Evaluation of immunogenicity and protection of the Mic1-3 knockout Toxoplasma gondii live attenuated strain in the feline host.

Toxoplasmosis is a zoonotic disease caused by the parasite Toxoplasma gondii. Up to a third of the global human population is estimated to carry a T. gondii infection, which can result in severe complications in immunocompromised individuals and pregnant women.

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.

Protection against lethal Neospora caninum infection in mice induced by heterologous vaccination with a mic1 mic3 knockout Toxoplasma gondii strain.

Neospora caninum and Toxoplasma gondii are closely related, obligate intracellular parasites infecting a wide range of vertebrate hosts and causing abortion and neonatal morbidity and mortality. Several lines of evidence suggest that cross immunity between these two pathogens could be exploited in the design of strategies for heterologous vaccination. We assessed the ability of an attenuated strain of T.

Direct effect in DNA radiolysis. Boron neutron capture enhancement of radiolysis in a medical fast-neutron beam.

SècheThis paper is devoted to the study of the molecular basis of the boron neutron capture enhancement of fast-neutron radiotherapy. Plasmid DNA was irradiated with a medical fast-neutron beam in the presence of either (10)B or (11)B. The number of induced SSBs and DSBs was much higher in samples containing (10)B compared to (11)B.

Radiolysis of lac repressor by gamma-rays and heavy ions: a two-hit model for protein inactivation.

Upon gamma-ray or argon ion irradiation of the lac repressor protein, its peptide chain is cleaved and the protein loses its lac operator-binding activity, as shown respectively by polyacrylamide gel electrophoresis and retardation gel electrophoresis. We developed phenomenological models that satisfactorily account for the experimental results: the peptide chain cleavage model considers that the average number of chain breaks per protomer is proportional to the irradiation dose and that the distribution of the number of breaks per protomer obeys Poisson's law. The repressor inactivation model takes into account the quaternary structure (a dimer of dimer) and the organization of the repressor in domains (two DNA binding sites, one per dimer).

Effect of strand orientation on the interaction of berenil with DNA triple helices.

Using circular dichroism spectroscopy the ability of berenil, a minor groove binding drug, to induce triple helix formation was investigated with two oligonucleotides designed to form two intramolecular triplexes containing T*A:T and G*G:C triplets, which differ only by the orientation of their third strand: 5'-d(G4A4G4-[T4]-C4T4C4-[T4]-G4T4G4), and 5'-d(G4T4G4-[T4]-G4A4G4-[T4]-C4T4C4), where [T4] represents a stretch of four thymine residues. We demonstrate that when added to the duplex form of these oligonucleotides, berenil induces triplex structure formation only if the orientation of third strand is anti-parallel to the purine strand.