Search results for " immune system"
showing 10 items of 893 documents
Dynamics of gut mucosal and systemic Th1/Th2 cytokine responses in interferon-gamma and interleukin-12p40 knock out mice during primary and challenge…
2009
Cryptosporidium parvum is an intracellular parasite causing enteritis which can become life-threatening in the immunocompromised host. CD4+ T cells and interferon (IFN)-gamma play dominant roles in host immune response to infection. However, effector mechanisms that are responsible for recovery from infection are poorly understood. In the present study we analyzed mice deficient in IFN-gamma or interleukin (IL)-12 in parallel to C57BL/6 wild type mice as models for murine cryptosporidiosis. Our results identified IFN-gamma as the key cytokine in the innate as well as adaptive immunity during primary and also challenge C. parvum infection. Furthermore, both Th1 and Th2 cytokines appear to co…
Peripherally Circulating CD4+ FOXP3+ CXCR3+ T Regulatory Cells Correlate with Renal Allograft Function
2012
Peripheral immunoregulation depends on T regulatory cell trafficking into the allograft to modulate the local alloresponse. Little is known about the relevance of trafficking receptors for Tregs after solid organ transplantation in humans. In this study, expression of the peripheral chemokine receptors CXCR3 and CCR5 on CD4+ FOXP3+ Treg cells was analysed and correlated with allograft function in renal transplant recipients. Flow cytometry analysis of peripheral blood mononuclear cells of 54 renal transplant recipients receiving a calcineurin inhibitor-based immunosuppression was performed for CD4, CD25, FOXP3, CXCR3 and CCR5 within the first 18 months post-transplantation. Correlation anal…
Cytokine components and mucosal immunity in the oviduct of Xenopus laevis (amphibia, pipidae)
2011
Abstract Most studies on the mucosal immunity in female reproductive tissues have been performed in mammals. In all species, apart from their reproductive strategies, immunity in the genital mucosa is required to defend the host against luminal pathogens. In this study we investigated the role of the innate immunity of the oviductal mucosa of Xenopus laevis , an amphibian characterized by external fertilization. In particular we examined the expression and localization of Interleukin-1β (IL1B), Macrophage migration inhibitory factor (MIF) and Interleukin-1 receptor type 1 (IL1R1) in different oviductal portions including an upper glandular region, an intermediate and a lower aglandular regi…
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/…
Dendritic Cell-Specific Deletion of β-Catenin Results in Fewer Regulatory T-Cells without Exacerbating Autoimmune Collagen-Induced Arthritis.
2015
Dendritic cells (DCs) are professional antigen presenting cells that have the dual ability to stimulate immunity and maintain tolerance. However, the signalling pathways mediating tolerogenic DC function in vivo remain largely unknown. The beta-catenin pathway has been suggested to promote a regulatory DC phenotype. The aim of this study was to unravel the role of beta-catenin signalling to control DC function in the autoimmune collagen-induced arthritis model (CIA). Deletion of beta-catenin specifically in DCs was achieved by crossing conditional knockout mice with a CD11c-Cre transgenic mouse line. Bone marrow-derived DCs (BMDCs) were generated and used to study the maturation profile of …
Differential requirements for antigen or homeostatic cytokines for proliferation and differentiation of human Vgamma9Vdelta2 naive, memory and effect…
2005
We have compared four human subsets of Vgamma9Vdelta2 T cells, naive (T(naive), CD45RA(+)CD27(+)), central memory (T(CM), CD45RA(-)CD27(+)), effector memory (T(EM), CD45RA(-)CD27(-)) and terminally differentiated (T(EMRA), CD45RA(+)CD27(-)), for their capacity to proliferate and differentiate in response to antigen or homeostatic cytokines. Cytokine responsiveness and IL-15R expression were low in T(naive) cells and progressively increased from T(CM) to T(EM) and T(EMRA) cells. In contrast, the capacity to expand in response to antigen or cytokine stimulation showed a reciprocal pattern and was associated with resistance to cell death and Bcl-2 expression. Whereas antigen-stimulated cells a…
Dendritic cells lentivirally engineered to overexpress interleukin-10 inhibit contact hypersensitivity responses, despite their partial activation in…
2010
Background Dendritic cells (DCs) constitute an attractive target for immunotherapeutic approaches. Because DCs are largely refractory to transfection with plasmid DNA, several viral transduction protocols were established. The potential side-effects of lentiviral transduction on the phenotype and activation state of DCs left unstimulated after transduction have not been assessed. There is a need to analyse these parameters as a result of the requirement of using DCs with a low activation state for therapeutic strategies intended to induce tolerance. Methods Lentivirally-transduced bone marrow (BM)-derived DCs (LV-DCs) in comparison with mock-transduced (Mock-DCs) and untreated DCs were anal…
Differential expression of mRNA encoding interleukin-12 p35 and p40 subunitsin situ
1994
Interleukin-12 (IL-12) is a heterodimeric cytokine that plays an important role in the regulation of the immune response. For biological activity the expression of both subunits of IL-12, p35 and p40, is required. Moreover, in the mouse the p40 chain of IL-12 specifically inhibits the effects of the IL-12 heterodimer. In the present study we have analyzed by in situ hybridization the expression of the p35 and p40 mRNA in the spleens of BALB/c and mutant (SCID, nude, beige) mice, unstimulated and after in vivo stimulation with lipopolysaccharide (LPS) and with staphylococcal enterotoxin B (SEB). In unstimulated spleens of BALB/c mice p35 and p40 mRNA were only detectable in a few strongly st…
Harnessing dendritic cells in cancer.
2011
Dendritic cells (DCs) are central to the initiation of tumor-specific immune responses. However, the tumor microenvironment generates immunosuppressive cells and soluble mediators that compromise DC functions and limit the success of DC-based therapies. Progress in understanding DC metabolism in cancer is uncovering novel therapeutic targets that could restore DC capacity to prime T cells and trigger effective anticancer responses. Accumulating evidence also indicates that conventional chemo- and radiotherapy protocols can cause DC activation, enhance antigen cross-presentation, selectively eliminate immunosuppressive cells and revert the immunosuppression state caused by cancer, suggesting…