Figure 5.

Calcium-induced differentiation of HaCaT cells decreases the infectivity of C. trachomatis D. (A) HaCaT cells in a monolayer system were exposed to high concentration (2 mM) of calcium (Ca²⁺) to induce differentiation up to 7 days. HaCaT exposed to calcium were infected with C. trachomatis D (without centrifugation). Infection was allowed to proceed for 24 h. Chlamydial inclusions decreased in samples exposed to high [Ca²⁺] C. trachomatis inclusions were stained with covalescent human sera (in yellow). A representative image from three independent experiments is shown. Scale bar = 10 μm. (B) C. trachomatis L2 or D inoculum was introduced to the top of the 3D organotypic cultures. Infections were allowed to proceed for 1, 3, or 5 days. C. trachomatis inclusions were stained with an anti-C. trachomatis LPS antibody. White line represents the bottom of the 3D culture. A representative image from two independent experiments is shown. Scale bar = 10 μm.