Immunogenetics2000)52:145±149 DOI 10.1007/s002510000249 BRIEF COMMUNICATION Tina Rich ´ Rachel Louise Allen ´ Anne-Marie Lucas Andrew Stewart ´ John Trowsdale Pellino-related sequences from Caenorhabditis elegans and Homo sapiens Received:10May2000/Revised:28August2000/Publishedonline:18October2000 Springer-Verlag 2000 Keywords Pellino´Innateimmunity´Toll´ Caenorhabditis elegans ´Vaccinia Toll receptor systems play an important role in our innate immune response to microbial infection Rock et al. 1998). Studies of related pathways in arthropods Hoffmann et al. 1999; Imler and Hoffmann 2000) have led to key advances in our understanding of these processes. Until recently, however, the possibil- ity that Toll signals may activate both immune and/or developmental pathways in Caenorhabditis elegans has been largely ignored. Early failures to identify Toll receptors or NFkB-like transcription factors in the C. elegans genome Ruvkun and Hobert 1998) led to the assumption that its Toll pathway was inoperable. Therefore, given the paucity of knowledge on innate immune responses for these animals, there was no impetus to develop C. elegans pathogenicity models. Recent database searches, however, have identified components of the elusive C. elegans Toll receptor pathwayRichetal.2000;TanandAusubel2000)and several groups now use C. elegans to study host-pa- thogen interactions Johnson and Liu 2000; Kurz and Ewbank 2000; Tan et al. 1999). The existence of a rudimentary immune response is further supported by evidence that antimicrobial peptides are encoded withinthe C. elegans genomeTanandAusubel2000). In fact, C. elegans is susceptible to infection from sev- eral different pathogens, making this genetically tract- able invertebrate an attractive model to study host- pathogen interactions. These developments are particularly important for the study of pathogens such as Pseudomonas aeruginosa whose natural hosts include humans. A suitable C. elegans model could, for example, provide a rapid system to screen candi- date antibacterial drugs. Consequently, it has now become important to identify and isolate cDNAs for eachcomponentofthe C. elegans Tollpathway. We previously used TBLASTN searches of high- throughput genomic sequences to identify C. elegans clones that would be predicted to translate proteins similar to Drosophila Pellino Rich et al. 2000). Pel- linoisanadapterproteinupstreamoftheCactus/Dor- sal complex that is recruited to the autophosphory- lated serine/threonine kinase, Pelle Grosshans et al. 1999). Pelle itself is activated following recruitment to the Toll-Tube complex Grosshans et al. 1994). Sequences were identified within the Chromosome Chr) V cosmid F25B4 that could encode a putative Pellino homologue Rich et al. 2000). To isolate the predicted open reading frame ORF), we designed primers flanking the ORF and used the polymerase chain reaction PCR) to amplify DNA from a nema- tode cDNA library Stratagene). An approximately 1.4-kbPCRproductwassubclonedintothe2.1-TOPO vector Invitrogen) and sequenced using ABI fluores- cent dye terminator technology. The sequence of the coding region is shown in Fig. 1. Comparison of the deduced amino acid sequence with our earlier predic- tion generated using Genescan at http://bioweb.pas- teur.fr) revealed that it was accurate up to the last exon,whereapredictedsplicesitewasnotused.Asa result we now show that the C. elegans pellino gene encodesaproteinthatisslightlyshorterthanfirstpre- dicted, but which in fact shows an increased similarity to Drosophila Pellino. The sequence identity shared between C. elegans and Drosophila Pellino is 47% over 421 amino acids). PSORT-II analysis predicts that C. elegans Pellino may translocate to the nucleus and a putative carboxyl-terminal nuclear localization signal is indicated in Fig. 1. A partial zinc finger T.Rich ) )´R.L.Allen´A.-M.Lucas´A.Stewart J.Trowsdale DepartmentofPathology,CambridgeUniversity, TennisCourtRoad,Cambridge,CB21QP,UK E-mail: tr219@mole.bio.cam.ac.uk Phone: +44-1223-333735 Fax: +44-1223-333730