Eimeria acervulina Microneme Protein 3 Inhibits Apoptosis of the Chicken Duodenal Epithelial Cell by Targeting the Casitas B-Lineage Lymphoma Protein.

Pu Wang,Yue Han,Simin Deng,Jiali Xu,Jinpeng Ying,Chiyu Guan,Xian Zhang,Yiran Zhu,Mianmian Chen,Yukun Jia,Weirong Wang,Houhui Song,Changyong Cheng,Jing Wang

doi:10.3389/fvets.2021.636809

Pu Wang, Yue Han + Show 12 more

Open Access

https://doi.org/10.3389/fvets.2021.636809

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Abstract

Eimeria acervulina (E. acervulina) causes coccidiosis in poultry which persists as economic pain worldwide. Most damage to the intestinal mucosa results from apoptosis of the infected intestinal epithelial cells. The Microneme protein 3 (MIC3) protein is a key virulence factor in some parasites involved in host cell apoptosis inhibition. Here, we studied whether and how MIC3 affects the apoptosis in E. acervulina infected chicken duodenal epithelial cells. Through flow cytometry (FCM), we found that the presence of merozoites and the overexpression of MIC3 significantly decreased apoptosis and the activity of caspase-3 in chicken duodenal epithelial cells at 4, 6, and 8 h post merozoite infection (P < 0.01). Silencing the Casitas B-lineage lymphoma (CBL) protein, a host receptor for MIC3 with shRNA was shown to promote apoptosis in the chicken duodenal epithelial cells. The early apoptotic rate of host cells in the lentiviral-MIC3 group was significantly lower than that in the lentiviral-MIC3 + shRNA CBL group at 4 h after MIC3 expression (P < 0.01), and it was moderately decreased in the lentiviral-MIC3 + shRNA CBL group compared with that in the shRNA CBL group. Our data indicated that MIC3 inhibited early apoptosis of E. acervulina infected chicken duodenal epithelial cells by targeting host receptor-CBL protein. These findings unveiled one of the mechanisms of how intracellular parasites affect the apoptosis of infected host cells, which provided a deeper understanding of their pathogenesis.

Highlights

Eimeria acervulina (E. acervulina) can cause pronounced pathological intestinal changes and death in infected chickens [1]
It has been confirmed that intracellular parasites such as Cryptosporidium parvum (C. parvum), Trypanosoma cruzi (T. cruzi), Theileria parvum (T. parvum), Toxoplasma gondii (T. gondii), Neospora caninum (N. caninum), Leishmania, and Plasmodium can inhibit host cell apoptosis after invading cells [8,9,10,11,12,13,14]
The MTT and flow cytometry assays results showed that the apoptosis rate of duodenal epithelial cells was ∼30%, and the death rate was

Summary

Introduction

Eimeria acervulina (E. acervulina) can cause pronounced pathological intestinal changes and death in infected chickens [1]. Each sporozoite undergoes multiple rounds of division to form multiple merozoites, EaMIC3 Inhibits Cell Apoptosis by CBL which cause cell damage [2]. Apoptosis represents a physiological form of cell death that occurs in most multicellular organisms. The second-generation schizonts of Eimeria necatrix have been shown to inhibit host cell apoptosis by activating the NF-κB signaling pathway in the early stage of infection [16]. After E. acervulina merozoites invaded bovine kidney cells, cell apoptosis was inhibited in the early stage [19]. It has not been reported how E. acervulina may affect the apoptosis in duodenal epithelial host cells

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