Avian leukosis virus p27 inhibits tumor necrosis factor α expression in RAW264.7 macrophages after stimulation with lipopolysaccharide

Abstract

Avian leukosis is a widely distributed disease caused by Avian leukosis virus (ALV). ALV p27 is a capsid protein and group specific antigen, whose role in host immune response is poorly understood. To explore ALV p27, we developed a RAW264.7 macrophage cell line stably expressing p27-GFP fusion protein. The cells of this line and control cell line expressing GFP protein only were compared in production of tumor necrosis factor alpha (TNF-alpha), interleukins IL-1beta, IL-6, IL-12, and in proliferative activity stimulated by the lipopolysaccharide (LPS). It was found that the ALV p27 expression markedly reduced the production of TNF-alpha, but did not affect the production of IL-1beta, IL-6, and 12, and cell proliferative activity. These results demonstrate that ALV p27 specifically inhibits TNF-alpha expression in the macrophages stimulated by LPS, suggesting a possible contribution of ALV p27 to immunosuppression detected in ALV-infected hosts. Avian leukosis virus; p27; tumor necrosis factor alpha; interleukins; macrophages; lipopolysaccharide.