Characterization of a 21kDa protein from Trypanosoma cruzi associated with mammalian cell invasion.
Trypanosoma cruzi genomic database was screened for hypothetical proteins that showed high probability of being secreted or membrane anchored and thus, likely involved in host-cell invasion. A sequence that codes for a 21kDa protein that showed high probability of being secreted was selected. After cloning this protein sequence, the results showed that it was a ubiquitous protein and secreted by extracellular amastigotes. The recombinant form (P21-His(6)) adhered to HeLa cells in a dose-dependent manner. Pretreatment of host cells with P21-His(6) inhibited cell invasion by extracellular amastigotes from G and CL strains. On the other hand, when the protein was added to host cells at the same time as amastigotes, an increase in cell invasion was observed. Host-cell pretreatment with P21-His(6) augmented invasion by metacyclic trypomastigotes. Moreover, polyclonal antibody anti-P21 inhibited invasion only by extracellular amastigotes and metacyclic trypomastigotes from G strain. These results suggested that P21 might be involved in T. cruzi cell invasion. We hypothesize that P21 could be secreted in the juxtaposition parasite-host cell and triggers signaling events yet unknown that lead to parasite internalization.
Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, SP, Brazil.
Claudio V
CV
da Silva
Silvia Y
SY
Kawashita
Christian M
CM
Probst
Bruno
B
Dallagiovanna
Mário C
MC
Cruz
Erika A
EA
da Silva
Thaís C B S
TC
Souto-Padrón
Marco A
MA
Krieger
Samuel
S
Goldenberg
Marcelo R S
MR
Briones
Norma W
NW
Andrews
Renato A
RA
Mortara
D000818:Animals; D002522:Chlorocebus aethiops; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011485:Protein Binding; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D017422:Sequence Analysis, DNA; D014349:Trypanosoma cruzi / Q000235:genetics / Q000472:pathogenicity*; D014709:Vero Cells; D037521:Virulence Factors / Q000737:chemistry / Q000235:genetics / Q000502:physiology*
D016054:DNA, Protozoan; D015800:Protozoan Proteins; D037521:Virulence Factors