Antibodies May Offer New Flu Immunization Approach
Antibodies targeting influenza A hemagglutinin provide broad-spectrum neutralization
TUESDAY, Feb. 24 (HealthDay News) -- Specific antibodies directed against proteins involved in viral fusion with a host cell recognize multiple influenza A hemagglutinin subtypes, including avian H5 and pandemic H1 viruses, suggesting a promising approach for a universal influenza treatment or vaccine, according to research published online Feb. 22 in Nature Structural & Molecular Biology.
Jianhua Sui, M.D., Ph.D., of the Harvard Medical School in Boston, and colleagues used an antibody phage-display library to identify 10 antibodies that potently inhibited H5N1 infection in cells. Three of these antibodies were then shown in mice to suppress influenza viral replication in the lungs, as well as to dramatically reduce the spread of the virus into the spleen.
A crystal structure of one of the neutralizing antibodies revealed it acted by preventing membrane fusion between the virus and the host cell, the researchers report. The structure showed that the heavy chain of the antibody was bound to the stem region of hemagglutinin, a highly conserved area of the influenza-specific protein, the report indicates.
The authors of an accompanying News and Views article state that this research "demonstrates that a universal immune-based treatment or vaccine may not be out of reach," adding this work shows "an important advance in the characterization of conserved epitopes of the influenza virus hemagglutinin."