Surface toll-like receptor 9 on immune cells and its immunomodulatory effect

Mengyuan Kou; Liying Wang

doi:10.3389/fimmu.2023.1259989

Surface toll-like receptor 9 on immune cells and its immunomodulatory effect

Front Immunol. 2023 Sep 1:14:1259989. doi: 10.3389/fimmu.2023.1259989. eCollection 2023.

Authors

Mengyuan Kou¹, Liying Wang²

Affiliations

¹ Department of Immunology, College of Basic Medical Sciences, Jilin University, Changchun, Jilin, China.
² Department of Molecular Biology, College of Basic Medical Sciences, Jilin University, Changchun, Jilin, China.

Abstract

Toll like receptor 9 (TLR9) has been considered as a crucial intracellular pattern recognition receptor in the immune system, which can directly or indirectly mediate innate and adaptive immune responses by recognizing CpG DNA in endosomes to initiate its downstream signaling. However, TLR9 can also be expressed on the membrane surface of some immune and non-immune cells, called surface TLR9 (sTLR9), which covers the TLR9 and its immunomodulatory role with a mysterious veil. In this review, we mainly focus on the sTLR9 expressed on neutrophils, B cells and erythrocytes, and its immunomodulatory roles displayed alone or in coordination with endosomal TLR9 (eTLR9), providing a theoretical reference for the application of its modulators.

Keywords: B cells; erythrocytes; immunomodulation; neutrophils; surface toll-like receptor 9.

Publication types

Review
Research Support, Non-U.S. Gov't

MeSH terms

B-Lymphocytes
Endosomes*
Erythrocytes
Signal Transduction
Toll-Like Receptor 9*

Substances

Toll-Like Receptor 9

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by the National Natural Science Foundation of China (8147888).