[Preparation of polyclonal antibody against sAPRIL and analysis of function in suppressing sAPRIL-mediated lymphocyte...

This study was aimed to prepare the polyclonal antibody against the soluble proliferation-inducing ligand (sAPRIL) antigen and to investigate its effects in suppressing sAPRIL mediated lymphocyte proliferation. Mutated recombinant sAPRIL protein, which lacks biological activity but maintains immunogenicity, was used as antigen to immunize humanized SCID mice. Sera were obtained at 6 weeks after immunization. Indirect ELISA and Western blot were used to detect the antibody titer and specificity. The inhibition of polyclonal antibodies on Raji and Jurkat cell proliferation stimulated by sAPRIL was assessed by the MTT assay. The results showed that the mutant of sAPRIL could induce the production of polyclonal antibodies against human sAPRIL. Western blot and indirect ELISA analyses indicated that the anti-serum had higher specificity with a titer of 1:640. Functional analysis revealed that these polyclonal antibodies significantly inhibited the proliferation of Raji and Jurkat cell stimulated by sAPRIL (p < 0.05). It is concluded the polyclonal antibody against human sAPRIL is successfully prepared, which can inhibit the proliferation of Raji and Jurkat cells stimulated by sAPRIL in vitro.