The influence of inflammatory agents on giant cell formation

The inoculation of live or dead BCG into the pocket formed by the insertion of glass coverslips into the subcutaneous tissue of mice caused a drastic reduction of giant cell formation on the glass surface. Conversely, when carrageenan was used, the number of polykaria increased. Live BCG also induced a decrease in the number of giant cell nuclei, whereas killed bacteria had no effect. In contrast, carrageenan caused the opposite phenomenon. The transformation of foreign body giant cells into Langhans type cells was almost blocked in the presence of live BCG. These data support the concept that inflammatory giant cell formation depends on the rate of macrophage turnover within the lesion.