Prepared and screened a modified TNF-α molecule as TNF-α autovaccine to treat LPS induced endotoxic shock and TNF-α induced cachexia in mouse

Overexpression of TNF-α in the body is critically involved in many diseases. A strategy to construct TNF-α autovaccine by introducing a T cell helper epitope to the protein has been developed and may be an alternative because it is cheaper and highly efficient. However, the induction of high level anti-TNF-α neutralizing autoantibodies by TNF-α autovaccine is depend on a proper T cell help epitope. In order to evaluate the effect of different T helper cell epitopes on the immunogenicity of mouse TNF-α (mTNF-α), three T helper cell epitopes, TT (QYIKANSKFIGITEL), HEL (NTDGSTDYGILQINSR), and PADRE (AKFVAAWTLKA), were chosen for this study. The sequence (amino acids 126–140) of mTNF-α was replaced with those of the T cell help epitopes, respectively. The three fusion proteins (mTNF-TT, mTNF-HEL, mTNF-PADRE) were expressed in Escherichia coli and purified with a simple strategy. The abilities of the proteins elicited TNF-α autoantibodies in BALB/c mice were investigated. The results showed that mTNF-PADRE is the most effective among the three modified TNF-α molecules. In the absence of adjuvant, the therapeutic effect of TNF-PADRE on LPS induced endotoxic shock mice and mTNF-α induced cachexia mice was observed. This study suggests that mTNF-PADRE may be a better candidate of mTNF-α autovaccine.