Cover photograph (Copyright © 2011, American Society for Microbiology. All Rights Reserved.): Exposure of gamma interferon (IFN-γ)-treated Chlamydia trachomatis to levo-1-methyl tryptophan (L-lMT) results in a unique chlamydial growth pattern characterized by a limited productive multiplication of the bacterium and an enhanced susceptibility to doxycycline. HeLa 229 epithelial cells were infected with C. trachomatis and cultured for 48 h in medium supplemented with 10 ng/ml IFN-γ and 0.2 mM L-1MT. The infected cells were trypsinized, washed with phosphate-buffered saline, and fixed with 2.5% glutaraldehyde–2% paraformaldehyde for transmission electron microscopy. The vacuole-like structure is a C. trachomatis inclusion containing a small number of chlamydial particles (green). (See related article on p. 4425.).