guanosine-triphosphate and Chlamydia-Infections

The clinical efficacy and safety of levofloxacin (LVFX) 500mg qd were evaluated in female patients with cervicitis with Chlamydia trachomatis and intrauterine infections. LVFX was administered orally at 500 mg qd for 7 days. Bacteriological efficacy was 94.4% (17/18) and clinical efficacy was 100% (16/16) at 14 to 21 days after the end of treatment in cervicitis. On the other hand, bacteriological efficacy and clinical efficacy at the end of treatment in intrauterine infections were 68.8% (11/16) and 94.7% (18/19), respectively. For safety, adverse drug reactions occurred in 9 of 43 patients (20.9%), i.e., increased y-GTP in 2 patients, glucose urine present in 2, and each of all other adverse reactions occurred in 1. All adverse drug reactions observed were either mild or moderate. Results suggested that LVFX 500 mg qd was effective and safe in the treatment of cervicitis with Chlamydia trachomatis and intrauterine infections.

Topics: Administration, Oral; Adult; Anti-Bacterial Agents; Chlamydia Infections; Chlamydia trachomatis; Drug Administration Schedule; Endometritis; Female; Glycosuria; Guanosine Triphosphate; Humans; Levofloxacin; Ofloxacin; Product Surveillance, Postmarketing; Treatment Outcome; Uterine Cervicitis; Young Adult

Persistence, a viable but non-replicating growth state, has been implicated in diseases caused by Chlamydia trachomatis. Starvation of distinct nutrients produces a superficially similar persistent state, implying convergence on a common intracellular environment. We employed host-pathogen dual RNA-sequencing under both iron- and tryptophan-starved conditions to systematically characterize the persistent chlamydial transcriptome and to define common contributions of the host cell transcriptional stress response in shaping the intracellular environment. The transcriptome of the infected host cells was highly specific to each nutritional stress, despite comparable effects on chlamydial growth and development in each condition. In contrast, the chlamydial transcriptomes between nutritional conditions were highly similar, suggesting some overlap in host cell responses to iron limitation and tryptophan starvation that contribute to a common persistent phenotype. We demonstrate that a commonality in the host cell responses is the suppression of GTP biosynthesis, a nucleotide for which Chlamydia are auxotrophic. Pharmacological inhibition of host IMP dehydrogenase (IMPDH1), which catalyzes the rate-limiting step in

Topics: Chlamydia Infections; Chlamydia trachomatis; Guanosine Triphosphate; Humans; Iron; Tryptophan

Human guanylate binding protein 1 (hGBP1) belongs to the dynamin superfamily of GTPases and conveys host defense against intracellular bacteria and parasites. During infection, hGBP1 is recruited to pathogen-containing vacuoles, such as Chlamydia trachomatis inclusions, restricts pathogenic growth, and induces the activation of the inflammasome pathway. hGBP1 has a unique catalytic activity to hydrolyze guanosine triphosphate (GTP) to guanosine monophosphate (GMP) in two consecutive cleavage steps. However, the functional significance of this activity in host defense remains elusive. Here, we generate a structure-guided mutant that specifically abrogates GMP production, while maintaining fast cooperative GTP hydrolysis. Complementation experiments in human monocytes/macrophages show that hGBP1-mediated GMP production is dispensable for restricting Chlamydia trachomatis growth but is necessary for inflammasome activation. Mechanistically, GMP is catabolized to uric acid, which in turn activates the NLRP3 inflammasome. Our study demonstrates that the unique enzymology of hGBP1 coordinates bacterial growth restriction and inflammasome signaling.

Topics: Chlamydia Infections; Chlamydia trachomatis; Cyclic GMP; GTP-Binding Proteins; Guanine Nucleotides; Guanosine Triphosphate; Humans; Hydrolysis; Inflammasomes; Macrophages; NLR Family, Pyrin Domain-Containing 3 Protein; Signal Transduction; THP-1 Cells; Uric Acid

Cell-autonomous immunity to the bacterial pathogen Chlamydia trachomatis and the protozoan pathogen Toxoplasma gondii is controlled by two families of Interferon (IFN)-inducible GTPases: Immunity Related GTPases (IRGs) and Guanylate binding proteins (Gbps). Members of these two GTPase families associate with pathogen-containing vacuoles (PVs) and solicit antimicrobial resistance pathways specifically to the intracellular site of infection. The proper delivery of IRG and Gbp proteins to PVs requires the autophagy factor Atg5. Atg5 is part of a protein complex that facilitates the transfer of the ubiquitin-like protein Atg8 from the E2-like conjugation enzyme Atg3 to the lipid phosphatidylethanolamine. Here, we show that Atg3 expression, similar to Atg5 expression, is required for IRG and Gbp proteins to dock to PVs. We further demonstrate that expression of a dominant-active, GTP-locked IRG protein variant rescues the PV targeting defect of Atg3- and Atg5-deficient cells, suggesting a possible role for Atg proteins in the activation of IRG proteins. Lastly, we show that IFN-induced cell-autonomous resistance to C. trachomatis infections in mouse cells depends not only on Atg5 and IRG proteins, as previously demonstrated, but also requires the expression of Atg3 and Gbp proteins. These findings provide a foundation for a better understanding of IRG- and Gbp-dependent cell-autonomous resistance and its regulation by Atg proteins.

Topics: Animals; Autophagy-Related Protein 5; Autophagy-Related Proteins; Chlamydia Infections; Chlamydia trachomatis; Chromosomes, Mammalian; Disease Resistance; GTP-Binding Proteins; Guanosine Triphosphate; Immunity; Inclusion Bodies; Interferon-gamma; Mice; Microtubule-Associated Proteins; Mutant Proteins; Protein Binding; Toxoplasma; Toxoplasmosis; Ubiquitin-Conjugating Enzymes; Vacuoles

Chlamydiae, which are obligate intracellular bacteria, replicate in a nonlysosomal vacuole, termed an inclusion. Although neither the host nor the chlamydial proteins that mediate the intracellular trafficking of the inclusion have been clearly identified, several enhanced green fluorescent protein (GFP)-tagged Rab GTPases, including Rab4A, are recruited to chlamydial inclusions. GFP-Rab4A associates with inclusions in a species-independent fashion by 2 h postinfection by mechanisms that have not yet been elucidated. To test whether chlamydial inclusion membrane proteins (Incs) recruit Rab4 to the inclusion, we screened a collection of chlamydial Incs for their ability to interact with Rab4A by using a yeast two-hybrid assay. From our analysis, we identified a specific interaction between Rab4A and Chlamydia trachomatis Inc CT229, which is expressed during the initial stages of infection. CT229 interacts with only wild-type Rab4A and the constitutively active GTPase-deficient Rab4AQ67L but not with the dominant-negative GDP-restricted Rab4AS22N mutant. To confirm the interaction between CT229 and Rab4A, we demonstrated that DsRed-CT229 colocalized with GFP-Rab4A in HeLa cells and more importantly wild-type and constitutively active GFP-Rab4A colocalized with CT229 at the inclusion membrane in C. trachomatis serovar L2-infected HeLa cells. Taken together, these data suggest that CT229 interacts with and recruits Rab4A to the inclusion membrane and therefore may play a role in regulating the intracellular trafficking or fusogenicity of the chlamydial inclusion.

Topics: Bacterial Proteins; Chlamydia Infections; Chlamydia trachomatis; Green Fluorescent Proteins; Guanosine Triphosphate; HeLa Cells; Humans; Intracellular Membranes; Membrane Proteins; Mutation; rab4 GTP-Binding Proteins