The RNA-binding protein ZC3H11A interacts with the nuclear poly(A)-binding protein PABPN1 and alters polyadenylation of viral transcripts.

Nuclear mRNA metabolism is regulated by multiple proteins, which either directly bind to RNA or form multiprotein complexes. The RNA-binding protein ZC3H11A is involved in nuclear mRNA export, NF-κB signaling, and is essential during mouse embryo development. Furthermore, previous studies have shown that ZC3H11A is important for nuclear-replicating viruses. However, detailed biochemical characterization of the ZC3H11A protein has been lacking. In this study, we established the ZC3H11A protein interactome in human and mouse cells. We demonstrate that the nuclear poly(A)-binding protein PABPN1 interacts specifically with the ZC3H11A protein and controls ZC3H11A localization into nuclear speckles. We report that ZC3H11A specifically interacts with the human adenovirus type 5 (HAdV-5) capsid mRNA in a PABPN1-dependent manner. Notably, ZC3H11A uses the same zinc finger motifs to interact with PABPN1 and viral mRNA. Further, we demonstrate that the lack of ZC3H11A alters the polyadenylation of HAdV-5 capsid mRNA. Taken together, our results suggest that the ZC3H11A protein may act as a novel regulator of polyadenylation of nuclear mRNA.

Fragile X-Related Protein FXR1 Controls Human Adenovirus Capsid mRNA Metabolism.

Human adenoviruses (HAdVs) are widespread pathogens causing a variety of diseases. A well-controlled expression of virus capsid mRNAs originating from the major late transcription unit (MLTU) is essential for forming the infectious virus progeny. However, regulation of the MLTU mRNA metabolism has mainly remained enigmatic. In this study, we show that the cellular RNA-binding protein FXR1 controls the stability of the HAdV-5 MLTU mRNAs, as depletion of FXR1 resulted in increased steady-state levels of MLTU mRNAs. Surprisingly, the lack of FXR1 reduced viral capsid protein accumulation and formation of the infectious virus progeny, indicating an opposing function of FXR1 in HAdV-5 infection. Further, the long FXR1 isoform interfered with MLTU mRNA translation, suggesting FXR1 isoform-specific functions in virus-infected cells. We also show that the FXR1 protein interacts with N6-methyladenosine (m6A)-modified MLTU mRNAs, thereby acting as a novel m6A reader protein in HAdV-5 infected cells. Collectively, our study identifies FXR1 as a regulator of MLTU mRNA metabolism in the lytic HAdV-5 life cycle. IMPORTANCE Human adenoviruses (HAdVs) are common pathogens causing various self-limiting diseases, such as the common cold and conjunctivitis. Even though adenoviruses have been studied for more than 6 decades, there are still gaps in understanding how the virus interferes with the host cell to achieve efficient growth. In this study, we identified the cellular RNA-binding protein FXR1 as a factor manipulating the HAdV life cycle. We show that the FXR1 protein specifically interferes with mRNAs encoding essential viral capsid proteins. Since the lack of the FXR1 protein reduces virus growth, we propose that FXR1 can be considered a novel cellular proviral factor needed for efficient HAdV growth. Collectively, our study provides new detailed insights about the HAdV-host interactions, which might be helpful when developing countermeasures against pathogenic adenovirus infections and for improving adenovirus-based therapies.

ZC3H11A loss of function enhances NF-κB signaling through defective IκBα protein expression.

ZC3H11A is a cellular protein associated with the transcription export (TREX) complex that is induced during heat-shock. Several nuclear-replicating viruses exploit the mRNA export mechanism of ZC3H11A protein for their efficient replication. Here we show that ZC3H11A protein plays a role in regulation of NF-κB signal transduction. Depletion of ZC3H11A resulted in enhanced NF-κB mediated signaling, with upregulation of numerous innate immune related mRNAs, including IL-6 and a large group of interferon-stimulated genes. IL-6 upregulation in the absence of the ZC3H11A protein correlated with an increased NF-κB transcription factor binding to the IL-6 promoter and decreased IL-6 mRNA decay. The enhanced NF-κB signaling pathway in ZC3H11A deficient cells correlated with a defect in IκBα inhibitory mRNA and protein accumulation. Upon ZC3H11A depletion The IκBα mRNA was retained in the cell nucleus resulting in failure to maintain normal levels of the cytoplasmic IκBα mRNA and protein that is essential for its inhibitory feedback loop on NF-κB activity. These findings indicate towards a previously unknown mechanism of ZC3H11A in regulating the NF-κB pathway at the level of IkBα mRNA export.

HCV Core/NS3 Protein Immunization with "N-Terminal Heat Shock gp96 Protein (rNT (gp96))" Induced Strong and Sustained Th1-Type Cytokines in Immunized Mice.

Feeble cellular responses induced by T cell-based vaccines are a major challenge for the development of an effective vaccine against Hepatitis C virus (HCV) infection. To address this challenge, the potential of N-terminal fragment of gp96 heat shock protein (rNT (gp96) as an adjuvant was evaluated and compared to that of the CpG (as a recognized Th1-type adjuvant) in the formulation of HCV core/NS3 antigens in three immunization strategies of protein/protein, DNA/DNA, and DNA/protein. Immunized mice were evaluated for elicited immune responses in week 3 (W3) and 11 post-immunizations. Our results demonstrated that the protein (subunit) vaccine formulated with rNT (gp96) in protein/protein strategy (core/NS3 + gp96) was significantly more efficient than CpG oligodeoxynucleotides (CpG ODN) formulation and all other immunization strategies in the induction of Th1-type cytokines. This group of mice (core/NS3 + gp96) also elicited a high level of anti-Core-NS3 total immunoglobulin G (IgG) with dominant IgG2a isotype at W3. Thus, the co-administration of recombinant NT (gp96) protein with rHCV proteins might be a promising approach in the formulation of HCV subunit vaccine candidates for induction of high levels of Th1 cytokines and humoral responses.

Role of CCCH-Type Zinc Finger Proteins in Human Adenovirus Infections.

The zinc finger proteins make up a significant part of the proteome and perform a huge variety of functions in the cell. The CCCH-type zinc finger proteins have gained attention due to their unusual ability to interact with RNA and thereby control different steps of RNA metabolism. Since virus infections interfere with RNA metabolism, dynamic changes in the CCCH-type zinc finger proteins and virus replication are expected to happen. In the present review, we will discuss how three CCCH-type zinc finger proteins, ZC3H11A, MKRN1, and U2AF1, interfere with human adenovirus replication. We will summarize the functions of these three cellular proteins and focus on their potential pro- or anti-viral activities during a lytic human adenovirus infection.

Trend in Prevalence of Hepatitis B Virus Infection Among Blood Donor Individuals: An Eleven-year of Experience in Lorestan, Iran.

BACKGROUND: Hepatitis B virus is one of the transfusion transmissible infections. Despite the availability of hepatitis B virus (HBV) vaccine and screening tests but still danger of virus transmission via blood transfusion is high in some regions. The objective of this study was to determine the trend of seroprevalence of hepatitis B in over an 11-year period (2005-2015). METHODS: In this study, 355,083 blood donors were estimated for hepatitis B surface antigen (HBs Ag) seropositivity during 2005-2015 who referred to blood infusion centers of Lorestan province. Third-generation ELISA method was used to detect HBs Ag. RESULTS: The prevalence of HBs Ag in blood donors was 0.29% (1017). It was decreased steadily from 2005 to 2015 (0.68% to 0.12%) but increased in 2008 year. The trend prevalence of HBs Ag seropositivity significantly decreased over the study period (P < 0.001). The decline in HBV infection rates was more prominent in regular and repeated donor's groups compared to people who donated blood for the first time (P < 0.001). CONCLUSIONS: The result of present study was indicated, Lorestan city in west of Iran can be classified as a low-income region because the low prevalence of HBs Ag in blood donors. Also the prevalence of HBs Ag in first-time donors was higher than other groups.

A non-pathogenic Leishmania tarentolae vector based- HCV polytope DNA vaccine elicits potent and long lasting Th1 and CTL responses in BALB/c mice model.

Despite successful anti-viral (DAAs) treatment of Hepatitis C virus (HCV) infection, recent data indicated the need for an effective vaccine. Preexisting anti-vector immunity is an obstacle for application of live vectors for antigen delivery and development of effective T-cell based HCV vaccines. Herein, we report construction of recombinant Leishmania tarentolae, a lizard (non-human) parasite, expressing an HCV polytope DNA, PT-NT(gp96), encoding for several immunogenic HCV epitopes and evaluation of its immunogenicity in three different prime/boost immunization groups (G) of BALB/c mice. Homologous prime/boost immunization by L.tarentolae-PT-NT(gp96) either with or without CpG (G1 and G2 respectively) and heterologous immunization with a PT-NT(gp96) encoding-pCDNA plasmid followed by L.tarentolae-PT-NT (G3) was undertaken. Immune responses were measured three and nine weeks (W) post immunization. Splenocytes (cultured with antigen-stimulant) of mice in G1 showed the highest percentage of specific CTL-cytolytic activity compared to G2 and G3 at both short (W3:70.98% versus 41.29% and 13.12%) and long (W9: 50% versus 24.5% and 20%) term periods, accompanied with high levels of secreted IFN-γ. Comparison of IFN-γ, IL-4, IL-17 and TNF-α cytokines levels obtained from the supernatant of antigen-stimulated splenocytes as well as antibodies level (as IgG1/IgG2a ratio; obtained from sera of immunized mice) indicated higher Th1 oriented responses for G1, G2 groups and balanced Th1-Th17 for G3. Results indicated the potential of L.tarentolae (+CpG), as a non-pathogenic live vaccine vector, for delivery and enhancement of immune responses against HCV-polytope antigens.

Elevated serum levels of adiponectin and interlukin-28B after IFN/RIB therapy in hepatitis C virus-infected patients.

INTRODUCTION: The interleukin 28B (IL28B) genotype is associated with changes of lipid metabolism in patients infected with hepatitis C virus (HCV). The association of steatosis with serum levels of adiponectin in chronic hepatitis C (CHC) patients has also been documented. This study aimed for the evaluation of serum levels of IL28B and adiponectin as well as the association of IL28B SNPs with different clinicopathological parameters in HCV-infected patients. METHODOLOGY: All 142 HCV-infected patients received peg-interferon plus ribavirin. Detection of rs8099917 and rs12979860 IL-28B genotypes was done with specific primers. Serum IL28 and adiponectin levels were measured using commercial ELISA kits. RESULTS: Higher levels of both IL28 and adiponectin were found in patients. In Genotype 3a (G3a) -infected patients, IL28 and adiponectin serum levels were significantly higher than those infected with G1a. A correlation was found between increasing levels of AST and ALT in G3a-infected patients and the decrease in IL28 and adiponectin serum levels, respectively, in contrast to G1a-infected patients. Higher levels of both IL28 and adiponectin were associated with both CT allele of rs12979860 and TT allele of rs8099917 in patients in comparison with corresponding alleles in controls. CONCLUSIONS: In contrast to other studies, this study showed higher serum adiponectin levels in HCV-infected patients compared to that in healthy controls. This finding is possibly due to adiponectin resistance caused by down-regulation of adiponectin receptors or tumorigenic effects of adiponectin. Our genotype-based analyses revealed, at least in part, the involvement of the viral factors in the outcome of HCV infection.