Neuroimmune processes associated with Wallerian degeneration support neurotrophin-3-induced axonal sprouting in the injured spinal cord
Lesions of the spinal cord cause two distinctive types of neuroimmune responses, a response at the lesion site that leads to additional tissue destruction and a more subtle response, termed Wallerian degeneration (WD), that occurs distal to the lesion site. We have evidence that the neuroimmune resp...
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Published in | Journal of neuroscience research Vol. 91; no. 10; pp. 1280 - 1291 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
United States
Blackwell Publishing Ltd
01.10.2013
Wiley Subscription Services, Inc |
Subjects | |
Online Access | Get full text |
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Summary: | Lesions of the spinal cord cause two distinctive types of neuroimmune responses, a response at the lesion site that leads to additional tissue destruction and a more subtle response, termed Wallerian degeneration (WD), that occurs distal to the lesion site. We have evidence that the neuroimmune response associated with WD may support tissue repair. Previously, we found that overexpression of neurotrophin‐3 (NT‐3) induced axonal growth in the spinal cord after a unilateral corticospinal tract (CST) lesion, but only if the immune system was intact and activated. We reasoned that a neuroimmune response associated with WD was involved in this neuroplasticity. To test this, we compared NT‐3‐induced axonal sprouting in athymic nude rats that lack functional T cells with rats with functional T cells and in nude rats grafted with CD4+ T cells or CD8+ T cells. There was no sprouting in nude rats and in nude rats grafted with CD8+ T cells. However, nude rats grafted with CD4+ T cells mounted a sprouting response. To determine which CD4+ subtype, type 1 T helper (Th1) or type 2 T helper (Th2) cells, was responsible, we grafted Th1 and Th2 cells into nude rats and tested whether they would support sprouting. Axonal sprouting was greater in rats grafted with Th2 cells, demonstrating that the Th2 subtype was responsible for supporting axonal sprouting. These data suggest that WD activates Th2 cells that, along with the direct effects of NT‐3 on CST axons, act to support axonal sprouting in the lesioned spinal cord. © 2013 Wiley Periodicals, Inc. |
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Bibliography: | NIH - No. NIAID P30AI036211; No. NCI P30CA125123; No. NCRR S10RR024574 (to support the Cytometry and Cell Sorting Core at Baylor College of Medicine). istex:A1577D192267E364D143DB56B62A15969FEBE0CA ark:/67375/WNG-7T70XNNQ-Q Christopher and Dana Reeve Foundation ArticleID:JNR23257 Department of Veterans Affairs, Veterans Health Administration, Office of Research and Development, Rehabilitation Research and Development Mission Connect, a project of the TIRR Foundation Craig H. Neilsen Foundation ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0360-4012 1097-4547 |
DOI: | 10.1002/jnr.23257 |