Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0043167 (pertussis)
 19,595 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The capacity of pertussis toxin (PT) to induce maturation and functional activities of human monocyte-derived dendritic cells (DCs) was investigated. Both native PT (nPT) and genetically detoxified PT (dPT) efficiently promoted expression on DCs of CD80, CD86, human leukocyte antigen-DR, and CD83 markers, alloreactive antigen presentation, and cytokine production, primarily interferon (IFN)-gamma. Although they did not affect interleukin (IL)-10 production by lipopolysaccharide (LPS)-stimulated DCs, both nPT and dPT strongly synergized with LPS for IL-12 production. PTs plus LPS-stimulated DCs secreted soluble factors fostering IFN-gamma but not IL-4 and IL-5 production by naive T cells. T helper type 1 (Th1) polarization was, as alloreactive antigen presentation, inhibited by anti-IL-12 monoclonal antibody. These findings support the notion that nPT, in addition to inducing specific immune response, is a potent Th1 adjuvant and that dPT fully preserves this adjuvanticity. The synergic interaction between PT and LPS in IL-12 production might be relevant for the mechanisms of vaccine-induced protection.
 ...
PMID:Native and genetically inactivated pertussis toxins induce human dendritic cell maturation and synergize with lipopolysaccharide in promoting T helper type 1 responses. 1213 31

Pertussis toxin (PTX) has been widely used as an adjuvant to induce Th1-mediated organ-specific autoimmune diseases in animal models. However, the cellular and molecular mechanisms remain to be defined. In this study, we showed that dendritic cells (DC) stimulated with PTX (PTX-DC) were able to substitute for PTX to promote experimental autoimmune uveitis (EAU). EAU induced by PTX-DC revealed a typical Th1 response, characterized by high uveitogenic retinal Ag interphotoreceptor retinoid-binding protein (IRBP)-specific IFN-gamma and IL-12 production in the draining lymph nodes, as well as increased levels of anti-IRBP IgG2a and decreased levels of anti-IRBP IgG1 in the serum of IRBP-immunized mice. Furthermore, PTX-DC preferentially induced T cells to produce the Th1 cytokine, IFN-gamma. After being stimulated with PTX, DC exhibited up-regulation of MHC class II, CD80, CD86, CD40, and DEC205. PTX-DC had also increased allostimulatory capacity and IL-12 and TNF-alpha production. Serum IL-12 was increased in naive mice that received PTX-DC i.p. In addition, PTX activated extracellular signal-regulated kinase in DC. Following the inhibition of extracellular signal-regulated kinase signaling, the maturation of PTX-DC was reduced. Subsequently, the ability of PTX-DC to promote IFN-gamma production by T cells in vitro and to induce EAU in vivo was blocked. The results suggest that PTX might exert an adjuvant effect on DC to promote their maturation and the production of proinflammatory cytokines, thereby eliciting a Th1 response.
 ...
PMID:Pertussis toxin enhances Th1 responses by stimulation of dendritic cells. 1257 36

Adenylate cyclase toxin (CyaA) from Bordetella pertussis can subvert host immune responses allowing bacterial colonization. Here we have examined its adjuvant and immunomodulatory properties and the possible contribution of lipopolysaccharide (LPS), known to be present in purified CyaA preparations. CyaA enhanced antigen-specific interleukin-5 (IL-5) and IL-10 production and immunoglobulin G1 antibodies to coadministered antigen in vivo. Antigen-specific CD4(+)-T-cell clones generated from mice immunized with antigen and CyaA had cytokine profiles characteristic of Th2 or type 1 regulatory T (Tr1) cells. Since innate immune cells direct the induction of T-cell subtypes, we examined the influence of CyaA on activation of dendritic cells (DC) and macrophages. CyaA significantly augmented LPS-induced IL-6 and IL-10 and inhibited LPS-driven tumor necrosis factor alpha and IL-12p70 production from bone marrow-derived DC and macrophages. CyaA also enhanced cell surface expression of CD80, CD86, and major histocompatibility class II on immature DC. The stimulatory activity of our CyaA preparation for IL-10 production and CD80, CD86, and major histocompatibility complex class II expression was attenuated following the addition of polymyxin B or with the use of DC from Toll-like receptor (TLR) 4-defective mice. However, treatment of DC with LPS alone at the concentration present in the CyaA preparation (0.2 ng/ml) failed to activate DC in vitro. Our findings demonstrate that activation of innate cells in vitro by CyaA is dependent on a second signal through a TLR and that CyaA can promote Th2/Tr1-cell responses by inhibiting IL-12 and promoting IL-10 production by DC and macrophages.
 ...
PMID:Adenylate cyclase toxin from Bordetella pertussis synergizes with lipopolysaccharide to promote innate interleukin-10 production and enhances the induction of Th2 and regulatory T cells. 1497 63

Inosine is an endogenous purine nucleoside, which is formed by adenosine deaminidase during adenosine breakdown and is released into the extracellular space from the sympathetic nervous system or injured cells. Here, we studied the biological activity of inosine on human dendritic cells (DC), which are specialized antigen presenting cells characterized by their ability to migrate from the blood to peripheral tissues, and then to secondary lymphoid organs where they initiate adaptive immune responses. In immature DC, inosine concentration-dependently stimulated Ca(2+)-transients, actin polymerization, and chemotaxis. Experiments with adenosine receptor antagonists and pertussis toxin (PTX) as well as desensitization studies suggested that the activity of inosine was mediated by a G protein-coupled receptor pathway independent of adenosine receptors. DC, induced to mature by lipopolysaccharide, lost their ability to respond towards inosine with these activities. Moreover, inosine did neither influence membrane expression of CD54, CD80, CD83, CD86, HLA-DR, and MHC class I molecules nor modulated secretion of interleukin (IL)-12, IL-10, and tumor necrosis factor alpha in immature and lipopolysaccharide-matured DC. In aggregate, our study indicates that inosine may be involved in the trafficking control system of immature DC, and mediates its chemotactic activity by a PTX-sensitive mechanism independent of adenosine receptors.
 ...
PMID:Inosine stimulates chemotaxis, Ca2+-transients and actin polymerization in immature human dendritic cells via a pertussis toxin-sensitive mechanism independent of adenosine receptors. 1497 44

Adenylate cyclase toxin (CyaA) of Bordetella pertussis belongs to the repeat in toxin family of pore-forming toxins, which require posttranslational acylation to lyse eukaryotic cells. CyaA modulates dendritic cell (DC) and macrophage function upon stimulation with LPS. In this study, we examined the roles of acylation and enzymatic activity in the immunomodulatory and lytic effects of CyaA. The adenylate cyclase activity of CyaA was necessary for its modulatory effects on murine innate immune cells. In contrast, acylation was not essential for the immunomodulatory function of CyaA, but was required for maximal caspase-3 activation and cytotoxic activity. The wild-type acylated toxin (A-CyaA) and nonacylated CyaA (NA-CyaA), but not CyaA with an inactive adenylate cyclase domain (iAC-CyaA), enhanced TLR-ligand-induced IL-10 and inhibited IL-12, TNF-alpha, and CCL3 production by macrophages and DC. In addition, both A-CyaA and NA-CyaA, but not iAC-CyaA, enhanced surface expression of CD80 and decreased CpG-stimulated CD40 and ICAM-1 expression on immature DC. Furthermore, both A-CyaA and NA-CyaA promoted the induction of murine IgG1 Abs, Th2, and regulatory T cells against coadministered Ags in vivo, whereas iAC-CyaA had more limited adjuvant activity. In contrast, A-CyaA and iAC-CyaA induced caspase-3 activation and cell death in macrophages, but these effects were considerably reduced or absent with NA-CyaA. Our findings demonstrate that the enzymatic activity plays a critical role in the immunomodulatory effects of CyaA, whereas acylation facilitates the induction of apoptosis and cell lysis, and as such, NA-CyaA has considerable potential as a nontoxic therapeutic molecule with potent anti-inflammatory properties.
 ...
PMID:Bordetella pertussis adenylate cyclase toxin modulates innate and adaptive immune responses: distinct roles for acylation and enzymatic activity in immunomodulation and cell death. 1600 68

CD47 is a membrane-associated glycoprotein that suppresses the function of immune cells. We previously reported that Langerhans cells (LCs) express Src homology 2 domain-containing protein tyrosine phosphatase substrate 1 (SHPS-1), a ligand for CD47, which plays an important role in the regulation of their motility. In this study, we show that LCs also express CD47, and that ligation of CD47 with SHPS-1-Fc fusion protein in vivo diminishes the development of the contact hypersensitivity response. We further demonstrate that CD47 engagement affects immune functions of LCs. CD47 engagement in vivo significantly inhibits the emigration of LCs from the epidermis into draining lymph nodes following treatment with haptens and tumor necrosis factor-alpha. The emigration of dendritic cells from skin explants into the medium and the chemotaxis of murine XS52 dendritic cells were significantly reduced by treatment with SHPS-1-Fc or an anti-CD47 mAb. Under explant culture system, SHPS-1-Fc treatment suppressed the expression of CD80 and CD86 of LCs. These effects on LCs and contact hypersensitivity response of CD47 ligation were reversed by treatment with pertussis toxin. These results suggest that the ligation of CD47 inhibits the migration of LCs and the expression of B7 costimulatory molecules, which results in inhibition of the contact hypersensitivity response.
 ...
PMID:Engagement of CD47 inhibits the contact hypersensitivity response via the suppression of motility and B7 expression by Langerhans cells. 1645 31

High mobility group box-1 (HMGB1) protein is a nonhistone, DNA-binding protein that plays a critical role in regulating gene transcription. Recently, HMGB1 has also been shown to act as a late mediator of endotoxic shock and to exert a variety of proinflammatory, extracellular activities. Here, we report that HMGB1 simultaneously acts as a chemoattractant and activator of dendritic cells (DCs). HMGB1 induced the migration of monocyte-derived, immature DCs (Mo-iDCs) but not mature DCs. The chemotactic effect of HMGB1 on iDCs was pertussis toxin-inhibitable and also inhibited by antibody against the receptor of advanced glycation end products (RAGE), suggesting that HMGB1 chemoattraction of iDCs is mediated by RAGE in a Gi protein-dependent manner. In addition, HMGB1 treatment of Mo-iDCs up-regulated DC surface markers (CD80, CD83, CD86, and HLA-A,B,C), enhanced DC production of cytokines (IL-6, CXCL8, IL-12p70, and TNF-alpha), switched DC chemokine responsiveness from CCL5-sensitive to CCL21-sensitive, and acquired the capacity to stimulate allogeneic T cell proliferation. Based on its dual DC-attracting and -activating activities as well as its reported capacity to promote an antigen-specific immune response, we consider HMGB1 to have the properties of an immune alarmin.
 ...
PMID:High mobility group box-1 protein induces the migration and activation of human dendritic cells and acts as an alarmin. 1696 86

The prerequisites of peripheral activation of self-specific CD4(+) T cells that determine the development of autoimmunity are incompletely understood. SJL mice immunized with myelin proteolipid protein (PLP) 139-151 developed experimental autoimmune encephalomyelitis (EAE) when pertussis toxin (PT) was injected at the time of immunization but not when injected 6 days later, indicating that PT-induced alterations of the peripheral immune response lead to the development of autoimmunity. Further analysis using IA(s)/PLP(139-151) tetramers revealed that PT did not change effector T cell activation or regulatory T cell numbers but enhanced IFN-gamma production by self-specific CD4(+) T cells. In addition, PT promoted the generation of CD4(+)CD62L(low) effector T cells in vivo. Upon adoptive transfer, these cells were more potent than CD4(+)CD62L(high) cells in inducing autoimmunity in recipient mice. The generation of this population was paralleled by higher expression of the costimulatory molecules CD80, CD86, and B7-DC, but not B7-RP, PD-1, and B7-H1 on CD11c(+)CD4(+) dendritic cells whereas CD11c(+)CD8alpha(+) dendritic cells were not altered. Collectively, these data demonstrate the induction of autoimmunity by specific in vivo expansion of CD4(+)CD62L(low) cells and indicate that CD4(+)CD62L(low) effector T cells and CD11c(+)CD4(+) dendritic cells may be attractive targets for immune interventions to treat autoimmune diseases.
 ...
PMID:Induction of autoimmunity by expansion of autoreactive CD4+CD62Llow cells in vivo. 1698 73

Pertussis toxin (PTX) has potent immunologic adjuvant activity in vivo and concomitantly enhances both T helper type (Th1) and Th2 cytokine responses. The PTX-induced enhancement of Th1 and Th2 immunity is mediated via the activation of antigen presenting cells (APCs), but the underlying mechanism is not known. Here we asked whether the adjuvant activity of PTX on T cell immunity was mediated by cytokines and/or costimulatory signals. The results show that in vivo blockade of CD28-CD80/86 costimulation essentially abrogated PTX-mediated enhancement of antigen-specific Th1 and Th2 responses. Blockade of CD40L-CD40 interactions was less efficient in inhibiting PTX-mediated enhancement of Th1 and Th2 responses. In contrast, the adjuvant activity of PTX was not mediated via cytokines, because neither Th1 nor Th2 responses were substantially impaired in mice deficient for IL-12, IFN-gamma, IL-4, IL-5, or IL-6. Collectively, the data suggest that PTX mediates its adjuvant effects on T cell cytokine differentiation and clonal expansion via the modulation of costimulatory molecules on APCs. Understanding the costimulatory pathways targeted by PTX could lead to the design of novel adjuvants that selectively induce Th1 or Th2 immunity.
 ...
PMID:Pertussis toxin-induced cytokine differentiation and clonal expansion of T cells is mediated predominantly via costimulation. 1760 18

Streptococcus gordonii, a potential mucosal vaccine delivery vector, is proficient at colonizing murine oral mucosa; however, it often fails to elicit significant antibody titers against its vaccine antigen payloads. The poor response may be due to an inability of S. gordonii to elicit cytokines needed to suppress mucosal tolerance; exogenously supplied cytokines, such as TNF, could overcome this effect. To test this, murine bone marrow-derived dendritic cells (BM-DCs) were stimulated with UV-killed S. gordonii PM14, that surface expresses a fragment of the immunodominant S1 subunit of pertussis toxin. Peptidoglycan (PGN), lipoteichoic acid (LTA), lipoprotein (LP), and DNA were also isolated from the bacteria, and used to stimulate BM-DCs. Stimulation with TNF, S. gordonii, PGN, LTA, or LP all resulted in increased surface expression of MHCII, CD80, and CD86, compared to unstimulated BM-DCs. Stimulation with S. gordonii elicited IL-6, IL-10, and IL-12p70 production from the BM-DCs, while stimulation with the bacterial components induced some or all of the three cytokines. When BM-DCs were simultaneously stimulated with S. gordonii and TNF, a marginal increase in surface marker upregulation was observed, and the two stimuli synergized to elicit substantially greater quantities of IL-6, IL-10, and IL-12p70. Synergy between TNF and the purified bacterial components was also observed. The effect of TNF was abolished when BM-DCs were obtained from mice deficient for either TNFR1 or TNFR2, and cytokine induction by S. gordonii was entirely dependent on functional MyD88. Synergistic IL-10 induction by S. gordonii and TNF was not observed in TLR-2(-/-) BM-DCs, and TNF was found to cause TLR-2 upregulation, providing at least a partial mechanism for the observed synergy. When S. gordonii and TNF were used to immunize mice, a more robust anti-S. gordonii IgG response was elicited as compared to immunization with S. gordonii alone. However, the addition of TNF did not result in stronger responses against the antigenic insert (S1 fragment) in immunized mice. These findings collectively demonstrate that TNF is able to prime BM-DCs to better respond to S. gordonii, through a mechanism at least partially involving TLR-2 upregulation.
 ...
PMID:Synergistic BM-DC activation and immune induction by the oral vaccine vector Streptococcus gordonii and exogenous tumor necrosis factor. 1927 29


1 2 Next >>