Single-nuclei RNA-seq reveals skin cell responses to Aeromonas hydrophila infection in Chinese longsnout catfish Leiocassis longirostris

Front Immunol. 2023 Oct 16:14:1271466. doi: 10.3389/fimmu.2023.1271466. eCollection 2023.

Abstract

As the primary natural barrier that protects against adverse environmental conditions, the skin plays a crucial role in the innate immune response of fish, particularly in relation to bacterial infections. However, due to the diverse functionality and intricate anatomical and cellular composition of the skin, deciphering the immune response of the host is a challenging task. In this study, single nuclei RNA-sequencing (snRNA-seq) was performed on skin biopsies obtained from Chinese longsnout catfish (Leiocassis longirostris), comparing Aeromonas hydrophila-infected subjects to healthy control subjects. A total of 19,581 single nuclei cells were sequenced using 10x Genomics (10,400 in the control group and 9,181 in the treated group). Based on expressed unique transcriptional profiles, 33 cell clusters were identified and classified into 12 cell types including keratinocyte (KC), fibroblast (FB), endothelial cells (EC), secretory cells (SC), immune cells, smooth muscle cells (SMC), and other cells such as pericyte (PC), brush cell (BC), red blood cell (RBC), neuroendocrine cell (NDC), neuron cells (NC), and melanocyte (MC). Among these, three clusters of KCs, namely, KC1, KC2, and KC5 exhibited significant expansion after A. hydrophila infection. Analysis of pathway enrichment revealed that KC1 was primarily involved in environmental signal transduction, KC2 was primarily involved in endocrine function, and KC5 was primarily involved in metabolism. Finally, our findings suggest that neutrophils may play a crucial role in combating A. hydrophila infections. In summary, this study not only provides the first detailed comprehensive map of all cell types present in the skin of teleost fish but also sheds light on the immune response mechanism of the skin following A. hydrophila infection in Chinese longsnout catfish.

Keywords: Aeromonas hydrophila; cell expansion; fish skin cell; immune response; single nuclei RNA-sequencing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aeromonas hydrophila / physiology
  • Animals
  • Catfishes* / genetics
  • Endothelial Cells
  • Humans
  • Immunity, Innate
  • RNA-Seq

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by the Investigation on Fishery Resources and Environment in Key Waters of Northwest China and Agriculture Research System of China (CARS-46), the Sichuan Science and Technology Planning Project (2021YFYZ0015), the Technology Program of Sichuan Academy of Agricultural Sciences (1 + 9KJGG004), the National Key Research and Development Program (2022YFD2400903), the Natural Science Foundation of Sichuan Province (2022NSFSC1743), and the Sichuan Freshwater Fish Innovation Team of the National Modern Agricultural Industrial Technology System.