1. Academic Validation
  2. Expression of Interleukin-2 receptor subunit gamma (IL-2Rγ) and its binding with IL-2 induced activation of CD4 T lymphocytes in flounder (Paralichthys olivaceus)

Expression of Interleukin-2 receptor subunit gamma (IL-2Rγ) and its binding with IL-2 induced activation of CD4 T lymphocytes in flounder (Paralichthys olivaceus)

  • Fish Shellfish Immunol. 2022 Mar;122:426-436. doi: 10.1016/j.fsi.2022.02.033.
Mengmeng Zhao 1 Jing Xing 2 Xiaoqian Tang 1 Xiuzhen Sheng 1 Heng Chi 1 Wenbin Zhan 3
Affiliations

Affiliations

  • 1 Laboratory of Pathology and Immunology of Aquatic Animals, KLMME, Ocean University of China, Qingdao, 266003, China.
  • 2 Laboratory of Pathology and Immunology of Aquatic Animals, KLMME, Ocean University of China, Qingdao, 266003, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, No. 1 Wenhai Road, Aoshanwei Town, Qingdao, China. Electronic address: [email protected].
  • 3 Laboratory of Pathology and Immunology of Aquatic Animals, KLMME, Ocean University of China, Qingdao, 266003, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, No. 1 Wenhai Road, Aoshanwei Town, Qingdao, China.
Abstract

Interleukin-2 receptor (IL-2R), as the specific ligand of interleukin-2 (IL-2), binds to IL-2 and transmits signals and then can induce the proliferation of T lymphocytes in mammals. In this paper, the subunit of IL-2R in flounder (Paralichthys olivaceus), interleukin-2 receptor subunit gamma (IL-2Rγ) was cloned, and polyclonal Antibodies (Abs) against its extracellular region were produced, then the expression of flounder IL-2Rγ (fIL-2Rγ) at transcriptional and cellular levels were characterized. Moreover, the interaction of flounder IL-2 (fIL-2) with fIL-2Rγ was investigated, and the variations on CD4+/IL-2Rγ+ cells in flounder after treatment with recombinant IL-2 (rIL-2), anti-IL-2Rγ Abs were detected, respectively. The results showed that fIL-2Rγ protein had a typical fibronectin type III (FN3) domain. The Abs could specifically recognize native fIL-2Rγ molecules at 39.9 kDa. FIL-2Rγ was localized on both T and B lymphocytes, and the percentages of CD4+/IL-2Rγ+ and IgM+/IL-2Rγ+ lymphocytes were high in spleen. In addition, pBiFC-VN173-IL-2Rγ plasmids could bind to pBiFC-VC155-IL-2 plasmids. The percentage of CD4+/IL-2Rγ+ lymphocytes was significantly decreased after blocking with anti-IL-2Rγ Abs both in vivo and in vitro. In the meantime, four T cell markers genes and six IL-2-IL-2R pathway genes were down-regulated in anti-IL-2Rγ Abs group. These results first demonstrated that fIL-2Rγ molecules were expressed on both T and B lymphocytes in flounder, and the bond between fIL-2Rγ and fIL-2 activated the CD4 T lymphocytes. This study gave a new sight into the exploration of IL-2R function on T lymphocytes proliferation in fish.

Keywords

CD4(+) T lymphocytes; Interaction; Interleukin-2; Interleukin-2 receptor subunit gamma; Paralichthys olivaceus.

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