a specific primed immune response in drosophila is dependent on phagocytes一个特定的启动免疫反应在果蝇是依赖于吞噬细胞.pdfVIP

A Specific Primed Immune Response in Drosophila Is Dependent on Phagocytes * Linh N. Pham, Marc S. Dionne, Mimi Shirasu-Hiza, David S. Schneider Department of Microbiology and Immunology, Stanford University, Stanford, California, United States of America Drosophila melanogaster, like other invertebrates, relies solely on its innate immune response to fight invading microbes; by definition, innate immunity lacks adaptive characteristics. However, we show here that priming Drosophila with a sublethal dose of Streptococcus pneumoniae protects against an otherwise-lethal second challenge of S. pneumoniae. This protective effect exhibits coarse specificity for S. pneumoniae and persists for the life of the fly. Although not all microbial challenges induced this specific primed response, we find that a similar specific protection can be elicited by Beauveria bassiana, a natural fly pathogen. To characterize this primed response, we focused on S. pneumoniae–induced protection. The mechanism underlying this protective effect requires phagocytes and the Toll pathway. However, activation of the Toll pathway is not sufficient for priming-induced protection. This work contradicts the paradigm that insect immune responses cannot adapt and will promote the search for similar responses overlooked in organisms with an adaptive immune response. Citation: Pham LN, Dionne MS, Shirasu-Hiza M, Schneider DS (2007) A specific primed immune response in Drosophila is dependent on phagocytes. PLoS Pathog 3(3): e26. doi:10.1371/journal.ppat.0030026 Introduction that innate immunity possesses the adaptive characteristics of