MBL generates human monoclonal antibodies against pandemic A type influenza virus

Medical & Biological Laboratories Co., Ltd. (MBL), with the collaboration of Osaka University, has successfully generated several fully human monoclonal antibodies against pandemic A (H1N1 and H3N2) type influenza virus by utilizing blood samples from volunteers who were inoculated with influenza vaccine.

Professor Kazuyoshi Ikuta, Ph. D., at the Department of Virology, Research Institute for Microbial Diseases, Osaka University, has confirmed through in vitro experiments that the fully generated human antibodies can neutralize H3N2 influenza virus strains. Professor Ikuta is now evaluating the preventative and therapeutic effects in an infected mouse model. After completing in vivo experiments in infected animal models with the neutralizing antibodies, MBL plans to commence a collaborative clinical development program with a pharmaceutical company. These neutralizing human IgG antibodies against the influenza virus are expected to be effective in severe infections. In combination with anti-viral drugs these antibodies will have greater success than anti-viral drugs alone.

The therapeutic antibodies were generated by using a special cell line, called SPYMEG. This novel cell line is a human lymphocyte fusion partner, it was co-developed by associate professor Naomasa Yamamoto, Ph. D., of Ohu University and MBL. SPYMEG is the cell line established by the cell fusion of MEG-01 with a murine myeloma cell line. Hybridoma cells of human origin are known to be prone to chromosome deletions. The SPYMEG cell line overcomes that problem, resulting in a higher reliability of cell fusion. Utilization of SPYMEG is a simpler and easier way to generate therapeutic monoclonal antibodies than chimerization, or humanization of mouse monoclonal antibodies generated from immunized mice.

At present, MBL is conducting collaborative research to generate neutralizing monoclonal antibodies against swine-origin influenza A (H1N1). MBL is preparing to collaborate with more institutions regarding other infectious viruses.

The fully human monoclonal antibodies against pandemic A (H1N1 and H3N2) type influenza viruses were generated by the utilization of SPYMEG. The antibodies, originated from the blood of a convalescent volunteer recovering from influenza infection or vaccination, are expected to be effective and very safe.

Additionally, the simple principle and wide range of applications of this method may lead to the generation of therapeutic and prophylactic drugs to various infections such as avian influenza A (H5N1).