by simultaneous treatment with IL-6. IL-6 was shown to activate STAT3, even in the presence of TGF-beta1, and thereby to activate proliferative and anti-apoptotic pathways. By comparison, human AIDS-NHL cell lines differed in their responsiveness to TGF-beta1 and IL-6. Analysis of a recently derived AIDS-NHL cell line, UMCL01-101, indicated that it represents immunoblastic AIDS-DLCBL. Like LCL-8664, UMCL01-101 was sensitive to TGF-beta1-mediated inhibition, rescued partially by IL-6, and demonstrated rapid STAT3 activation following IL-6 treatment even in the presence of TGF-beta1. CONCLUSION: These studies indicate that the sensitivity of immunoblastic AIDS- or SAIDS-DLBCL to TGF-beta1-mediated growth inhibition may be overcome through the stimulation of proliferative and anti-apoptotic signals by IL-6, particularly through the rapid activation of STAT3

Low sintering temperature of (Zn0.65Mg0.35)TiO3–xCaTiO3-based dielectric with controlled temperature coefficient

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Low sintering temperature of (Zn0.65Mg0.35)TiO3–xCaTiO3-based dielectric with controlled temperature coefficient

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Disminución drástica de la temperatura de sinterización del Ba (Zn_1/3Ta_2/3) O₃ mediante la adición de una fase vítrea y sales de litio

International audienceThe complex perovskite oxide Ba(Zn1/3Ta2/3)O3 (BZT) has been studied for its attractive dielectric properties which make this material interesting for applications such as multilayer ceramics capacitors or hyperfrequency resonators. Nevertheless, BZT ceramic requires high temperature to be correctly sintered (@1450°C), that is too high to envisage a silver co-sintering (Tf(Ag) = 961°C). For this reason, the lowering of the sintering temperature of BZT by glass phase’s additions has been investigated. This material is sinterable at low temperature with combined glass phase –lithium salt additions, and exhibits, at 1MHz very low dielectric losses combined with relatively high dielectric constant and a good stability of this later versus temperature. The 5 wt% of ZnO-SiO2-B2O3 glass phase and 1 wt% of LiF added BZT sample sintered at 900°C exhibits a relative density higher than 95% and attractive dielectric properties: a dielectric constant εr of 32, low dielectrics losses (tan (δ) 95%) y las propiedades dieléctricas de interés: la constante dieléctrica de 32, bajas pérdidas dieléctricas (tan (δ) <10-3) y un coeficiente de temperatura de la permitividad τε de -10ppm / ° C. Las propiedades dieléctricas obtenidas y la compatibilidad con los electrodos de plata hacen esta cerámica adecuada para su aplicación como LTTC

CaZn1/3Nb2/3O3-based dielectric ceramics for silver co-sintering applications

International audienceThe Ca(Zn1/3Nb2/3)O3 (CZN) complex perovskite oxide has been studied for its attractive dielectric properties (εr=34, Qxf=15 890GHz, τf=-48 ppm.°C-1) for applications such as multilayer ceramics capacitors or hyperfrequency resonators. Nevertheless, high temperatures (>1250°C) are required to obtain well dense CZN ceramic, prohibiting any silver co-sintering (Tf (Ag) = 961°C). For that reason, the sintering temperature lowering of CZN by glass phase’s additions has been investigated. This material is finally sinterable at low temperature with combined glass phase -lithium salt additions, and exhibits, at 1MHz, very low dielectric losses, a relatively high dielectric constant with a good stability versus temperature. The 2%weight of ZnO-SiO2-B2O3 glass phase and 1%wt of LiF added CZN sample sintered at 920°C exhibits a relative density higher than 95% and attractive dielectric properties: a dielectric constant εr of 22, low dielectrics losses (tan (δ)< 10-3), a temperature coefficient of the permittivity τε<100 ppm.°C-1, and an insulating resistivity higher than 1013Ω.cm. Its interesting properties and its co-sinterability with silver electrodes make this ceramic suitable for L.T.C.C applications

Low sintering temperature of (Zn0.65Mg0.35)TiO3–xCaTiO3-based dielectric with controlled temperature coefficient

International audienc

ZnTiO3 ceramic sintered at low temperature with glass phase addition for LTCC applications

International audienc

Disminución drástica de la temperatura de sinterización del Ba (Zn_1/3Ta_2/3) O₃ mediante la adición de una fase vítrea y sales de litio.

International audienceThe complex perovskite oxide Ba(Zn1/3Ta2/3)O3 (BZT) has been studied for its attractive dielectric properties which make this material interesting for applications such as multilayer ceramics capacitors or hyperfrequency resonators. Nevertheless, BZT ceramic requires high temperature to be correctly sintered (@1450°C), that is too high to envisage a silver co-sintering (Tf(Ag) = 961°C). For this reason, the lowering of the sintering temperature of BZT by glass phase’s additions has been investigated. This material is sinterable at low temperature with combined glass phase –lithium salt additions, and exhibits, at 1MHz very low dielectric losses combined with relatively high dielectric constant and a good stability of this later versus temperature. The 5 wt% of ZnO-SiO2-B2O3 glass phase and 1 wt% of LiF added BZT sample sintered at 900°C exhibits a relative density higher than 95% and attractive dielectric properties: a dielectric constant εr of 32, low dielectrics losses (tan (δ) 95%) y las propiedades dieléctricas de interés: la constante dieléctrica de 32, bajas pérdidas dieléctricas (tan (δ) <10-3) y un coeficiente de temperatura de la permitividad τε de -10ppm / ° C. Las propiedades dieléctricas obtenidas y la compatibilidad con los electrodos de plata hacen esta cerámica adecuada para su aplicación como LTT

Low temperature sintering of ZnTiO3/TiO2 based dielectric with controlled temperature coefficient

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