Coevolution of Cryptosporidium tyzzeri and the house mouse (Mus musculus).

Two house mouse subspecies occur in Europe, eastern and northern Mus musculus musculus (Mmm) and western and southern Mus musculus domesticus (Mmd). A secondary hybrid zone occurs where their ranges meet, running from Scandinavia to the Black Sea. In this paper, we tested a hypothesis that the apicomplexan protozoan species Cryptosporidium tyzzeri has coevolved with the house mouse. More specifically, we assessed to what extent the evolution of this parasite mirrors divergence of the two subspecies. In order to test this hypothesis, we analysed sequence variation at five genes (ssrRNA, Cryptosporidium oocyst wall protein (COWP), thrombospondin-related adhesive protein of Cryptosporidium 1 (TRAP-C1), actin and gp60) in C. tyzzeri isolates from Mmd and Mmm sampled along a transect across the hybrid zone from the Czech Republic to Germany. Mmd samples were supplemented with mice from New Zealand. We found two distinct isolates of C. tyzzeri, each occurring exclusively in one of the mouse subspecies (C. tyzzeri-Mmm and C. tyzzeri-Mmd). In addition to genetic differentiation, oocysts of the C. tyzzeri-Mmd subtype (mean: 4.24×3.69µm) were significantly smaller than oocysts of C. tyzzeri-Mmm (mean: 4.49×3.90 µm). Mmm and Mmd were susceptible to experimental infection with both C. tyzzeri subtypes; however, the subtypes were not infective for the rodent species Meriones unguiculatus, Mastomys coucha, Apodemus flavicollis or Cavia porcellus. Overall, our results support the hypothesis that C. tyzzeri is coevolving with Mmm and Mmd.

The effect of interferon-gamma and lipopolysaccharide on the growth of Francisella tularensis LVS in murine macrophage-like cell line J774.

BACKGROUND: Francisella tularensis, a causative agent of human tularemia, displaying the ability to proliferate inside the human cells. AIMS: To evaluate the growth potential of F. tularensis LVS strain in macrophage-like cell line J774 modulated by recombinant interferon gamma and E. coli derived lipopolysaccharide. RESULTS: Stimulation of J774 cells either by interferon-gamma or lipopolysaccharide alone, or especially in combination before infection F. tularensis, revealed protective effects. Higher concentrations of stimulating agents were needed to inhibit ongoing F. tularensis infection. CONCLUSIONS: Stimulation of J774 cell line by combination of interferon-gamma with lipopolysaccharide inhibits the intracellular growth of F. tularensis.

Rapid test for early detection of mycoplasma contamination of the continuous cell line J774.2.

The authors describe a rapid, simple and inexpensive method for the routine testing of mycoplasma contamination of the continuous mouse macrophage-like cell line J774.2 using specific anti-mouse monoclonal antibodies (antiCD14, antiCD80) and flow cytometry.

Platelets activation in patients undergoing PTCA and their responsiveness after in vitro stimulation.

We evaluated expression of platelet activation markers in blood samples of 15 patients who underwent percutaneous transluminal coronary angioplasty (PTCA) by flow cytometry. Analysis was performed before the beginning of PTCA, during initial coronary angiography and after the end of PTCA or after a stent placement, respectively. We evaluated platelet-derived microparticles, platelet-leukocyte aggregates, platelet aggregates and a membrane expression of CD62P and CD63 molecules. Responsiveness of platelets to the activation in vitro with thrombin-receptor activating protein-6 (TRAP-6) was tested simultaneously. Statistically significant differences between patient samples were found only in the expression of the activation markers CD62P (before PTCA 0.22%, during 0.39%, after 0.67%), CD63 (0.26%/0.45%/0.85%) and platelet-leukocyte aggregates (13.57%/18.39%/23.63%). In the same group the expression of all constitutive membrane markers was statistically significantly decreased: in patients undergoing PTCA was the expression of CD9: 87.98% (in comparison with control group 94.98%), CD31: 87.10% (92.78%), CD36: 87.37% (90.98%), CD41: 88.09% (95.62%), CD42a: 88.54% (94.98%), CD42a: 88.31% (94.13%).