The Development Of Therapeutic Vaccine Of Human Interleukin-8

Interleukin-8 is a chemokine belonging to the C-X-C subgroup of the chemokine family. It can induce the chemotaxis of neutrophil, T lymphacyte and basophil and activate various functions of neutrophils, including degranulation and respiratory burst. Beside its pro-inflammation effect, IL-8 has Angiogenic activities. IL-8 plays an important role in the development of many diseases, such as rheumatoid arthritis, reperfusion injury, pulmonary diseases and so on. These make IL-8 a very attractive target to intervene inflammatory disease. Neutralizing the activity of excessive IL-8 with monoclonal anti-IL-8 antibody is the most preferable choice to treat the IL-8-mediate diseases. This strategy has showed very promising effect in many animal disease models such as LPS-induced ARDS, in which anti-IL-8 mAb can prevent the ARDS and improve the rate of survive. Treatment of COPD with a mAb recognizing IL-8 has already been in the clinical trail. The result of phase II showed that the mAb can improve the dyspnea in patient significantly. Anti-IL-8 mAb also showed promising effect in animal tumor models by blocking the Angiogenic activities of IL-8.Although anti-self protein mAb have showed promising effect in treatment of some acute and chronic diseases, the cost and inconvenient to use haverestricted the widely application of therapeutic mAb. So, compare to the passive vaccination with antibodies, active vaccination with therapeutic vaccines is more easily to be accepted. Currently, the research of therapeutic vaccine is involved in the treatment of many disease including chronic viral infection, allergies, cancer, Alzheimer's disease, diabetes, hypertension, obesity and rheumatoid arthritis. There is accumulating evidence from animal model that it is possible to induce disease-modifying levels of specific antibodies. Active vaccination of mice against murine TNF-a demonstrated that it was possible to specifically induce high titers of TNF-a-neutralizing antibodies. An additional proof-of-concept in humans for antibody based therapeutic vaccination has been obtained in patients with advanced pancreatic cancer, in which induction of antibodies against the peptide hormone gastrin prolonged the life of vaccinated individuals.On the basis that neutralizing the activity of excess IL-8 with mAb has promising effect in animal disease models, we intended to construct vaccine that can induce high titer neutralizing antibody against IL-8 in the present study.The gene of IL-8 was modified by DNA synthesis and the activity motif (ELR) was mutant so that it has no bioactivity (rmhIL-8). To enhance the immunogecity of IL-8, the amino acid sequence of 26-39 was substituted by a universal Th helper cell epitope TT (rmhIL-8- TT).The genes were all cloned and expressed successfully in E.Coli and the expression form of rmh-IL-8 and GST- rmh-IL-8-TT was partly soluble. The expression form of Thio-rmhIL-8-TT was inclusion body. We purified the fusion and non-fusion proteins by ion-exchange and affinity chromotagraph. We got a mimotope from the phage display random peptide library and conjugated the mimotope with KLH. We also chemically conjugated the protein rmhIL-8 with KLH. Rats were immunized with the five candidate vaccines: rmhIL-8, KLH- rmhIL-8, GST- rmhIL-8-TT, Thio-rmhIL-8-TT, KLH-mimotope. The...