Abstract: Objective · To eliminate the effects of intraperitoneal injection of transmembrane activator and calcium modulator and cyclophilin ligand interactor-Ig (TACI-Ig) on the opitc neuritis and the integrity of myelin sheath in mice.  Methods · Twenty-four C57BL/6J mice were randomly divided into 4 groups, which were blank control group, saline control group, low-dose (0.4 mg/kg) TACI-Ig group and high-dose (4 mg/kg) TACI-Ig group, with 6 mice in each group. All groups were received intraperitoneal injection every other day. The saline control group received 0.2 mL saline injection in the same way, and the blank control group was not given any intervention. After 20 d of treatment, the eyeballs and optic nerve tissues were collected from each mouse under anaesthesia, embedded in paraffin and stained with hematoxylin-eosin (H-E) and Luxol fast blue (LFB), respectively.  Results · H-E staining indicated that optic nerve fibers arranged closely both in blank and saline control groups and the staining of tissues was uniform. The optic nerve structure of low-dose TACI-Ig group was similar to blank and saline control groups, while in high-dose of TACI-Ig group, the infiltration of inflammatory cells was observed. The inflammatory cell infiltration scores were not significantly different in all groups (P=0.610 3). The retinal structures of all groups were clear and distinct to observe, and single ganglion cells arranged tightly with complete cell shape, visible nucleus and uniform distribution. There was no difference in the retina structure among 4 groups. LFB staining indicated that there was no significant loss of the optic nerve myelin in 4 groups by microscope observation (P=0.473 6).  Conclusion · Low-dose (0.4 mg/kg) TACI-Ig injection wouldn’t damage the normal structure of optic nerves and retinal ganglion cells, meanwhile high-dose (4 mg/kg) of TACI-Ig injection might cause minor infiltration of inflammatory cells into retina.

Key words:  TACI-Ig, B lymphocyte stimulator, optic nerve, demyelination