Inhibition of intracellular multiplication of adenovirus by interaction between infected and uninfected cells

The possibility that virus multiplication may be inhibited by interaction of infected cells with uninfected cells was tested by experiments, using human adenovirus type 12 (Ad 12). Permissive human cells (human embryonic kidney = HEK, KB or HeLa) were infected and seeded on uninfected or infected “nonpermissive” cell (human embryonic lung = HEL) monolayers, and virus yields or proportions of viral antigen-synthesizing cells were compared with each other. Both the virus yields and the proportions of viral antigen-positive cells were not reduced significantly when seeded on infected HEL cells, while when seeded on uninfected HEL cells both of them were reduced remarkably, compared with the yield and the proportion of controls seeded on glass. Similar results were obtained regardless of the type of permissive cells, HEK, KB, or HeLa. Similar reduction of the yield was observed when seeded on HEL cells infected with Ad 12 inactivated by heat or by antiserum, and partial reduction was observed when seeded on HEL cells infected with UV-inactivated Ad 12, depending on the extent of UV dosis. These experiments showed that intracellular virus multiplication may be inhibited by interaction of infected cells with uninfected cells, and this may be due to the difference in the cell surface structure.