Differential expression of immunity-related genes in larval Manduca sexta tissues in response to gut and systemic infection

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • Yvette M. von Bredow - , Justus-Liebig-Universität Gießen (Autor:in)
  • Petra Prochazkova - , Czech Academy of Sciences (Autor:in)
  • Jiri Dvorak - , Czech Academy of Sciences (Autor:in)
  • Frantisek Skanta - , Czech Academy of Sciences (Autor:in)
  • Tina E. Trenczek - , Justus-Liebig-Universität Gießen (Autor:in)
  • Martin Bilej - , Czech Academy of Sciences (Autor:in)
  • Christoph Rüdiger von Bredow - , Professur für Angewandte Zoologie, Justus-Liebig-Universität Gießen, Technische Universität Dresden (Autor:in)

Abstract

Introduction: The midgut epithelium functions as tissue for nutrient uptake as well as physical barrier against pathogens. Additionally, it responds to pathogen contact by production and release of various factors including antimicrobial peptides, similar to the systemic innate immune response. However, if such a response is restricted to a local stimulus or if it appears in response to a systemic infection, too is a rather underexplored topic in insect immunity. We addressed the role of the midgut and the role of systemic immune tissues in the defense against gut-borne and systemic infections, respectively. Methods: Manduca sexta larvae were challenged with DAP-type peptidoglycan bacteria – Bacillus thuringiensis for local gut infection and Escherichia coli for systemic stimulation. We compared the immune response to both infection models by measuring mRNA levels of four selected immunity-related genes in midgut, fat body, hematopoietic organs (HOs), and hemocytes, and determined hemolymph antimicrobial activity. Hemocytes and HOs were tested for presence and distribution of lysozyme mRNA and protein. Results: The midgut and circulating hemocytes exhibited a significantly increased level of lysozyme mRNA in response to gut infection but did not significantly alter expression in response to a systemic infection. Conversely, fat body and HOs responded to both infection models by altered mRNA levels of at least one gene monitored. Most, but not all hemocytes and HO cells contain lysozyme mRNA and protein. Discussion: These data suggest that the gut recruits immune-related tissues in response to gut infection whereas systemic infections do not induce a response in the midgut. The experimental approach implies a skewed cross-talk: An intestinal infection triggers immune activity in systemic immune organs, while a systemic infection does not elicit any or only a restricted immune response in the midgut. The HOs, which form and release hemocytes in larval M. sexta, i) synthesize lysozyme, and ii) respond to immune challenges by increased immune gene expression. These findings strongly suggest that they not only provide phagocytes for the cellular immune response but also synthesize humoral immune components.

Details

OriginalspracheEnglisch
Aufsatznummer1258142
Seitenumfang14
FachzeitschriftFrontiers in cellular and infection microbiology
Jahrgang13(2023)
PublikationsstatusVeröffentlicht - 2023
Peer-Review-StatusJa

Externe IDs

PubMed 37900309

Schlagworte

Ziele für nachhaltige Entwicklung

Schlagwörter

  • Bacillus thuringiensis, comparative immune response, gut immunity, hematopoietic organ, insect immunity, insect midgut, lysozyme