Figure 5
From: Uptake and intra-inclusion accumulation of exogenous immunoglobulin by Chlamydia-infected cells
Sequestration of pre-labeled IgG within the chlamydial inclusion. Cells infected with C. trachomatis serovar K were incubated at 24 hpi with FITC-labeled IgG and fixed 1 h later. Visualization of DNA using DAPI (A) confirms that the J774A.1 macrophages are intact and robust. Rabbit anti-Chlamydia antibodies labeled with TRITC-conjugated anti-rabbit IgG (B) shows a well-developed inclusion while accumulation of FITC-labeled IgG (C) within it is readily apparent. A merge of images A-C with a DIC micrograph (D) shows the cells are generally healthy during infection. (E) Cells that were similarly exposed to FITC-labeled IgG but were not permeabilized, show sequestration of the labeled IgG. In this absence of anti-Chlamydia staining DIC imaging and DAPI were used to identify infected cells. (F) Chlamydia-infected cells were also incubated with FITC-labeled F(ab')2 fragments. These cells exhibit no intracellular accumulation of this fluorescent label. (bar = 10 μm).