A Novel Calcium-Dependent Protein Kinase 1 Inhibitor Potently Prevents Transmission to Foetuses in Mouse.

Treatments currently used to prevent congenital toxoplasmosis are non-specific of and have grievous side effects. To develop a more specific and less toxic drug, we have designed SP230, an imidazo[1,2-]pyridazine salt targeting the calcium-dependent protein kinase 1 (CDPK1) and active against acute toxoplasmosis in mice. Efficiency of SP230 to inhibit foetal transmission of the parasite was evaluated in a mouse model of congenital toxoplasmosis.

Engineering and Functional Evaluation of Neutralizing Antibody Fragments Against Congenital Toxoplasmosis.

Maternal-fetal transmission of Toxoplasma gondii tachyzoites acquired during pregnancy has potentially dramatic consequences for the fetus. Current reference-standard treatments are not specific to the parasite and can induce severe side effects. In order to provide treatments with a higher specificity against toxoplasmosis, we developed antibody fragments-single-chain fragment variable (scFv) and scFv fused with mouse immunoglobulin G2a crystallizable fragment (scFv-Fc)-directed against the major surface protein SAG1.

[Tricks and misuses of rapid diagnostic testing for malaria diagnosis].

Molecular biology or immunochromatographic tests are conventionally offered as aids in the routine diagnosis of malaria. However, the interpretation of their results requires a precise knowledge of their limits, both by the biologist and the physician. It is in particular conditioned by thorough interview of the patient in order to seek a history of recent or even older malaria disease.

Early life stress in mice is a suitable model for Irritable Bowel Syndrome but does not predispose to colitis nor increase susceptibility to enteric infections.

Neonatal period is characterized by an immature intestinal barrier. Scattered evidence suggests that early life stressful events induce long lasting alterations of intestinal homeostasis mimicking Irritable Bowel Syndrome (IBS). Those observations highlighting defect of intestinal barrier by early life stress questioned its potential role as a risk factor for gastrointestinal disorders such as colitis and infections.

Imidazo[1,2-b]pyridazines targeting Toxoplasma gondii calcium-dependent protein kinase 1 decrease the parasite burden in mice with acute toxoplasmosis.

The current therapeutic arsenal for toxoplasmosis is restricted to drugs non-specific to the parasite which cause important side effects. Development of more efficient and specific anti-Toxoplasma compounds is urgently needed. Imidazo[1,2-b]pyridazines designed to inhibit the calcium-dependent protein kinase 1 of Toxoplasma gondii (TgCDPK1) and effective against tachyzoite growth in vitro at submicromolar ranges were modified into hydrochloride salts to be administered in vivo in a mouse model of acute toxoplasmosis.

Synthetic parasites: a successful mucosal nanoparticle vaccine against Toxoplasma congenital infection in mice.

Aim: Development of protein vaccine to prevent congenital infection is a major public health priority. Our goal is the design of mucosal synthetic pathogen inducing protective immune responses against congenital toxoplasmosis.

Materials & Methods: Mice were immunized intranasally, establishing pregnancy and challenging orally.

Pulmonary toxoplasmosis in immunocompromised patients with interstitial pneumonia: a single-centre prospective study assessing PCR-based diagnosis.

Aims: Pulmonary toxoplasmosis has become a very rare parasitic infection since the advent of highly active antiretroviral therapies. It is generally diagnosed by the direct microscopic observation of Toxoplasma gondii tachyzoites in bronchoalveolar lavage fluid (BALF). The aim of this study was to assess possible improvements in diagnostic performance associated with the use of real-time PCR.

[Toxoplasmic cyst and heart transplant: a case report of serological reactivation in an acute graft rejection context].

We describe the case of a serological reactivation in a Toxoplasma-seropositive subject, following a cardiac transplantation transmitting cysts contained in the myocardial tissue. In a context of acute graft rejection, primary chemoprophylaxis enables to avoid onset of opportunistic toxoplasmosis, emerging with immunodepletion performed by high-dose steroids. Then, we draw up a brief review of the bibliographical literature about pathophysiological mechanisms of toxoplasmic reactivation in heart transplants.

Interleukin 17 receptor signaling is deleterious during Toxoplasma gondii infection in susceptible BL6 mice.

Th17 cells are involved in host defense against several pathogens. Using interleukin (IL) 17RA-deficient mice, we demonstrated reduced ileitis with diminished neutrophil recruitment and inflammatory lesions in the ileum, in the regional lymph node, in the spleen, and in the liver at day 7 and prolonged survival after Toxoplasma gondii infection. In addition, IL-17A antibody neutralization reduced inflammation and enhanced survival in BL6 mice.

Tissue culture assays using Caco-2 cell line differentiate virulent from non-virulent Listeria monocytogenes strains.

Within the group of Listeria sp., only L. monocytogenes is pathogenic for humans and numerous studies of L.

Host cell protein tyrosine kinases are activated during the entry of Listeria monocytogenes. Possible role of pp60c-src family protein kinases.

Listeria monocytogenes is able to invade a wide range of cell types by inducing its own internalization. Little is known, however, about the host cell proteins affecting the entry process which involves triggering the host cell signal transduction mechanism. We report here that entry of L.

Cell proliferation enhances entry of Listeria monocytogenes into intestinal epithelial cells by two proliferation-dependent entry pathways.

Bacterial entry into intestinal host cells is the result of a fairly sophisticated manipulation of host cell machinery by the pathogens. To study further the potential cell target of Listeria spp., the in-vitro entry of L.

The loss of contact inhibition and anchorage-dependent growth are key steps in the acquisition of Listeria monocytogenes susceptibility phenotype by non-phagocytic cells.

We have previously demonstrated that intestinal and kidney finite cell lines were resistant to L monocytogenes invasion (ie allowed low bacterial entry and no intracellular multiplication) in contrast to the continuous cell lines which were susceptible to Listeria invasion (ie allowed high bacterial entry and intracellular multiplication) (Velge et al (1994a) Med Microbial Immunol 183, 145). The aim of this study was to discover whether epigenetic or genetic cellular modifications could convert L monocytogenes resistant cells into a susceptible phenotype and to determine the cellular steps involved in Listeria susceptibility. Among the 5-azacytidine treated finite cell lines, the untransformed immortal cell lines established remained resistant to L monocytogenes invasion whereas the weakly transformed continuous cell lines established were converted into a susceptible phenotype.

Protein tyrosine kinase inhibitors block the entries of Listeria monocytogenes and Listeria ivanovii into epithelial cells.

The internalization of Listeria by intestinal epithelial cells is still poorly understood, however it is becoming apparent that microorganisms have developed the ability to interact with host cell receptor molecules to induce their own internalization. In this report we show that inhibition of cell tyrosine phosphorylation by protein tyrosine kinase (PTK) inhibitors blocks L. monocytogenes entry into both finite and immortalized intestinal cell lines.