Phagocytosis by HeLa Cells and Their Susceptibility to Infection by Human Tubercle Bacilli. ∗

Summary

When human tubercle bacilli are added to cultures of HeLa cells, the amount of intracellular growth that ensues depends upon the culture medium on the HeLa cells. If the medium is one containing 40% human serum, 10% chick embryo extract, and 50% BSS, little growth is seen within cells. However, if instead of human serum, certain horse serums are used, tubercle bacilli are rapidly taken up by the cells and luxuriant intracellular growth follows, even if the culture medium is later changed to one containing human serum in place of the horse serum. The mode of action of the horse serum media appears to be due to an increase in phagocytosis, since such media also increase the amount of phagocytosis of dead tubercle bacilli and carbon particles.