Depression of circulating interferon response in Balb-c mice after urethan treatment

Influence of a carcinogenic agent, 7.12 dimethylbenz (alpha) anthracene (DMBA), on production of interferon alpha/beta in murine and human cells

Interferon production in mouse and human cells induced by paramyxovirus was inhibited by pretreatment of cells with 7.12 dimethylbenz (alpha) anthracene. The inhibition was moderate but reproducible. It was most pronounced in mouse fibroblast cells, somewhat less in the mouse L-929 cell line and in human embryo fibroblast cells. Addition of the microsomal activator systems was necessary in the human system. A possible employment of this phenomenon in testing carcinogenic potential is discussed.

A survey of the effect of metals on the immune response

Evidence has been presented that the effect of metals on the immune response is highly variable: either enhancement or suppression may occur, depending on metal dose, route of inoculation, nature of antigenic stimulus, time of metal administration in relation to antigen, or the specific class of immunoglobulins produced. Very little is known of the mechanisms of metal-induced suppression or enhancement; mitogenicity of some metals may be involved in their stimulatory effects on immunity.An evaluation of available data shown no significant difference in the effect of carcinogenic and noncarcinogenic metals on immunity; the general effect of carcinogenic metals appears to be that of immunosuppression, but enhancement of immunity may also occur.Additional studies are needed to define immunological effects of carcinogenic and noncarcinogenic metals. Few experiments have analyzed the effects of these metals on cellular aspects of immunity, and, especially on those immunological reactions that play a role in tumor suppression or enhancement.