Characterization of human anti-BAFF scFv-Fc that inhibits the activity of BAFF in vivo

To investigate the effects of human anti-BAFF scFv-Fc against the hsBAFF, ICR mice were randomly divided into six groups: control, hsBAFF (1 mg·kg⁻¹), hsBAFF (1 mg·kg⁻¹) + Ab (1 mg·kg⁻¹), hsBAFF (1 mg·kg⁻¹) + Ab (2 mg·kg⁻¹), hsBAFF (1 mg·kg⁻¹) + human IgG (1 mg·kg⁻¹) and hsBAFF (1 mg·kg⁻¹) + human IgG (2 mg·kg⁻¹) groups.  The effects of scFv-Fc administration on the proliferation of B lymphocytes were evaluated using an MTT assay.  The titres of antibody in the serum and B lymphocytes differentiation were assessed by ELISA and flow cytometry, respectively.  The results showed that administration of scFv-Fc to mice injected with hsBAFF significantly prevented human BAFF-induced increases in splenic B cell numbers and serum immunoglobulin levels.  Furthermore, this fully human antibody would avoid inducing the human anti-mouse antibody (HAMA) response when used in humans.  These findings suggest that the compact antibody may be useful in therapeutic or diagnostic application of the BAFF-associated autoimmune diseases in human.