Pneumococcal Antigenic Polysaccharide Substances from Animal Tissues

Summary Polysaccharide-containing fractions have been prepared from 12 organs and tissues of mice 2 to 3 weeks after injection of 0.5 mg of specific pneumococcus polysaccharide type I, II, or III, an amount known to produce immunological paralysis. The materials stimulated a high degree of immunity in mice against the homologous pneumococcus infection. Similar fractions prepared from tissues of normal mice were devoid of immunizing ability. Those from most tissues of immunized mice (after a 0.002-mg dose of specific polysaccharide) were found to stimulate a low degree of immunity. Tests of similar polysaccharide-containing fractions from tissues of albino and C3H mice 8 to 9 months after a “paralyzing” injection of specific polysaccharide showed that but little type I antigenicity remained, and no type III, but that high titer immunity against type II could still be induced by the homologous polysaccharides isolated from both albino and C3H strains of mice. In one experiment similar fractions prepared from organs and tissues of guinea pigs and rabbits injected with pneumococcal polysaccharides, especially type II, stimulated some immunity in mice against homologous pneumococcus infection.