Trypanosoma cruzi antigens induce inflammatory angiogenesis in a mouse subcutaneous sponge model

Acute inflammation and angiogenesis are persistent features of several pathological conditions induced by biological agents leading to the resolution of local and systemic events. Glycoproteins derived from the protozoan Trypanosoma cruzi are suggested to mediate angiogenesis induced by inflammatory cells with still undescribed mechanisms. In this study, we investigated the effects of total antigen from trypomastigote forms of T. cruzi (Y strain), inoculated in sponges 24h after implantation in mice, on angiogenesis, inflammatory cell pattern and endogenous production of inflammatory and angiogenic mediators on days 1, 4, 7 and 14 post-implant. There was an increase in hemoglobin content and in the number of blood vessels associated with T. cruzi antigen stimuli on the 14th day, assessed by the hemoglobin of the implants and by morphometric analysis. However, these antigens were not able to increase type I collagen content on the 14th day. Parasite antigens also induced high production of vascular endothelial growth factor (VEGF) and inflammatory mediators TNF-alpha, CCL2 and CCL5 on the 7th day in sponges when compared to the unstimulated group. Neutrophils and macrophages were determined by measuring myeloperoxidase (MPO) and N-acetyl-β-d-glucosaminidase (NAG) enzyme activities, respectively. Only NAG was increased after stimulation with antigens, starting from day 4 and peaking at day 7. Together, these data showed that antigens from the Y strain of T. cruzi are able to promote inflammatory neovascularization probably induced by macrophage-induced angiogenic mediators in T. cruzi antigen-stimulated sponges in Swiss mice.