Drug & Device Development

Plant-derived MAb to HBV surface antigen may provide treatment alternative

Last Updated: 2004-06-23 16:00:16 -0400 (Reuters Health)

By Megan Rauscher

NEW YORK (Reuters Health) - Japanese scientists have successfully used transgenic tobacco cells to produce the human monoclonal antibody (MAb) to hepatitis B virus (HBV) surface antigen (HbsAg).

This work demonstrates the "feasibility of producing MAbs to HbsAg in plants as an alternative to anti-HBs human immunoglobulins," Dr. Akira Yano from the National Institute of Public Health in Tokyo and colleagues write in the June issue of the Journal of Medical Virology.

"Our plant-derived MAb has the potential to be a cheap and effective pharmaceutical" for the prevention and treatment of HBV infection, Dr. Yano told Reuters Health.

The parental human cell line -- TAPC301-CL4 -- originated from Epstein-Barr virus (EBV) transformed B-cell lines obtained from peripheral blood of a healthy individual with high anti-HB titers. Previously, Dr. Yano's team showed that the CL4MAb generated by the TAPC301-CL4 cells "neutralized the HBV (adr subtype) activity in vivo."

However, because MAbs from EBV transformed cells are not recommended for human use, the team cloned the cDNA of the whole CL4MAb and introduced it into the genome of cultured tobacco cells.

The resulting MAb, dubbed B303, displayed anti-HB properties similar to its parent. "B303 MAb interacted with cell surface HBsAgs and showed complement-dependent cytotoxicity in a manner that was similar to HBIg that are used clinically," they report.

Dr. Yano and colleagues believe the MAb B303 has "potential for both prevention and therapy of HBV infection."

"From the technical point of view," Dr. Yano continued, "several recent reports suggest that the remaining problems could be resolved in the next several years. The most indeterminate problems," the scientist said, "might come from society. Should we use transgenic-plant-derived pharmaceuticals?"

"I would prefer to use plant-derived than blood-derived antibodies," Dr. Yano said, because there is less risk of infectious contaminants."

Dr. Yano and colleagues say they are "confident," that, in time, transgenic plant derived biopharmaceuticals will become "both safe and economical for promotion of global health."

J Med Virol 2004;73:208-215.