Cellular Immune Response to Parasite Infection in the Drosophila Lymph Gland Is Developmentally Regulated

Developmental Biology

Richard Paul Sorrentino¹  Shubha Govind¹  Yves Carton¹ 

[1] Department of Biology, City College of New York and Graduate School and University Center of the City University of New York, 138th Street and Convent Avenue, New York, New York, 10031

关键词: cellular immune competence;    steroid hormone;    signal transduction;    parasites;    Drosophila;   

DOI  :  10.1006/dbio.2001.0542

学科分类：生物科学（综合）

来源: Academic Press

【 摘 要 】

Themechanismsbywhichanorganismbecomesimmunecompetentduringitsdevelopmentarelargelyunknown.Wheninfectedbyeggsofparasiticwasps,Drosophilalarvaemountacomplexcellularimmunereactioninwhichspecializedhostbloodcells,lamellocytesandcrystalcells,areactivatedandrecruitedtobuildacapsulearoundtheparasiteeggtoblockitsdevelopment.Here,wereportthatparasitizationbythewaspLeptopilinaboulardileadstoadramaticincreaseinthenumberofbothlamellocytesandcrystalcellsintheDrosophilalarvallymphgland.Furthermore,alimitedburstofmitosisfollowsshortlyafterinfection,suggestingthatbothcelldivisionanddifferentiationoflymphglandhemocytesarerequiredforencapsulation.Thesechanges,observedinthelymphglandsofthird-instar,butneverofsecond-instarhosts,arealmostalwaysaccompaniedbydispersaloftheanteriorlobesthemselves.Toconfirmalinkbetweenhostdevelopmentandimmunecompetence,weinfectedmutanthostsinwhichdevelopmentisblockedduringlarvalorlatelarvalstages.Wefoundthat,ingeneticbackgroundswhereecdysonelevelsarelow(ecdysoneless)orecdysonesignalingisblocked(nonpupariatingalleleofthetranscriptionfactorbroad),theencapsulationresponseisseverelycompromised.Inthethird-instarecdysonelesshosts,postinfectionmitoticamplificationinthelymphglandsisabsentandthereisareductionincrystalcellmaturationandpostinfectioncirculatinglamellocyteconcentration.Theseresultssuggestthatanecdysone-activatedpathwaypotentiatesprecursorsofeffectorcelltypestorespondtoparasitizationbyproliferationanddifferentiation.Weproposethat,byaffectingaspecificpoolofhematopoieticprecursors,thispathwaythusconfersimmunecapacitytothird-instarlarvae.

【 授权许可】

Unknown