Search results for "interleukin 12"
showing 10 items of 123 documents
Cutaneous leishmaniasis: Distinct functions of dendritic cells and macrophages in the interaction of the host immune system with Leishmania major
2017
Leishmaniasis is transmitted by sand flies leading to parasite inoculation into skin. In the mammalian host, the parasite primarily resides in skin macrophages (MΦ) and dendritic cells (DC). MΦ are silently invaded by the parasite eliciting a stress response, whereas DC become activated, release IL-12, and prime antigen-specific T cells. Here we review the basics of the immune response against this human pathogen and elucidate the role and function DC and MΦ for establishment of protective immunity against leishmaniasis. We focus on cell type-specific differences in parasite uptake, phagocyte activation and processing of parasite antigens to facilitate an understanding how their respective …
B cells participate in thymic negative selection of murine auto-reactive CD4+ T cells.
2010
It is well documented that thymic epithelial cells participate in the process of negative selection in the thymus. In recent years it was reported that also dendritic cells enter the thymus and contribute to this process, thus allowing for the depletion of thymocytes that are specific to peripherally expressed self-antigens. Here we report that also B cells may take part in the elimination of auto-reactive thymocytes. Using a unique mouse model we show that B cells induce negative selection of self-reactive thymocytes in a process that leads to the deletion of these cells whereas regulatory T cells are spared. These findings have direct implication in autoimmunity, as expression of a myelin…
Isolation of CD4+ T cells from murine lungs: a method to analyze ongoing immune responses in the lung.
2007
The regulation of the cellular immune response in lung diseases is not yet fully understood. Isolating different subsets of immune cells directly from the lung is therefore an indispensable method of gaining detailed knowledge on the function of these cells in this organ. This protocol describes a method of isolating and magnetically labeling CD4+ lung T cells, which are then loaded and retained on the column while all other cells run through it (positive selection). The yield of this isolation is approximately 5 x 10(5) to 1.5 x 10(6) CD4+ cells from a murine lung. These cells can be further investigated by several methods such as flow cytometry, western blot analysis, RT-PCR, immunostaini…
Th9 Cells: A Novel CD4 T-cell Subset in the Immune War against Cancer
2015
Abstract CD4 T cells are key components of the immune system that shape the anticancer immune response in animal models and in humans. The biology of CD4 T cells is complex because naïve T cells can differentiate into various subpopulations with various functions. Recently, a new population called Th9 cells was described. These cells are characterized by their ability to produce IL9 and IL21. They were first described in the context of parasite infections and allergic processes. However, some reports described their presence in the tumor bed in mice and humans. Their high secretion of IL9 and IL21 in the tumor bed contributes to their anticancer functions. Indeed, these cytokines trigger th…
The role of CD8+ T cells and their local interaction with CD4+ T cells in myelin oligodendrocyte glycoprotein35-55-induced experimental autoimmune en…
2013
Abstract T cells have an essential role in the induction of multiple sclerosis and its animal model experimental autoimmune encephalomyelitis (EAE). Although for CD4+ T cells it is well established that they contribute to the disease, less is known about the role of CD8+ T cells. Our aim was to determine the individual contribution of CD4+ and CD8+ T cells in myelin oligodendrocyte glycoprotein (MOG)35–55–induced EAE. We investigated MOG35–55–activated CD8+ T cells to clarify their potential to induce or attenuate EAE. We monitored the behavior of CD8+ T cells and their interaction with CD4+ T cells directly at the site of inflammation in the CNS using intravital imaging of the brainstem of…
Comparison of allergen-stimulated dendritic cells from atopic and nonatopic donors dissecting their effect on autologous naive and memory T helper ce…
2000
Abstract Background: Because of their production of IL-12, mature dendritic cells (DC) are potent inducers of T H 1 responses. However, recent reports have demonstrated that DCs can also induce T H 2 differentiation. Objective: In the current study we investigated which immune response is induced by DCs in naive CD45RA + or memory CD45R0 + CD4 + T cells from atopic individuals (patients with grass pollen, birch pollen, or house dust mite allergy) compared with nonatopic control subjects. Methods: Immature DCs, generated from peripheral blood monocytes from atopic and nonatopic donors, were pulsed with the respective allergen and fully matured. Then the mature DCs were cocultured in vitro wi…
Differential Regulatory Capacity of CD25+ T Regulatory Cells and Preactivated CD25+ T Regulatory Cells on Development, Functional Activation, and Pro…
2004
Abstract CD25+ T regulatory (Treg) cells play a central role regarding the maintenance of peripheral tolerance via suppression of autoaggressive CD4+ T cells, CD8+ T cells, and Th1 cells. In this study we demonstrate that CD25+ Treg cells can also suppress the differentiation of murine conventional CD4+ T cells toward Th2 cells in a contact-dependent manner. However, the cytokine production and proliferation of established Th2 cells could not be inhibited by freshly isolated CD25+ Treg cells, whereas a strong inhibition of differentiated Th2 cells by in vitro preactivated CD25+ Treg cells could be observed. Inhibition of both conventional CD4+ T cells and Th2 cells is accompanied by a stron…
The receptor NLRP3 is a transcriptional regulator of TH2 differentiation.
2015
The receptor NLRP3 is involved in the formation of the NLRP3 inflammasome that activates caspase-1 and mediates the release of interleukin 1β (IL-1β) and IL-18. Whether NLRP3 can shape immunological function independently of inflammasomes is unclear. We found that NLRP3 expression in CD4(+) T cells specifically supported a T helper type 2 (TH2) transcriptional program in a cell-intrinsic manner. NLRP3, but not the inflammasome adaptor ASC or caspase-1, positively regulated a TH2 program. In TH2 cells, NLRP3 bound the Il4 promoter and transactivated it in conjunction with the transcription factor IRF4. Nlrp3-deficient TH2 cells supported melanoma tumor growth in an IL-4-dependent manner and …
Adoptive transfer of protective immunity from Cryptosporidium parvum-infected interferon-gamma and interleukin-12-deficient mice to naive recipients.
2008
We investigated the possibility of transfer immunity from Cryptosporidium parvum-infected interferon-gamma (GKO) and interleukin-12p40 (IL-12KO) deficient C57BL/6 mice to naive mice by transfer of intraepithelial lymphocytes (IELs) and CD4(+) T cells from spleen and mesenteric lymph nodes (MLNs). Three days after the transfer recipients were infected with C. parvum. IELs isolated from GKO donor mice after resolution of infection (day 15) but not at the peak of infection (day 8) significantly reduced the parasite load in recipient mice. In IL-12KO mice, IELs and also CD4(+) T cells isolated from the spleen and MLNs of donor mice at the peak of infection (day 5) and after resolution (day 15) …
Co-activation of naive CD4+ T cells and bone marrow-derived mast cells results in the development of Th2 cells
1995
Activation of naive dense CD4+ T cells by plate-bound anti-CD3 antibodies favors the development of Th1 cells which, upon re-stimulation, produce significant amounts of IFN-gamma but no IL-4. However, co-activation of such naive T cells in the presence of IgE [anti-dinitrophenyl (DNP)]-loaded bone marrow-derived mast cells (BMMC) on plates coated with anti-CD3 antibodies and DNP-BSA led to the development of IL-4-producing Th2 cells. The same result could be observed if irradiated (800 rad) BMMC were applied as co-stimulators. Moreover, BMMC could be replaced by the supernatant of IgE-activated BMMC suggesting that a soluble mediator, presumably IL-4, was responsible for this effect. This a…