Role of crustacean female sex hormone in regulating immune response in the mud crab, Scylla paramamosain

• DOI: 10.1016/j.fsi.2023.109094
• Publication Date: 2023-09-28T01:19:42Z
• Authors: Yanan Wang; An Liu; Yuzhen Huang; Li Lu; Songlin Guo; Haihui Ye
• Keywords: Scylla paramamosain; Eyestalk; Portunus trituberculatus

Crustacean female sex hormone (CFSH) is responsible for sexual differentiation in crustaceans. The CFSH exhibited an interleukin-17 domain homologous to vertebrate IL-17, a family of inflammatory cytokines that play vital roles in immune defense. However, the immunoregulation of CFSH in crustaceans is a mystery. Therefore, this study aimed to investigate the immune regulatory roles of CFSH and CFSHR in the mud crab Scylla paramamosain. This study's immunofluorescence result revealed that Sp-CFSHR was highly expressed in granulocytes and semi-granulocytes but had moderate expression in hyalinocytes. The expression level of Sp-CFSH transcript in eyestalk ganglia and Sp-CFSHR in hemocytes were significantly up-regulated by the Poly (I:C) stimulation but significantly down-regulated in response to the lipopolysaccharide (LPS) stimulation. In our study, in vitro experiment exhibited that the nuclear transcription factors NF-κB signaling molecules (Sp-Dorsal and Sp-Relish), Sp-STAT, apoptosis-related gene Sp-IAP, and phagocytosis related gene (Sp-Rab5) expressions were significantly increased in hemocytes by recombinant CFSH (rCFSH) in vitro, but the pro-inflammatory cytokine gene (Sp-IL-16) expression was significantly suppressed. Finally, the rCFSH injection significantly up-regulated Sp-Dorsal, Sp-Relish, Sp-IAP, Sp-Caspase, Sp-ALF2, and C-type lectin (Sp-CTL-B) expressions in hemocytes as well as enhanced the bacterial clearance of the mud crab. In conclusion, our results suggested that CFSH may be a counterpart of vertebrate IL-17 in crustaceans that can enhance innate immunity to defense against Vibrionaceae infection via the NF-κB and/or JAK-STAT signaling pathways. This study provides the first evidence that CFSH is involved in the immunoregulation in crustaceans and enriches the insight of neuroendocrine-immune regulatory system, which providing new ideas for disease prevention in the mud crab industry.