Eimeria tenellaROPkinaseEtROP1induces G0/G1 cell cycle arrest and inhibits host cell apoptosis

Abstract

Coccidia are obligate intracellular protozoan parasites responsible for human and veterinary diseases. Eimeria tenella, the aetiologic agent of caecal coccidiosis, is a major pathogen of chickens. In Toxoplasma gondii, some kinases from the rhoptry compartment (ROP) are key virulence factors. ROP kinases hijack and modulate many cellular functions and pathways, allowing T. gondii survival and development. E. tenella's kinome comprises 28 putative members of the ROP kinase family; most of them are predicted, as pseudokinases and their functions have never been characterised. One of the predicted kinase, EtROP1, was identified in the rhoptry proteome of E. tenella sporozoites. Here, we demonstrated that EtROP1 is active, and the N‐terminal extension is necessary for its catalytic kinase activity. Ectopic expression of EtROP1 followed by co‐immunoprecipitation identified cellular p53 as EtROP1 partner. Further characterisation confirmed the interaction and the phosphorylation of p53 by EtROP1. E. tenella infection or overexpression of EtROP1 resulted both in inhibition of host cell apoptosis and G0/G1 cell cycle arrest. This work functionally described the first ROP kinase from E. tenella and its noncanonical structure. Our study provides the first mechanistic insight into host cell apoptosis inhibition by E. tenella. EtROP1 appears as a new candidate for coccidiosis control.

A Novel Rhoptry Protein as Candidate Vaccine against Eimeria tenella Infection

“…The distribution of Et-ROPK-Eten5-A and Et-GRA12 in sporozoites and merozoites of E. tenella was assessed using immunofluorescence and a mouse anti-rEt-ROPK-Eten5-A antibody and mouse anti-Et-GRA12 antibody. Et-ROPK-Eten5-A was distributed in the apical area of sporozoites, which was similar to the localization of Et-ROP1 protein [34]. A previous report showed that free second-generation merozoites had a long, slender body with two rhoptries at the apical pole [35].…”

The Growth of Eimeria tenella: Characterization and Application of Quantitative Methods to Assess Sporozoite Invasion and Endogenous Development in Cell Culture

“…Sporozoites ready to invade show overexpression of five different surface antigens (SAGs) which are important proteins in the recognition and attachment of the host cell (Tabares et al, 2004 ), as well overexpression of apical membrane antigen-1 (AMA1) and three rhoptry neck proteins (RONs) which are components of the moving junction, an essential structure for the invasion of the host cell in many Apicomplexa parasites (Besteiro et al, 2011 ). Three rhoptry kinases (ROPK), essential for intracellular survival through interaction with host proteins (Diallo et al, 2019 ), are also overexpressed by these pre-invading sporozoites. Once sporozoites have invaded the host cell (4 hpi), a switch in repertoire of SAG protein expression was observed, with four different SAGs found overexpressed here.…”

Eimeria bovis infections induce G1 cell cycle arrest and a senescence-like phenotype in endothelial host cells

“…Consequently, we additionally analysed typical markers of senescence as cell cycle-related status in E. bovis -infected cells. So far, parasite-triggered alteration of the host cellular cell cycle is a well-known feature acting on different phases and molecules of the cell cycle in a parasite-specific and even host cell type-specific fashion (Bouzahzah et al ., 2008 ; Brunet et al ., 2008 ; Molestina et al ., 2008 ; Wiens et al ., 2014 ; Kim et al ., 2016 ; Diallo et al ., 2019 ; Velásquez et al ., 2019 ). Thus, L. amazonensis interferes early in cell cycle by G 0 /G 1 phase arrest (Kuzmenok et al ., 2005 ), Encephalitozoon infections induce an accumulation of host cells in the S phase (Scanlon et al ., 2000 ).…”

“…In a cell type-specific manner, T. gondii was shown to induce a shift from G 0 /G 1 through the S phase with the accumulation of host cells in the S phase at the G 2 /M boundary in human foreskin fibroblasts, to trigger host cellular arrest in the G 2 phase in a human trophoblast cell line, in human dermal fibroblasts and in an L6 rat myoblast cell line (Brunet et al ., 2008 ; Kim et al ., 2016 ) or to mediate a G 2 /M arrest in primary bovine endothelial cells (Velásquez et al ., 2019 ). Referring to Eimeriidae, the only available report indicated a G 0 /G 1 arrest in E. tenella -infected host cells (Diallo et al ., 2019 ). In the case of Plasmodium spp., Plasmodium falciparum infections affected mitosis and led to a lack of cell division in HepG2 cells (Hanson et al, 2015 ) but cell cycle-dependent reactions neither played a role in Plasmodium berghei - or Plasmodium yoelii -infected mouse models nor in P. falciparum -infected primary hepatocytes.…”

“…In a transcriptome-based approach, E. bovis infection was shown to modulate gene transcription of cell cycle-related molecules, such as cyclin D2, cyclin E1, CDK2AP1, GADD45A or CDK inhibitor 1C in BUVECs (Taubert et al ., 2010 ). In the case of the avian species Eimeria tenella , a G 0 /G 1 arrest of HEK293T cells was induced upon transfection with an E. tenella rhoptry kinase 1 (Diallo et al ., 2019 ).…”