Humans have been using antibody therapies to treat infectious disease for more than 100 years. Blood plasma from influenza survivors administered to sick patients in 1912 may have contributed to their dramatic turnaround. In the years since, immune proteins from survivors have been administered to infected individuals in an attempt to combat diseases like Lassa fever, SARS, and even Ebola.
It’s hard, however, to find survivors who can donate plasma containing these lifesaving immune proteins. Now, a team led by researchers at the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) in Frederick, Maryland, has used genetically engineered cows to produce large amounts of human antibodies against hantavirus, an often deadly disease mainly transmitted from rodents to people. In animal models, at least, these antibodies provided robust protection against the virus, opening the door to therapies to treat and prevent hantavirus, for which there is no cure. The bioproduction technique also holds promise for generating antibodies against other infectious agents.
The work is preliminary and needs to be tested in people, but the team calls it a “proof-of-concept” that human antibodies can be grown in animals and retain their activity against disease. “I’m personally very excited about it. I think that this offers potential for treatment of patients with hantavirus infection,” says Greg Mertz, an infectious disease specialist at the University of New Mexico, Albuquerque, who was not involved in the research. “If you extrapolate this to other diseases, there are some where this approach might be promising.”
The USAMRIID researchers, led by virologist Jay Hooper, teamed up with SAB Biotherapeutics in Sioux Falls, South Dakota, to use genetically engineered cows that, when presented with an antigen, could produce fully human polyclonal antibodies against both the Sin Nombre hantavirus strain, first isolated from the Four Corners region of the southwestern United Sates, and the Andes hantavirus strain, which is prevalent in Chile. There, it infects an average of 55 people annually and kills about a third of them. After a lengthy incubation period and a few days of fever and muscle aches, the virus attacks the lungs and often causes acute respiratory failure leading to death. There is no cure, and the experimental vaccines would be logistically challenging to use even if they passed clinical trials.
Via Dr. Stefan Gruenwald