Description |
Recent evidence suggests a role for phagocytic cells of the reticuloendothelial system in host resistance to viral infections. The purpose of these studies was to investigate the interaction of polyoma virus with mouse peritoneal exudate cells (primarily macrophages) in vitro. This interaction was examined by fluorescent antibody techniques and autoradiography. Cells were observed at varying intervals after addition of the virus. As early as 12 hours, viral antigen was noted in the cytoplasm of some of the cells, and fluorescence appeared to accumulate in the majority of the cells during the next 2 days. This accumulation of fluorescence was compared in thioglycollate stimulated and unstimulated peritoneal cells as well as in cells from suckling and adult animals. Neither stimulation of the cells nor maturity of the donor seemed to affect the observed interaction. It was further noted that a few phagocytic cells showed nuclear fluorescence suggesting that polyoma virus was replicating in a small percentage of antigen containing cells. This was also verified by autoradiography. The percentage of nuclear staining cells was the 'same in stimulated and unstimulated and was not related to maturity of the donor. The results suggest: (1) the majority of peritoneal exudate macrophages take up virus as shown by specific fluorescent staining in cytoplasm, irrespective of stimulation or age of donor animal. (2) A small percentage of cells appear to permit replication of polyoma ,virus as evident by nuclear staining and autoradiography. (3) The greater susceptibility of newborn compared with adult animals to viral infection and tumor formation does not appear to be associated with increased susceptibility of newborn macrophages to viral infection. |