Production of IFN-γ by lung lymphocytes in response to MADB106 tumor cells. Total lung lymphocytes were incubated in the presence of MADB106 tumor cells. At selected time intervals (2, 6, 24 and 96 h), the levels of IFN-γ cytokine were determined in culture supernatants. In addition, B cells were removed from total lung lymphocyte cultures. After 1 and 4 days of culture, supernatants were collected and the level of IFN-γ determined using ELISA techniques. Vertical bars and error bars represent the mean ± SE (n = 4). Asterisks indicate statistical differences (P less than or equal to 0.05) in the cytokine production by lung cells.