Role of adrenal cortical function in toxicity of polyriboinosinic-polyribocytidylic acid and its component homopolymers

An alternative mechanism for gluten toxicity in coeliac disease

The pathogenesis of gluten-sensitive enteropathies is unknown, although a peptidase deficiency and an immune defect have been postulated. The effect of plant-derived lectins on cells has led to an alternative concept in which a defect of the cell surface membrane allows gluten to act as a lectin and this reaction initiates cell toxicity. The proposed abnormality is viewed as a structural change produced by incomplete oligosaccharide chains in surface-membrane glycoproteins.

Interferon production linked to toxicity of polyriboinosinic acid-polyribocytidylic acid

Different procedures have been used in attempts to increase the production of interferon by polyriboinosinic acid-polyribocytidylic acid (poly [rI].poly [rC]) in mice: simultaneous injection of lead acetate, cycloheximide, or actinomycin D and prior injection of Freund's adjuvant, chlorite-oxidized oxyamylose (COAM), endotoxin, or Brucella abortus. In the experimental conditions tested, lead acetate, cycloheximide, Freund's adjuvant, and COAM brought about a parallel increase in interferon production and toxicity (lethality) of poly (rI).poly (rC); actinomycin D, endotoxin, and B. abortus increased the lethality of poly (rI).poly (rC) without a concomitant raise of its interferon-inducing capacity. Our results indicate that no significant increase in interferon production (or antiviral activity, as far as the antiviral activity is accounted for by interferon production) without an accompanying increase in toxicity can be achieved with poly (rI).poly (rC) and that it might be impossible to increase its therapeutic ratio (ratio of maximum tolerated dose to minimum effective dose).

Antiviral activity of polyribocytidylic acid in cells primed with polyriboinosinic acid

Separate administration of polyribocytidylic acid [poly(rC)] and polyriboinosinic acid [poly(rI)] to cell cultures in vitro resulted in an antiviral activity identical to or greater than that resulting from addition of the poly(rI) * poly(rC) complex. Priming of cells with poly(rI), followed by treatment with poly(rC), gave a consistently greater antiviral activity than poly(rI) * poly(rC) itself. This priming effect was obtained in several cell cultures challenged with different viruses. In vivo, the antiviral activity of poly(rI) * poly(rC) was only partially restored if poly(rI) and poly(rC) were injected separately; prior injection of poly(rI) proved superior in restoring this antiviral activity as compared to prior injection of poly(rC).