title: Apoptosis in the pathogenesis of Nosema ceranae (Microsporidia: Nosematidae) in honey bees (Apis mellifera).
abstract: Nosema ceranae is a parasite of the epithelial ventricular cells of the honey bee that belongs to the microsporidian phylum, a biological group of single-cell, spore-forming obligate intracellular parasites found in all major animal lineages. The ability of host cells to accommodate a large parasitic burden for several days suggests that these parasites subvert the normal host cells to ensure optimal environmental conditions for growth and development. Once infected, cells can counteract the invasive pathogen by initiating their own death by apoptosis as a defence strategy. To determine whether N. ceranae blocks apoptosis in infected ventricular cells, cell death was assessed in sections of the ventriculum from experimentally infected honey bees using the TUNEL assay and by immunohistochemistry for caspase-3. Ventricular epithelial cells from infected bees were larger than those in the uninfected control bees, and they contained N. ceranae at both mature and immature stages in the cytoplasm. Apoptotic nuclei were only observed in some restricted areas of the ventriculum, whereas apoptosis was typically observed throughout the epithelium in uninfected bees. Indeed, the apoptotic index was higher in uninfected versus infected ventriculi. Our results suggested that N. ceranae prevents apoptosis in epithelial cells of infected ventriculi, a mechanism possible designed to enhance parasite development.
authors.affiliation: Laboratorio de Patología Apícola, Centro Apícola Regional, JCCM, 19180, Marchamalo, Spain. mhiges@jccm.es
authors.forename: Mariano
authors.initials: M
authors.lastname: Higes
authors.forename: Ángeles
authors.initials: Á
authors.lastname: Juarranz
authors.forename: Joyce
authors.initials: J
authors.lastname: Dias-Almeida
authors.forename: Silvia
authors.initials: S
authors.lastname: Lucena
authors.forename: Cristina
authors.initials: C
authors.lastname: Botías
authors.forename: Aránzazu
authors.initials: A
authors.lastname: Meana
authors.forename: Pilar
authors.initials: P
authors.lastname: García-Palencia
authors.forename: Raquel
authors.initials: R
authors.lastname: Martín-Hernández
mesh_terms: D000818:Animals; D017209:Apoptosis; D001516:Bees / Q000276:immunology / Q000382:microbiology*; D053148:Caspase 3 / Q000032:analysis; D004847:Epithelial Cells / Q000382:microbiology; D041981:Gastrointestinal Tract / Q000382:microbiology; D054884:Host-Pathogen Interactions; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D016818:Nosema / Q000472:pathogenicity*
chemical_list: D053148:Caspase 3