Expression of rabbit interleukin-4 and characterization of its biologic activity on T and B-cells

The purpose of the current study was to express recombinant rabbit IL-4 (rRbIL-4) and to characterize its biological activity. The cDNA of RbIL-4 was cloned into an insect cell expression vector that allowed for constitutive expression in Sf9 cells and incorporated a 6-histidine tag on the recombinant protein for purification. The purified protein corresponded to the predicted size of rRbIL-4 and was recognized by an anti-human IL-4 antibody in immunoblotting. As shown for IL-4 from other species, a dose-dependent proliferative response was observed in T-lymphoblasts cultured with rRbIL-4. rRbIL-4 also induced increased expression of MHC class II molecules on the surface of rabbit B-cells in a dose-dependent manner. These results indicate that we have produced recombinant rabbit IL-4 that exhibits expected biological activity on rabbit B and T-cells.