Subcapsular sinus macrophages prevent CNS invasion on peripheral infection with a neurotropic virus

Macrophages that populate the lymph nodes are known to clear viruses from the lymph and to initiate antiviral humoral immune responses. It is now shown that these macrophages also have another function: they prevent lymph-borne neurotropic viruses from entering the central nervous system. The mechanism is dependent on the production of type I interferon.