FIG. 3.

Requirement for phagocytosis by monocytes of M. tuberculosis bacilli for activation of CD4⁺ and γδ T cells. Monocytes (MO) were incubated with M. tuberculosis (MTB) in the presence (CCD-MO+MTB) or absence (MO+MTB) of cytochalasin D (CCD) for 120 min, after which they were washed and irradiated before coculture with CD4⁺ (A) and γδ (B) T-cell lines in a proliferation assay. Results are means and standard deviations of triplicate wells and are representative of five experiments. Monocyte targets were from the same donor as the CD4⁺ T-cell line, and the γδ T-cell line was derived from an unrelated donor.