Toxoplasma gondii microneme protein MIC3 induces macrophage TNF-α production and Ly6C expression via TLR11/MyD88 pathway.
Toxoplasma gondii is the most successful parasite worldwide. It is of great interest to understand how T. gondii induce different immune responses in different hosts. In this study, we found that a peptide of T. gondii microneme protein MIC3 induced TNF-α production, NF-κB phosphorylation, iNOS tran...
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Format: | Article |
Language: | English |
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Public Library of Science (PLoS)
2023-02-01
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Series: | PLoS Neglected Tropical Diseases |
Online Access: | https://doi.org/10.1371/journal.pntd.0011105 |
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author | Jingfan Qiu Yanci Xie Chenlu Shao Tianye Shao Min Qin Rong Zhang Xinjian Liu Zhipeng Xu Yong Wang |
author_facet | Jingfan Qiu Yanci Xie Chenlu Shao Tianye Shao Min Qin Rong Zhang Xinjian Liu Zhipeng Xu Yong Wang |
author_sort | Jingfan Qiu |
collection | DOAJ |
description | Toxoplasma gondii is the most successful parasite worldwide. It is of great interest to understand how T. gondii induce different immune responses in different hosts. In this study, we found that a peptide of T. gondii microneme protein MIC3 induced TNF-α production, NF-κB phosphorylation, iNOS transcription and Ly6C expression in mouse macrophage RAW264.7 cells. MyD88 inhibition, small interfering RNA against Tlr11 and CRISPR/Cas9-mediated knock-out of Tlr11 all reduced MIC3-induced TNF-α production, NF-κB phosphorylation, iNOS transcription and Ly6C expression. Additionally, we determined the location of MIC3 peptide in mouse macrophages using immunofluorescence. MIC3 could both adhere to the cell membrane of mouse macrophages and enter the cells. These results suggest that MIC3 triggered the immune responses in mouse macrophages via TLR11/MyD88/NF-κB pathway. It is known that human macrophages lacking TLR11. We predicted that the immune responses induced by MIC3 in human macrophages were significantly different from those in mouse macrophages. As expected, MIC3 peptide failed to induce TNF-α expression, iNOS expression and NF-κB phosphorylation in human THP-1 derived macrophages. MIC3 induced macrophage immune responses via TLR11. Intriguingly, the amino acid sequence of MIC3 is completely different from the well-known TLR11 ligand profilin, which generates a potent IL-12p40, TNF-α and IL-6 response. In marked contrast to profilin, MIC3 could not induce IL-12p40 expression in both mouse RAW264.7 cells and human THP-1 derived macrophages. Furthermore, the simulated tertiary structure of MIC3 peptide shows poor similarity with the crystal structure of profilin, suggesting that MIC3 might be a different ligand from profilin. These findings about MIC3 and TLR11 will provide us with important insights into the pathogenesis of toxoplasmosis and coevolution during host-parasite interaction. |
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issn | 1935-2727 1935-2735 |
language | English |
last_indexed | 2024-04-10T06:33:22Z |
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spelling | doaj.art-c9e3c3eee56b4b5b8b87d13b24fb22342023-03-01T05:32:33ZengPublic Library of Science (PLoS)PLoS Neglected Tropical Diseases1935-27271935-27352023-02-01172e001110510.1371/journal.pntd.0011105Toxoplasma gondii microneme protein MIC3 induces macrophage TNF-α production and Ly6C expression via TLR11/MyD88 pathway.Jingfan QiuYanci XieChenlu ShaoTianye ShaoMin QinRong ZhangXinjian LiuZhipeng XuYong WangToxoplasma gondii is the most successful parasite worldwide. It is of great interest to understand how T. gondii induce different immune responses in different hosts. In this study, we found that a peptide of T. gondii microneme protein MIC3 induced TNF-α production, NF-κB phosphorylation, iNOS transcription and Ly6C expression in mouse macrophage RAW264.7 cells. MyD88 inhibition, small interfering RNA against Tlr11 and CRISPR/Cas9-mediated knock-out of Tlr11 all reduced MIC3-induced TNF-α production, NF-κB phosphorylation, iNOS transcription and Ly6C expression. Additionally, we determined the location of MIC3 peptide in mouse macrophages using immunofluorescence. MIC3 could both adhere to the cell membrane of mouse macrophages and enter the cells. These results suggest that MIC3 triggered the immune responses in mouse macrophages via TLR11/MyD88/NF-κB pathway. It is known that human macrophages lacking TLR11. We predicted that the immune responses induced by MIC3 in human macrophages were significantly different from those in mouse macrophages. As expected, MIC3 peptide failed to induce TNF-α expression, iNOS expression and NF-κB phosphorylation in human THP-1 derived macrophages. MIC3 induced macrophage immune responses via TLR11. Intriguingly, the amino acid sequence of MIC3 is completely different from the well-known TLR11 ligand profilin, which generates a potent IL-12p40, TNF-α and IL-6 response. In marked contrast to profilin, MIC3 could not induce IL-12p40 expression in both mouse RAW264.7 cells and human THP-1 derived macrophages. Furthermore, the simulated tertiary structure of MIC3 peptide shows poor similarity with the crystal structure of profilin, suggesting that MIC3 might be a different ligand from profilin. These findings about MIC3 and TLR11 will provide us with important insights into the pathogenesis of toxoplasmosis and coevolution during host-parasite interaction.https://doi.org/10.1371/journal.pntd.0011105 |
spellingShingle | Jingfan Qiu Yanci Xie Chenlu Shao Tianye Shao Min Qin Rong Zhang Xinjian Liu Zhipeng Xu Yong Wang Toxoplasma gondii microneme protein MIC3 induces macrophage TNF-α production and Ly6C expression via TLR11/MyD88 pathway. PLoS Neglected Tropical Diseases |
title | Toxoplasma gondii microneme protein MIC3 induces macrophage TNF-α production and Ly6C expression via TLR11/MyD88 pathway. |
title_full | Toxoplasma gondii microneme protein MIC3 induces macrophage TNF-α production and Ly6C expression via TLR11/MyD88 pathway. |
title_fullStr | Toxoplasma gondii microneme protein MIC3 induces macrophage TNF-α production and Ly6C expression via TLR11/MyD88 pathway. |
title_full_unstemmed | Toxoplasma gondii microneme protein MIC3 induces macrophage TNF-α production and Ly6C expression via TLR11/MyD88 pathway. |
title_short | Toxoplasma gondii microneme protein MIC3 induces macrophage TNF-α production and Ly6C expression via TLR11/MyD88 pathway. |
title_sort | toxoplasma gondii microneme protein mic3 induces macrophage tnf α production and ly6c expression via tlr11 myd88 pathway |
url | https://doi.org/10.1371/journal.pntd.0011105 |
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