The study of differences of antigenicity in rabbit intervertebral disc

Abstract

Objective To reveal and compare the immunogenicity of glycoprotein from nucleus pulposus and collagen from anulus fibrosus in rabbit intervertebral disc. Methods According to the similarity principle of genome biology and the amount of nucleus pulposus in different intervertebral disc, Glycoprotein from nucleus pulposus was harvested from the intervertebral disc of 20 rabbits and placed into the psoas by anterolateral approach. Similar implantation of collagen from anulus fibrosus was performed in another 20 rabbits. The implantations of autologous muscle in rabbits serve as a control group.After one week,two weeks, four weeks, six weeks and eight weeks, the rabbits were killed, the tissue was harvested. HE staining was applied to detect the degree of vascularization and infiltration of lymphocytes. Immunohistochemistry were used for analysis of T-helper cells (CD4+) and cytotoxic T cells (CD8+) in the tissue. Results HE staining showed the infiltration of lymphocytes was found just one week after implantation and vascularization was seen at the 2nd week in the glycoprotein implanted group. However in collagen implant group,small amounts of lymphocytic and atypical vascularization were seen at the 4th week. Immunohistochemistry revealed that the proportion of activated T cells (CD4+ and CD8+) was significantly higher in the glycoproteinimplanted group at all time points, as compared with the collagen-implanted group and sham group. The proportion of activated T cells was higher in collagen-implated group than that of in sham group . Conclusion The glycoprotein in nucleus pulposus is easier to induce the differentiation and mature of T cell. The antigenicity of glycoprotein in nucleus pulposus was stronger than that of collagen in anulus fibrosus in rabbit intervertebral discs. Key words: Intervertebral disk; Autoimmunity; Antigens; Glycoproteins; Collagen