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  3. Immunological characteristics of Interleukin-2 receptor subunit beta (IL-2Rβ) in flounder (Paralichtlys olivaceus): Implication for IL-2R function

Immunological characteristics of Interleukin-2 receptor subunit beta (IL-2Rβ) in flounder (Paralichtlys olivaceus): Implication for IL-2R function

  • Fish Shellfish Immunol. 2019 Oct;93:641-651. doi: 10.1016/j.fsi.2019.07.059.
Xiujuan Zhou 1,  Jing Xing 2,  Xiaoqian Tang 3,  Xiuzhen Sheng 1,  Wenbin Zhan 3
Affiliations

Affiliations

  • 1 Laboratory of Pathology and Immunology of Aquatic Animals, KLMME, Ocean University of China, 5 Yushan Road, Qingdao, 266003, China.
  • 2 Laboratory of Pathology and Immunology of Aquatic Animals, KLMME, Ocean University of China, 5 Yushan Road, Qingdao, 266003, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China. Electronic address: [email protected].
  • 3 Laboratory of Pathology and Immunology of Aquatic Animals, KLMME, Ocean University of China, 5 Yushan Road, Qingdao, 266003, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China.
PMID: 31344456 DOI: 10.1016/j.fsi.2019.07.059
Abstract

Interleukin-2 receptor subunit beta of flounder (Paralichthys olivace, fIL-2Rβ) was annotated on the NCBI, its gene was cloned and characterized functionally in this study. And then the Amino acids sequences and tertiary structure of fIL-2Rβ were analyzed, respectively. RT-PCR and ImageJ analyzed showed that fIL-2Rβ mRNA were expressed in the gill, spleen, kidney, intestines, liver, blood, muscle and skin, which showed high signals in spleen and blood. And then the recombinant protein of fIL-2Rβ extracellular region and its polyclonal Antibodies were produced, native fIL-2Rβ molecules in flounder peripheral blood leukocytes (PBLs) were identified at 60.7 kDa by Mass spectrometry, which were in accordance with the molecular mass of full fIL-2Rβ protein calculated on the predicted protein sequence. Then the IL-2Rβ+ cell in T/B lymphocytes were characterized by Flow cytometry and indirect immunofluorescence assay, respectively. The results showed that the percentages of IL-2Rβ+ leukocytes, IL-2Rβ+/CD4+, IL-2Rβ+/IgM+ lymphocytes were 18.4 ± 2.7%, 4.5 ± 0.8%, 4.3% ± 0.5 in PBLs, and were 13.6 ± 0.9%, 4.6 ± 1.1%, 6.1% ± 0.4 in spleen, similarly, the percentages of IL-2Rβ+ leukocytes, IL-2Rβ+/CD4+, IL-2Rβ+/IgM+ lymphocytes were 9.4 ± 0.3%, 4.0 ± 0.5%, 5.7 ± 0.1% in head kidney, respectively. After KLH injection, compared with control group, the gene expression of IL-2, IL-2Rβ, CD3, TCR, CD79b and IgM in spleen of flounder were up-regulated, respectively (p < 0.05). And the FCM results showed that the percentages of IL-2Rβ+ leukocytes in PBLs were significantly increased post Keyhole limpet hemocyanin (KLH) injection, which peaked 23.9 ± 0.9% at 9th day (p < 0.05). To our knowledge, those results first reported that the characteristics of IL-2R and IL-2R + molecules were expressed on both B and T lymphocytes in fish. At the same time, this study lays a foundation for further exploring the interaction between IL-2 and IL-2R to promote cell proliferation and carrying out biological functions.

Keywords

Interleukin-2; Interleukin-2 receptor; Paralichthys olivace; T/B lymphocytes.

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