Persistent expression of Ia antigen and viral genome in visna-maedi virus-induced inflammatory cells. Possible role of lentivirus-induced interferon.
In this study we investigated the pathogenesis of the lymphoproliferative response in the chronic-active visna maedi virus-induced inflammatory lesions. Viral RNA expression was confined to macrophages, but only in tissues showing inflammatory lesions. A persistent and high level of Ia antigen expression was seen in macrophage-like cells in the inflammatory lesions, and the amounts of viral RNA and Ia expression were closely correlated. A small subpopulation of macrophages contained both viral RNA and Ia antigen, and these were found in greatest number in the lung. In vitro experiments showed that a lentivirus-induced interferon (LV-IFN) could induce Ia antigens in normal sheep spleen and lymph node cells as well as in a transformed sheep macrophage cell line. Ia antigen expression in macrophages was transient in the absence of a continuing IFN stimulus and persisted for at least 2 wk in the presence of LV-IFN. LV-IFN also restricted viral replication in macrophages. It is suggested that LV-IFN induced by the inflammatory cells in visna-maedi lesions may induce Ia antigen expression in macrophages, thereby indirectly causing the lymphoproliferative response and restricted virus replication.
P G
PG
Kennedy
O
O
Narayan
Z
Z
Ghotbi
J
J
Hopkins
H E
HE
Gendelman
J E
JE
Clements
D000818:Animals; D002478:Cells, Cultured; D005814:Genes, Viral; D000949:Histocompatibility Antigens Class II / Q000032:analysis / Q000096:biosynthesis*; D006801:Humans; D007372:Interferons / Q000096:biosynthesis / Q000502:physiology*; D008168:Lung / Q000276:immunology / Q000382:microbiology; D008198:Lymph Nodes / Q000276:immunology / Q000382:microbiology; D008262:Macrophage Activation; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D011021:Pneumonia, Progressive Interstitial, of Sheep / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D011650:Pulmonary Alveoli / Q000166:cytology; D012367:RNA, Viral / Q000378:metabolism; D012756:Sheep; D013154:Spleen / Q000276:immunology / Q000382:microbiology; D014779:Virus Replication; D014790:Visna-maedi virus / Q000235:genetics / Q000276:immunology* / Q000502:physiology
D000949:Histocompatibility Antigens Class II; D012367:RNA, Viral; D007372:Interferons