What does hemagglutinin mean?
Hemagglutinin is a specialized term for a substance that makes red blood cells clump together, a process called agglutination. In virology, the word commonly refers to a surface glycoprotein found on influenza viruses. This protein binds to receptors on host cells and contributes to viral entry; it can also interact with red blood cells in laboratory tests. The related sense includes antibodies that cause red blood cells to aggregate by binding specific antigens on their surfaces. Hemagglutinin is consequently important in vaccine design, diagnostic serology, and studies of viral infection. Although the word may sound like an ordinary laboratory term, it is best known for naming one of the influenza virus's most recognizable proteins. Its dual association with cell clumping and viral attachment makes it useful whenever researchers need to describe substances that connect cells or particles together.
nounA substance, especially a viral surface protein or antibody, that causes red blood cells to clump together by binding to antigens on their surfaces.
- Any substance, such as an antibody, that causes red blood cells to clump together.
- A viral surface glycoprotein, especially that of influenza viruses, that binds to receptors on host cells and can cause red blood cells to agglutinate.
"The influenza virus hemagglutinin helps newly infected cells take up additional virus particles."
"The laboratory measured antibodies to the influenza hemagglutinin in the patient's serum."
"A hemagglutinin can cause red blood cells to form a characteristic lattice when the appropriate antibodies are present."
The plural is used when referring to distinct hemagglutinins, such as antibodies or viral proteins with different specificities.
"The researchers compared hemagglutinins from several influenza virus strains."
The influenza virus's hemagglutinin is a molecular grappling hook: it grips one cell, then helps the virus enter another.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does hemagglutinin come from?
Hemagglutinin combines an element meaning “blood” with agglutinin, a term derived from Latin agglutinare, “to glue together.” The blood element comes from Greek haima, while agglutinin was formed from agglutination with the suffix -in. The compound emerged in the late nineteenth century as medical researchers distinguished substances that specifically agglutinated red blood cells from agglutinins more generally.
How hemagglutinin is actually used
This is a technical term used principally in immunology, virology, serology, and related biomedical fields. It is most often encountered in discussions of influenza, viral entry, and red-cell agglutination assays.
Easily confused with hemagglutinin
An agglutinin is any substance that causes particles such as cells or bacteria to clump together, whereas a hemagglutinin specifically agglutinates red blood cells.
A hemagglutinin makes red blood cells clump together, while a hemolysin causes them to rupture and release their contents.