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Active suppression of D. melanogaster immune response by long gland products of the parasitic wasp Leptopilina boulardi
To develop inside their insect hosts, endoparasitoid wasps must either evade or overcome the host’s immune system. Several ichneumonid and braconid wasps inject polydnaviruses that display well-studied immune suppressive effects. However, little is known about the strategies of immunoevasion used by...
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Published in: | Journal of insect physiology 2003-05, Vol.49 (5), p.513-522 |
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Main Authors: | , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | To develop inside their insect hosts, endoparasitoid wasps must either evade or overcome the host’s immune system. Several ichneumonid and braconid wasps inject polydnaviruses that display well-studied immune suppressive effects. However, little is known about the strategies of immunoevasion used by other parasitoid families, such as figitid wasps. The present study provides experimental evidence, based on superparasitism and injection experiments, that the figitid species
Leptopilina boulardi uses an active mechanism to suppress the
Drosophila melanogaster host immune response, i.e. the encapsulation of the parasitoid eggs. The immune suppressive factors are localised in the long gland and reservoir of the female genital tractus, where virus-like particles (VLPs) have been observed. Parasitism experiments using a host tumorous strain indicate that these factors do not destroy host lamellocytes but that they impair the melanisation pathway. Interestingly, they are not susceptible to heating and are not depleted with prolonged oviposition experience, in contrast to observations reported for
L. heterotoma, another figitid species. The mechanisms that prevent encapsulation of eggs from
L. boulardi and
L. heterotoma differ in several respects, suggesting that different physiological strategies of immunosuppression might be used by specialised and generalist parasitoids. |
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ISSN: | 0022-1910 1879-1611 |
DOI: | 10.1016/S0022-1910(03)00054-4 |