SHP-2 Mediates Cryptosporidium parvum Infectivity in Human Intestinal Epithelial Cells

Abstract

The parasite, Cryptosporidium parvum, induces human gastroenteritis through infection of host epithelial cells in the small intestine. During the initial stage of infection, C. parvum is reported to engage host mechanisms at the host cell-parasite interface to form a parasitophorous vacuole. We determined that upon infection, the larger molecular weight proteins in human small intestinal epithelial host cells (FHs 74 Int) appeared to globally undergo tyrosine dephosphorylation. In parallel, expression of the cytoplasmic protein tyrosine phosphatase Src homology-2 domain-containing phosphatase 2 (SHP-2) increased in a time-dependent manner. SHP-2 co-localized with the C. parvum sporozoite and this interaction increased the rate of C. parvum infectivity through SH2-mediated SHP-2 activity. Furthermore, we show that one potential target that SHP-2 acts upon is the focal adhesion protein, paxillin, which undergoes moderate dephosphorylation following infection, with inhibition of SHP-2 rescuing paxillin phosphorylation. Importantly, treatment with an inhibitor to SHP-2 and with an inhibitor to paxillin and Src family kinases, effectively decreased the multiplicity of C. parvum infection in a dose-dependent manner. Thus, our study reveals an important role for SHP-2 in the pathogenesis of C. parvum. Furthermore, while host proteins can be recruited to participate in the development of the electron dense band at the host cell-parasite interface, our study implies for the first time that SHP-2 appears to be recruited by the C. parvum sporozoite to regulate infectivity. Taken together, these findings suggest that SHP-2 and its down-stream target paxillin could serve as targets for intervention.

Dysregulation of focal adhesion kinase upon Toxoplasma gondii infection facilitates parasite translocation across polarised primary brain endothelial cell monolayers

“…Under these conditions, a significant elevation in the transmigration frequencies of T. gondii tachyzoites is observed. (Varughese, Kasper, Anneken, & Yadav, 2015). Although that study did not address the impact of infection on polarisation or barrier integrity, it is plausible that similar mechanisms explain the dephosphorylation of FAK upon T. gondii infection.…”

Potential Sabotage of Host Cell Physiology by Apicomplexan Parasites for Their Survival Benefits

“…Furthermore, the cryptosporidial binding leads to the formation of sphingolipid-enriched membrane microdomains which attracts Gal/GalNAc epitope containing glycoproteins on the host membrane parasite interface, activating PI3-K ( 192 ). The PI3-K cascade successively activates Cdc42, N-WASP, and Arp2/3 (actin-related protein 2/3) resulting in the formation of actin plaque ( 74 , 124 , 194 ). The parasite recruited src tyrosine kinase subsequently phosphorylates cortactin stimulating the polymerization and rearrangement of the actin cortex in the cell periphery through activation of Arp2/3 complex proteins (Figure 1 ) ( 74 , 195 ).…”

Role of SHP2 protein tyrosine phosphatase in SERT inhibition by enteropathogenic E. coli (EPEC)

“…Similar mechanisms of interactions between SHP2 and bacterial proteins were reported for enterohemorrhagic E. coli and Epstein-Barr virus (18,23). Interestingly, recent studies showed that the parasite Cryptosporidium parvum also uses SHP2 to increase infectivity in human intestinal epithelial cells (38).…”