Tacaribe arenavirus uses macropinocytosis as an alternative entry pathway

ROLDAN, J. S.; FORLENZA, M. B.; CANDURRA, N. A.

Rosario

Congreso; L Reunion SAIB; 2014

Tacaribe virus (TCRV) is a nonpathogenic member of the New World (NW) arenavirus family where pathogenic viruses such as Junin virus are found. NW arenaviruses utilize the transferrin receptor 1 (TfR1) from their natural host but pathogenic virus also use the human one. The main goal of this work is to characterize the alternative TCRV entry pathway and the role of the hTfR in it. We use CHO, TRVb (which luck endogenous TfR1) and TRVb1 cells (which stably express hTfR1) and treated with different compounds: cytochalasin D (cyt D) and latrunculin A (lat A), which collapse the actin filament; wortmannin (wort), a PI3K inhibitor and amiloride (amil), an inhibitor of the Na+/H+-exchanger. Wild type (wt) and dominant negative (dn) construction of Rab5 and Rab7 (early and late endosome marker respectably) were also used. After treatment with the drugs or transfections, cells were infected with TCRV. We quantify viral production and percentage of infected cells. In CHO, TRVb and TRVb1 cells, cyt D and lat A inhibit both parameters (70-90%) but wort and amil only reduce these parameters in TRVb1 cells (50-60%). In regard to Rab 5 and Rab7 dn, a reduction on TCRV infection was found only in TRVb and TRVb1 cells (50-70%). These results allow us to postulate that TCRV may use the macropinocytosis pathway to enter in TRVb1 cells and this could be a secondary pathway use in CHO and TRVb cells.