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The immune response of Drosophila


Drosophila mounts a potent host defence when challenged by various microorganisms. Analysis of this defence by molecular genetics has now provided a global picture of the mechanisms by which this insect senses infection, discriminates between various classes of microorganisms and induces the production of effector molecules, among which antimicrobial peptides are prominent. An unexpected result of these studies was the discovery that most of the genes involved in the Drosophila host defence are homologous or very similar to genes implicated in mammalian innate immune defences. Recent progress in research on Drosophila immune defence provides evidence for similarities and differences between Drosophila immune responses and mammalian innate immunity.

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The author acknowledges invaluable exchanges with C. A. Janeway, R. A. Ezekowitz, F. Kafatos, T. Ganz and B. Beutler over many years, as well as the strongly motivating influence of H. G. Boman in the early period of these studies. I am particularly indebted to present and former associates of this group, namely P. Bulet, J. L. Dimarcq, D. Ferrandon, C. Hetru, D. Hoffmann, J. L. Imler, M. Lagueux, B. Lemaitre, E. Levashina, M. Meister, J. M. Reichhart and J. Royet.

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Figure 1: The Toll and Imd pathways in the control of expression of genes encoding antimicrobial peptides.
Figure 2: Selected members of the PGRP and GNBP families.
Figure 3: Parallels between the functions of interleukin-1 and Spaetzle.
Figure 4: Parallels between the TNFR and Imd pathways.


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