Scientists have identified a new HIV-suppressing protein in the blood of people infected with the virus. In laboratory studies, the protein, called CXCL4 or PF-4, binds to HIV such that it cannot attach to or enter a human cell. The research was led by Paolo Lusso, M.D., Ph.D., chief of the Section of Viral Pathogenesis in the Laboratory of Immunoregulation at the National Institute of Allergy and Infectious Diseases (NIAID), part of NIH.
CXCL4 belongs to a family of molecules called chemokines that help regulate the movement of immune cells around the body. In the mid-1990s, four chemokines-three discovered by Dr. Lusso, Robert Gallo, M.D., and their colleagues-were found in laboratory experiments to function as HIV inhibitors. These chemokines as well as CXCL4 may regulate the level of virus replication in infected individuals and thus the pace at which HIV disease progresses.