Functional differences of three CXCL10 homologues in the giant spiny frog Quasipaa spinosa. (August 2020)

• Record Type: Journal Article
• Authors: Liu, Ze-Peng; Gu, Wen-Bin; Wang, Shao-Yu; Wang, Lan-Zhi; Zhou, Yi-Lian; Dong, Wei-Ren; Shu, Miao-An
• Is Part Of: Developmental and comparative immunology. Volume 109(2020)
• Publication Date: 2020-08
• Subjects: CXCL10 -- Quasipaa spinosa -- Immune response -- Proliferation -- Migration; Immunology -- Periodicals; Developmental immunology -- Periodicals; 616.079
• DOI: 10.1016/j.dci.2020.103719
• Languages: English
• ISSNs: 0145-305X

Abstract

Abstract: Chemokines are a superfamily of structurally related chemotactic cytokines exerting significant roles in acting as a bridge between the innate and adaptive immune responses. In this study, we identified three CXC motif chemokine 10 (CXCL10) homologues ( Qs CXCL10-1, Qs CXCL10-2 and Qs CXCL10-3) from giant spiny frog Quasipaa spinosa . All three deduced Qs CXCL10 proteins contained four conserved cysteine residues as found in other known CXC chemokines. Phylogenetic analysis showed that Qs CXCL10-1, 2, 3 and other CXCL10s in amphibian were grouped together to form a separate clade. These three QsCXCL10 s were highly expressed in spleen and blood. Upon infection with Staphylococcus aureus or Aeromonas hydrophila, the expressions of QsCXCL10 s were markedly increased in spleen and blood during biotic stresses. Meanwhile, the QsCXCL10 s transcription in liver could also be up-regulated under abiotic stresses such as cold and heat stresses. The recombinant proteins of frog CXCL10 homologues were produced and purified in E. coli and possessed similar but differential bioactivities. Both rCXCL10-1 and rCXCL10-2 had strong effects on the up-regulation of pro-inflammatory cytokines ( TNF-α, IL-1β and IL-8 ) in vivo, whereas rCXCL10-3 induced a weak expression of these cytokines. Moreover, the rCXCL10-1 and rCXCL10-2 could strongly promote splenocyte proliferation and induce lymphocytes migration, while rCXCL10-3 had limited effects on these biological processes. All three frog chemokines triggered their functional activities by engaging CXC motif chemokine receptor 3 (CXCR3). Taken together, these results revealed that the three Qs CXCL10s had similar but differential functional activities in mediating immune responses and host defenses, which might contribute to a better understanding of the functional evolution of CXCL10 in vertebrates. Highlights: Three CXCL10 were identified and characterized in the giant spiny frog Quasipaa spinosa. Qs CXCL10s responded to both biotic stresses and abiotic stresses. Recombinant Qs CXCL10 proteins (rCXCL10s) enhanced the transcription levels of TNF-α, IL-1β and IL-8 in vivo . rCXCL10s could promote splenocyte proliferation and induce lymphocytes migration by engaging CXCR3.