| Autor: |
Kaoru Murakami, Daisuke Kamimura, Rie Hasebe, Mona Uchida, Nobuya Abe, Reiji Yamamoto, Jing-Jing Jiang, Yasuhiro Hidaka, Yuko Nakanishi, Shuzo Fujita, Yuki Toda, Nobuhiro Toda, Hiroki Tanaka, Shizuo Akira, Yuki Tanaka, Masaaki Murakami |
| Jazyk: |
angličtina |
| Rok vydání: |
2021 |
| Předmět: |
|
| Zdroj: |
Frontiers in Immunology, Vol 12 (2021) |
| Druh dokumentu: |
article |
| ISSN: |
1664-3224 |
| DOI: |
10.3389/fimmu.2021.675909 |
| Popis: |
The lipopolysaccharides (LPSs) of Rhodobacter are reported to be TLR4 antagonists. Accordingly, the extract of Rhodobacter azotoformans (RAP99) is used as a health supplement for humans and animals in Japan to regulate immune responses in vivo. We previously analyzed the LPS structure of RAP99 (RAP99-LPS) and found it is different from that of E. coli-LPS but similar to lipid A from Rhodobacter sphaeroides (RSLA), a known antagonist of TLR4, with both having three C14 fatty acyl groups, two C10 fatty acyl groups, and two phosphates. Here we show that RAP99-LPS has an immune stimulatory activity and acts as a TLR4 agonist. Pretreatment of RAP99-LPS suppressed E. coli-LPS-mediated weight loss, suggesting it is an antagonist against E. coli-LPS like other LPS isolated from Rhodobacter. However, injections of RAP99-LPS caused splenomegaly and increased immune cell numbers in C57BL/6 mice but not in C3H/HeJ mice, suggesting that RAP99-LPS stimulates immune cells via TLR4. Consistently, RAP99-LPS suppressed the lung metastasis of B16F1 tumor cells and enhanced the expression of TLR3-mediated chemokines. These results suggest that RAP99-LPS is a TLR4 agonist that enhances the activation status of the immune system to promote anti-viral and anti-tumor activity in vivo. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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