Absence of macrophage involvement in the passive serum therapy of Friend leukemia virus-induced disease.

The possible involvement of host macrophages in the passive serum therapy of Friend leukemia virus (FLV)-induced disease has been examined with the use of agents inhibiting normal macrophage functions, including silica and a tumor-produced macrophage chemotaxis inhibitor. Under conditions in which macrophage chemotaxis inhibitor. Under conditions in which macrophage functions are at least transiently abrogated by these agents, no effect was seen on the anti-fLV protection afforded by the passive administration of chimpanzee anti-FLV antiserum to infected DBA/2 mice, as monitored by the development of virus-induced splenomegaly and the level of infectious virus. The macrophage inhibitors also did not influence the appearance of the host antiviral humoral immune response which normally accompanies serum protection. These results suggest that the normal functioning of host macrophages do not play a central role in the passive serum therapy protective mechanism leading to resistance to FLV infection.