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Kong L, Wu L, Guo Z, Mu L, Yang Y, Bian X, Li B, Pan X, Fu S, Ye J. A Siglec-1-like lectin from Nile tilapia (Oreochromis niloticus) possesses functions of agglutination and mediation of macrophage phagocytic activity. FISH & SHELLFISH IMMUNOLOGY 2020; 102:203-210. [PMID: 32330627 DOI: 10.1016/j.fsi.2020.04.034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 04/14/2020] [Accepted: 04/16/2020] [Indexed: 06/11/2023]
Abstract
Siglec-1, one of the sialic acid-binding immunoglobulin-type lectins, is closely related to the recognition of host-pathogen and cell-cell interactions in the adaptive and innate immune systems. In this communication, a Siglec-1-like gene (OnSiglec-1-like) from Nile tilapia (Oreochromis niloticus) was analyzed. Relative expression revealed that the OnSiglec-1-like was expressed in all tested tissues, and the highest expression was found in the anterior kidney. Upon Streptococcus agalactiae (S. agalactiae) infection, the expression of OnSiglec-1-like was up-regulated in anterior kidney and spleen significantly in vivo. Additionally, the same phenomenon was observed in anterior kidney leukocytes upon LPS and S. agalactiae challenges as well in vitro. Western-blotting and ELISA analyses revealed that recombinant OnSiglec-1-like protein possessed high binding activity to LTA, LPS and S. agalactiae. Further, the recombinant OnSiglec-1-like was able to agglutinate S. agalactiae. Moreover, with the digestion of specific sialidase, the phagocytic ability of macrophages to S. agalactiae was greatly enhanced. Taken together, these results indicated that the Siglec-1-like possesses conserved functions of agglutination and promotion of macrophage phagocytic activity in Nile tilapia.
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Affiliation(s)
- Linghe Kong
- Institute of Modern Aquaculture Science and Engineering, School of Life Sciences, South China Normal University, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, Guangdong, 510631, PR China
| | - Liting Wu
- Institute of Modern Aquaculture Science and Engineering, School of Life Sciences, South China Normal University, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, Guangdong, 510631, PR China
| | - Zheng Guo
- Institute of Modern Aquaculture Science and Engineering, School of Life Sciences, South China Normal University, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, Guangdong, 510631, PR China.
| | - Liangliang Mu
- Institute of Modern Aquaculture Science and Engineering, School of Life Sciences, South China Normal University, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, Guangdong, 510631, PR China
| | - Yanjian Yang
- Institute of Modern Aquaculture Science and Engineering, School of Life Sciences, South China Normal University, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, Guangdong, 510631, PR China
| | - Xia Bian
- Institute of Modern Aquaculture Science and Engineering, School of Life Sciences, South China Normal University, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, Guangdong, 510631, PR China
| | - Bingxi Li
- Institute of Modern Aquaculture Science and Engineering, School of Life Sciences, South China Normal University, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, Guangdong, 510631, PR China
| | - Xunbin Pan
- Institute of Modern Aquaculture Science and Engineering, School of Life Sciences, South China Normal University, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, Guangdong, 510631, PR China
| | - Shengli Fu
- Institute of Modern Aquaculture Science and Engineering, School of Life Sciences, South China Normal University, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, Guangdong, 510631, PR China
| | - Jianmin Ye
- Institute of Modern Aquaculture Science and Engineering, School of Life Sciences, South China Normal University, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, Guangdong, 510631, PR China.
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Dong J, Wei Y, Sun C, Tian Y, Hu J, Shi H, Zhang D, Lu M, Ye X. Interaction of Group B Streptococcus sialylated capsular polysaccharides with host Siglec-like molecules dampens the inflammatory response in tilapia. Mol Immunol 2018; 103:182-190. [PMID: 30291999 DOI: 10.1016/j.molimm.2018.09.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 09/20/2018] [Accepted: 09/21/2018] [Indexed: 01/09/2023]
Abstract
Group B Streptococcus (GBS, S. agalactiae) infection in tilapia (Oreochromis niloticus) causes widespread death of this species and is a significant issue for the aquaculture industry. The major virulence factor for GBS is its sialylated capsular polysaccharides (CPs). These CPs interact with sialic acid-binding immunoglobulin-like lectins (Siglecs) on the host immune cells to regulate the downstream inflammatory response and evade detection. Previously, we cloned multiple Siglec-like molecules from an O. niloticus cDNA library, all of which were shown to interact with the sialylated CPs of GBS. In the present study, we investigated the effects of GBS infection on the expression of pro- and anti-inflammatory cytokines in O. niloticus as well as OnSiglec-like-transfected macrophage cells. Eukaryotic expression vectors containing full-length OnSiglec-1-like, -4b-like, -14-like were constructed and used to transfect RAW264 macrophages in vitro as well as live tilapia in vivo prior to GBS infection. The expression of the anti-inflammatory cytokine interleukin (IL)-10 and the pro-inflammatory cytokines tumor necrosis factor (TNF)-α, IL-6, and interferon (INF)-β were then analyzed by qPCR. Our results indicate that as infection progressed, IL-10 expression was significantly upregulated, while that of TNF-α and IL-6 were significantly downregulated in the OnSiglec-like-transfected cells. INF-β expression was also downregulated in cells transfected with OnSiglec-1-like and -4b-like, but was not significantly effected in OnSiglec-14-like-transfected cells. Notably, the magnitude of these cytokine expression changes was greatly decreased when a ΔneuA GBS mutant was used to infect the OnSiglec-1-like-transfected cells. In GBS-infected tilapia, IL-10 expression was significantly upregulated in all tissues, whereas INF-β expression in the spleen, kidney, and gills was significantly downregulated at 12 hpi. While the expression of TNF-α was slightly upregulated, this change was not significant. In GBS ΔneuA mutant-infected O. niloticus, IL-10 expression in all of the tissues was significantly lower than that observed for the wild-type GBS group, while TNF-α expression was higher in the mutant infected group. There was no significant difference in INF-β expression between the two groups. Taken together, sialylated CPs on GBS appear to interact with host OnSiglec-like molecules to transmit negative regulatory signals via enhanced anti-inflammatory cytokine IL-10 production and reduced pro-inflammatory cytokine production, ultimately leading to dampening of the host immune response. The results of this study further elucidate the molecular mechanism underlying GBS infection in tilapia and also provide candidate drug target molecules.
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Affiliation(s)
- Junjian Dong
- Key Laboratory of Tropical and Subtropical Fisheries Resource, Application and Cultivation, Ministry of Agriculture, Pearl River Fisheries Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China
| | - Yuanzheng Wei
- Guangdong Laboratory Animals Monitoring Institute, Guangzhou, 510663, China
| | - Chengfei Sun
- Key Laboratory of Tropical and Subtropical Fisheries Resource, Application and Cultivation, Ministry of Agriculture, Pearl River Fisheries Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China
| | - Yuanyuan Tian
- Key Laboratory of Tropical and Subtropical Fisheries Resource, Application and Cultivation, Ministry of Agriculture, Pearl River Fisheries Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China
| | - Jie Hu
- Key Laboratory of Tropical and Subtropical Fisheries Resource, Application and Cultivation, Ministry of Agriculture, Pearl River Fisheries Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China
| | - Hongya Shi
- Key Laboratory of Tropical and Subtropical Fisheries Resource, Application and Cultivation, Ministry of Agriculture, Pearl River Fisheries Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China
| | - Dengfeng Zhang
- Key Laboratory of Tropical and Subtropical Fisheries Resource, Application and Cultivation, Ministry of Agriculture, Pearl River Fisheries Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China
| | - Maixin Lu
- Key Laboratory of Tropical and Subtropical Fisheries Resource, Application and Cultivation, Ministry of Agriculture, Pearl River Fisheries Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China
| | - Xing Ye
- Key Laboratory of Tropical and Subtropical Fisheries Resource, Application and Cultivation, Ministry of Agriculture, Pearl River Fisheries Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China.
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