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Guangming Zhong - One of the best experts on this subject based on the ideXlab platform.

  • Adoptive Transfer of Group 3-Like Innate Lymphoid Cells Restores Mouse Colon Resistance to Colonization of a Gamma Interferon-Susceptible Chlamydia Muridarum Mutant.
    Infection and immunity, 2021
    Co-Authors: Chenchen Song, Bernard P Arulanandam, John J. Koprivsek, Huixiang Yang, Lijian Tao, Guangming Zhong
    Abstract:

    ABSTRACT The obligate intracellular bacterium Chlamydia Muridarum can colonize the mouse colon for a long period, but a gamma interferon (IFN-γ)-susceptible mutant clone fails to do so. Nevertheless, the mutant’s colonization is rescued in mice deficient in interleukin-7 receptor (IL-7R) (lacking both lymphocytes and innate lymphoid cells [ILCs]) or IFN-γ but not in mice lacking recombination-activated gene 1 (Rag1−/− mice) (lacking adaptive immunity lymphocytes), indicating a critical role of ILC-derived IFN-γ in regulating Chlamydial colonization. In the current study, we have used an adoptive transfer approach for further characterizing the responsible ILCs. First, intestinal ILCs isolated from Rag1−/− mice were able to rescue IL-7R-deficient mice to restrict the colonization of the IFN-γ-susceptible Chlamydia Muridarum mutant. Second, the responsible ILCs were localized to the intestinal lamina propria since ILCs from the lamina propria but not the intraepithelial compartment conferred the restriction. Third, lamina propria ILCs enriched for RORγt expression but not those negative for RORγt rescued the IL-7R-deficient mice to restrict mutant colonization, indicating a critical role of group 3-like ILCs (ILC3s) since RORγt is a signature transcriptional factor of ILC3s. Fourth, a portion of the ILC3s expressed IFN-γ, thus defined as ex-ILC3s, and the transfer of the ex-ILC3s conferred colon resistance to mutant Chlamydia Muridarum colonization in IFN-γ-deficient mice. Finally, genetically labeled RORγt-positive (RORγt+) ILCs were able to inhibit mutant colonization. Thus, we have demonstrated that ILC3s are sufficient for regulating Chlamydial colonization, laying a foundation for further revealing the mechanisms by which an obligate intracellular bacterium activates colonic ILC3s.

  • A primary study on genes with selected mutations by in vitro passage of Chlamydia Muridarum strains.
    Pathogens and disease, 2019
    Co-Authors: Zhou Zhou, Na Liu, Yingzi Wang, Arthur Wirekoh Emmanuel, Xiaoxing You, Jiulin Liu, Guangming Zhong
    Abstract:

    OBJECTIVE This study is to investigate the functions of newly discovered genes in Chlamydia Muridarum (C. Muridarum) strains with single gene differences. METHODS Using whole genome sequencing and plaque formation assays, C. Muridarum parental and passaging strains were established, and the isogenic clones expressing certain genotypes were isolated. Strains with single gene differences were obtained. Based on prediction, the valuable strains with single gene differences of tc0412, tc0668 or tc0237 were subjected to the in vitro and in vivo experiments for biological characterization and virulence analysis. RESULTS Insertional -472840T mutation of the tc0412 gene (T28T/B3 type) matching with the nonmutant tc0668 gene and tc0237 gene with point mutations G797659T (Q117E) might slow the growth of Chlamydia due to the lack of a plasmid. The nonmutant tc0668 in the strain might induce a high incidence of hydrosalpinx in mice, while tc0668 with a G797659T point mutation was significantly attenuated. Compared with the nonmutant tc0237, the strains containing mutant tc0237 were characterized by reduced centrifugation dependence during infection. CONCLUSION The identification and characterization of these genes might contribute to the comprehensive understanding of the pathogenic mechanism of Chlamydia.

  • IL-10 promotes Chlamydia Muridarum infection in mice through inhibiting IFN-γ and IL-2 expression
    Chinese journal of microbiology and immunology, 2019
    Co-Authors: Xin Wang, Xiaoqing Luo, Guangming Zhong
    Abstract:

    Objective To study the possible molecular mechanism of IL-10 in promoting Chlamydia Muridarum infection in mice. Methods C57BL/6 wild-type and IL-10 gene knockout (IL-10-/-) mice were infected with Chlamydia Muridarum. Indirect immunofluorescence assay was used to detect the growth of Chlamydia Muridarum in the intestinal and genital tracts. The severity of genital diseases was assessed by hydrosalpinx scoring. Expression of IFN-γ and IL-2 in blood was measured by ELISA. Results Compared with the wild-type group, Chlamydia clearance in the intestinal and genital tracts of IL-10-/- mice was significantly faster, and the expression of IFN-γ and IL-2 increased significantly. In addition, wild-type mice showed more serious hydrosalpinx. Conclusions IL-10 delays Chlamydia trachomatis clearance and promotes Chlamydia infection through inhibiting the expression of IFN-γ and IL-2, which aggravates hydrosalpinx. Key words: Chlamydia trachomatis; IL-10; Cytokine; Immunity

  • The Genital Tract Virulence Factor pGP3 Is Essential for Chlamydia Muridarum Colonization in the Gastrointestinal Tract.
    Infection and immunity, 2017
    Co-Authors: Lili Shao, Quanzhong Liu, Yuanjun Liu, David E Nelson, Yumeng Huang, Tianyuan Zhang, Jose Melero, Guangming Zhong
    Abstract:

    ABSTRACT The cryptic plasmid is essential for Chlamydia Muridarum dissemination from the genital tract to the gastrointestinal (GI) tract. Following intravaginal inoculation, a C. Muridarum strain deficient in plasmid-encoded pGP3 or pGP4 but not pGP5, pGP7, or pGP8 failed to spread to the mouse gastrointestinal tract, although mice infected with these strains developed productive genital tract infections. pGP3- or pGP4-deficient strains also failed to colonize the gastrointestinal tract when delivered intragastrically. pGP4 regulates pGP3, while pGP3 does not affect pGP4 expression, indicating that pGP3 is critical for C. Muridarum colonization of the gastrointestinal tract. Mutants deficient in GlgA, a chromosome-encoded protein regulated by pGP4, also consistently colonized the mouse gastrointestinal tract. Interestingly, C. Muridarum colonization of the gastrointestinal tract positively correlated with pathogenicity in the upper genital tract. pGP3-deficient C. Muridarum strains did not induce hydrosalpinx or spread to the GI tract even when delivered to the oviduct by intrabursal inoculation. Thus, the current study not only has revealed that pGP3 is a novel Chlamydial colonization factor in the gastrointestinal tract but also has laid a foundation for investigating the significance of gastrointestinal Chlamydia.

  • IL-6-mediated signaling pathways limit Chlamydia Muridarum infection and exacerbate its pathogenicity in the mouse genital tract.
    Microbes and infection, 2017
    Co-Authors: Xin Sun, Min Xue, Luying Wang, Qi Tian, Guangming Zhong
    Abstract:

    Chlamydia Muridarum induction of mouse hydrosalpinx, depending on both tubal infection and inflammation, has been used for investigating Chlamydia trachomatis pathogenesis. We now report that IL-6 both inhibits C. Muridarum infection and exacerbates pathogenicity in the mouse genital tract. When intravaginally inoculated with a high dose of C. Muridarum, IL-6-deficient mice developed more extensive genital tract infection with severe hydrosalpinx, suggesting that IL-6 is required for controlling the high dose infection but not essential for C. Muridarum-induced pathology. However, at a low dose, IL-6-deficient mice still developed more extensive infection in the genital tract but no longer with significant pathology, suggesting that IL-6 is required for both controlling the low dose infection and exacerbating the low dose infection-induced pathology. The lack of hydrosalpinx in IL-6-deficient mice correlated with significantly reduced inflammatory infiltration in the oviduct tissue and decreased spleen CD4+ and CD8+ T cells that produce TNFα. Thus, IL-6-dependent pathways are important for both limiting Chlamydial colonization in the genital tract mucosal tissues regardless of the infection doses and exacerbating Chlamydial pathogenicity in the upper genital tract when IL-6-independent pathogenic mechanisms are not yet activated with a low infection dose.

Kyle H. Ramsey - One of the best experts on this subject based on the ideXlab platform.

  • The Chlamydia Muridarum plasmid revisited : new insights into growth kinetics.
    Wellcome open research, 2018
    Co-Authors: Rachel J. Skilton, Kyle H. Ramsey, Yibing Wang, Nicholas R. Thomson, Colette E O'neill, Simone Filardo, Peter Marsh, Angèle Bénard, Ian N. Clarke
    Abstract:

    Background: Research in Chlamydial genetics is challenging because of its obligate intracellular developmental cycle. In vivo systems exist that allow studies of different aspects of basic biology of Chlamydiae, the murine Chlamydia Muridarum model is one of great importance and thus an essential research tool. C. Muridarum carries a plasmid that has a role in virulence.  Our aim was to compare and contrast the C. Muridarum plasmid-free phenotype with that of a chromosomally isogenic plasmid-bearing strain, through the inclusion phase of the developmental cycle. Methods: We measured infectivity for plasmid bearing and plasmid-cured C. Muridarum by inclusion forming assays in McCoy cells and in parallel bacterial chromosome replication by quantitative PCR, throughout the developmental cycle. In addition to these studies, we have carefully monitored Chlamydial inclusion formation by confocal microscopy and transmission electron microscopy. A new E.coli /Chlamydial shuttle vector (pNigg::GFP) was constructed using standard cloning technology and used to transform C. Muridarum for further phenotypic studies. Results: We have advanced the definition of the Chlamydial phenotype away from the simple static observation of mature inclusions and redefined the C. Muridarum plasmid-based phenotype on growth profile and inclusion morphology. Our observations on the growth properties of plasmid-cured C. Muridarum challenge the established interpretations, especially with regard to inclusion growth kinetics. Introduction of the shuttle plasmid pNigg::GFP into plasmid-cured C. Muridarum restored the wild-type plasmid-bearing phenotype and confirmed that loss of the plasmid was the sole cause for the changes in growth and chromosomal replication. Conclusions: Accurate growth curves and sampling at multiple time points throughout the developmental cycle is necessary to define plasmid phenotypes.  There are subtle but important (previously unnoticed) differences in the overall growth profile of plasmid-bearing and plasmid-free C. Muridarum .  We have proven that the differences described are solely due to the plasmid pNigg.

  • The Chlamydia Muridarum plasmid revisited : new insights into growth kinetics [version 1; referees: 2 approved]
    Wellcome, 2018
    Co-Authors: Rachel J. Skilton, Kyle H. Ramsey, Yibing Wang, Nicholas R. Thomson, Simone Filardo, Peter Marsh, Angèle Bénard, Colette O'neill, Ian N. Clarke
    Abstract:

    Background: Research in Chlamydial genetics is challenging because of its obligate intracellular developmental cycle. In vivo systems exist that allow studies of different aspects of basic biology of Chlamydiae, the murine Chlamydia Muridarum model is one of great importance and thus an essential research tool. C. Muridarum carries a plasmid that has a role in virulence.  Our aim was to compare and contrast the C. Muridarum plasmid-free phenotype with that of a chromosomally isogenic plasmid-bearing strain, through the inclusion phase of the developmental cycle. Methods: We measured infectivity for plasmid bearing and plasmid-cured C. Muridarum by inclusion forming assays in McCoy cells and in parallel bacterial chromosome replication by quantitative PCR, throughout the developmental cycle. In addition to these studies, we have carefully monitored Chlamydial inclusion formation by confocal microscopy and transmission electron microscopy. A new E.coli/Chlamydial shuttle vector (pNigg::GFP) was constructed using standard cloning technology and used to transform C. Muridarum for further phenotypic studies. Results: We have advanced the definition of the Chlamydial phenotype away from the simple static observation of mature inclusions and redefined the C. Muridarum plasmid-based phenotype on growth profile and inclusion morphology. Our observations on the growth properties of plasmid-cured C. Muridarum challenge the established interpretations, especially with regard to inclusion growth kinetics. Introduction of the shuttle plasmid pNigg::GFP into plasmid-cured C. Muridarum restored the wild-type plasmid-bearing phenotype and confirmed that loss of the plasmid was the sole cause for the changes in growth and chromosomal replication. Conclusions: Accurate growth curves and sampling at multiple time points throughout the developmental cycle is necessary to define plasmid phenotypes.  There are subtle but important (previously unnoticed) differences in the overall growth profile of plasmid-bearing and plasmid-free C. Muridarum.  We have proven that the differences described are solely due to the plasmid pNigg

  • The genetic basis of plasmid tropism between Chlamydia trachomatis and Chlamydia Muridarum
    Pathogens and disease, 2014
    Co-Authors: Yibing Wang, Kyle H. Ramsey, Lesley T. Cutcliffe, Rachel J. Skilton, Nicholas R. Thomson, Ian N. Clarke
    Abstract:

    The development of genetic transformation technology for Chlamydia trachomatis using its endogenous plasmid has recently been described. Chlamydia Muridarum cannot be transformed by the C. trachomatis plasmid, indicating a barrier between Chlamydial species. To determine which regions of the plasmid conferred the species specificity, we used the novel approach of transforming wild-type C. Muridarum carrying the endogenous plasmid pNigg and forced recombination with the C. trachomatis vector pGFP::SW2 which carries the complete C. trachomatis plasmid (pSW2). Penicillin and chloramphenicol-resistant transformants expressing the green fluorescent protein were selected. Recovery of plasmids from these transformants showed they were recombinants. The differences between the pSW2 and pNigg allowed identification of the recombination breakpoints and showed that pGFP::SW2 had exchanged a ~ 1 kbp region with pNigg covering CDS 2. The recombinant plasmid (pSW2NiggCDS2) is maintained under antibiotic selection when transformed into plasmid-cured C. Muridarum. The ability to select for recombinants in C. Muridarum shows that the barrier is not at transformation, but at the level of plasmid replication or maintenance. Our studies show that CDS 2, together with adjoining sequences, is the main determinant of plasmid tropism.

  • a role for cxc chemokine receptor 2 in the pathogenesis of urogenital Chlamydia Muridarum infection in mice
    Fems Immunology and Medical Microbiology, 2010
    Co-Authors: Hyo Y. Lee, Justin H. Schripsema, Ira M. Sigar, John N. Kasimos, Candace M. Murray, Shanon R. Lacy, Kyle H. Ramsey
    Abstract:

    We tested the hypothesis that a specific chemokine receptor, CXC chemokine receptor-2 (CXCR2), mediates acute inflammatory damage during Chlamydial urogenital infection, which ultimately leads to the chronic sequelae of hydrosalpinx — a surrogate marker of infertility. Homozygous CXCR2 genetic knockouts (CXCR2−/−), heterozygous littermates (CXCR2+/−) or homozygous wild-type (wt) controls (CXCR2+/+) were infected intravaginally with Chlamydia Muridarum . Although no change was observed in the infection in the lower genital tract based on CXCR zygosity, a delay in the ascension of infection into the upper genital tract was seen in CXCR2−/− mice. Significantly elevated peripheral blood neutrophil counts were observed in CXCR2−/− mice when compared with controls. Reduced rates of acute inflammatory indices were observed in the affected tissue, indicating reduced neutrophil extravasation capacity in the absence of CXCR2. Of note was a reduction in the postinfection development of hydrosalpinx that correlated with CXCR2 zygosity, with both CXCR2−/− (13%) and their CXCR2+/− (35%) littermates displaying significantly lower rates of hydrosalpinx formation than the wt CXCR2-sufficient mice (93%). We conclude that CXCR2 ligands are a major chemotactic signal that induces damaging acute inflammation and the resulting chronic pathology during the repair phase of the host response, but are dispensable for the resolution of infection.

  • A role for CXC chemokine receptor‐2 in the pathogenesis of urogenital Chlamydia Muridarum infection in mice
    FEMS immunology and medical microbiology, 2010
    Co-Authors: Hyo Y. Lee, Justin H. Schripsema, Ira M. Sigar, John N. Kasimos, Candace M. Murray, Shanon R. Lacy, Kyle H. Ramsey
    Abstract:

    We tested the hypothesis that a specific chemokine receptor, CXC chemokine receptor-2 (CXCR2), mediates acute inflammatory damage during Chlamydial urogenital infection, which ultimately leads to the chronic sequelae of hydrosalpinx — a surrogate marker of infertility. Homozygous CXCR2 genetic knockouts (CXCR2−/−), heterozygous littermates (CXCR2+/−) or homozygous wild-type (wt) controls (CXCR2+/+) were infected intravaginally with Chlamydia Muridarum . Although no change was observed in the infection in the lower genital tract based on CXCR zygosity, a delay in the ascension of infection into the upper genital tract was seen in CXCR2−/− mice. Significantly elevated peripheral blood neutrophil counts were observed in CXCR2−/− mice when compared with controls. Reduced rates of acute inflammatory indices were observed in the affected tissue, indicating reduced neutrophil extravasation capacity in the absence of CXCR2. Of note was a reduction in the postinfection development of hydrosalpinx that correlated with CXCR2 zygosity, with both CXCR2−/− (13%) and their CXCR2+/− (35%) littermates displaying significantly lower rates of hydrosalpinx formation than the wt CXCR2-sufficient mice (93%). We conclude that CXCR2 ligands are a major chemotactic signal that induces damaging acute inflammation and the resulting chronic pathology during the repair phase of the host response, but are dispensable for the resolution of infection.

Kenneth W. Beagley - One of the best experts on this subject based on the ideXlab platform.

  • Chlamydia Muridarum major outer membrane protein-specific antibodies inhibit in vitro infection but enhance pathology in vivo
    2011
    Co-Authors: Kelly A. Cunningham, Alison J. Carey, Louise M. Hafner, Peter Timms, Kenneth W. Beagley
    Abstract:

    PROBLEM Chlamydia trachomatis is a significant worldwide health problem, and the often-asymptomatic disease can result in infertility. To develop a successful vaccine, a complete understanding of the immune response to Chlamydial infection and development of genital tract pathology is required. METHOD OF STUDY We utilized the murine genital model of Chlamydial infection. Mice were immunized with Chlamydial major outer membrane protein, and vaginal lavage was assessed for the presence of neutralizing antibodies. These samples were then pre-incubated with Chlamydia Muridarum and administered to the vaginal vaults of immune-competent female BALB/c mice to determine the effect on infection. RESULTS The administration of C. Muridarum in conjunction with neutralizing antibodies reduced the numbers of mice infected, but a surprising finding was that this accelerated the development of severe oviduct pathology. CONCLUSION Antibodies play an under-recognized role in Chlamydial infection and pathology development, which possibly involves interaction with Th1 immunity.

  • Chlamydia Muridarum Major Outer Membrane Protein‐Specific Antibodies Inhibit In Vitro Infection but Enhance Pathology In Vivo
    American journal of reproductive immunology (New York N.Y. : 1989), 2011
    Co-Authors: Kelly A. Cunningham, Alison J. Carey, Louise M. Hafner, Peter Timms, Kenneth W. Beagley
    Abstract:

    PROBLEM Chlamydia trachomatis is a significant worldwide health problem, and the often-asymptomatic disease can result in infertility. To develop a successful vaccine, a complete understanding of the immune response to Chlamydial infection and development of genital tract pathology is required. METHOD OF STUDY We utilized the murine genital model of Chlamydial infection. Mice were immunized with Chlamydial major outer membrane protein, and vaginal lavage was assessed for the presence of neutralizing antibodies. These samples were then pre-incubated with Chlamydia Muridarum and administered to the vaginal vaults of immune-competent female BALB/c mice to determine the effect on infection. RESULTS The administration of C. Muridarum in conjunction with neutralizing antibodies reduced the numbers of mice infected, but a surprising finding was that this accelerated the development of severe oviduct pathology. CONCLUSION Antibodies play an under-recognized role in Chlamydial infection and pathology development, which possibly involves interaction with Th1 immunity.

  • CD4+ T cells reduce the tissue burden of Chlamydia Muridarum in male BALB/c mice.
    Vaccine, 2010
    Co-Authors: Kelly A. Cunningham, Alison J. Carey, Peter Timms, Kenneth W. Beagley
    Abstract:

    Abstract Male Chlamydial infections are becoming more recognised as an aetiological agent in infertility. An IFN-γ response is required for protection against Chlamydia in females, but may have the potential to induce pathology in the immune-privileged male reproductive tract. We examined the induction of immunity following intranasal immunisation with major outer membrane protein (MOMP) of Chlamydia Muridarum in male BALB/c mice, and the role of MOMP-specific CD4 + T cells in clearance of an intrapenile infection. Here we report that adoptive transfer of MOMP-specific CD4 + T cells into naive mice confers partial protective immunity, which significantly reduces the tissue burden of Chlamydia .

  • Effects of inoculating dose on the kinetics of Chlamydia Muridarum genital infection in female mice.
    Immunology and cell biology, 2009
    Co-Authors: Alison J. Carey, Kelly A. Cunningham, Louise M. Hafner, Peter Timms, Kenneth W. Beagley
    Abstract:

    Chlamydia trachomatis infections have been implicated in problems such as pelvic inflammatory disease and infertility in females. Although there are some studies examining the kinetics of ascending infection, there is limited information on the kinetics of pathology development and cellular infiltrate into the reproductive tissues in relation to the effects of inoculating dose, and a better understanding of these is needed. The murine model of female genital tract Chlamydia Muridarum infection is frequently used as a model of human C. trachomatis reproductive tract infection. To investigate the kinetics of ascending genital infection and associated pathology development, female BALB/c mice were intravaginally infected with C. Muridarum at doses ranging from 5 x 10(2) to 2.6 x 10(6) inclusion forming units. We found that the inoculating dose affects the course of infection and the ascension of bacteria, with the highest dose ascending rapidly to the oviducts. By comparison, the lowest dose resulted in the greatest bacterial load in the lower reproductive tract. Interestingly, we found that the dose did not significantly affect inflammatory cell infiltrate in the various regions. Overall, this data show the effects of infectious dose on the kinetics of ascending Chlamydial infection and associated inflammatory infiltration in BALB/c mice.

  • poly immunoglobulin receptor mediated transport of iga into the male genital tract is important for clearance of Chlamydia Muridarum infection
    American Journal of Reproductive Immunology, 2008
    Co-Authors: Kelly A. Cunningham, Alison J. Carey, Peter Timms, Jane M Finnie, Shisan Bao, Charmere Coon, Russell C Jones, Odilia L C Wijburg, Richard A Strugnell, Kenneth W. Beagley
    Abstract:

    Problem: Chlamydia trachomatis is the most common sexually transmitted infection worldwide. While infection in females requires a Th1 response for clearance, such a response in males may disrupt the immune privileged nature of the male reproductive tract, potentially contributing to infertility. Method of study: We investigated the role of IgA in protection against an intrapenile Chlamydia Muridarum infection of C57BL/6 and pIgR−/− mice. Results: Here, we show that the poly immunoglobulin receptor is the main pathway for IgA transport into the male reproductive tract. The high levels of IgA seen in prostatic fluid of wild-type mice correlate with reduction in Chlamydial infection both in vitro and in vivo. Conclusion: These findings indicate that a Chlamydia vaccine that induces neutralizing IgA in the prostate will aid in the protection against infection in males.

Toni Darville - One of the best experts on this subject based on the ideXlab platform.

  • Steroids alone or as adjunctive therapy with doxycycline fail to improve oviduct damage in mice infected with Chlamydia Muridarum.
    Clinical and vaccine immunology : CVI, 2014
    Co-Authors: Tammy E. Corr, Charles W. Andrews, Catherine M. O'connell, Jeanne E. Sullivan, Lauren C. Frazer, Toni Darville
    Abstract:

    In women, Chlamydia trachomatis can ascend from the cervix to the fallopian tubes, where an overly aggressive host inflammatory response can cause scarring that leads to chronic pelvic pain, infertility, or ectopic pregnancy. Although screening and treatment programs for women have resulted in decreased rates of sequelae, morbidities associated with oviduct scarring continue to occur. Since corticosteroids have anti-inflammatory and antifibrotic effects, we tested the ability of dexamethasone to inhibit inflammation and prevent oviduct scarring in mice genitally infected with Chlamydia Muridarum. The administration of 1 or 2.5 mg/kg of body weight of dexamethasone on days 7 to 21 of infection resulted in reduced accumulation of inflammatory cells in the oviducts compared to that in controls. However, a concomitant increase in bacterial burden was observed, and chronic oviduct disease was not reduced. Adjunctive administration of a prolonged (21-day) or short (3-day) course of dexamethasone in combination with the antibiotic doxycycline also failed to reduce chronic oviduct pathology compared to antibiotic treatment alone. Steroids administered alone or adjunctively with antibiotics failed to prevent oviduct damage in this murine model of C. trachomatis infection.

  • The recall response induced by genital challenge with Chlamydia Muridarum protects the oviduct from pathology but not from reinfection.
    Infection and immunity, 2012
    Co-Authors: Melissa M. Riley, Charles W. Andrews, Catherine M. O'connell, Lauren C. Frazer, Matthew A. Zurenski, Margaret Mintus, Toni Darville
    Abstract:

    The significant morbidities of ectopic pregnancy and infertility observed in women after Chlamydia trachomatis genital infection result from ascension of the bacteria from the endocervix to the oviduct, where an overly aggressive inflammatory response leads to chronic scarring and Fallopian tube obstruction. A vaccine to prevent Chlamydia-induced disease is urgently needed. An important question for vaccine development is whether sterilizing immunity at the level of the oviduct is essential for protection because of the possibility that a Chlamydial component drives a deleterious anamnestic T cell response upon oviduct reinfection. We show that mice inoculated with attenuated plasmid-cured strains of Chlamydia Muridarum are protected from oviduct pathology upon challenge with wild-type C. Muridarum Nigg despite induction of a response that did not prevent reinfection of the oviduct. Interestingly, repeated abbreviated infections with Nigg also elicited recall responses that protected the oviduct from pathology despite low-level reinfection of this vulnerable tissue site. Challenged mice displayed significant decreases in tissue infiltration of inflammatory leukocytes with marked reductions in frequencies of neutrophils but significant increases in frequencies of CD4 Th1 and CD8 T cells. An anamnestic antibody response was also detected. These data indicate that exposure to a live attenuated Chlamydial vaccine or repeated abbreviated genital infection with virulent Chlamydiae promotes anamnestic antibody and T cell responses that protect the oviduct from pathology despite a lack of sterilizing immunity at the site.

  • Enhanced neutrophil longevity and recruitment contribute to the severity of oviduct pathology during Chlamydia Muridarum infection.
    Infection and immunity, 2011
    Co-Authors: Lauren C. Frazer, Charles W. Andrews, Catherine M. O'connell, Matthew A. Zurenski, Toni Darville
    Abstract:

    Our previous studies revealed that intravaginal infection of mice with a plasmid-deficient strain of Chlamydia Muridarum, CM3.1, does not induce the development of oviduct pathology. In this study, we determined that infection with CM3.1 resulted in a significantly reduced frequency and absolute number of neutrophils in the oviducts during acute infection. This reduction in neutrophils was associated with significantly lower levels of neutrophil chemokines in the oviducts and decreased production of neutrophil chemokines by oviduct epithelial cells infected with CM3.1 in vitro. Infection with CM3.1 also resulted in an increased frequency of late apoptotic/dead neutrophils in the oviduct. Examination of the ability of Chlamydia trachomatis to prevent neutrophil apoptosis in vitro revealed that C. trachomatis strain D/UW-3/Cx exhibited an enhanced ability to prevent neutrophil apoptosis compared to plasmid-deficient CTD153, and this effect was dependent on the presence of CD14(high) monocytes. The presence of monocytes also resulted in enhanced neutrophil cytokine production and increased production of tissue-damaging molecules in response to D/UW-3/Cx relative to results with CTD153. Attempts to use antibody-mediated depletion to discern the specific role of neutrophils in infection control and pathology in vivo revealed that although Ly6G(high) neutrophils were eliminated from the blood and oviducts with this treatment, immature neutrophils and high levels of tissue-damaging molecules were still detectable in the upper genital tract. These data support the role of neutrophils in Chlamydia-induced pathology and reveal that novel methods of depletion must be developed before their role can be specifically determined in vivo.

  • Stimulator of IFN Gene Is Critical for Induction of IFN-β during Chlamydia Muridarum Infection
    Journal of immunology (Baltimore Md. : 1950), 2010
    Co-Authors: Daniel Prantner, Toni Darville, Uma M. Nagarajan
    Abstract:

    Type I IFN signaling has recently been shown to be detrimental to the host during infection with Chlamydia Muridarum in both mouse lung and female genital tract. However, the pattern recognition receptor and the signaling pathways involved in Chlamydial-induced IFN-β are unclear. Previous studies have demonstrated no role for TLR4 and a partial role for MyD88 in Chlamydial-induced IFN-β. In this study, we demonstrate that mouse macrophages lacking TLR3, TRIF, TLR7, or TLR9 individually or both TLR4 and MyD88, still induce IFN-β equivalent to wild type controls, leading to the hypothesis that TLR-independent cytosolic pathogen receptor pathways are crucial for this response. Silencing nucleotide-binding oligomerization domain 1 in HeLa cells partially decreased Chlamydial-induced IFN-β. Independently, small interfering RNA-mediated knockdown of the stimulator of IFN gene (STING) protein in HeLa cells and mouse oviduct epithelial cells significantly decreased IFN-β mRNA expression, suggesting a critical role for STING in Chlamydial-induced IFN-β induction. Conversely, silencing of mitochondria-associated antiviral signaling proteins and the Rig-I–like receptors, RIG-I, and melanoma differentiation associated protein 5, had no effect. In addition, induction of IFN-β depended on the downstream transcription IFN regulatory factor 3, and on activation of NF-κB and MAPK p38. Finally, STING, an endoplasmic reticulum-resident protein, was found to localize in close proximity to the Chlamydial inclusion membrane during infection. These results indicate that C. Muridarum induces IFN-β via stimulation of nucleotide-binding oligomerization domain 1 pathway, and TLR- and Rig-I–like receptor-independent pathways that require STING, culminating in activation of IFN regulatory factor 3, NF-κB, and p38 MAPK.

  • two different homing pathways involving integrin β7 and e selectin significantly influence trafficking of cd4 cells to the genital tract following Chlamydia Muridarum infection
    American Journal of Reproductive Immunology, 2009
    Co-Authors: Kathleen A. Kelly, Ann M. Chan, Anthony W Butch, Toni Darville
    Abstract:

    Problem Chlamydia trachomatis causes STI and reproductive dysfunction worldwide which is not preventable with antibiotics. Identifying a population of endocervical T cells to target in vaccine development would enhance efficacy. Method of study  Trafficking of murine CD4+ lymphocytes to Chlamydia Muridarum infected genital tract (GT) tissue in vivo was measured using adoptive transfer studies of fluorescent CD4+ T cells from integrin β7−/− mice or mice which lack E-selectin on endothelial cells. Results  Murine in vivo migration studies showed that lack of α4β7 or E-selectin significantly reduced trafficking of CD4 T cells to the GT of mice infected with C. Muridarum. Conclusion  CD4+ T cells use at least two different adhesive mechanisms involving an integrin of the mucosal homing pathway and selectin pathway to accumulate in the GT during C. Muridarum infection.

Zhangsheng Yang - One of the best experts on this subject based on the ideXlab platform.

  • The Chromosome-Encoded Hypothetical Protein TC0668 Is an Upper Genital Tract Pathogenicity Factor of Chlamydia Muridarum.
    Infection and immunity, 2015
    Co-Authors: Turner Conrad, Zhangsheng Yang, Zhou Zhou, Jin Dai, Jonathon Keck, Siqi Gong, Patrick Matulich, Noah Beltrami, Chaoqun Chen, Guangming Zhong
    Abstract:

    We previously associated a missense mutation of the tc0668 gene of serial in vitro-passaged Chlamydia Muridarum, a murine model of human urogenital C. trachomatis, with severely attenuated disease development in the upper genital tract of female mice. Since these mutants also contained a TC0237 Q117E missense mutation that enhances their in vitro infectivity, an effort was made here to isolate and characterize a tc0668 single mutant to determine its individual contribution to urogenital pathogenicity. Detailed genetic analysis of C. Muridarum passages revealed a truncated variant with a G216* nonsense mutation of the 408-amino-acid TC0668 protein that does not produce a detectable product. Intracellular growth and infectivity of C. Muridarum in vitro remain unaffected in the absence of TC0668. Intravaginal inoculation of the TC0668 null mutant into C3H/HeJ mice results in a typical course of lower genital tract infection but, unlike a pathogenic isogenic control, is unable to elicit significant chronic inflammation of the oviduct and fails to induce hydrosalpinx. Thus, TC0668 is demonstrated as an important chromosome-encoded urogenital pathogenicity factor of C. Muridarum and the first with these characteristics to be discovered for a Chlamydia pathogen.

  • Chlamydia Muridarum Induction of Glandular Duct Dilation in Mice
    Infection and immunity, 2015
    Co-Authors: Xin Sun, Zhangsheng Yang, Jianlin Chen, Hongbo Zhang, Jin Dai, Lingli Tang, Sheena Rippentrop, Min Xue, Guangming Zhong
    Abstract:

    Although Chlamydia-induced hydrosalpinx in women and mice has been used as a surrogate marker for tubal infertility, the medical relevance of nontubal pathologies, such as uterine horn dilation, developed in mice following Chlamydial infection remains unclear. We now report that the uterine horn dilation correlates with glandular duct dilation detected microscopically following Chlamydia Muridarum infection. The dilated glandular ducts pushed the uterine horn lumen to closure or dilation and even broke through the myometrium to develop extrusion outside the uterine horn. The severity scores of uterine horn dilation observed macroscopically correlated well with the number of cross sections of the dilated glandular ducts counted under microscopy. Chlamydial infection was detected in the glandular epithelial cells, potentially leading to inflammation and dilation of the glandular ducts. Direct delivery of C. Muridarum into the mouse uterus increased both uterine horn/glandular duct dilation and hydrosalpinx. However, the Chlamydial plasmid, which is essential for the induction of hydrosalpinx, was not required for the induction of uterine horn/glandular duct dilation. Screening 12 strains of mice for uterine horn dilation following C. Muridarum infection revealed that B10.D2, C57BL/10J, and C57BL/6J mice were most susceptible, followed by BALB/cJ and A/J mice. Deficiency in host genes involved in immune responses failed to significantly alter the C. Muridarum induction of uterine horn dilation. Nevertheless, the Chlamydial induction of uterine horn/glandular duct dilation may be used to evaluate plasmid-independent pathogenicity of Chlamydia in susceptible mice.

  • In Vitro Passage Selects for Chlamydia Muridarum with Enhanced Infectivity in Cultured Cells but Attenuated Pathogenicity in Mouse Upper Genital Tract
    Infection and immunity, 2015
    Co-Authors: Chaoqun Chen, Zhangsheng Yang, Turner Conrad, Zhou Zhou, Jin Dai, Guangming Zhong
    Abstract:

    Although modern Chlamydia Muridarum has been passaged for decades, there are no reports on the consequences of serial passage with strong selection pressure on its fitness. In order to explore the potential for Pasteurian selection to induce genomic and phenotypic perturbations to C. Muridarum, a starter population was passaged in cultured cells for 28 generations without standard infection assistance. The resultant population, designated CMG28, displays markedly reduced in vitro dependence on centrifugation for infection and low incidence and severity of upper genital tract pathology following intravaginal inoculation into mice compared to the parental C. Muridarum population, CMG0. Deep sequencing of CMG0 and CMG28 revealed novel protein variants in the hypothetical genes TC0237 (Q117E) and TC0668 (G322R). In vitro attachment assays of isogenic plaque clone pairs with mutations in either TC0237 and TC0668 or only TC0237 reveal that TC0237(Q117E) is solely responsible for enhanced adherence to host cells. Paradoxically, double mutants, but not TC0237(Q117E) single mutants, display severely attenuated in vivo pathogenicity. These findings implicate TC0237 and TC0668 as novel genetic factors involved in Chlamydial attachment and pathogenicity, respectively, and show that serial passage under selection pressure remains an effective tool for studying Chlamydia pathogenicity.

  • plasmid encoded pgp3 is a major virulence factor for Chlamydia Muridarum to induce hydrosalpinx in mice
    Infection and Immunity, 2014
    Co-Authors: Zhangsheng Yang, Shuping Hou, Quanzhong Liu, Yuanjun Liu, Yina Sun, Yumeng Huang, Siqi Gong, Chaoqun Chen, Joel B Baseman
    Abstract:

    Hydrosalpinx induction in mice by Chlamydia Muridarum infection, a model that has been used to study C. trachomatis pathogenesis in women, is known to depend on the cryptic plasmid that encodes eight genes designated pgp1 to pgp8. To identify the plasmid-encoded pathogenic determinants, we evaluated C. Muridarum transformants deficient in the plasmid-borne gene pgp3, -4, or -7 for induction of hydrosalpinx. C. Muridarum transformants with an in-frame deletion of either pgp3 or -4 but not -7 failed to induce hydrosalpinx. The deletion mutant phenotype was reproduced by using transformants with premature termination codon insertions in the corresponding pgp genes (to minimize polar effects inherent in the deletion mutants). Pgp4 is known to regulate pgp3 expression, while lack of Pgp3 does not significantly affect Pgp4 function. Thus, we conclude that Pgp3 is an effector virulence factor and that lack of Pgp3 may be responsible for the attenuation in C. Muridarum pathogenicity described above. This attenuated pathogenicity was further correlated with a rapid decrease in Chlamydial survival in the lower genital tract and reduced ascension to the upper genital tract in mice infected with C. Muridarum deficient in Pgp3 but not Pgp7. The Pgp3-deficient C. Muridarum organisms were also less invasive when delivered directly to the oviduct on day 7 after inoculation. These observations demonstrate that plasmid-encoded Pgp3 is required for C. Muridarum survival in the mouse genital tract and represents a major virulence factor in C. Muridarum pathogenesis in mice.

  • complement factor c5 but not c3 contributes significantly to hydrosalpinx development in mice infected with Chlamydia Muridarum
    Infection and Immunity, 2014
    Co-Authors: Zhangsheng Yang, Turner Conrad, Pavel Dutow, Andreas Klos, Jianlin Chen, Zhou Zhou, Guangming Zhong
    Abstract:

    ABSTRACT Hydrosalpinx is a pathological hallmark of tubal infertility associated with Chlamydial infection. However, the mechanisms of hydrosalpinx remain unknown. Here, we report that complement factor 5 (C5) contributes significantly to Chlamydial induction of hydrosalpinx. Mice lacking C5 (C5 −/− ) failed to develop any hydrosalpinx, while ∼42% of the corresponding wild-type mice (C5 +/+ ) did so following intravaginal infection with Chlamydia Muridarum. Surprisingly, deficiency in C3 (C3 −/− ), an upstream component of the complement system, did not affect mouse susceptibility to Chlamydial induction of hydrosalpinx. Interestingly, C5 activation was induced by Chlamydial infection in oviducts of C3 −/− mice, explaining why the C3 −/− mice remained susceptible to Chlamydial induction of hydrosalpinx. Similar levels of live Chlamydial organisms were recovered from oviduct tissues of both C5 −/− and C5 +/+ mice, suggesting that C5 deficiency did not affect C. Muridarum ascending infection. Furthermore, C5 −/− mice were still more resistant to hydrosalpinx induction than C5 +/+ mice, even when live C. Muridarum organisms were directly delivered into the upper genital tract, both confirming the role of C5 in promoting hydrosalpinx and indicating that the C5-facilitated hydrosalpinx was not due to enhancement of ascending infection. The C5 −/− mice displayed significantly reduced lumenal inflammatory infiltration and cytokine production in oviduct tissue, suggesting that C5 may contribute to Chlamydial induction of hydrosalpinx by enhancing inflammatory responses.