Depression of viral interferon induction in cell monolayers by coal dust.

Hahon, N. (1974). British Journal of Industrial Medicine, 31, 201-208. Depression of viral interferon induction in cell monolayers by coal dust. Studies on the induction of interferon by influenza virus revealed that this adaptive cellular response was depressed completely or partially in coal dust-treated human or simian cell monolayers. Maximal inhibition of interferon production occurred with coal particles ranging in size from <2-0 to 19 1 JIM and with coal dust concentrations ranging from 0'1 to 0-001 g per 3 x 107 cells. The longer coal dust remained in contact with cells before the addition of viral inducer, the more likely was interferon production inhibited. Interferon depression was independent of the rank and geographic source of coal dust and of the virus/cell multiplicity of infection. Enhanced interferon yields resulted in normal and coal dust-treated cells when they were pretreated or primed with interferon. Neither interferon antagonists, interference with virus-cell integration, nor adsorption by coal dust accounted for the depression of interferon yields. The data suggest that coal particles per se act on cells in a subtle manner to interpose in the inductive process of interferon synthesis.