Ricin-B-lectin enhances microsporidia <italic>Nosema bombycis</italic> infection in <italic>Bm</italic>N cells from silkworm <italic>Bombyx mori</italic>

Abstract

Nosema bombycis is an obligate intracellular parasitic fungus that utilizes a distinctive mechanism to infect Bombyx mori Spore germination can be used for host cell invasion; however, the detailed mechanism remains to be elucidated. The ricin-B-lectin (RBL) gene is significantly differentially regulated after N. bombycis spore germination, and NbRBL might play roles in spore germination and infection. In this study, the biological function of NbRBL was examined. Protein sequence analysis showed that NbRBL is a secreted protein that attaches to carbohydrates. The relative expression level of the NbRBL gene was low during the first 30 h post-infection (hpi) in BmN cells, and high expression was detected from 42 hpi. Gene cloning, prokaryotic expression, and antibody preparation for NbRBL were performed. NbRBL was detected in total and secreted proteins using western blot analysis. Subcellular localization analysis showed that NbRBL is an intracellular protein. Spore adherence and infection assays showed that NbRBL could enhance spore adhesion to BmN cells; the proliferative activities of BmN cells incubated with anti-NbRBL were higher than those in negative control groups after N. bombycis infection; and the treatment groups showed less damage from spore invasion. We therefore, propose that NbRBL is released during spore germination, enhances spore adhesion to BmN cells, and contributes to spore invasion.

Comparative Transcriptome Investigation of Nosema ceranae Infecting Eastern Honey Bee Workers

“…These results together demonstrate that the MAPK signaling pathway is likely to play a vital part in N. ceranae infection, but there were differences in this signaling pathway in N. ceranae when infecting different honey bee species. Ricin, a type of toxic heterodimer protein in castor seed, has a ricin chain B (RTB) that connects a ricin chain A (RTA) via a disulfide bond [ 33 ]. Lectins are proteins that recognize the glycan ligand.…”

The ins and outs of host‐microsporidia interactions during invasion, proliferation and exit

“…Most of these proteins have no predicted function and are enriched for those that are not widely conserved in microsporidia (Campbell et al, 2013; Reinke, Balla, Bennett, & Troemel, 2017). One such protein, ricin‐B‐lectin, is also secreted from N. bombycis spores (NbRBL) and antibodies against this protein partially decrease spore attachment to host cells (Liu et al, 2016).…”

Gold nanoparticles electroporation enhanced polyplex delivery to mammalian cells

“…In chemical-mediated nonviral delivery systems, potent therapeutic molecules are condensed and/or Abbreviations: AuNP, gold nanoparticle; FNP, fluorophorelabeled AuNP; GFP, green fluorescence protein; Luc, luciferase; PEI, polyethylenimine; siRNA, small interfering RNA protected by cationic chemicals via forming polymer-DNA complexes (polyplex) or lipid-DNA complexes (lipoplex) to overcome multiple delivery barriers. They serve as the favorable alternative to their virus-mediated counterparts and have been successfully tested for both in vitro and in vivo delivery of plasmids, oligonucleotides, ribozyme, and small interfering RNAs (siRNAs) [9][10][11][12][13][14][15][16][17][18][19][20][21]. However, many of these systems still suffer insufficient delivery efficiency and cell viability, which often ties with their poor nanoparticle quality, slow and inefficient cellular uptake and endosome escape, and serious cytotoxicity from free cationic molecules after the unpacking of lipoplex or polyplex.…”