CHICAGO --- Researchers at Northwestern University Medical School have discovered a human protein that provides a pathway for herpes simplex virus to infect lymphocytes, important cells of the immune system. This human protein is not only the first "portal of entry" for herpes simplex virus to be identified, but is also a previously unknown member of an important family of cell surface molecules known as the TNF/NGF receptor family. The normal function of these receptors is to receive signals required to induce cells of the immune or other system to proliferate or to die.
A report of the protein discovery appears in the Nov. 1 issue of the Journal Cell.
"Knowing how this virus penetrates lymphocytes takes researchers one step closer to understanding how recurrent herpetic disease can occur in persons with normal immune systems and will lead to development of new classes of antiviral drugs," said Patricia G. Spear, who heads the laboratory at Northwestern where the discovery was made. Spear is the Guy and Anne Youmans Professor and chair of the department of microbiology-immunology at Northwestern.
Herpes simplex virus is highly prevalent in humans, in part because it can establish latent infections in nerve cells and persist indefinitely with periodic reactivation of the virus. Consequences of viral replication include cold sores and fever blisters, similar lesions on the genitalia, corneal destruction, encephalitis and severe disease of newborns. The virus can bind to many types of human cells but is capable of penetrating only certain cell types.
Rebecca Montgomery, a research associate in Spear's laboratory, cloned a human gene that induces production of a protein that allows herpes simplex virus to penetrate into lymphocytes. Morgyn Warner and Brian Lum, other members of Spear's research group, also contributed to this work. Ongoing research in Spear's laboratory is directed toward identifying other cell surface proteins that can mediate entry of herpes simplex virus into other cell types, including nerve cells, and defining the relevant mechanisms of entry into different human cells.