T cell-derived IL-10 determines leishmaniasis disease outcome and is suppressed by a dendritic cell based vaccine.

In the murine model of Leishmania major infection, resistance or susceptibility to the parasite has been associated with the development of a Th1 or Th2 type of immune response. Recently, however, the immunosuppressive effects of IL-10 have been ascribed a crucial role in the development of the different clinical correlates of Leishmania infection in humans. Since T cells and professional APC are important cellular sources of IL-10, we compared leishmaniasis disease progression in T cell-specific, macrophage/neutrophil-specific and complete IL-10-deficient C57BL/6 as well as T cell-specific and complete IL-10-deficient BALB/c mice.

Natural killer cells support the induction of protective immunity during dendritic cell-mediated vaccination against Leishmania major.

Dendritic cell (DC)-mediated vaccination against Leishmania major induces a parasite-specific T helper 1 (Th1) response and long-lasting protective immunity in susceptible mice. As the cytokine interleukin-12 required for induction of this Th1 response is not derived from the transferred DC, but has to be produced by the vaccinated host, we examined cross-presentation of transferred DC via resident DC of the host and cross-activation with natural killer (NK) cells as mechanisms supporting the induction of protective immunity after DC-mediated vaccination. Co-culture with DC that had been conditioned ex vivo by loading with L.

Fragments of antigen-loaded dendritic cells (DC) and DC-derived exosomes induce protective immunity against Leishmania major.

Upon loading with parasite antigen and adoptive transfer, dendritic cells (DC) are able to confer protection against the protozoan parasite Leishmania major. In the present study, we investigated whether viable DC are required for inducing protection. We provide evidence that L.

Phospholipase PlaB is a new virulence factor of Legionella pneumophila.

We previously identified Legionella pneumophila PlaB as the major cell-associated phospholipase A/lysophospholipase A with contact-dependent hemolytic activity. In this study, we further characterized this protein and found it to be involved in the virulence of L. pneumophila.

Split immune response after oral vaccination of mice with recombinant Escherichia coli Nissle 1917 expressing fimbrial adhesin K88.

Enterotoxigenic Escherichia coli (ETEC) are a leading cause of diarrhoea in piglets and newborn calves. Massive efforts have therefore been made to develop a vaccine for the induction of protective mucosal immunity against ETEC. Since it has been shown that the probiotic strain E.

Vaccination with plasmacytoid dendritic cells induces protection against infection with Leishmania major in mice.

DC-based vaccination against Leishmania major induces a parasite-specific Th1 response and long-lasting protective immunity in susceptible mice. Since distinct DC subsets have been proposed to direct the predominant development of either Th1 or Th2 cells, we analyzed the capability of plasmacytoid DC (pDC) to induce protection and elicit a Th1 response against L. major.

Human monocytoid cells as a model to study Toll-like receptor-mediated activation.

THP-1 2A9, a subclone of the monocytoid cell line THP-1 and known to be exquisitely sensitive to LPS, was tested for TNF production following triggering by excess doses of TLR ligands. TLR2, TLR4 and TLR5 agonists, but neither TLR3 nor TLR9 agonists, induced TNF production. When used at lower concentrations, priming by calcitriol strongly influenced the sensitivity of cells to LPS and different TLR2 triggers (lipoteichoic acid (LTA), trispalmitoyl-cysteyl-seryl-lysyl-lysyl-lysyl-lysine (Pam3Cys) and peptidoglycan (PGN)).

Nitric oxide and metalloproteinases in canine articular ligaments: a comparison between the cranial cruciate, the medial genual collateral and the femoral head ligament.

Osteoarthritis due to cranial cruciate ligament (CCL) rupture or hip dysplasia is one of the most important causes of chronic lameness in dogs. This study aimed at comparing nitric oxide (NO) production by the CCL with that of the femoral head ligament (FHL) and the medial collateral ligament (MCL), and investigating the pathway of NO production and the concomitant metalloproteinase (MMP) activity in the presence or absence of an inflammatory stimulus. Ligaments of normal dogs were subjected to different stimuli, and NO and MMP activity from explant culture supernatants were compared.

Toll-like receptor-4 is involved in eliciting an LPS-induced oxidative burst in neutrophils.

The lipopolysaccharide (LPS) receptor complex of mononuclear phagocytes is composed of Toll-like receptor-4 (TLR4), MD-2 and CD14. Other phagocyte populations may express similar LPS receptors. The transmembrane glycoprotein TLR4 was shown to induce or upregulate a variety of gene products, which collectively are the mediators of an LPS effect.