The repetitive domain of Trypanosoma cruzi trans-sialidase enhances the immune response against the catalytic domain.

CARLOS ANDRES BUSCAGLIA; CAMPETELLA, O. E.; LEGUIZAMÓN, M. S.; FRASCH, A. C.

JOURNAL OF INFECTIOUS DISEASES

Año: 1998 vol. 177 p. 431 - 436

0022-1899

Trypanosoma cruzi trans-sialidase consists of a C-terminal domain composed essentially of immunodominant amino acid repeat units (SAPA-repeats) and an amino region responsible for the enzymatic activity (catalytic domain). To investigate the possible function(s) of SAPA-repeats, recombinant trans-sialidases either containing or lacking the C-terminal region were tested in mice. The presence of SAPA-repeats in the intravenously injected protein has two consequences. First, they enhance the persistence of the trans-sialidase activity in blood. Second, SAPA-repeats promoted the production of antibodies directed to the catalytic domain that inhibit trans-sialidase activity. These results suggest that SAPA-repeats modulate the trans-sialidase activity in blood.