A functional immune response is crucial to prevent and limit infections with Streptococcus pneumoniae.
Dendritic cells (DCs) play a central role in orchestrating the adaptive and innate immune responses by communicating with other cell types via antigen presentation and secretion of cytokines.
Biovision MilpitasBrdU Cell Proliferation Assay Kit Non-radioactive Assay, detects as less as 50-100 proliferating cells
In this study, we set out to understand how pneumococci activate human monocyte-derived DCs to produce interleukin-12 (IL-12) p70, an important cytokine during pneumococcal infections. We show that IL-12p70 production requires uptake of bacteria as well as the presence of the adaptor molecule TRIF, which is known to transfer signals of Toll-like receptor 3 (TLR3) or TLR4 from the endosome into the cell.
While TLR4 is redundant for IL-12p70 production in DCs, we found that TLR3 is required to induce full IL-12p70 secretion. Influenza A virus (IAV) infection of DCs did not induce IL-12p70 but markedly upregulated TLR3 expression that during coinfection with S. pneumoniae significantly enhanced IL-12p70 secretion. Finally, we show that pneumococcal RNA can act as a bacterial stimulus for TLR3 and that it is a key signal to induce IL-12p70 production during challenge of DCs with pneumococci.
OBJECTIVE
Streptococcus pneumoniae, a common colonizer of the nose, is the causative agent of severe and deadly diseases. A well-orchestrated immune response is vital to prevent and limit these diseases. Dendritic cells (DCs) reside in the mucosal linings of the lungs and sample antigens. They are activated by pathogens to present antigens and secrete cytokines. While many studies focus on murine models, we focused our work on human monocyte-derived DCs. We found that pneumococcal RNA is an important stimulus in DCs to activate the endosomal receptor TLR3, a receptor previously not identified to sense pneumococci, and its adaptor molecule TRIF.
This leads to secretion of the cytokine interleukin-12 (IL-12). Severe pneumococcal pneumonia occurs closely after influenza A virus (IAV) infection. We show that IAV infection upregulates TLR3 in DCs, which sensitizes the cells to endosomal pneumococcal RNA. This new insight contributes to unlock the interplay between pneumococci, IAV, and humans.
Calcium mobilization treatment acts as a joint signal for interleukin-12 induction mediated by TLR (<em> il </ em> – <em> 12p70 </ em>) secretion by dendritic cells originating from murine bone marrow.
We strive to determine whether the pharmacological calcium mumigation agent can act in collaboration with receptor signals such as toll (TLR) to induce high-level IL-12 production from dendritic cells originating from murine bone marrow. We found that calcium mobilization was induced without IL-12, but dramatically increased the secretion of IL-12P70 caused by TLR ligands. Increased production of IL-12 induced by calcium ionophore plus single TLR ligands, but not through double ligands of TLR, inhibited by Cyclosporine Calcineurin A antagonists, suggesting different mechanisms from IL-12 induction.
Dendritic cells activated with calciabionofore plus TLR9 ODN1826 ligands can cause Th1 polarization in Murine Naïve T cells at the same level or superior to dendritic cells that are activated with the most efficient TLR ligand pairs; ODN1826 plus lipopolysaccharide bacteria. Parallel analysis of 38 soluble products related to inflammation shows increased calciumophores limited to a set of small factors. This data shows the previously unscrupulous activation signal for IL-12 production by dendritic cells.
Receptors such as toll road 3 / trif depend on <em> il </ em> 12p70 </ em> secretion mediated by Streptococcus pneumoniae RNA and priming by influenza coinfected viruses in human dendritic cells.
Functional immune responses are very important to prevent and limit infection with streptococcus pneumoniae. Dendritic cells (DCS) play a central role in regulating adaptive and innate immune responses by communicating with other types of cells through antigen presentations and cytokine secretions. In this study, we departed to understand how Pneumococci activated DC which was derived from the human monocy to produce interleukin-12 (IL-12) P70, an important cytokine during pneumococcal infection. We show that the production of IL-12P70 requires absorption of bacteria and the existence of adapter molecular trifs, which are known to transfer receptor signals such as toll (TLR3) or TLR4 from endosome into cells.
While the TLR4 is excessive for the production of IL-12P70 in DCS, we find that TLR3 is needed to induce full-12p70 secretion. Influenza A Virus (IAV) DCS infection does not induce IL-12P70 but significantly reveals the expression of TLR3 which during co-infection with S. pneumoniae significantly increases the secretion of IL-12P70 significantly. Finally, we showed that RNA pneumococci can act as a bacterial stimulus for TLR3 and that it is a key signal to induce IL-12P70 production during the DCS challenge with pneumococci.
Objective
Streptococcus pneumoniae, common nose invaders, is an agent of causing severe and deadly disease. The immune response that is well organized is very important to prevent and limit this disease. Dendritic cells (DCS) are in the lung mucous layer and sample antigen. They are activated by pathogens to serve antigens and remove cytokines. While many studies focus on murine models, we focus our work on DCS monocyte-human derivatives. We found that the Pneumococcal RNA was an important stimulus in DC to activate TLR3 endosom receptors, previous receptors were not identified to feel pneumococci, and the adapter molecules trif.
Description: Description of target: The protein encoded by this gene is a secreted cytokine that is important for the proliferation of T and B lymphocytes. The receptor of this cytokine is a heterotrimeric protein complex whose gamma chain is also shared by interleukin 4 (IL4) and interleukin 7 (IL7). The expression of this gene in mature thymocytes is monoallelic, which represents an unusual regulatory mode for controlling the precise expression of a single gene. The targeted disruption of a similar gene in mice leads to ulcerative colitis-like disease, which suggests an essential role of this gene in the immune response to antigenic stimuli.;Species reactivity: Human;Application: ;Assay info: Assay Methodology: Quantitative Sandwich ELISpot Immunoassay;Sensitivity:
Description: Description of target: The protein encoded by this gene is a pleiotropic cytokine produced by activated T cells. This cytokine is a ligand for interleukin 4 receptor. The interleukin 4 receptor also binds to IL13, which may contribute to many overlapping functions of this cytokine and IL13. STAT6, a signal transducer and activator of transcription, has been shown to play a central role in mediating the immune regulatory signal of this cytokine. This gene, IL3, IL5, IL13, and CSF2 form a cytokine gene cluster on chromosome 5q, with this gene particularly close to IL13. This gene, IL13 and IL5 are found to be regulated coordinately by several long-range regulatory elements in an over 120 kilobase range on the chromosome. Two alternatively spliced transcript variants of this gene encoding distinct isoforms have been reported.;Species reactivity: Human;Application: ;Assay info: Assay Methodology: Quantitative Sandwich ELISpot Immunoassay;Sensitivity:
Description: Description of target: This gene encodes a cytokine that functions in inflammation and the maturation of B cells. In addition, the encoded protein has been shown to be an endogenous pyrogen capable of inducing fever in people with autoimmune diseases or infections. The protein is primarily produced at sites of acute and chronic inflammation, where it is secreted into the serum and induces a transcriptional inflammatory response through interleukin 6 receptor, alpha. The functioning of this gene is implicated in a wide variety of inflammation-associated disease states, including suspectibility to diabetes mellitus and systemic juvenile rheumatoid arthritis. Alternative splicing results in multiple transcript variants.;Species reactivity: Human;Application: ;Assay info: Assay Methodology: Quantitative Sandwich ELISpot Immunoassay;Sensitivity:
Description: Description of target: This gene encodes a cytokine that acts as a growth and differentiation factor for both B cells and eosinophils. The encoded cytokine plays a major role in the regulation of eosinophil formation, maturation, recruitment and survival. The increased production of this cytokine may be related to pathogenesis of eosinophil-dependent inflammatory diseases. This cytokine functions by binding to its receptor, which is a heterodimer, whose beta subunit is shared with the receptors for interleukine 3 (IL3) and colony stimulating factor 2 (CSF2/GM-CSF). This gene is located on chromosome 5 within a cytokine gene cluster which includes interleukin 4 (IL4), interleukin 13 (IL13), and CSF2 . This gene, IL4, and IL13 may be regulated coordinately by long-range regulatory elements spread over 120 kilobases on chromosome 5q31.;Species reactivity: Human;Application: ;Assay info: Assay Methodology: Quantitative Sandwich ELISpot Immunoassay;Sensitivity:
Description: Description of target: The protein encoded by this gene is a cytokine produced primarily by monocytes and to a lesser extent by lymphocytes. This cytokine has pleiotropic effects in immunoregulation and inflammation. It down-regulates the expression of Th1 cytokines, MHC class II Ags, and costimulatory molecules on macrophages. It also enhances B cell survival, proliferation, and antibody production. This cytokine can block NF-kappa B activity, and is involved in the regulation of the JAK-STAT signaling pathway. Knockout studies in mice suggested the function of this cytokine as an essential immunoregulator in the intestinal tract. Mutations in this gene are associated with an increased susceptibility to HIV-1 infection and rheumatoid arthritis.;Species reactivity: Human;Application: ;Assay info: Assay Methodology: Quantitative Sandwich ELISpot Immunoassay;Sensitivity:
Description: Description of target: This gene encodes a subunit of a cytokine that acts on T and natural killer cells, and has a broad array of biological activities. The cytokine is a disulfide-linked heterodimer composed of the 35-kD subunit encoded by this gene, and a 40-kD subunit that is a member of the cytokine receptor family. This cytokine is required for the T-cell-independent induction of interferon (IFN)-gamma, and is important for the differentiation of both Th1 and Th2 cells. The responses of lymphocytes to this cytokine are mediated by the activator of transcription protein STAT4. Nitric oxide synthase 2A (NOS2A/NOS2) is found to be required for the signaling process of this cytokine in innate immunity.;Species reactivity: Human;Application: ;Assay info: Assay Methodology: Quantitative Sandwich ELISpot Immunoassay;Sensitivity:
Description: Description of target: This gene encodes an immunoregulatory cytokine produced primarily by activated Th2 cells. This cytokine is involved in several stages of B-cell maturation and differentiation. It up-regulates CD23 and MHC class II expression, and promotes IgE isotype switching of B cells. This cytokine down-regulates macrophage activity, thereby inhibits the production of pro-inflammatory cytokines and chemokines. This cytokine is found to be critical to the pathogenesis of allergen-induced asthma but operates through mechanisms independent of IgE and eosinophils. This gene, IL3, IL5, IL4, and CSF2 form a cytokine gene cluster on chromosome 5q, with this gene particularly close to IL4.;Species reactivity: Human;Application: ;Assay info: Assay Methodology: Quantitative Sandwich ELISpot Immunoassay;Sensitivity:
Description: Description of target: The protein encoded by this gene is a proinflammatory cytokine produced by activated T cells. This cytokine regulates the activities of NF-kappaB and mitogen-activated protein kinases. This cytokine can stimulate the expression of IL6 and cyclooxygenase-2 (PTGS2/COX-2), as well as enhance the production of nitric oxide (NO). High levels of this cytokine are associated with several chronic inflammatory diseases including rheumatoid arthritis, psoriasis and multiple sclerosis.;Species reactivity: Human;Application: ;Assay info: Assay Methodology: Quantitative Sandwich ELISpot Immunoassay;Sensitivity:
Description: Description of target: The protein encoded by this gene is a cytokine that shares sequence similarity with IL17. This cytokine is expressed by activated T cells, and has been shown to stimulate the production of several other cytokines, including IL6, IL8, and CSF2/GM_CSF. This cytokine is also found to inhibit the angiogenesis of endothelial cells and induce endothelial cells to produce IL2, TGFB1/TGFB, and monocyte chemoattractant protein-1.;Species reactivity: Human;Application: ;Assay info: Assay Methodology: Quantitative Sandwich ELISpot Immunoassay;Sensitivity:
This leads to the secretion of the interleukin-12 cytokine (IL-12). Severe pneumococcal pneumonia occurred tightly after influenza virus (IAV) infection. We show that IAV infection confirms TLR3 in DCS, which is sensitive to cells against endosomal pneumococcal RNA. This new insight contributes to opening interactions between Pneumococci, IAV, and humans.
