Characterization and functional analysis of the small heat shock protein HSP19.5 in Bombyx mori in response to Nosema bombycis infection

J Invertebr Pathol. 2025 Jun:210:108289. doi: 10.1016/j.jip.2025.108289. Epub 2025 Feb 21.

Abstract

Small heat shock proteins (sHSPs) are molecular chaperones known for their role in maintaining cellular homeostasis and protecting cells from various environmental stresses. This study focuses on the silkworm small heat shock protein HSP19.5 and its potential functions in the context of Nosema bombycis infection, a microsporidian pathogen causing severe disease in the sericulture industry. We cloned and characterized HSP19.5 and revealed its expression patterns in different silkworm tissues and developmental stages. Our results indicate that HSP19.5 expression is significantly up-regulated in response to N. bombycis infection, suggesting a role in the host stress response. Through a series of experiments, including RNA interference and overexpression analyses, we demonstrated that HSP19.5 promotes N. bombycis proliferation, possibly by inhibiting host cell apoptosis and regulating intracellular ROS levels. The cytoplasmic localization of HSP19.5 in silkworm cells is consistent with its function as a molecular chaperone. The results enhance our understanding of the complex host-pathogen interactions between silkworms and N. bombycis, and provides insights that may inform the development of novel strategies to control the pebrine disease.

Keywords: Apoptosis; Bombyx mori; Host-pathogen interaction; Nosema bombycis; Small heat shock proteins.

MeSH terms

  • Animals
  • Bombyx* / genetics
  • Bombyx* / metabolism
  • Bombyx* / microbiology
  • Heat-Shock Proteins, Small* / genetics
  • Heat-Shock Proteins, Small* / metabolism
  • Host-Pathogen Interactions
  • Insect Proteins* / genetics
  • Insect Proteins* / metabolism
  • Microsporidiosis
  • Nosema* / physiology

Substances

  • Insect Proteins
  • Heat-Shock Proteins, Small

Supplementary concepts

  • Nosema bombycis