title: Neuro-immune lessons from an annelid: The medicinal leech.
abstract: An important question that remains unanswered is how the vertebrate neuroimmune system can be both friend and foe to the damaged nervous tissue. Some of the difficulty in obtaining responses in mammals probably lies in the conflation in the central nervous system (CNS), of the innate and adaptive immune responses, which makes the vertebrate neuroimmune response quite complex and difficult to dissect. An alternative strategy for understanding the relation between neural immunity and neural repair is to study an animal devoid of adaptive immunity and whose CNS is well described and regeneration competent. The medicinal leech offers such opportunity. If the nerve cord of this annelid is crushed or partially cut, axons grow across the lesion and conduction of signals through the damaged region is restored within a few days, even when the nerve cord is removed from the animal and maintained in culture. When the mammalian spinal cord is injured, regeneration of normal connections is more or less successful and implies multiple events that still remain difficult to resolve. Interestingly, the regenerative process of the leech lesioned nerve cord is even more successful under septic than under sterile conditions suggesting that a controlled initiation of an infectious response may be a critical event for the regeneration of normal CNS functions in the leech. Here are reviewed and discussed data explaining how the leech nerve cord sensu stricto (i.e. excluding microglia and infiltrated blood cells) recognizes and responds to microbes and mechanical damages.
authors.affiliation: Université de Lille, CNRS UMR8198, Unité d'Evolution, Ecologie et Paléontologie (EEP), Species Interactions and Comparative Immunology (SPICI) Team, 59655 Villeneuve d'Ascq, France. Electronic address: aurelie.tasiemski@univ-lille1.fr.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Tasiemski
authors.affiliation: Université de Lille, INSERM U-1192, Laboratoire de Protéomique, Réponse Inflammatoire, Spectrométrie de Masse (PRISM), 59655 Villeneuve d'Ascq, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Salzet
mesh_terms: D000818:Animals; D000845:Annelida / Q000276:immunology*; D023181:Antimicrobial Cationic Peptides / Q000378:metabolism; D002490:Central Nervous System / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate; D007865:Leeches / Q000276:immunology*; D008322:Mammals; D023421:Models, Animal; D015213:Neuroimmunomodulation; D009474:Neurons / Q000502:physiology*; D051192:Receptors, Pattern Recognition / Q000378:metabolism; D012038:Regeneration / Q000276:immunology
chemical_list: D023181:Antimicrobial Cationic Peptides; D051192:Receptors, Pattern Recognition
keywords: Annelid; Antimicrobial peptides; CNS; Neuro-immunity; Regeneration; Sensing receptors