Expression of Matrix Metalloproteinases Subsequent to Urogenital Chlamydia muridarum Infection of Mice

The central hypothesis of this study was that matrix metalloproteinases (MMPs) would be enhanced following murine chlamydial infection and that their expression would vary in mouse strains that differ in their susceptibility to chronic chlamydia-induced disease. To address this hypothesis, female C3H/HeN and C57BL/6 mice were infected intravaginally with Chlamydia muridarum. Uterine and oviduct tissues were assessed for transcription of MMP genes and their tissue inhibitors. An increased activity of MMP genes relative to preinfection tissues was observed in the C3H/HeN mice when compared to C57BL/6 mice. Using gelatin zymography, we detected constitutive MMP-2 activity in both strains of mice but an increase in MMP-9. Casein zymography indicated the presence of two elastase-like activities consistent with MMP-12 and possibly MMP-7. Western blotting and antigen capture enzyme-linked immunoassay also confirmed an increase in MMP-9 but constitutive MMP-2 expression subsequent to the infection in both strains of mice. In C57BL/6 mice, MMP-9 was present in monomer and dimer form throughout the 56-day monitoring period. C3H/HeN mice produced dimeric MMP-9, but increases in the monomer form were also observed through day 14. Post-translational modification of MMP-9 between the two strains also differed. Immunohistochemistry revealed neutrophils as a prominent source for MMP-9 in both strains of mice. We conclude that differences in the relative expression and activity of MMPs, particularly MMP-9, occur in mice differing in their susceptibility to the development of chronic chlamydial disease. These differences may account for disparate outcomes with regard to chronic sequelae of the disease

Unimpaired sentence comprehension after anterior temporal cortex resection

Contains fulltext : 73404.pdf (publisher's version ) (Closed access

Plasmid coding sequence-five influences infectivity and virulence in a mouse model of Chlamydia trachomatis urogenital infection

The native plasmid of both Chlamydia muridarum and C. trachomatis has been shown to control virulence and infectivity in mice and in lower primates. We have recently described the development of a plasmid-based genetic transformation protocol for Chlamydia trachomatis that for the first time provides a platform for the molecular dissection of the function of the chlamydial plasmid and its individual genes or coding sequences (CDS). In the present study, we transformed a plasmid-free lymphogranuloma venereum isolate of C. trachomatis, serovar L2, with either the original shuttle vector (pGFP::SW2) or a derivative of pGFP::SW2 carrying a deletion of the plasmid CDS5 gene (pCDS5KO). Female mice were inoculated with these strains either intravaginally or transcervically. We found that transformation of the plasmid-free isolate with the intact pGFP::SW2 vector significantly enhanced infectivity and induction of host inflammatory responses when compared to the plasmid-free parental isolate. Transformation with pCDS5KO resulted in infection courses and inflammatory responses not significantly different from those observed in mice infected with the plasmid-free isolate. These results indicate a critical role of plasmid CDS5 in in vivo fitness and in induction of inflammatory responses. To our knowledge, these are the first in vivo observations ascribing infectivity and virulence to a specific plasmid gen

Use of consensus methodology to determine candidate items for systemic lupus erythematosus classification criteria

Objective. Given the complexity and heterogeneity of systemic lupus erythematosus (SLE), high-performing classification criteria are critical to advancing research and clinical care. A collaborative effort by the European League Against Rheumatism and the American College of Rheumatology was undertaken to generate candidate criteria, and then to reduce them to a smaller set. The objective of the current study was to select a set of criteria that maximizes the likelihood of accurate classification of SLE, particularly early disease. Methods. An independent panel of international SLE experts and the SLE classification criteria steering committee (conducting SLE research in Canada, Mexico, United States, Austria, Germany, Greece, France, Italy, and Spain) ranked 43 candidate criteria. A consensus meeting using nominal group technique (NGT) was conducted to reduce the list of criteria for consideration. Results. The expert panel NGT exercise reduced the candidate criteria for SLE classification from 43 to 21. The panel distinguished potential "entry criteria," which would be required for classification, from potential "additive criteria." Potential entry criteria were antinuclear antibody (ANA) = 1:80 (HEp-2 immunofluorescence), and low C3 and/or low C4. The use of low complement as an entry criterion was considered potentially useful in cases with negative ANA. Potential additive criteria included lupus nephritis by renal biopsy, autoantibodies, cytopenias, acute and chronic cutaneous lupus, alopecia, arthritis, serositis, oral mucosal lesions, central nervous system manifestations, and fever. Conclusion. The NGT exercise resulted in 21 candidate SLE classification criteria. The next phases of SLE classification criteria development will require refinement of criteria definitions, evaluation of the ability to cluster criteria into domains, and evaluation of weighting of criteria. Copyright © 2019. All rights reserved

Stimulation of the cytosolic receptor for peptidoglycan, Nod1, by infection with Chlamydia trachomatis or Chlamydia muridarum.

International audienceInfection of epithelial cells by the intracellular pathogen, Chlamydia trachomatis, leads to activation of NF-kappaB and secretion of pro-inflammatory cytokines. We find that overexpression of a dominant-negative Nod1 or depletion of Nod1 by RNA interference inhibits partially the activation of NF-kappaB during chlamydial infection in vitro, suggesting that Nod1 can detect the presence of Chlamydia. In parallel, there is a larger increase in the expression of pro-inflammatory genes following Chlamydia infection when primary fibroblasts are isolated from wild-type mice than from Nod1-deficient mice. The Chlamydia genome encodes all the putative enzymes required for proteoglycan synthesis, but proteoglycan from Chlamydia has never been detected biochemically. Since Nod1 is a ubiquitous cytosolic receptor for peptidoglycan from Gram-negative bacteria, our results suggest that C. trachomatis and C. muridarum do in fact produce at least the rudimentary proteoglycan motif recognized by Nod1. Nonetheless, Nod1 deficiency has no effect on the efficiency of infection, the intensity of cytokine secretion, or pathology in vaginally infected mice, compared with wild-type controls. Similarly, Rip2, a downstream mediator of Nod1, Toll-like receptor (TLR)-2, and TLR4, increases only slightly the intensity of chlamydial infection in vivo and has a very mild effect on the immune response and pathology. Thus, Chlamydia may not produce sufficient peptidoglycan to stimulate Nod1-dependent pathways efficiently in infected animals, or other receptors of the innate immune system may compensate for the absence of Nod1 during Chlamydia infection in vivo