title: Immune response of the ant Camponotus floridanus against pathogens and its obligate mutualistic endosymbiont.
abstract: Numerous insect species harbor mutualistic endosymbionts that play a role in nutrient cycling or confer other fitness benefits to their hosts. Insect hosts face the problem of having to maintain such mutualistic bacteria while staging an immune response towards pathogens upon infection. In addition, hosts may regulate the number of endosymbionts present in their tissues via the innate immune system. Camponotus floridanus ants harbor the obligate endosymbiont Blochmannia floridanus in specialized midgut cells and ovaries. We identified genes transcriptionally induced in response to septic injury by suppression subtractive hybridization (SSH). Among these were genes involved in pathogen recognition (e.g. GNBP), signal transduction (e.g. MAPK-kinase), antimicrobial activity (e.g. defensin and hymenoptaecin), or general stress response (e.g. heat shock protein). A quantitative analysis of immune-gene expression revealed different expression kinetics of individual factors and also characteristic expression profiles after injection of gram-negative and gram-positive bacteria. Likewise, B. floridanus injected into the hemocoel elicited a comparable immune response of its host C. floridanus. Thus, the host immune system may contribute to controlling the endosymbiont population.
authors: Lehrstuhl für Mikrobiologie, Biozentrum, Universität Würzburg, Germany.
authors: Carolin
authors: C
authors: Ratzka
authors: Chunguang
authors: C
authors: Liang
authors: Thomas
authors: T
authors: Dandekar
authors: Roy
authors: R
authors: Gross
authors: Heike
authors: H
authors: Feldhaar
mesh_terms: D000818:Animals; D001000:Ants / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D058491:Bacterial Load; D004269:DNA, Bacterial / Q000032:analysis / Q000096:biosynthesis; D023082:Defensins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D004064:Digestive System / Q000276:immunology* / Q000382:microbiology; D004755:Enterobacteriaceae / Q000276:immunology*; D005260:Female; D015870:Gene Expression; D020869:Gene Expression Profiling; D015723:Gene Library; D049750:Genome, Insect; D006090:Gram-Negative Bacteria; D006094:Gram-Positive Bacteria; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D007109:Immunity / Q000235:genetics*; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics / Q000378:metabolism; D009693:Nucleic Acid Hybridization; D010053:Ovary / Q000276:immunology* / Q000382:microbiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D015398:Signal Transduction; D013559:Symbiosis / Q000235:genetics / Q000276:immunology*
chemical_list: D004269:DNA, Bacterial; D023082:Defensins; D006360:Heat-Shock Proteins; D020929:Mitogen-Activated Protein Kinase Kinases