Interferon-γ (IFN-γ) represents one of the most important innate immunity responses in a host to combat infections of many human viruses including human herpesviruses. Human N-myc interactor (Nmi) protein, which has been shown to interact with signal transducer and activator of transcription (STAT) proteins including STAT1, is important for the activation of IFN-γ induced STAT1-dependent transcription of many genes responsible for IFN-γ immune responses. However, no proteins encoded by herpesviruses have been reported to interact with Nmi and inhibit Nmi-mediated activation of IFN-γ immune responses to achieve immune evasion from IFN-γ responses. In this study, we show strong evidence that the UL23 protein of human cytomegalovirus (HCMV), a human herpesvirus, specifically interacts with Nmi. This interaction was identified through a yeast two-hybrid screen and co-immunoprecipitation in human cells. We observed that Nmi, when bound to UL23, was not associated with STAT1, suggesting that UL23 binding of Nmi disrupts the interaction of Nmi with STAT1. In cells overexpressing UL23, we observed (a) significantly reduced levels of Nmi and STAT1 in the nuclei, the sites where these proteins act to induce transcription of IFN-γ stimulated genes, and (b) decreased levels of the induction of the transcription of IFN-γ stimulated genes. UL23-deficient HCMV mutants induced higher transcription of IFN-γ stimulated genes and exhibited lower titers than parental and control revertant viruses expressing functional UL23 in IFN-γ treated cells. Thus, UL23 appears to interact directly with Nmi and inhibit nuclear translocation of Nmi and its associated protein STAT1, leading to a decrease of IFN-γ induced responses and an increase of viral resistance to IFN-γ. Our results further highlight the roles of UL23-Nmi interactions in facilitating viral immune escape from IFN-γ responses and enhancing viral resistance to IFN antiviral effects. Interferon-γ (IFN-γ) responses are vital for a host to combat infections of many human viruses including human herpesviruses. Upon treatment of IFN-γ, transcription of many genes responsible for IFN-γ immune responses is activated primarily by the signal transducer and activator of transcription (STAT) proteins such as STAT1 protein. Human N-myc interactor (Nmi) protein has been shown to interact with STAT proteins including STAT1 and activate IFN-γ induced STAT-dependent transcription. However, no proteins encoded by herpesviruses have been reported to interact with Nmi and inhibit Nmi-mediated activation of IFN-γ immune responses to achieve immune evasion from IFN-γ responses. In this study, we show strong evidence that the UL23 protein of human cytomegalovirus (HCMV), a human herpesvirus, specifically interacts with Nmi protein. UL23 appears to interact directly with Nmi and inhibit nuclear translocation of Nmi and its associated protein STAT1, leading to a decrease of IFN-γ responses and an increase of viral resistance to IFN-γ. Blocking UL23 expression led to higher transcription of IFN-γ stimulated genes and significant inhibition of viral growth in infected cells. These results suggest that interfering with Nmi function may represent an effective mechanism for a herpesvirus to block Nmi-mediated IFN-γ responses and increase viral resistance to IFN-γ. This also provides a potentially new therapeutic strategy to treat HCMV infection by modulating Nmi activity with blocking the expression of a viral protein.

Salmonella enterica, a common food-borne bacterial pathogen, is believed to change its protein expression profile in the presence of different environmental stress such as that caused by the exposure to hydrogen peroxide (H2O2), which can be generated by phagocytes during infection and represents an important antibacterial mechanism of host cells. Among Salmonella proteins, the effectors of Salmonella pathogenicity island 1 and 2 (SPI-1 and SPI-2) are of particular interest since they are expressed during host infection in vivo and are important for invasion of epithelial cells and for replication in organs during systemic infection, respectively. However, the expression profiles of these proteins upon exposure to H2O2 or to host cells in vivo during the established phase of systemic infection have not been extensively studied.

RNase P ribozyme can be engineered to be a sequence-specific gene-targeting agent with promising application in both basic research and clinical settings. By using an in vitro selection system, we have previously generated RNase P ribozyme variants that have better catalytic activity in cleaving an mRNA sequence than the wild type ribozyme. In this study, one of the variants was used to target the mRNA encoding human cytomegalovirus (HCMV) essential transcription factor immediate-early protein 2 (IE2). The variant was able to cleave IE2 mRNA in vitro 50-fold better than the wild type ribozyme. A reduction of about 98% in IE2 expression and a reduction of 3500-fold in viral production was observed in HCMV-infected cells expressing the variant compared to a 75% reduction in IE2 expression and a 100-fold reduction in viral production in cells expressing the ribozyme derived from the wild type sequence. These results suggest that ribozyme variants that are selected to be highly active in vitro are also more effective in inhibiting the expression of their targets in cultured cells. Our study demonstrates that RNase P ribozyme variants are efficient in reducing HCMV gene expression and growth and are potentially useful for anti-viral therapeutic application.

Antimicrobial resistance has become a major global health concern. In this context, the present study aimed to explore endophytic microorganisms from Emblica urinaria as a potential source of antimicrobial metabolites. E. urinaria samples were collected and identified based prior to the isolation of endophytes. The endophytes were then isolated and assessed in terms of their antimicrobial activity against different pathogen strains, including Gram-positive (MRSA_Methicillin-resistant Staphylococcus aureus, Bacillus subtilis, and Streptococcusfaecalis), Gram-negative (Escherichia coli, Pseudomonas aeruginosa, and Klebisiella pneumoniae) strains, and Candida albicans, using agar plug method. The endophytes with detectable antimicrobial activity were identified using morphological and molecular methods (Internal Transcribed Spacer sequencing_ITS). Afterwards, the culture conditions of the most potential strain were optimized, using one factor at a time, and Response surface methodology. Eventually, its major bioactive compounds was preliminarily screened using LC-MS-MS method. The results showed that a total of eleven endophytes strains were isolated from E. urinaria. Four of the eleven strains demonstrated promising antimicrobial activity against both Gram-positive and Gram-negative strains. Especially, an antifungal activity against C. albicans was detected for the first time in E. urinaria endophytes. These endophytes were identified to be Colletotrichum aeschynomenes (CD-R1), Diaporthe etinsideae (CD-T1), Phyllosticta fallopiae (CD-R4), and Albifimbria viridis (CD-L1). The CD-L1 (Albifimbria viridis) was the strain with the most relevant antimicrobial activities. Its opitmal culture conditions was determined to be Potato Dextrose Broth (PDB), with five days of incubation, under agitation, at an intial inoculum size of 10⁵ spores/mL, pH 6, and with sucrose (32.5 g/L) and potato extract (200 g/L) as carbon and nitrogen source, respectively. In terms of its metabolites’ chemical compotision, LC–MS/MS profiling detected seven metabolite features putatively annotated as verrucarin-, roridin-, and trichoverrin-type trichothecene derivatives. This study was the first study that focus on the antimicrobial potential of E. urinaria endophytes and reconfirmed the important role of endophytes metabolites as an abundant source for antimicrobial agents.

Vulvovaginal candidiasis (VVC) is a common fungal infection among reproductive-age women and is increasingly challenged by the emergence of non-albicans Candida species and reduced azole susceptibility. This prospective cross-sectional study investigated 235 symptomatic reproductive-age women attending two healthcare facilities in Ho Chi Minh City, Vietnam, to determine VVC prevalence, Candida species distribution, pregnancy-associated patterns, antifungal susceptibility, and diagnostic performance. Vaginal swabs were cultured on Sabouraud Dextrose Agar and CHROMagar™ Candida, while species identification was confirmed by PCR-RFLP targeting the ITS region. Susceptibility to fluconazole and clotrimazole was assessed using the disk diffusion method. Candida spp. was detected in 55.7% of participants. C. albicans accounted for 50.3% of isolates, whereas non-albicans Candida species represented 49.7%, indicating a substantial species shift. VVC was more frequent among pregnant women, particularly in the third trimester. Most C. albicans, C. tropicalis, and C. parapsilosis isolates remained susceptible to azoles; however, C. glabrata showed markedly reduced susceptibility to fluconazole and clotrimazole. CHROMagar™ Candida reliably identified C. albicans but misclassified several non-albicans Candida isolates compared with PCR-RFLP. These findings highlight the need for routine species-level diagnosis, antifungal susceptibility testing, and strengthened VVC surveillance in reproductive and antenatal healthcare settings in Vietnam.