Effects of autoimmunity on recovery of function in adult rats following spinal cord injury.
The central nervous system (CNS) is considered to be an immune-privileged site. For a long time, autoimmunity-induced inflammation has been viewed as an important mediator of secondary damage in the CNS following injury. However, other studies also suggest that autoimmunity is protective and beneficial. To investigate whether protective autoimmunity is present following spinal cord injury (SCI), we employed neonatally thymectomized (Tx) rats which contain few T lymphocytes in their peripheral blood, and passively immunized them with T lymphocytes activated by myelin basic protein (MBP) or spinal cord homogenate (SCH). Here we report that, among Tx, sham-Tx (sTx) and normal rats that received a contusive SCI, no significant histological and behavioral differences were found, suggesting that the endogenous T lymphocytes had no significant influence on the pathogenesis of secondary SCI. In rats passively immunized with MBP- or SCH-activated T cells (MBP-T or SCH-T, respectively), similar numbers of CD4(+) T cells were found to infiltrate into the injured spinal cords. However, only the MBP-T immunization showed neuroprotection, evidenced by the reduction of post-traumatic neuronal losses and improvement of functional recovery. These results collectively suggest that not all T lymphocytes against CNS antigens are neuroprotective and that a subpopulation of them, such as those of MBP-T cells, could be beneficial for SCI repair.
Lü
He-Zuo
HZ
Department of Neurobiology, Shanghai Jiaotong University School of Medicine, 280 South Chongqing Road, Shanghai 200025, PR China.
Xu
Liang
L
Zou
Jian
J
Wang
Yan-Xia
YX
Ma
Zheng-Wen
ZW
Xu
Xiao-Ming
XM
Lu
Pei-Hua
PH
D000704:Analysis of Variance; D000818:Animals; D015551:Autoimmunity / Q000276:immunology*; D002470:Cell Survival / Q000276:immunology; D019610:Cytoprotection; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D007116:Immunization, Passive; D007249:Inflammation / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology; D008854:Microscopy, Electron; D009043:Motor Activity / Q000276:immunology; D009046:Motor Neurons / Q000276:immunology*; D004676:Myelin Basic Protein / Q000276:immunology; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function / Q000276:immunology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013116:Spinal Cord / Q000276:immunology; D013119:Spinal Cord Injuries / Q000276:immunology*; D013194:Staining and Labeling; D013601:T-Lymphocytes / Q000276:immunology*; D013904:Thoracic Vertebrae / Q000276:immunology; D013934:Thymectomy; D013997:Time Factors
D004676:Myelin Basic Protein