Verifiable hypotheses for thymosin β4-dependent and -independent angiogenic induction of Trichinella spiralis-triggered nurse cell formation

Trichinella spiralis has been reported to induce angiogenesis for nutrient supply and waste disposal by the induction of the angiogenic molecule vascular endothelial cell growth factor (VEGF) during nurse cell formation. However, the action mechanism to induce VEGF in nurse cells by T. spiralis is not known. Hypoxia in nurse cells was suggested as a possible mechanism; however, the presence of hypoxic conditions in infected muscle or nurse cells and whether hypoxia indeed induces the expression of VEGF and subsequent angiogenesis in the infected muscle are both a matter of debate. Our recent studies have shown that thymosin β4, a potent VEGF inducing protein, is expressed in the very early stages of T. spiralis muscle infection suggesting the induction of VEGF in early stage nurse cells. Nevertheless, we now show that hypoxic conditions were not detected in any nurse cell stage but were detected only in the accumulated inflammatory cells. These studies propose that induction of angiogenesis by VEGF in T. spiralis-infected nurse cells was mediated by thymosin β4 and is unrelated to hypoxic conditions.

Detection of tyrosine phosphorylated proteins in Trichinella spiralis L1 larvae

Western-blotting analysis showed the presence of tyrosine phosphorylated proteins in crude extracts of T. spiralis larvae and these phosphorylated proteins were located by immunofluorescence on the striations of the larval cuticle. The patterns of phosphorylated proteins were modified when larvae were incubated with bile.

The phenomenon of apoptosis in the course of experimental trichinellosis in mice

Mice infected with 200 Trichinella spiralis larvae were killed at 3-69 days post infection (dpi) and the jejunum and masseter muscles were sectioned in a cryostat and examined in the Tunell method with "In situ Cell Detected Kid POD" of Boehringer-Mannheim. Data concering the exact localization and dynamic of apoptic cells in both organs are presented. The authors conclude that apoptosis plays a important role in the pathogenesis of trichinellosis.

Macrophages during infection with Trichinella spiralis in mice

Behaviour of macrophages in experimental mice trichinellosis was investigated using the immunoenzymatic technique with monoclonal antibodies CD11b/CD18 within the framework of avidin-biotin-DAB. The maximum and earliest mobilization of macrophages 7 day post infection (dpi) was observed in the lamina propria of the intestinal mucosa. The highest level of macrophages in the muscles tissue was noted on day 21 of infection, however as early as in 28 dpi, their maximum level was observed inside the larval capsules. They line, especially between 35-42 dpi internal capsule surface.