Search results for "cells"
showing 10 items of 7920 documents
Single and Synergistic Effects of Type 2 Cytokines on Eosinophils and Asthma Hallmarks
2020
Abstract The type 2 cytokines IL-5, IL-13, and IL-4 play an important role in the induction and progression of asthma. According to the Global Initiative for Asthma guidelines, blood eosinophil numbers are one marker that helps to guide treatment decisions in patients suffering from severe forms of asthma. Effects of type 2 cytokines were analyzed, alone or in combination, on eosinophils in blood and other compartments and on the development of asthma symptoms. C57BL/6 mice received a single intranasal application of equimolar amounts of IL-5, IL-13, and IL-4, alone or in combination. Numbers, activation state, and migratory behavior of eosinophils in bone marrow (BM), blood, lung, and bron…
Growth factors and cell kinetics: a mathematical model applied to Il-3 deprivation on leukemic cell lines.
1992
We assume the existence of a specific G1 protein which is an initiator of DNA replication. This initiator is supposed to be synthesized according to Michaelis-Menten kinetics. In order to start DNA replication, it is assumed that this G1 specific protein must be produced in a required amount. Intra-cellular growth inhibitors and extra-cellular growth factors control the production of the initiator. This model allows to calculate the average G1 phase time as a function of the various chemical concentrations of nutrients, enzymes, growth inhibitors and growth factors. This model is compared to cell kinetics experiments on a leukemic cell line responding to Interleukin 3 deprivation. The curve…
A Role for Leukocyte-Derived IL-1RA in DC Homeostasis Revealed by Increased Susceptibility of IL-1RA-Deficient Mice to Cutaneous Leishmaniasis
2011
Dendritic cell (DC)-derived IL-1α/β plays a critical role in the induction of T helper type 1 (Th1)-dependent immunity against Leishmania . DCs from susceptible BALB/c mice produce less IL-1α/β when compared with resistant C57BL/6 mice, contributing to aberrant Th2 development and ultimate death of infected mice. We have extended our studies of the role of IL-1 in leishmaniasis using IL-1RA -/- BALB/c mice that are characterized by upregulated IL-1 receptor signaling. Unexpectedly, infection of IL-1RA -/- mice led to significantly worsened disease outcome with larger lesions, dramatically higher parasite burdens, and decreased IFN-γ production by antigen-specific T cells. We determined that…
Ex vivoevidence for PGE2and LTB4involvement in cutaneous leishmaniasis: relation with infection status and cytokine production
1996
SUMMARYEx vivoculture of spleen cells from BALB/c mice infected with 2 × 106Leishmania major(L.major) promastigotes were cultured with ConcanavalinA (ConA) or leishmanial antigen (L. Ag) and tested for prostaglandin E2(PGE2) and for leukotriene B4(LTB4), in order to study their involvement in the evolution of cutaneous leishmaniasis and the connexion with lymphokine-mediated responses. The data were compared with those obtained in BALB/c mice protected againstL. majorby sublethal irradiation (550 rad; cured mice). In the unprotected BALB/c mice the levels of PGE2that were responsible for the depression of interferon-γ (IFN-γ) and tumour necrosis factor-α (TNFα) Th1-associated cytokines and …
Synthetic multivalent glycopeptide-lipopeptide antitumor vaccines: impact of the cluster effect on the killing of tumor cells.
2014
Multivalent synthetic vaccines were obtained by solid-phase synthesis of tumor-associated MUC1 glycopeptide antigens and their coupling to a Pam3 Cys lipopeptide through click reactions. These vaccines elicited immune responses in mice without the use of any external adjuvant. The vaccine containing four copies of a MUC1 sialyl-TN antigen showed a significant cluster effect. It induced in mice prevailing IgG2a antibodies, which bind to MCF-7 breast tumor cells and initiate the killing of these tumor cells by activation of the complement-dependent cytotoxicity complex.
Immune Modulating Effects of NKT Cells in a Physiologically Low Dose Leishmania major Infection Model after αGalCer Analog PBS57 Stimulation
2014
Leishmaniasis is a parasitic infection affecting ∼12 million people worldwide, mostly in developing countries. Treatment options are limited and no effective vaccines exist to date. Natural Killer T (NKT) cells are a conserved innate-like lymphocyte population with immunomodulating effects in various settings. A number of reports state a role of NKT cells in different models of Leishmania infection. Here, we investigated the effect of NKT cells in a physiologically relevant, intradermal low dose infection model. After inoculation of 103 infectious-stage L. major, comparable numbers of skin-immigrating NKT cells in both susceptible BALB/c mice and resistant C57BL/6 mice were noted. Compared …
A protective role for interleukin 18 in interferon γ-mediated innate immunity to Cryptosporidium parvum that is independent of natural killer cells.
2012
Innate immunity against some intracellular parasitic protozoa involves interleukin 18 (IL-18)-mediated interferon γ (IFN-γ) production by natural killer (NK) cells, but the role of IL-18 in innate resistance to Cryptosporidium infection is unknown. Adult Rag2(-/-)γc(-/-) mice that lack NK cells, T cells, and B cells demonstrated resistance to Cryptosporidium parvum infection that was IFN-γ dependent. Treatment with anti-IL-18-neutralizing antibodies resulted in loss of resistance correlating with reduced intestinal IFN-γ expression. Intestinal mature IL-18 expression increased in vivo during infection and also in the intestinal epithelial cell line CMT-93 following combined IFN-γ treatment/…
Fat-storing cells of the rat liver synthesize and secrete C1-esterase inhibitor; modulation by cytokines.
1992
During liver fibrogenesis, fat-storing cells transform into myofibroblast-like cells and produce increasing amounts of extracellular matrix proteins. Because fat-storing cells produce α2-macroglobulin, an important serine protease inhibitor (serpin), we investigated whether fat-storing cells also synthesize C1-esterase inhibitor, another important serpin. C1-esterase inhibitor synthesis was studied in rat fatstoring cells at day 0, 3 and 7 after isolation by biosynthetic labeling, immunoprecipitation and sodium dodecyl sulfate–polyacrylamide gel electrophoresis. Messenger RNA was examined by Northern-blot analysis. C1-esterase inhibitor gene expression and synthesis were detectable in fresh…
Monophosphoryl lipid A coating of hydroxyethyl starch nanocapsules drastically increases uptake and maturation by dendritic cells while minimizing th…
2015
Enhancing delivery of antigens to dendritic cells (DCs) is essential for the induction of vigorous antigen-specific cellular immune responses. Aim of the present study was to evaluate the properties of hydroxyethyl starch nanocapsules (HES-NCs) functionalized with anti-CD40, anti-DEC205, interferon-γ (IFNγ) and/or monophosphoryl lipid A (MPLA) with respect to the overall uptake, the released cytokine profile, and the influence on phenotypic maturation of human monocyte-derived DCs using flow cytometry, confocal microscopy and enzyme-linked immunosorbent assays. NC uptake by DCs was significantly enhanced by functionalizing NCs with anti-CD40 or MPLA. With respect to the cytokine profile and…
Cytotoxicity of natural products and derivatives toward MCF-7 cell monolayers and cancer stem-like mammospheres
2015
Abstract Although cancer stem-like cells (CSCs) are rare, they can enter a non-proliferative or dormant state and resist therapy. Furthermore, quiescent CSCs are responsible for metastases that can appear after curative surgical treatment of a primary tumor. Because of drug resistance of CSCs, the development of novel therapies is urgently required that specifically target CSCs. Purpose The aim of the present study was to investigate the potential of a panel of natural products and derivatives to inhibit CSC-enriched mammospheres of MCF-7 breast cancer cells. Methods CD44high/CD24low cells were identified by flow cytometry and maintained as mammospheres. As a control, we used two clinically…