Neospora caninum Dense Granule Protein 7 Regulates the Pathogenesis of Neosporosis by Modulating Host Immune Response

Abstract

is a protozoan parasite closely related to Neosporosis caused by is considered one of the main causes of abortion in cattle and nervous-system dysfunction in dogs, and identification of the virulence factors of this parasite is important for the development of control measures. Here, we used a luciferase reporter assay to screen the dense granule proteins genes of , and we found that NcGRA6, NcGRA7, and NcGRA14 are involved in the activation of the NF-κB, calcium/calcineurin, and cAMP/PKA signals. To analyze the functions of these proteins and cyclophilin, we successfully knocked out their genes in the Nc1 strain using plasmids containing the CRISPR/Cas9 components. Among the deficient lines, the -deficient parasites showed reduced virulence in mice. An RNA sequencing analysis of infected macrophage cultures showed that NcGRA7 mainly regulates the host cytokine and chemokine production. The levels of gamma interferon in the ascites fluid, CXCL10 expression in the peritoneal cells, and CCL2 expression in the spleen were lower 5 days after infection with the-deficient parasite than after infection with the parental strain. The parasite burden and the degree of necrosis in the brains of mice infected with the -deficient parasite were also lower than in those of the parental strain. Collectively, our data suggest that both the NcGRA7-dependent activation of the inflammatory response and the parasite burden are important in virulence. invades and replicates in a broad range of host species and cells within those hosts. The effector proteins exported by induce its pathogenesis by modulating the host immunity. We show that most of the transcriptomic effects in-infected cells depend upon the activity of NcGRA7. A deficiency in NcGRA7 reduced the virulence of the parasite in mice. This study demonstrates the importance of NcGRA7 in the pathogenesis of neosporosis.

Neospora caninum infection induces an isolate virulence-dependent pro-inflammatory gene expression profile in bovine monocyte-derived macrophages

“…In T. gondii, differences in the activation of this pathway have been related to parasite type since type II strains induce a higher NF-κB activation than type I and III strains, which affects cytokine expression and virulence [59]. Activation of the NF-ƙB signalling pathway upon N. caninum infection has been previously reported in murine MØs, and it has been related to the expression of N. caninum 14-3-3 protein [40] and dense granule proteins NcGRA6, NcGRA7 and NcGRA14 [60]. However, the higher levels of mRNA expression found for the DEG of the NF-ƙB signalling pathway in Nc-Spain1H infection seems not to correlate with a higher expression of those dense granule proteins for this isolate [23].…”

Mechanism of Dayuanyin in the treatment of coronavirus disease 2019 based on network pharmacology and molecular docking

“…6, hsa04657 (IL-17 signaling pathway), hsa04933 (AGE-RAGE signaling pathway in diabetic complications), and hsa0406 (cytokine-cytokine receptor interaction pathway) enriched the highest number of genes, indicating that these pathways may play an important role in the mechanism of action of DYY in the treatment of COVID-19. The IL-17 signaling pathway is involved in the body's immune response [25,26] and inflammatory response [27]. The AGE-RAGE signaling pathway has important protective effects on bones and the heart and participates in oxidative stress response [25] and fibrosis transduction [22].…”

Proteomic Characterization of Host-Pathogen Interactions during Bovine Trophoblast Cell Line Infection by Neospora caninum

“…While efforts have been focused on determining virulence factors in N. caninum [41,42,55] and transcriptomic or proteomic differences between isolates [15,17], less attention has been paid to host-pathogen interactions, which are essential for a holistic understanding of infection biology and disease processes. In this study, for the first time, the proteomes of bovine trophoblast cells (target cells for N. caninum) infected with two well-differentiated isolates, the high-virulence Nc-Spain7 and the low-virulence Nc-Spain1H isolates, were studied at different time points of the tachyzoite lytic cycle post infection.…”