AUTHOR=Silveira Anna Clara Azevedo , Uombe Nelsa Paula Inácio , Velikkakam Teresiama , Borges Bruna Cristina , Teixeira Thaise Lara , de Almeida Vitelhe Ferreira , Torres Jhoan David Aguillon , Pereira Cecília Luiza , de Souza Guilherme , Teixeira Samuel Cota , Servato João Paulo Silva , Silva Marcelo José Barbosa , Mineo Tiago Wilson Patriarca , Ribas Rosineide Marques , Mortara Renato Arruda , da Silveira José Franco , da Silva Claudio Vieira 

TITLE=The Trypanosoma cruzi pleiotropic protein P21 orchestrates the intracellular retention and in-vivo parasitism control of virulent Y strain parasites

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=14

YEAR=2024

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2024.1412345

DOI=10.3389/fcimb.2024.1412345

ISSN=2235-2988

ABSTRACT=<p>P21 is a protein secreted by all forms of <italic>Trypanosoma cruzi</italic> (<italic>T. cruzi</italic>) with recognized biological activities determined in studies using the recombinant form of the protein. In our recent study, we found that the ablation of P21 gene decreased Y strain axenic epimastigotes multiplication and increased intracellular replication of amastigotes in HeLa cells infected with metacyclic trypomastigotes. In the present study, we investigated the effect of P21 <italic>in vitro</italic> using C2C12 cell lines infected with tissue culture-derived trypomastigotes (TCT) of wild-type and P21 knockout (TcP21<sup>−/−</sup>) Y strain, and <italic>in vivo</italic> using an experimental model of <italic>T. cruzi</italic> infection in BALB/c mice. Our <italic>in-vitro</italic> results showed a significant decrease in the host cell invasion rate by TcP21<sup>−/−</sup> parasites as measured by Giemsa staining and cell count in bright light microscope. Quantitative polymerase chain reaction (qPCR) analysis showed that TcP21<sup>−/−</sup> parasites multiplied intracellularly to a higher extent than the scrambled parasites at 72h post-infection. In addition, we observed a higher egress of TcP21<sup>−/−</sup> trypomastigotes from C2C12 cells at 144h and 168h post-infection. Mice infected with Y strain TcP21<sup>−/−</sup> trypomastigotes displayed higher systemic parasitemia, heart tissue parasite burden, and several histopathological alterations in heart tissues compared to control animals infected with scrambled parasites. Therewith, we propose that P21 is important in the host–pathogen interaction during invasion, cell multiplication, and egress, and may be part of the mechanism that controls parasitism and promotes chronic infection without patent systemic parasitemia.</p>