A Specific Primed Immune Response in Drosophila Is Dependent on Phagocytes

Department of Microbiology and Immunology, Stanford University, Stanford, California, United States of America.
PLoS Pathogens (Impact Factor: 7.56). 04/2007; 3(3):e26. DOI: 10.1371/journal.ppat.0030026
Source: PubMed


Author Summary

Due to the common practice of vaccination and prominence of AIDS, people are already aware of the distinction between adaptive and innate immunity without realizing it. All organisms have an innate immune response, but only vertebrates possess T cells and the ability to produce antibodies. It has been a long-standing assumption that invertebrate immune systems are not adaptive and respond identically to multiple challenges. In this study, we demonstrate that the fly innate immune response adapts to repeated challenges; flies preinoculated with dead Streptococcus pneumoniae are protected against a second, otherwise-lethal dose. Although the underlying mechanisms are likely to be very different, this primed response is reminiscent to vaccine-induced protection in that it exhibits coarse specificity (dead S. pneumoniae only protects against itself), persists for the life of the fly and is dependent on phagocytic cells. This result prompts the obvious question of whether the innate immune system of vertebrates shares a similar biology. Such a finding is of particular interest since immunocompromised individuals only possess an innate immune system.

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    • "This may hold special relevance for newly described, somewhat controversial phenomena such as invertebrate immune priming. Priming enhances the probability of host survival upon repeated exposure to microbes and is thought to often be mediated by hemocytes (Pham et al. 2007), which are under delayed DI. However, immune priming also suffers from repeatability issues and shows inconsistent penetrance across developmental stages (Trauer and Hilker 2013), consistent with DI effects. "
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    The American Naturalist 11/2015; 186(4). DOI:10.1086/682705 · 3.83 Impact Factor
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    • "Thus, T. ni are unlikely to encounter an abundance of these bacteria on their host plants; thus it might be possible that their response will be different to unfamiliar contaminants. Different bacterial species probably elicit different responses, exemplified by the fact that immune priming can be specific to the taxonomic type, species or strain of pathogens (Sadd & Schmid-Hempel, 2006; Pham et al., 2007; Roth et al., 2009). We used two Gram-negative bacteria belonging to the same genus, whereas Freitak et al. (2007) used both Gram-negative and positive bacteria of differing genera. "
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