Bleeding assessment in a large cohort of patients with Osteogenesis Imperfecta.

Background: Osteogenesis Imperfecta (OI) is characterised by bone fragility. Among several features, easy bruising and multiple case reports on haemorrhagic events have been reported. This paper describes the diverse manifestations of bleeding and bruising in a large cohort of 328 OI patients.

A molecular marker of artemisinin-resistant Plasmodium falciparum malaria.

Plasmodium falciparum resistance to artemisinin derivatives in southeast Asia threatens malaria control and elimination activities worldwide. To monitor the spread of artemisinin resistance, a molecular marker is urgently needed. Here, using whole-genome sequencing of an artemisinin-resistant parasite line from Africa and clinical parasite isolates from Cambodia, we associate mutations in the PF3D7_1343700 kelch propeller domain ('K13-propeller') with artemisinin resistance in vitro and in vivo.

Mic1-3 Knockout Toxoplasma gondii is a good candidate for a vaccine against T. gondii-induced abortion in sheep.

This study assessed the effectiveness of a mutant strain of Toxoplasma gondii (RH strain) lacking the mic1 and mic3 genes (Mic1-3KO) against Toxoplasma abortion in sheep. Ewes were inoculated subcutaneously with 10(5) Mic1-3KO tachyzoïtes in three independent experiments. Following vaccination, Mic1-3KO induced a mild febrile response and serum IgG antibodies, which persisted throughout the experiments.

A vaccine based on exosomes secreted by a dendritic cell line confers protection against T. gondii infection in syngeneic and allogeneic mice.

Our results show that exosomes secreted by SRDC pulsed in vitro with Toxoplasma gondii-derived antigens (Exo-TAg) induced protective responses against infection with the parasite in both syngeneic and allogeneic mice. After oral infection, syngeneic CBA/J mice exhibited significantly fewer cysts in their brains and allogeneic C57BL/6 mice survived. This protection was associated with strong humoral responses in vivo in serum from both CBA/J and C57BL/6 mice, and with high levels of anti-TAg IgA antibodies in intestinal secretions from CBA/J mice alone.

The methylerythritol phosphate pathway for isoprenoid biosynthesis in coccidia: presence and sensitivity to fosmidomycin.

The apicoplast is a recently discovered, plastid-like organelle present in most apicomplexa. The methylerythritol phosphate (MEP) pathway involved in isoprenoid biosynthesis is one of the metabolic pathways associated with the apicoplast, and is a new promising therapeutic target in Plasmodium falciparum. Here, we check the presence of isoprenoid genes in four coccidian parasites according to genome database searches.

Generation of specific Th1 and CD8+ T-cell responses by immunization with mouse CD8+ dendritic cells loaded with HIV-1 viral lysate or envelope glycoproteins.

Immunization with antigen-pulsed dendritic cells (DCs) can be used to elicit optimal immune responses. We developed the SRDC cell line, with a morphology, phenotype and activity similar to mouse splenic CD4(-)CD8alpha(+)CD205(+)CD11b(-) dendritic cells, which induce a polarized Th1 immune response. We evaluated the ability of SRDCs pulsed with HIV-1 viral lysate, oligomeric soluble gp140 or capsid p24 to induce specific antibody and T-cell responses in CBA/J mice.

Mic1-3 knockout of Toxoplasma gondii is a successful vaccine against chronic and congenital toxoplasmosis in mice.

Background: We evaluated a new vaccine, Mic1-3KO, against both chronic and congenital toxoplasmosis in mice. Mic1-3KO is a mutant strain of Toxoplasma gondii RH that lacks the mic1 and mic3 genes.

Methods: OF1 mice were vaccinated with Mic1-3KO tachyzoites and challenged orally with T.

Induction of protective immunity against toxoplasmosis in mice by immunization with Toxoplasma gondii RNA.

Toxoplasma gondii enters the mucosal surfaces of the host, and so immunity at these sites is of major interest. Due to the compartmentalization of the immune response, systemic immunization does not induce high levels of immunity at mucosal surfaces. Intranasal immunization has been shown to be very effective in inducing both systemic and mucosal immune responses.

A novel CD4-CD8alpha+CD205+CD11b- murine spleen dendritic cell line: establishment, characterization and functional analysis in a model of vaccination to toxoplasmosis.

Dendritic cells (DCs) play an essential role in the induction of immune responses to pathogen infections. Native DCs are difficult to obtain in large numbers and consequently the vast majority of DCs employed in all experiments are derived from bone marrow progenitors. In an attempt to solve this problem, we have established a novel CD8alpha(+) DC line (H-2(k)) from spleen, which we have named SRDC line, and which is easy to culture in vitro.

Evaluation of protective effect of DNA vaccination with genes encoding antigens GRA4 and SAG1 associated with GM-CSF plasmid, against acute, chronical and congenital toxoplasmosis in mice.

To develop a multiantigenic vaccine against toxoplasmosis, two Toxoplasma gondii antigens, SAG1 and GRA4 selected on the basis of previous immunological and immunization studies, were chosen. We showed that DNA-based immunization with plasmids expressing GRA4 (pGRA4) or SAG1 (pSAG1mut) reduced mortality of susceptible C57BL/6 mice upon oral challenge with cysts of the 76K type II strain (62% survival). Immunization with pGRA4 and pSAG1mut, enhanced the protection (75% survival).

Synergistic role of micronemal proteins in Toxoplasma gondii virulence.

Apicomplexan parasites invade cells by a unique mechanism involving discharge of secretory vesicles called micronemes. Microneme proteins (MICs) include transmembrane and soluble proteins expressing different adhesive domains. Although the transmembrane protein TRAP and its homologues are thought to bridge cell surface receptors and the parasite submembranous motor, little is known about the function of other MICs.

Chicken primary enterocytes: inhibition of Eimeria tenella replication after activation with crude interferon-gamma supernatants.

A reproducible and original method for the preparation of chicken intestine epithelial cells from 18-day-old embryos for long-term culture was obtained by using a mechanical isolation procedure, as opposed to previous isolation methods using relatively high concentrations of trypsin, collagenase, or EDTA. Chicken intestine epithelial cells typically expressed keratin and chicken E-cadherin, in contrast to chicken embryo fibroblasts, and they increased cell surface MHC II after activation with crude IFN-gamma containing supernatants, obtained from chicken spleen cells stimulated with concanavalin A or transformed by reticuloendotheliosis virus. Eimeria tenella was shown to be able to develop until the schizont stage after 46 hr of culture in these chicken intestinal epithelial cells, but it was not able to develop further.

Both expansion of regulatory GR1+ CD11b+ myeloid cells and anergy of T lymphocytes participate in hyporesponsiveness of the lung-associated immune system during acute toxoplasmosis.

Oral infection with Toxoplasma gondii leads to transient systemic hyporesponsiveness. In this report, we characterized the presence in the lungs of GR1(+) CD11b(+) myeloid cells that have potent nitric oxide-dependent immunoregulatory properties. We also demonstrated the interleukin 2-reversible anergy of both pulmonary CD8(+) and CD4(+) activated T lymphocytes with infection.

Toxoplasma gondii antigen-pulsed-dendritic cell-derived exosomes induce a protective immune response against T. gondii infection.

It was previously demonstrated that immunizing mice with spleen dendritic cells (DCs) that had been pulsed ex vivo with Toxoplasma gondii antigens triggers a systemic Th1-biased specific immune response and induces protection against infection. T. gondii can cause severe sequelae in the fetuses of mothers who acquire the infection during pregnancy, as well as life-threatening neuropathy in immunocompromised patients, in particular those with AIDS.

The MIC3 gene of Toxoplasma gondii is a novel potent vaccine candidate against toxoplasmosis.

Infection with the intracellular protozoan parasite Toxoplasma gondii causes serious public health problems and is of great economic importance worldwide. The micronemal protein MIC3, which is a potent adhesin of T. gondii, could be a significant candidate vaccine against toxoplasmosis.

Protective mucosal Th2 immune response against Toxoplasma gondii by murine mesenteric lymph node dendritic cells.

Toxoplasma gondii, an obligate intracellular parasite pathogen which initially invades the intestinal epithelium before disseminating throughout the body, may cause severe sequelae in fetuses and life-threatening neuropathy in immunocompromised patients. Immune protection is usually thought to be performed through a systemic Th1 response; considering the route of parasite entry it is important to study and characterize the local mucosal immune response to T. gondii.

Prospects for a human Toxoplasma vaccine.

Human toxoplasmosis is usually benign, but may occasionally lead to severe or lethal damages when combined with immunosuppressive states or when transmitted to the fetus during pregnancy. Only a vaccine could prevent these harmful effects. The oral route is the natural portal of entry of T.

The Toxoplasma gondii protein MIC3 requires pro-peptide cleavage and dimerization to function as adhesin.

Attachment and invasion of host cells by apicomplexan parasites involve the exocytosis of the micronemal proteins (MICs). Most MICs are adhesins, which show homology with adhesive domains from higher eukaryote proteins and undergo proteolytic processing of unknown biological significance during their transport to micronemes. In Toxoplasma gondii, the micronemal homodimeric protein MIC3 is a potent adhesin that displays features shared by most Apicomplexa MICs.

Establishment and characterization of partially differentiated chicken enterocyte cell clones.

Three enterocyte cell clones were established in vitro from the intestine of a PA12 hen embryo. These cells exhibited epithelioid morphology and grew as monolayers. The cells were continuously propagated in culture up to 250 passages.

Dendritic cells as effector cells: gamma interferon activation of murine dendritic cells triggers oxygen-dependent inhibition of Toxoplasma gondii replication.

Toxoplasma gondii is an obligate intracellular parasite that infects a wide variety of nucleated cells in its numerous intermediate hosts, including humans. Much interest has focused on the ability of gamma interferon (IFN-gamma)-activated macrophages to prevent intracellular replication, but some other cells (e.g.

[Identification and molecular characterization of a Toxoplasma gondii microneme].

Protozoan of the phylum Apicomplexa are of high medical and veterinary importance, causing diseases such as malaria, toxoplasmosis and cryptosporidiosis. Invasive stages of apicomplexans possess organelles named micronemes, which are involved in the invasion process. We have recently characterized a protein in micronemes of Toxoplasma gondii, TgMIC3, which possess adhesive properties to host cell surface.

Immunogenicity of synthetic peptides from the Sm31 antigen (cathepsin B) of the Schistosoma mansoni adult worms.

The chemical synthesis of peptides may simplify the production of molecules for diagnosis of Schistosoma mansoni. Seventeen polymeric, 20-amino acids long, peptides comprising the entire Sm31 molecule of the adult worm, were synthesized under the t-boc strategy and their immunogenicity was evaluated. Of these, 10 peptides were immunogenic in rabbits.

Anti-SAG1 peptide antibodies inhibit the penetration of Toxoplasma gondii tachyzoites into enterocyte cell lines.

The initial attachment of Toxoplasma tachyzoites to the target host cell is an important event in the life-cycle of the parasite and a critical stage in infection. Previous studies have shown that polyclonal antibodies directed against the major surface antigen of Toxoplasma gondii (SAG1) inhibit the infection of enterocyte cell lines. Here, we demonstrate that antibodies raised against a central peptide (V41T) of SAG1 and the SAGI protein itself are able to inhibit the infection of various cell lines by the tachyzoites.

The microneme protein MIC3 of Toxoplasma gondii is a secretory adhesin that binds to both the surface of the host cells and the surface of the parasite.

Assay of the adhesion of cultured cells on Toxoplasma gondii tachyzoite protein Western blots identified a major adhesive protein, that migrated at 90 kDa in non-reducing gels. This band comigrated with the previously described microneme protein MIC3. Cellular binding on Western blots was abolished by MIC3-specific monoclonal and polyclonal antibodies.