All primary antibodies were preabsorbed with a bacterial lysate containing GST alone before use. In addition, for some experiments, the primary antibodies were absorbed with either the corresponding or heterologous

fusion proteins immobilized onto glutathione-conjugated agarose beads (Pharmacia). The absorption was carried out by incubating the antibodies with bead-immobilized antigens for 1 h at room temperature (RT) or overnight at 4°C PI3K inhibitor followed by pelleting the beads. The remaining supernatants were used for immunostaining. The immunofluorescence images were acquired using an Olympus AX-70 fluorescence microscope equipped with multiple filter sets and Simple PCI imaging software (Olympus, Melville, NY) as described previously [40]. An Olympus FluoView laser confocal microscope (Olympus, Center Valley, PA) was used to further analyze some of the immunofluorescence

samples at the University of Texas Health Science Center at San Antonio institutional core facility as described previously [29]. The images were processed using Adobe Photoshop (Adobe Systems, San Jose, CA). 4. Western blot assay The Western blot assay was carried out as described elsewhere [38, 55]. Briefly, HeLa cells with or without C. trachomatis infection and with or without fractionation (into pellet and S100 fractions), purified chlamydial RB and EB organisms, GST fusion proteins or fractionated bacterial periplasmic or cytosolic samples were resolved in SDS polyacrylamide gels. The resolved protein bands were transferred to nitrocellulose membranes LY333531 in vivo Sodium butyrate for antibody detection. The primary antibodies used included: mouse pAb and mAb 6A2 against cHtrA, mouse pAb against CT067 (all Selleck AZD5363 current study), mAb 100a against CPAF [26], mAb MC22 against chlamydial major outer membrane protein [MOMP; ref [26]], mAb W27 against host cell HSP70 (cat#Sc-24, Santa Cruz Biotechnology, CA), mAb against FLAG tag (cat#F3165, Sigma, St. Luis, MO) and rabbit polyclonal antibody against bacterial GroEL (cat#G6532, Sigma, St. Luis, MO). The anti-MOMP antibody was used to ensure that all lanes with chlamydial organism-containing samples were loaded with equivalent amounts of the organisms

while the lanes without chlamydial organism samples should be negative for MOMP. The anti-HSP70 antibody was used to make sure that equal amounts of normal HeLa and Chlamydia-infected HeLa samples were loaded and to also check whether the cytosolic fractions are contaminated with components from the pellet fractions during cellular fractionation (see below). All primary antibodies used in the current study were pre-absorbed with an excess amount of bacterial lysates containing the GST alone. The primary antibody binding was probed with an HRP (horse radish peroxidase)-conjugated goat anti-mouse IgG secondary antibody (Jackson ImmunoResearch, West Grove, PA) and visualized with an enhanced chemiluminescence (ECL) kit (Santa Cruz Biotech). Some of the C.