Inactive trans-sialidase knock-in increments Trypanosoma cruzi in vivo virulence

CARLA PASCUALE; JUAN M. BURGOS; POSTAN, MIRIAM; OSCAR CAMPETELLA; MARÍA SUSANA LEGUIZAMÓN

Congreso; XI Congreso Sociedad Argentina de Protozoologia; 2017

SAP

T. cruzi trans-sialidase (TS) has arised as a relevant parasite virulence factor. TS gene family contains alleles encoding for active (aTS) and inactive (iTS) TS isoforms with a His342Tyr conserved mutation. We have reported that, in contrast to high-virulent strains (DTUs II, V and VI), lower-virulence strains (DTUs I, III and IV) do not contain iTS genes. Previous in vitro results using recombinant iTS protein suggest that it could play a different or complementary pathogenic role to that of aTS. We have constructed a recombinant iTS-encoding gene where a 3XFLAG epitope was inserted (T-iTS) and used to transfect iTSnull-parasites (K98 DTU I). Flow Citometry, Confocal Microscopy, Western Blot and TS activity evaluation showed its adequate expression and localization. Here we analyzed the infection rates of different clones, T-iTS, T-aTS (transfected with iTS and aTS, respectively) and T-O (transfected with empty vector), on different in vitro cell cultures and in murine model.