Giardiasis is the most common diarrheal disease caused by parasites, commonly leading to weight loss, and may cause malnutrition, especially in children. The aim of our group is to build on our previous studies of endocytosis in the intestinal parasite Giardia lamblia, extending our focus to the function of exosome-like vesicles released by strains with different virulence. We will advance in the molecular characterization of exosomes from different strains and drug-resistant parasites to further analyze the role of these vesicles in pathogenesis, antiparasitic resistance, and triggering of antigenic variation. This will disclose whether long distance pathogen-to-pathogen and pathogen-to-host communication via extracellular vesicles represents a novel mechanism to control complex virulence phenotypes.



Dr. Constanza Feliziani

Assistant Researcher. CONICET


Biol. Juliana Musso

Doctoral Fellow. FONCYT

Bioq. Gabriel Luna Pizarro

Doctoral Fellow. FONCYT

Research SUPPORT

2019-2022. PICT 2017-2435. FONCYT. ROLE: PI

2020-2023. PICT 2018-0154. FONCYT. ROLE: PII




  1. Touz MC, Nores MJ, Slavin I, Carmona C, Conrad JT, Mowatt MR, Nash TE, Coronel CE, and Lujan HD. The activity of a developmentally regulated cysteine proteinase is required for cyst wall formation in the primitive eukaryote Giardia lamblia. J Biol Chem. 277 (10) 8474-81. 2002.
  2. Touz MC, Nores MJ, Slavin I, Piacenza L, Acosta D, Carmona C, and Lujan HD. Membrane-associated dipeptidyl peptidase IV is involved in encystation-specific gene expression during Giardia differentiation. Biochem J. 364 (Pt 3) 703-10. 2002.
  3. Touz MC, Gottig N, Nash TE, and Lujan HD. Identification and characterization of a novel secretory granule calcium-binding protein from the early branching eukaryote Giardia lamblia. J Biol Chem. 277 (52) 50557-63. 2002.
  4. Touz MC*, Lujan HD, Hayes SF, and Nash TE. Sorting of encystation-specific cysteine protease to lysosome-like peripheral vacuoles in Giardia lamblia requires a conserved tyrosine-based motif. J Biol Chem. 278 (8) 6420-6. 2003.
  5. Lujan HD and Touz MC. Protein trafficking in Giardia lamblia. Cell Microbiol. 5 (7) 427-34. 2003. Review.
  6. Touz MC*, Kulakova L, and Nash TE. Adaptor protein complex 1 mediates the transport of lysosomal proteins from a Golgi-like organelle to peripheral vacuoles in the primitive eukaryote Giardia lamblia. Mol Biol Cell. 15(7):3053-60. 2004.
  7. Touz MC*, Conrad JT, and Nash TE. A novel palmitoyl acyl transferase controls surface protein palmitoylation and cytotoxicity in Giardia lamblia. Mol Microbiol. Nov;58(4):999-1011. 2005.
  8. Touz MC*, Rópolo AS, Rivero MR, Vranych CV, Conrad JT, Svard SG, and Nash TE. Arginine Deiminase Plays Multiple Regulatory Roles In The Biology Of Giardia Lamblia. Journal of Cell Science. 121(Pt 17):2930-8. 2008. Cover.
  9. Rivero MR, Vranych CV, Bisbal M, Maletto BA, Rópolo AS, Touz MC*. Adaptor Protein 2 Regulates Receptor-Mediated Endocytosis and Cyst Formation in Giardia lamblia. Biochem J. 428 (1) 33-45. 2010.
  10. Andrea S. Rópolo and Maria C. Touz. A lesson in survival, by Giardia lamblia. Invited mini-review. ScientificWorldJournal. 2010 Oct 12;10:2019-31. Review.
  11. Rivero MR, Miras SL, Quiroga R, Rópolo AS, Touz MC*. Giardia lamblia low-density lipoprotein receptor-related protein is involved in selective lipoprotein endocytosis and parasite replication. Mol Microbiol. 2011 Mar;79(5):1204-19.Cover.
  12. Maria C. Touz*, Maria R. Rivero, Silvana L. Miras, Juan S. Bonifacino. Lysosomal protein trafficking in Giardia lamblia: common and distinct features. Front Biosci (Elite Ed). 2012 Jan 1;4:1898-1909.
  13. Rivero MR, Miras SL, Feliziani C, Zamponi N, Quiroga R, Hayes SF, Rópolo AS, Touz MC*. Vacuolar Protein Sorting Receptor in Giardia lamblia. PLoS One. 2012;7(8):e43712. IF: 3.7 Q1
  14. Miras SL, Merino MC, Gottig N, Rópolo AS, Touz MC*. The giardial VPS35 retromer subunit is necessary for multimeric complex assembly and interaction with the vacuolar protein sorting receptor. Biochim Biophys Acta. 2013 Jun 26;1833(12):2628-2638. doi: 10.1016/j.bbamcr.2013.06.015.
  15. Feliziani C, Zamponi N, Gottig N, Rópolo AS, Lanfredi-Rangel A, Touz MC*. The giardial ENTH protein participates in lysosomal protein trafficking and endocytosis. Biochim Biophys Acta. 2015 Mar;1854(3):646-59.
  16. Feliziani C, Valdez-Taubas J, Moyano S, Quassollo G, Poprawski J, Wendland B, Touz MC*. Vestiges of Ent3p/Ent5p function in the giardial epsin homolog. Biochim Biophys Acta. 2016 Feb 2. pii: S0167-4889(16)30017-9. doi: 10.1016/j.bbamcr.2016.02.001.
  17. Zamponi N, Feliziani C, Touz MC*. Endocytosis in Giardia: Evidence of Absence. Trends Parasitol. 2016 Nov;32(11):838-840. doi: 10.1016/
  18. Feliziani C, Touz MC*. To a better understanding of the giardial ENTH protein function. Biosci Trends. 2017 Jan 24. doi: 10.5582/bst.2016.01225. Review.
  19. Zamponi N, Zamponi E, Mayol GF, Lanfredi-Rangel A, Svärd SG, Touz MC*. Endoplasmic reticulum is the sorting core facility in the Golgi-lacking protozoan Giardia lamblia. 2017 Sep;18(9):604-621. doi: 10.1111/tra.12501. Cover.
  20. Touz MC*, Zamponi N. Sorting without a Golgi complex. Traffic. 2017 Jul 11. doi: 10.1111/tra.12500. Review.
  21. Touz MC*, Feliziani C, Rópolo AS*. Membrane-Associated Proteins in Giardia lamblia. Genes (Basel). 2018 Aug 10;9(8). pii: E404. doi: 10.3390/genes9080404. Review.
  22. Frontera LS, Moyano S, Quassollo G, Lanfredi-Rangel A, Rópolo AS, and Touz MC*. Lactoferrin and lactoferricin endocytosis halt Giardia cell growth and prevent infective cyst production. Scientific Reports. Sci Rep. 2018 Dec 21;8(1):18020. doi: 10.1038/s41598-018-36563-1. IF: 4.4 Q1
  23. Rópolo AS, Feliziani C, Touz MC*. Unusual proteins in Giardia duodenalis and their role in survival. Adv Parasitol. 2019;106:1-50. doi: 10.1016/bs.apar.2019.07.001.
  24. Moyano S, Musso J, Feliziani C, Zamponi N, Frontera LS, Ropolo AS, Lanfredi-Rangel A, Lalle M, Touz M*. Exosome Biogenesis in the Protozoa Parasite Giardia lamblia: A Model of Reduced Interorganellar Crosstalk. Cells. 2019 Dec 9;8(12). pii: E1600. doi: 10.3390/cells8121600.
  25. Maria Romina Rivero, Constanza Feliziani, Carlos De Angelo, Karina Tiranti, Oscar Daniel Salomon & Maria Carolina Touz. Giardia spp., the most ubiquitous protozoan parasite in Argentina: human, animal and environmental surveys reported in the last 40 years. Parasitology Research. 2020 August 15. doi:10.1007/s00436-020-06853-7.