TY - JOUR
T1 - Cryptosporidium parvum invasion of biliary epithelia requires host cell tyrosine phosphorylation of cortactin via c-Src
AU - Chen, Xian Ming
AU - Huang, Bing Q.
AU - Splinter, Patrick L.
AU - Cao, Hong
AU - Zhu, Guan
AU - McNiven, Mark A.
AU - Larusso, Nicholas F.
N1 - Funding Information:
Supported by National Institutes of Health grants DK57993 and DK24031 (to N.F.L.), DK44650 (to M.A.M.), and AI44594 (to G.Z.) and by the Mayo Foundation.
PY - 2003/7/1
Y1 - 2003/7/1
N2 - Background & Aims: Cryptosporidium parvum invasion of epithelia requires polymerization of host cell actin at the attachment site. We analyzed the role of host cell c-Src, a cytoskeleton-associated protein tyrosine kinase, in C. parvum invasion of biliary epithelia. Methods: In vitro models of biliary cryptosporidiosis using a human biliary epithelial cell line were used to assay the role of c-Src signaling pathway in C. parvum invasion. Results: c-Src and cortactin, an actin-binding protein and a substrate for c-Src, were recruited to the parasite-host cell interface during C. parvum invasion. Tyrosine phosphorylation of cortactin in infected cells was also detected. Inhibition of host cell c-Src significantly blocked C. parvum-induced accumulation and tyrosine phosphorylation of cortactin and actin polymerization at the attachment sites, thereby inhibiting C. parvum invasion of biliary epithelial cells. A triple mutation of tyrosine of cortactin in the epithelia also diminished C. parvum invasion. In addition, proteins originating from the parasite were detected within infected cells at the parasite-host cell interface. Antiserum against C. parvum membrane proteins blocked accumulation of c-Src and cortactin and significantly decreased C. parvum invasion. No accumulation of the endocytosis-related proteins, dynamin 2 and clathrin, was found at the parasite-host cell interface; also, inhibition of dynamin 2 did not block C. parvum invasion. Conclusions: C. parvum invasion of biliary epithelial cells requires host cell tyrosine phosphorylation of cortactin by a c-Src-mediated signaling pathway to induce actin polymerization at the attachment site, a process associated with microbial secretion but independent of host cell endocytosis.
AB - Background & Aims: Cryptosporidium parvum invasion of epithelia requires polymerization of host cell actin at the attachment site. We analyzed the role of host cell c-Src, a cytoskeleton-associated protein tyrosine kinase, in C. parvum invasion of biliary epithelia. Methods: In vitro models of biliary cryptosporidiosis using a human biliary epithelial cell line were used to assay the role of c-Src signaling pathway in C. parvum invasion. Results: c-Src and cortactin, an actin-binding protein and a substrate for c-Src, were recruited to the parasite-host cell interface during C. parvum invasion. Tyrosine phosphorylation of cortactin in infected cells was also detected. Inhibition of host cell c-Src significantly blocked C. parvum-induced accumulation and tyrosine phosphorylation of cortactin and actin polymerization at the attachment sites, thereby inhibiting C. parvum invasion of biliary epithelial cells. A triple mutation of tyrosine of cortactin in the epithelia also diminished C. parvum invasion. In addition, proteins originating from the parasite were detected within infected cells at the parasite-host cell interface. Antiserum against C. parvum membrane proteins blocked accumulation of c-Src and cortactin and significantly decreased C. parvum invasion. No accumulation of the endocytosis-related proteins, dynamin 2 and clathrin, was found at the parasite-host cell interface; also, inhibition of dynamin 2 did not block C. parvum invasion. Conclusions: C. parvum invasion of biliary epithelial cells requires host cell tyrosine phosphorylation of cortactin by a c-Src-mediated signaling pathway to induce actin polymerization at the attachment site, a process associated with microbial secretion but independent of host cell endocytosis.
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U2 - 10.1016/S0016-5085(03)00662-0
DO - 10.1016/S0016-5085(03)00662-0
M3 - Article
C2 - 12851885
AN - SCOPUS:0038054141
VL - 125
SP - 216
EP - 228
JO - Gastroenterology
JF - Gastroenterology
SN - 0016-5085
IS - 1
ER -