Majie Cataplasm Alleviates Asthma by Regulating Th1/Th2/Treg/Th17 Balance.

INTRODUCTION: T cells play a critical role in inflammatory diseases. The aim of the present study was to investigate the effects of Majie cataplasm (MJC) on asthma and to propose a possible mechanism involved in this process. METHODS: Airway inflammation, infiltration of inflammatory cells, levels of interleukin (IL)-4, IL-10, IL-17, and interferon (IFN)-γ, levels of Th2, Treg, Th17, and Th1 cells, and the expressions of IL-4, IL-10, IL-17, IFN-γ, GATA binding protein 3 (GATA-3), Foxp3, RAR-related orphan receptor gamma (RORγt), and T-bet were detected. RESULT: MJC treatment reduced lung airway resistance and inflammatory infiltration in lung tissues. MJC treatment also reduced the numbers of eosinophils and neutrophils in the blood and bronchoalveolar lavage fluid (BALF). The levels of IL-4 and IL-17 in the blood, BALF, and lungs were suppressed by MJC, and IFN-γ and IL-10 were increased. Furthermore, MJC suppressed the percentage of Th2 and Th17 and increased the percentage of Th1 and Treg in spleen cells. In addition, MJC can inhibit asthma by increasing expressions of IFN-γ, IL-10, T-bet, and Foxp3, as well as decreasing expressions of IL-4, IL-17, GATA-3, and RORγt. CONCLUSION: MJC may improve airway hyperresponsiveness and inflammation by regulating Th1/Th2/Treg/Th17 balance in ovalbumin-induced rats. And MJC may be a new source of anti-asthma drugs.

Nucleic Acid Detection through RNA-Guided Protease Activity in Type III-E CRISPR-Cas Systems.

RNA-guided protease activity was recently discovered in the type III-E CRISPR-Cas systems (Craspase), providing a novel platform for engineering a protein probe instead of the commonly used nucleic acid probe in nucleic acid detection assays. Here, by adapting a fluorescence readout technique using the affinity- and fluorescent protein dual-tagged Csx30 protein substrate, we have established an assay monitoring Csx30 cleavage by target ssRNA-activated Craspase. Four Craspase-based nucleic acid detection systems for genes from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), norovirus, and the influenza virus (IFV) were reconstituted with demonstrated specificity. The assay could reliably detect target ssRNAs at concentrations down to 25 pM, which could be further improved approximately 15 000-fold (ca. 2 fM) by incorporating a recombinase polymerase isothermal preamplification step. Importantly, the species-specific substrate cleavage specificity of Craspase enabled multiplexed diagnosis, as demonstrated by the reconstituted composite systems for simultaneous detection of two genes from the same virus (SARS-CoV-2, spike and nsp12) or two types of viruses (SARS-CoV-2 and IFV). The assay could be further expanded by diversifying the fluorescent tags in the substrate and including Craspase systems from various species, thus potentially providing an easily adaptable platform for clinical diagnosis.

Controllable Solid-Phase Fabrication of an Fe2O3/Fe5C2/Fe-N-C Electrocatalyst toward Optimizing the Oxygen Reduction Reaction in Zinc-Air Batteries.

Preparing advanced electrocatalysts via solid-phase reactions encounters the challenge of low controllability for multiconstituent hybridization and microstructure modulation. Herein, a hydrothermal-mimicking solid-phase system is established to fabricate novel Fe2O3/Fe5C2/Fe-N-C composites consisting of Fe2O3/Fe5C2 nanoparticles and Fe,N-doped carbon species with varying morphologies. The evolution mechanism featuring a competitive growth of different carbon sources in a closed hypoxic space is elucidated for a series of Fe2O3/Fe5C2/Fe-N-C composites. The size and dispersity of Fe2O3/Fe5C2 nanoparticles, the graphitization degree of the carbonaceous matrix, and their diverse hybridization states lead to disparate electrocatalytic behaviors for the oxygen reduction reaction (ORR). Among them, microspherical Fe2O3/Fe5C2/Fe-N-C-3 exhibits an optimal ORR performance and the as-assembled zinc-air battery shows all-round superiority to the Pt/C counterpart. This work presents a mild solid-phase fabrication technique for obtaining a variety of nanocomposites with effective control over composition hybridization and microstructural modulation, which is significantly important for the design and optimization of advanced electrocatalysts.

Modulating Coordination of Iron Atom Clusters on N,P,S Triply-Doped Hollow Carbon Support towards Enhanced Electrocatalytic Oxygen Reduction.

Constructing atom-clusters (ACs) with in situ modulation of coordination environment and simultaneously hollowing carbon support are critical yet challenging for improving electrocatalytic efficiency of atomically dispersed catalysts (ADCs). Herein, a general diffusion-controlled strategy based on spatial confining and Kirkendall effect is proposed to construct metallic ACs in N,P,S triply-doped hollow carbon matrix (MACs /NPS-HC, M=Mn, Fe, Co, Ni, Cu). Thereinto, FeACs /NPS-HC with the best catalytic activity for oxygen reduction reaction (ORR) is thoroughly investigated. Unlike the benchmark sample of symmetrical N-surrounded iron single-atoms in N-doped carbon (FeSAs /N-C), FeACs /NPS-HC comprises bi-/tri-atomic Fe centers with engineered S/N coordination. Theoretical calculation reveals that proper Fe gathering and coordination modulation could mildly delocalize the electron distribution and optimize the free energy pathways of ORR. In addition, the triple doping and hollow structure of carbon matrix could further regulate the local environment and allow sufficient exposure of active sites, resulting in more enhanced ORR kinetics on FeACs /NPS-HC. The zinc-air battery assembled with FeACs /NPS-HC as cathodic catalyst exhibits all-round superiority to Pt/C and most Fe-based ADCs. This work provides an exemplary method for establishing atomic-cluster catalysts with engineered S-dominated coordination and hollowed carbon matrix, which paves a new avenue for the fabrication and optimization of advanced ADCs.

Expression profile screening and bioinformatics analysis of CircRNA, LncRNA, and mRNA in HeLa cells infected with Chlamydia muridarum.

We have previously shown that circRNAs in host cells are involved in the process of Chlamydia trachomatis infection. In this study we aimed to identify significantly altered circRNAs/lncRNAs/mRNAs in Chlamydia muridarum infected cells and investigate their biological functions in the interaction between Chlamydia muridarum and host cells. For this purpose, circRNA, lncRNA and mRNA expression profiles were screened and identified in HeLa cells with or without Chlamydia muridarum infection by microarray. Bioinformatics analyses including Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and Gene Ontology (GO) analysis were then carried out and the circRNA-miRNA ceRNA network was constructed. The differentially expressed circRNAs and lncRNAs were selected for validation by RT-qPCR. The results shown that a total of 834 circRNAs, 2149 lncRNAs and 1283 mRNAs were found to be differentially expressed. Enrichment analysis of GO and KEGG showed that the dysregulated genes involved nuclear-transcribed mRNA catabolic process, protein binding, RNA catabolic process and translation, the MAPK signaling pathway, apoptosis, Toll-like receptor signaling pathway, cAMP signaling pathway and Notch signaling pathway may play important roles in Chlamydia infection. Our study provides a systematic outlook on the potential function of non-coding RNAs in the molecular basis of Chlamydia infection.

N-Doped Carbon as a Promoted Substrate for Ir Nanoclusters toward Hydrogen Oxidation in Alkaline Electrolytes.

Development of effective electrocatalysts toward hydrogen oxidation with a low content of noble metals has attracted the attention of the catalytic community. In this work, a novel catalyst composed of nitrogen-doped carbon acting as the substrate and Ir nanoclusters as active species was prepared, which was then employed as an effective catalyst for the hydrogen oxidation reaction (HOR) in an alkaline electrolyte. In 0.1 M KOH, the optimized catalyst provides an exchange current density of 0.144 mA cmIr-2 for HOR that outperforms the catalytic activity of the commercial Pt/C catalyst with a Pt content of 20 wt %. The substrate induces highly active Ir sites that markedly boosted the electrocatalytic activity for HOR. The nitrogen-doped carbon substrate increases the stability of Ir nanoclusters and decreases the absorption energy of hydrogen on Ir sites; at the same time, the higher electrostatic potential around the adsorbed hydrogen on Ir/N-doped carbon also enables them to be easily attracted by OH- species, both of which enhanced the catalytic activity. The excellent catalytic activity and the understanding shown here will give some hints for the development of HOR catalysts used in alkaline electrolytes.

14-day famciclovir treatment significantly reduces the incidence of postherpetic neuralgia in elderly patients with herpes zoster.

WHAT IS KNOWN AND OBJECTIVE: Pain is the main symptom of herpes zoster (HZ), whilst postherpetic neuralgia (PHN) is a long-term unbearable pain, which seriously affects the quality of life of patients and is also the most intractable problem for clinicians. Early antiviral treatment is considered as a key measure to reduce acute pain and PHN. Nevertheless, most patients still have long-term pain after 7 days of antiviral treatment, and some patients will develop PHN. This study aimed to investigate whether prolonged duration of antiviral therapy could reduce HZ acute pain and the occurrence of PHN. METHODS: The outpatient data of HZ patients over 50 years old who visited the Dermatology Department from January 2016 to May 2018 were retrospectively analysed. According to the different courses of treatment of famciclovir (FCV), the patients were divided into 7-day FCV group and 14-day FCV group. The numerical rating scale (NRS) score at the first visit and on the 7th, 14th and 21st days after the start of treatment, the adverse drug reactions and the incidence of PHN were compared between the two groups. RESULTS: A total of 219 patients were involved in the analysis. For acute pain control, the 14-day FCV group was better than the 7-day FCV group. For patients with mild initial pain, there was no significant difference in NRS between the two treatments. For patients with moderate-to-severe initial pain, the NRS in the 14-day FCV group was significantly lower than that of the 7-day FCV group on the 14th and 21st days after starting treatment. PHN occurred in patients with moderate-to-severe initial pain, and the incidence was significantly lower in the 14-day FCV group than in the 7-day FCV group. There was no significant difference in the number of adverse reactions between the two groups. WHAT IS NEW AND CONCLUSION: Compared with the traditional 7-day antiviral therapy, the 14-day course of FCV can reduce the acute pain and the incidence of PHN in elderly patients with HZ, especially in patients with moderate to severe initial pain. Prolonging the course of medication did not increase the side effects.

Clinical features in maxillary sinus fungus ball in patients with malignant hematological disease.

PURPOSE: Previous studies on fungus balls have primarily focused on immunocompetent patients, and only a few studies have described the clinical characteristics of fungus balls in malignant hematological disease (MHD) patients. Therefore, we compared the clinical features of maxillary sinus fungus ball (MSFB) between immunosuppressive patients with MHD and immunocompetent patients. METHODS: Twenty patients with MHD and 40 randomly selected immunocompetent patients were enrolled and divided into MHD and non-MHD groups. All patients were diagnosed with MSFB and their clinical features were retrospectively analyzed. RESULTS: Patients in the MHD group had non-specific clinical symptoms and endoscopic manifestations of MSFB, similar to those in the non-MHD group. On computed tomography (CT), the MHD group showed higher Lund-Mackay scores, lesser single sinus opacifications, more multiple sinus opacifications on the affected side, and more bilateral opacifications compared to the non-MHD group. The MHD group had a lower frequency of central hyper-density and heterogeneous opacifications than the non-MHD group. There were no significant differences between the two groups in terms of the fungal-infected side, lateral sinus wall ratio, sclerosis of the lateral sinus wall, erosion of the inner sinus wall, and nasal septum deviation. CONCLUSION: The clinical symptoms and endoscopic manifestations of MSFB in patients with MHD were similar to those of immunocompetent patients. However, more atypical signs and wider mucosal inflammation were found on CT scans of MSFB patients with MHD. These results indicate that caution should be executed when excluding the possibility of fungus balls in immunosuppressive patients.

The Genital Tract Virulence Factor pGP3 Is Essential for Chlamydia muridarum Colonization in the Gastrointestinal Tract.

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.

Fabrication of Porous ZnO/Co3O4 Composites for Improving Cycling Stability of Supercapacitors.

To tackle the issue of poor cycling stability for metal oxide nanoparticles as supercapacitor electrode, porous ZnO/Co3O4 composites were fabricated via solid-state thermolysis of [CoZn(BTC)(NO3)](2H2O)(0.5DMF) under air atmosphere. The results demonstrate that the products are mesoporous polyhedron structure with the diameter of about 10 µm, which are constructed by many interconnected nanocrystals with the sizes of around 20 nm. ZnO/Co3O4 composites as supercapacitor electrode exhibited excellent cyclic stability capacity, showing a maximum specific capacitance of 106.7 F g-1 and a capacity retention of 102.7 F · g-1 after 1000 cycles at 0.5 A · g-1. The superior electrochemical performance was contributed to ZnO/Co3O4 composites with porous structures and small size, which shortened the route of electronic transmission as well as ions insertion and desertion processes. Additionally, the synergetic effect of bimetallic oxides improved the electrochemical stability.

PmpI antibody reduces the inhibitory effect of Vp1 on Chlamydia trachomatis infectivity.

Chlamydia trachomatis is the most common cause of bacterial sexually transmitted infections. The effect of antibiotic treatment is not satisfactory, and there is currently no vaccine to prevent C. trachomatis infection. Our results showed that Chlamydia virus CPG1 capsid protein Vp1 treatment significantly inhibited C. trachomatis growth in cell culture, and the inclusion numbers of different C. trachomatis serotypes were decreased. In addition, we conducted a preliminary investigation of the possible mechanisms behind the Vp1 inhibition effects and the C. trachomatis molecules targeted by Vp1. Using far-western blot and GST pull-down assay, we found that purified Vp1 can bind to the C. trachomatis outer membrane protein PmpI. PmpI polyclonal antibody treatment markedly reduced the inhibitory effect of Vp1 on C. trachomatis infectivity. On the basis of these experimental results, we infer that PmpI participates in the inhibitory effect of Vp1 and may be a potential receptor of Vp1 in the outer membrane of C. trachomatis. Our research provides clues regarding the molecular mechanisms underlying the interactions between chlamydia virus and chlamydia.

Identification of proteins differentially expressed by Chlamydia trachomatis treated with chlamydiaphage capsid protein VP1 during intracellular growth.

Chlamydia trachomatis infection is one of the most prevalent sexually transmitted diseases. Our research pertains to the inhibitory effect and molecular mechanism of the chlamydiaphage capsid protein VP1 on the growth of Chlamydia trachomatis. In this research, the capsid protein VP1 of the guinea-pig conjunctivitis chlamydiaphage phiCPG1 was expressed, purified and identified, and then, it was applied to the cultivation of different serovars of Chlamydia trachomatis and Chlamydia psittaci. The inhibitory effect was observed in each serovar of Chlamydia trachomatis (D, E, F, G, H, I, K, and L2) and Chlamydia psittaci inoculated with VP1 protein. The inhibition affection of VP1 on the growth of Chlamydia trachomatis was caused by the changes of expressions of some related proteins including 36 proteins up-regulated and 81 proteins down-regulated in the development cycle of Ct through the label-free test, and the transcription levels of these proteins, including Hc1, pmpD, and MOMP, were confirmed by RT-PCR. It provides information that is essential for understanding the mechanism of chlamydiaphage capsid protein VP1 on chlamydia and a new direction for further clinical treatment of chlamydial infection.

[Persistent chlamydial genital infection in Tianjin area: An epidemiological study].

OBJECTIVE: To investigate the epidemic features of persistent genital chlamydial infection (GCI) in Tianjin area. METHODS: We statistically analyzed the clinical data about the persistent GCI patients received at the Venereal Disease Clinic of Tianjin Medical University General Hospital from 2009 to 2011. RESULTS: A total of 158 patients with persistent GCI were received from Tianjin area. The patients ranged in age from 19 to 67 years, 39.24% from 20 to 29 and 34.81% from 30 to 39 years, 36.71% with commercial occupation, and 55.06% with college education or above. The sex partners of the patients included their spouses (32.91%) and waitresses (41.77%). The incidence probability of persistent GCI was higher in the females (59.49%) than in the males. Many of the patients were complicated with infections of mycoplasma, syphilis, candida albicans, or condyloma acuminatum. CONCLUSIONS: The epidemic trend of persistent GCI is rather grim in Tianjin area. New measures have to be developed targeting the epidemiological features of persistent GCI for better prevention and control of the disease.

Kapok Fiber: A Natural Biomaterial for Highly Specific and Efficient Enrichment of Sialoglycopeptides.

Cancer development and chronic diseases are associated with the overexpression of sialoglycans terminated to the surface proteins and lipids of cancer cells compared with normal cells. The isolation and detection of sialoglycopeptides from complex peptides mixture still remain challenges due to their low abundance, low ionization, and losses of sialic acid residues and water molecule during analytical processes. In this study, kapok fiber, a natural fiber derived from the kapok tree (Bombax ceiba L.), has shown excellent capability to specifically and efficiently enrich sialoglycopeptides, without losses of sialic acid residues and water molecule from sialoglycans. The main components on the surface of kapok fiber are syringyl and guaiacyl lignins which play an important role in isolating sialoglycopeptides from complex peptide mixtures.

Sensitivity of the Standard Chlamydia trachomatis Culture Method Is Improved After One Additional In Vitro Passage.

BACKGROUND: Chlamydia trachomatis causes the most common bacterial sexually transmitted infection (STI) worldwide. Although highly sensitive nucleic acid amplification tests (NAATs) are used to routinely diagnose chlamydial infection, C. trachomatis isolation by cell culture is still preferred for legal cases and epidemiological studies because of its high specificity; however, the sensitivity of traditional two-passage diagnostic cultures is significantly lower than that of NAATs. Therefore, we sought to analyze if additional in vitro passaging of clinical samples would improve detection sensitivity of C. trachomatis. METHODS: Clinical swabs (n = 428) were collected from Tianjin Medical University General Hospital, grown in McCoy cells for up to five passages, and analyzed for the presence of inclusions by iodine staining. Results were confirmed by routine PCR-based methods. RESULTS: Viable C. trachomatis organisms were detected in 91 (21.26%) swabs with the traditional two-passage protocol, which increased to 145 (33.88%) and 149 (34.81%) following three and four passages, respectively. Thus, the standard protocol yielded a false-negative rate of nearly 39%. Subsequent PCR-based diagnostics revealed a concordance rate of 80.98% between these two methods without any false negatives. CONCLUSION: The results of this study support the use of a three-passage Chlamydia culture procedure to increase the detection sensitivity of this method.

Suppression of oxidative stress and improvement of liver functions in mice by ursolic acid via LKB1-AMP-activated protein kinase signaling.

BACKGROUND AND AIM: Hepatic cirrhosis is the final stage of liver dysfunction, characterized by diffuse fibrosis, which is the main response to the liver injury. This study is to investigate the effects of ursolic acid (UA) on liver functions and fibrosis in bile duct ligation (BDL) mice and to determine the underlying mechanisms. METHODS: Cultured hepatocytes were treated with lipopolysaccharide (LPS) in the presence or absence of UA. The reactive oxygen species (ROS) level, protein levels of IκBα, iNOS and Cox-2, and NF-κB activation were detected, respectively. C57/BL6 and AMP-activated protein kinase (AMPK)α2(-/-) mice were subjected to BDL for 14 days. UA was administered by gavage. The markers of liver function and oxidative stress, and liver histopathology were analyzed after treatment. RESULTS: Treatment of hepatocytes with UA dose-dependently activates AMPK, which is abolished by silence of liver kinase B1 (LKB1). LPS significantly increased ROS productions, apoptosis, NF-κB activation, and expressions of iNOS and Cox-2 in cultured hepatocytes. All these effects were blocked by co-incubation with UA. Importantly, silence of LKB1, AMPK, or iNOS/Cox-2 by small interference RNA transfection reversed UA-induced effects in cultured cells. In an animal study, 14-day BDL induced liver fibrosis and liver injury, accompanied with increased oxidative stress and protein expressions of iNOS and Cox-2 in liver. Treatment of UA significantly attenuated the BDL-induced detrimental effects in wild-type mice but not in AMPKα2(-/-) mice. CONCLUSION: UA via LKB1-AMPK signaling offers protective effects on BDL-induced liver injury in mice, which may be related to inhibition of oxidative stress.

Transformation of Chlamydia muridarum reveals a role for Pgp5 in suppression of plasmid-dependent gene expression.

Transformation of Chlamydia trachomatis should greatly advance the chlamydial research. However, significant progress has been hindered by the failure of C. trachomatis to induce clinically relevant pathology in animal models. Chlamydia muridarum, which naturally infects mice, can induce hydrosalpinx in mice, a tubal pathology also seen in women infected with C. trachomatis. We have developed a C. muridarum transformation system and confirmed Pgp1, -2, -6, and -8 as plasmid maintenance factors, Pgp3, -5, and -7 as dispensable for in vitro growth, and Pgp4 as a positive regulator of genes that are dependent on plasmid for expression. More importantly, we have discovered that Pgp5 can negatively regulate the same plasmid-dependent genes. Deletion of Pgp5 led to a significant increase in expression of the plasmid-dependent genes, suggesting that Pgp5 can suppress the expression of these genes. Replacement of pgp5 with a mCherry gene, or premature termination of pgp5 translation, also increased expression of the plasmid-dependent genes, indicating that Pgp5 protein but not its DNA sequence is required for the inhibitory effect. Replacing C. muridarum pgp5 with a C. trachomatis pgp5 still inhibited the plasmid-dependent gene expression, indicating that the negative regulation of plasmid-dependent genes is a common feature of all Pgp5 regardless of its origin. Nevertheless, C. muridarum Pgp5 is more potent than C. trachomatis Pgp5 in suppressing gene expression. Thus, we have uncovered a novel function of Pgp5 and developed a C. muridarum transformation system for further mapping chlamydial pathogenic and protective determinants in animal models.

Signaling via tumor necrosis factor receptor 1 but not Toll-like receptor 2 contributes significantly to hydrosalpinx development following Chlamydia muridarum infection.

Chlamydial infection in the lower genital tract can lead to hydrosalpinx, which is accompanied by activation of both pattern recognition receptor TLR2- and inflammatory cytokine receptor TNFR1-mediated signaling pathways. In the current study, we compared the relative contributions of these two receptors to chlamydial induction of hydrosalpinx in mice. We found that mice with or without deficiencies in TLR2 or TNFR1 displayed similar time courses of live organism shedding from vaginal swabs, suggesting that these receptor-mediated signaling pathways are not required for controlling chlamydial lower genital infection. However, mice deficient in TNFR1 but not TLR2 developed significantly reduced hydrosalpinx. The decreased pathogenicity correlated with a significant reduction in interleukin-17 by in vitro-restimulated splenocytes of TNFR1-deficient mice. Although TLR2-deficient mice developed hydrosalpinx as severe as that of wild-type mice, peritoneal macrophages from mice deficient in TLR2 but not TNFR1 produced significantly reduced cytokines upon chlamydial stimulation, suggesting that reduced macrophage responses to chlamydial infection do not always lead to a reduction in hydrosalpinx. Thus, we have demonstrated that the signaling pathways triggered by the cytokine receptor TNFR1 play a more significant role in chlamydial induction of hydrosalpinx than those mediated by the pattern recognition receptor TLR2, which has laid a foundation for further revealing the chlamydial pathogenic mechanisms.

Plasmid-encoded Pgp3 is a major virulence factor for Chlamydia muridarum to induce hydrosalpinx in mice.

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.

Bioengineered tunable memristor based on protein nanocage.

Bioengineered protein-based nanodevices with tunable and reproducible memristive performance are fabricated by combining the unique high loading capacity of Archaeoglobus fulgidus ferritin with OWL-generated nanogaps. By tuning the iron amount inside ferritin, the ON/OFF ratio of conductance switching can be modulated accordingly. Higher molecular loading exhibits better memristive performance owing to the higher electrochemical activity of the ferric complex core.