Adjuvant Effects of a Crystalline Silica on IgE and IgG1 Antibody Production in Mice and Their Prevention by the Macrophage Stabilizer Poly-2-Vinylpyridine N-Oxide

A crystalline silica (standard quartz DQ12 with particle size less than 5 microns) is able to stimulate in Balb/c mice the production of IgE and IgG1 antibody to a single 1-microgram dose of ovalbumin. The adjuvant effects of silica on both IgE and IgG1 antibody production are prevented by pretreatment of animals with poly-2-vinylpyridine N-oxide, a polymer that protects macrophages from the well-documented toxic effects of silica. These results indicate that adjuvanticity of silica is, at least partly, correlated to the damage induced on macrophages.