Immune cell distribution and immunoglobulin levels change following sciatic nerve injury in a rat model

Objective(s): To investigate the systemic and local immune status of two surgical rat models of sciatic nerve injury, a crushed sciatic nerve, and a sciatic nerve transection Materials and Methods:Twenty-four adult male Sprague-Dawley rats were randomly divided into three groups: sham-operation (control group), sciatic nerve crush, and sciatic nerve transaction. Sciatic nerve surgery was performed. The percentage of CD۴+ cells and the CD۴+/CD۸+ratio were determined by flow cytometry. Serum IgM and IgG levels were analyzed by ELISA. T-cells (CD۳) and macrophages (CD۶۸) in sciatic nerve tissue sections were identified through immunohistochemistry. Results: Compared to sham-operated controls, in rats that underwent nerve injury, the percentage of CD۴+ cells and the CD۴+/CD۸+ ratio in the peripheral blood were significantly  decreased ۷ days after surgery, serum IgM levels were increased ۱۴ days after surgery, and serum IgG levels were increased ۲۱ days after surgery. There were a large number of CD۳+ cells and a small number of CD۶۸+ cells in sciatic nerve tissue sections ۲۱ days after surgery, indicating T-cell and macrophage activation and infiltration. Local IgG deposition was also detected at the nerve injury site ۲۱ days after surgery. Conclusion: Rat humoral and cellular immune status changed following sciatic nerve injury, particularly with regard to the cellular immune response at the nerve injury site.

Keywords:

Immune status , Nerve regeneration , Nerve repair , Sciatic nerve injury