Figure 2.

Induction of tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) by cytoadherence-deficient mutants of Mycoplasma pneumoniae. THP-1 cells (2 × 10⁵ cells/500 μl) were infected with 50 μl of the indicated amounts of wild-type or mutants of M. pneumoniae. After 6 hr incubation, amounts of TNF-α (a) and IL-1β (b) in culture medium were measured by ELISA. THP-1 cells (2 × 10⁵ cells/500 ml) were infected with 50 ml of M. pneumoniae (OD₅₉₅ = 0.1). Amounts of TNF-α (c) and IL-1β (d) in culture medium were measured by ELISA at the indicated time post-infection. All values represent the means and SD of three assays. An asterisk indicates that the P-value is < 0.01 for a comparison with wild-type of M. pneumoniae by multiple comparison.