title: Silkworm ferritin 1 heavy chain homolog is involved in defense against bacterial infection through regulation of haemolymph iron homeostasis.
abstract: Iron functions as a nutrient and a potential toxin in all organisms. It plays a key role in the interaction between microbes and their hosts as well. Microbial infection disrupts iron homeostasis in the host; meanwhile the host endeavors to keep the homeostasis through iron transport and storage. Transferrins and ferritins are the major iron-binding proteins that affect iron distribution in insects. In this study, we investigated a possible involvement of Bombyx mori ferritin 1 (BmFer1) heavy chain homolog in the defense against bacterial infection in the silkworm larvae. The BmFer1 mRNA abundance was up-regulated in hemocytes, but not in fat body, after Pseudomonas aeruginosa or Staphylococcus aureus infection. The infection resulted in elevated iron levels in the hemolymph. Injection of recombinant BmFer1 protein into hemocoel reduced the plasma iron level after infection, limited the bacterial growth in the hemolymph, and resulted in a lower mortality caused by infection. Our study indicated that B. mori ferritin-1 may restrict iron access of the invading bacteria to block their growth as a defense strategy.
authors.affiliation: Department of Entomology, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Sohail Ahmed
authors.initials: SA
authors.lastname: Otho
authors.affiliation: Department of Entomology, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Kangkang
authors.initials: K
authors.lastname: Chen
authors.affiliation: Department of Entomology, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Yongdong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Entomology, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.affiliation: Department of Entomology, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China; Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, Northwest A&F University, Yangling, Shaanxi 712100, China. Electronic address: zhiqiang.lu@nwsuaf.edu.cn.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Lu
mesh_terms: D000818:Animals; D001052:Apoferritins / Q000235:genetics / Q000378:metabolism*; D012831:Bombyx / Q000276:immunology*; D006434:Hemocytes / Q000502:physiology*; D006458:Hemolymph / Q000276:immunology / Q000382:microbiology; D006706:Homeostasis; D054884:Host-Pathogen Interactions; D007113:Immunity, Innate; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D007501:Iron / Q000378:metabolism; D011552:Pseudomonas Infections / Q000276:immunology*; D011550:Pseudomonas aeruginosa / Q000254:growth & development / Q000276:immunology*; D013203:Staphylococcal Infections / Q000276:immunology*; D013211:Staphylococcus aureus / Q000254:growth & development / Q000276:immunology*; D015854:Up-Regulation
chemical_list: D019476:Insect Proteins; D001052:Apoferritins; D007501:Iron
keywords: Bacterial infection; Bombyx mori; Defense; Ferritin; Iron homeostasis