TgROP18 targets IL20RB for host-defense-related-STAT3 activation during Toxoplasma gondii infection

Abstract

Background: Toxoplasma gondii is an opportunistic protozoan infecting almost one-third of the world's population. Toxoplasma gondii rhoptry protein 18 (TgROP18) is a key virulence factor determining the parasite's acute virulence and is secreted into host cells during infection. We previously identified the interaction of TgROP18 and host cell immune-related receptor protein IL20RB, and observed the activation of STAT3 in human keratinocytes (HaCaT) cells infected by the rop16 knockout RH strain, though TgROP16 is regarded as being responsible for host STAT3 activation during T. gondii invasion. Therefore, we hypothesize TgROP18 can activate host STAT3 through binding to IL20RB. Methods: CRISPR-CAS9 technology was used to generate the ROP16 and ROP18 double knockout RH strain, RH-∆rop16∆rop18. SDS-PAGE and western blot were used to detect STAT3 activation in different HaCaT cells with high endogenous IL20RB expression treated with T. gondii tachyzoites infection, recombinant ROP18, or IL-20. FRET and coimmunoprecipitation (Co-IP) was used to detect the protein-protein interaction. Results: We observed that TgROP18 was involved in a synergic activation of the host JAK/STAT3 pathway together with TgROP16 in human HaCaT cells infected with T. gondii or treated with recombinant TgROP18 protein, stimulating host proinflammatory immune responses such as expression of TNF-α. The effect of recombinant ROP18 on STAT3 phosphorylation was presented in a dose-dependent manner. Additionally, TgROP18 was identified to target IL20RB on its extracellular domain. When we treated different cell lines with the recombinant ROP18, STAT3 phosphorylation could only be observed in the cells with endogenous IL20RB expression, such as HaCaT cells. Conclusions: These findings indicate that TgROP18-IL20RB interaction upon T. gondii invasion was involved in STAT3 activation, which is associated with host cell defense.

B7-H4 reduction induced by Toxoplasma gondii infection results in dysfunction of decidual dendritic cells by regulating the JAK2/STAT3 pathway

“…Studies have shown that T. gondii infection upregulated p-STAT3(705) expression in bone marrow-derived macrophages [ 48 ] and the A549 cell line [ 49 ]. For p-STAT3(727), however, no significant differences were found after RH T. gondii infection in human HaCaT cells [ 50 ]. To date, no studies about p-STAT3(727) expression have been reported in human dDCs with T. gondii infection.…”

Identification of IL20RB as a Novel Prognostic and Therapeutic Biomarker in Clear Cell Renal Cell Carcinoma

“…This pathway is identified to have the ability to trigger epidermal hyperplasia, and skin inflammation thereby is supposed to be related with the pathogenesis of chronic inflammation and autoimmune diseases [ 15 ]. Although IL20RB was initially found to be involved in many nonmalignant diseases, such as psoriasis [ 16 ], rheumatoid arthritis [ 17 ], vitiligo [ 18 ], ulcerative colitis [ 19 ], glaucoma [ 20 ], asthma [ 21 ], endometriosis [ 22 ], and chronic rhinosinusitis [ 23 ] as well as infectious diseases [ 24 ], novel discoveries indicate IL20RB could also play an important role in malignant diseases. Recently, increasing evidence supports IL20RB also plays a vital role in human cancers such as colorectal adenocarcinoma [ 25 ], breast cancer [ 26 ], and esophageal carcinoma [ 27 ], while its role in ccRCC still remains unclear.…”

Anti-infection roles of miR-155-5p packaged in exosomes secreted by dendritic cells infected with Toxoplasma gondii

“…The isolated exosomes and the transfected cells were collected and lysed using lysis buffer (Beyotime Biotechnology, Shanghai, China), total proteins were loaded for sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS-PAGE), and WB was performed as described previously [ 29 ]. The following primary antibodies were used: CD9 rabbit monoclonal antibody (mAb; 1:1000), TSG101 rabbit mAb (1:1000), HSP70 rabbit mAb (1:1000), iNOS rabbit mAb (1:1000), p65 rabbit mAb (1:1000), and SOCS1 rabbit mAb (1:1000) purchased from Abcam (MA, USA); GAPDH mouse mAb (1:1000), phosphorylated IκB alpha (Ser32/Ser36) mouse mAb (1:1000), and phosphorylated NF-κB p65 (S536) mouse mAb (1:1000) purchased from Affinity Biosciences (OH, USA); and IKBα rabbit mAb (1:1000) purchased from GeneTex (Santa Cruz, CA, USA).…”