Immunological Characterization of (Tight Skin/NZB)F1 Hybrid Mice with Connective Tissue and Autoimmune Features Resembling Human Systemic Sclerosis

Abstract A new murine model of Systemic Sclerosis (SSc) has been developed by breeding the Tsk+/+ pa tight skin mouse (TSK) and the autoimmune disease-prone NZB strain to produce an F1 hybrid displaying the connective tissue abnormalities of the TSK parent and the autoimmune abnormalities of the NZB parent. The interscapular skin thickness in the (TSK/NZB)F1 was significantly greater than in the (+pa/NZB)F1 litter mates. Protein biosynthesis in skin punch biopsies was over 3.5 times higher in the (TSK/NZB)F1 mice than in controls. Hydroxyproline analyses confirmed that the increase in protein synthesis was primarily in collagen. These (TSK/NZB)F1 mice were tested for a number of cellular and humoral autoimmune manifestations. Autoantibodies, including antinuclear antibodies (ANA) and anti-DNA, were present in their sera, and the proliferative response to autologous lymphocyte stimulation (AMLR) was decreased as is commonly observed in murine and human autoimmune disorders. These results indicate that the (TSK/NZB)F1 mice display connective tissue and immunologic abnormalities resembling those present in human SSc and, therefore, these mice may be a valuable model for the study of the disease.