This study was concerned with the handling of ingested tubercle bacilli by normal human
macrophages. Intracellular growth was determined after exposure of macrophages to viable
bacilli in vitro and the effect of various cytokines, alone or in combination, on bacilli
growth/survival was determined. It was found that Mycobacterium tuberculosis (M. tb) grew
quite readily in untreated cultured human macrophages. Treatment with soluble factors
showed that a crude lymphokine containing supernatant elicited with Concanavalin A (Con …