CD4(+) T cell-mediated facial motoneuron survival after injury: Distribution pattern of cell death and rescue throughout the extent of the facial motor nucleus.
We have previously demonstrated that CD4(+) T cells transiently rescue facial motoneurons (FMN) from axotomy-induced death in immunodeficient mice. Three subpopulations of motoneurons have been observed within the facial motor nucleus following axotomy: one that always survives axotomy (50%), one that is amenable to rescue from axotomy-induced death through the addition of neurotrophic factors or CD4(+) T cells (30-40%), and one that always dies after axotomy (10-15%). The objective of this study was to anatomically map the extent of axotomy-induced cell death and immune cell rescue in the facial nucleus to study the differential survival capabilities of each subpopulation. Wild-type (WT) mice, recombinase activating gene 2 knockout (RAG-2 KO) mice, and RAG-2 KO mice reconstituted with CD4(+) T cells were subjected to right facial nerve axotomy. At 4 weeks post-axotomy, topographical mapping of axotomy-induced cell death throughout the rostro-caudal extent of the facial nucleus was accomplished in accordance with previously published maps of the subnuclear arrangement of the facial neurons. The results indicate that all 3 subpopulations of FMN can be found in each of the subnuclear groups throughout the entire rostro-caudal extent of the facial nucleus. These data are discussed in context of recent work in amyotrophic lateral sclerosis, a fatal motoneuron disease.
Canh
Minh-Y
MY
Department of Cell Biology, Neurobiology and Anatomy Loyola University Chicago, Maywood, IL 60153, USA.
Serpe
Craig J
CJ
Sanders
Virginia
V
Jones
Kathryn J
KJ
D000818:Animals; D019771:Axotomy; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002450:Cell Communication / Q000276:immunology; D016923:Cell Death / Q000276:immunology; D002470:Cell Survival / Q000276:immunology; D004268:DNA-Binding Proteins / Q000235:genetics; D005154:Facial Nerve / Q000276:immunology / Q000473:pathology; D020220:Facial Nerve Injuries / Q000276:immunology* / Q000473:pathology*; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009046:Motor Neurons / Q000166:cytology* / Q000276:immunology*
D004268:DNA-Binding Proteins; C499308:Rag2 protein, mouse