Fig. 3.

CD4+ αβ T cell responses in the lumbar lymph nodes 7 days after adult rat mSNIs. a Schematic presentation of the lymphadenectomy for region-specific targeting of CD4+ αβ T cells in the inflamed tissues. CD4+ αβ T cells in the spleen are broadly activated with blood-borne, MHC II-dependent pathogenic antigens from all the inflamed tissues; these T cells hence infiltrate into not only the target inflamed tissues but also other inflamed tissues. By contrast, CD4+ αβ T cells in the local lymph nodes are specifically activated with MHC II-dependent pathogenic antigens from the target inflamed tissues; these T cells hence selectively infiltrate into the target inflamed tissues. Therefore, these features rationalize the lymphadenectomy as a satisfactory method for region-specific targeting of CD4+ αβ T cells in the target inflamed tissues. b Schematic illustration of the LLNs as the specific local lymph nodes to drain possible pathogenic antigens in the cerebrospinal fluid (CSF) compartment at the lumbar vertebral levels. c, d Gross morphologies (c) and relative weights (d) of LLNs from mSNIed and sham-operated rats (n = 5/group). *P < 0.05, independent Student’s t test. e Reactive changes of CD4+ αβ T cells in LLNs from mSNIed and sham-operated rats (n = 5/group). DC dendritic cell, DR dorsal root, DRG dorsal root ganglion, LLN lumbar lymph node, LN lymphoid nodule, M medulla, mSNI modified spared nerve injury, PCZ paracortical zone, SAA subarachnoid angle, SAS subarachnoid space, SC spinal cord, VR ventral root