RRC ID 3025
著者 Rubin-de-Celis SS, Uemura H, Yoshida N, Schenkman S.
タイトル Expression of trypomastigote trans-sialidase in metacyclic forms of Trypanosoma cruzi increases parasite escape from its parasitophorous vacuole.
ジャーナル Cell Microbiol
Abstract Trypanosoma cruzi actively invades mammalian cells by forming parasitophorous vacuoles (PVs). After entry, the parasite has to escape from these vacuoles in order to replicate inside the host cell cytosol. Trans-sialidase (TS), a parasite enzyme that is used to obtain sialic acid from host glycoconjugates, has been implicated in cell invasion and PV exit, but how the enzyme acts in these processes is still unknown. Here we show that trypomastigotes derived from infected mammalian cells express and release 20 times more TS activity than axenic metacyclic trypomastigotes, which correspond to the infective forms derived from the insect vector. Both forms have the same capacity to invade mammalian cells, but cell derived trypomastigotes exit earlier from the vacuole. To test whether high TS expression is responsible for this increased exit from the PV, trypomastigote TS was expressed on the surface of metacyclic forms. Transfected and non-transfected metacyclics attached to and invaded HeLa or CHO cells equally. In contrast, metacyclics expressing TS on the surface escaped earlier from the vacuole than non-transfected metacyclics, or metacyclics expressing TS in their cytoplasm. Sialic acid may act as a barrier, which is removed by surface and/or secreted TS, because all types of parasites escaped earlier from the vacuoles of sialic acid-deficient Lec 2 cells than wild-type CHO cells. In addition, trypomastigotes and metacyclic forms expressing TS differentiated earlier into amastigotes. These results indicate that the increased expression of TS in cell-derived trypomastigotes is responsible for the earlier exit from the PV to the cytoplasm and their subsequent differentiation into amastigotes.
巻・号 8(12)
ページ 1888-98
公開日 2006-12-1
DOI 10.1111/j.1462-5822.2006.00755.x
PII CMI755
PMID 16824037
MeSH Animals CHO Cells Cricetinae Cytosol / parasitology Glycoproteins / chemistry Glycoproteins / physiology* HeLa Cells Host-Parasite Interactions Humans Life Cycle Stages Neuraminidase / chemistry Neuraminidase / physiology* Trypanosoma cruzi / enzymology* Trypanosoma cruzi / growth & development Trypanosoma cruzi / physiology Vacuoles / parasitology
IF 3.43
引用数 69
WOS 分野 MICROBIOLOGY CELL BIOLOGY
リソース情報
病原微生物 T. cruzi Y strain