Structures containing galectin-3 are recruited to the parasitophorous vacuole containing Trypanosoma cruzi in mouse peritoneal macrophages
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Trypanosoma cruzi has a complex life cycle where the infective forms for the vertebrate host are trypomastigotes and amastigotes. Both forms invade and lyse their parasitophorous vacuole (PV) membrane, entering into the cytoplasm of its host cells. Galectin-3 (Gal-3) is a protein abundantly distributed in macrophages and epithelial cells. Previous studies demonstrated that Gal-3 binds to a 45KDa mucin of trypomastigotes surface, enhancing its adhesion to the extracellular matrix and even its entry into cells. Gal-3 has another novel cytoplasmic function recently described: a vacuole lyses marker in intracellular bacteria. Considering (1) the importance of Gal-3 during T. cruzi early infection and (2) the importance of T. cruzi PV lyses for parasite differentiation and replication, this study intended to explore a possible recruitment of structures containing Gal-3 (G3CSs) to T. cruzi PVs. Microscopy analyses showed these G3CSs around PVs after 30 and 90 min of amastigotes and trypomastigotes infection, respectively. This recruitment was specific for T. cruzi PVs since we did not observe the same distribution at macrophages vacuoles containing fluorescent microspheres (FM). Concomitantly, this study intended to analyze the participation of actin cytoskeleton in T. cruzi PV maturation. We observed that actin filaments form a “belt-like” structure around trypomastigotes and amastigotes PVs, also labeled for Gal-3. At the time proposed for PV lysis, we observed an actin disassembling while LAMP-1 was recruited to PVs membrane. However, this pattern was maintained in macrophages derived from Gal-3 knockout mice, revealing that the actin belt structure forms independently from Gal-3. Taken together, these data suggest that G3CSs are recruited to vicinity of T. cruzi PV and that actin filaments localize and remain around T. cruzi PVs until the time of its lysis.
KeywordsTrypanosoma cruzi Galectin-3 Actin filaments LAMP-1 and macrophages
The authors thank Luzinete da Silva, Juliana Fernandes, Noêmia Rodrigues, Rachel Rachid, Thiago Luiz de Barros Moreira for the technical assistance and Ricardo Vilela for operating Leica Sp5 confocal laser scanning microscope (INMETRO). We also thank Dr. Marc Benhamou for kindly supplying the anti-galectin-3 M3/38 antibody. This work was supported by the Conselho Nacional de Desenvolvimento Cientifico e Tecnológico (CNPq), Financiadora de Estudos e Projetos (FINEP), Fundação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), and the Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ).
- Chen HY, Liu FT, Yang RY (2005) Roles of galectin-3 in immune responses. Arch Immunol Ther Exp (Warsz) 53(6):497–504Google Scholar
- de Souza W, de Carvalho TM, Barrias ES (2010) Review on Trypanosoma cruzi: host cell interaction. Int J Cell Biol 2010. doi:10.1155/2010/295394Google Scholar
- Forestier CL, Machu C, Loussert C, Pescher P, Spath GF (2011) Imaging host cell-Leishmania interaction dynamics implicates parasite motility, lysosome recruitment, and host cell wounding in the infection process. Cell Host Microbe 9(4):319–330. doi: 10.1016/j.chom.2011.03.011 PubMedCrossRefGoogle Scholar
- Newman GR (1989) LRWhite embedding medium for colloidal gold methods. In: Hayat MA (ed) Colloidal gold: principles, methods and applications., vol 2. Academic Press, pp 47–73Google Scholar
- Procopio DO, da Silva S, Cunningham CC, Mortara RA (1998) Trypanosoma cruzi: effect of protein kinase inhibitors and cytoskeletal protein organization and expression on host cell invasion by amastigotes and metacyclic trypomastigotes. Exp Parasitol 90(1):1–13. doi: 10.1006/expr.1998.4314 PubMedCrossRefGoogle Scholar