Human adenovirus among hospitalized children with respiratory tract infections in Beijing, China, 2017-2018

BACKGROUND

Human adenoviruses (HAdVs) cause a wide range of diseases. However, the genotype diversity and epidemiological information relating to HAdVs among hospitalized children with respiratory tract infections (RTIs) is limited. Here, we describe the epidemiology and genotype distribution of HAdVs associated with RTIs in Beijing, China.

METHODS

Nasopharyngeal aspirates (NPA) were collected from hospitalized children with RTIs from April 2017 to March 2018. HAdVs were detected by a TaqMan-based quantitative real-time polymerase chain reaction (qPCR) assay, and the hexon gene was used for phylogenetic analysis. Epidemiological data were analyzed using statistical product and service solutions (SPSS) 21.0 software.

RESULTS

HAdV was detected in 72 (5.64%) of the 1276 NPA specimens, with most (86.11%, 62/72) HAdV-positives cases detected among children < 6 years of age. HAdV-B3 (56.06%, 37/66) and HAdV-C2 (19.70%, 13/66) were the most frequent. Of the 72 HAdV-infected cases, 27 (37.50%) were co-infected with other respiratory viruses, most commonly parainfluenza virus (12.50%, 9/72) and rhinovirus (9.72%, 7/72). The log number of viral load ranged from 3.30 to 9.14 copies per mL of NPA, with no significant difference between the HAdV mono- and co-infection groups. The main clinical symptoms in the HAdV-infected patients were fever and cough, and 62 (86.11%, 62/72) were diagnosed with pneumonia. Additionally, HAdVs were detected throughout the year with a higher prevalence in summer.

CONCLUSIONS

HAdV prevalence is related to age and season. HAdV-B and HAdV-C circulated simultaneously among the hospitalized children with RTIs in Beijing, and HAdV-B type 3 and HAdV-C type 2 were the most frequent.

The generation and biological activity of a long-lasting recombinant human interferon-λ1

The previously generated recombinant human (rh) interferon (IFN)-λ1 protein has a short half-life, and this feature makes it challenging to conduct studies on potential clinical applications for rhIFN-λ1. In an attempt to overcome this difficulty, we constructed a 'long-life' version of rhIFN-λ1. This modified rhIFN-λ1, named rhIFN-λ1-CTPON, has a human chorionic gonadotropin β subunit carboxyl-terminal peptide (CTP) and an N-glycosylation sequence linked to its C-terminus. We confirmed the sequence of rhIFN-λ1-CTPON by mass spectrometry and then measured its biological activities. The results show that rhIFN-λ1-CTPON had antiviral activity and anti-proliferation activity in vitro that were similar to those of rhIFN-λ1 and that it similarly promoted natural killer cell cytotoxicity. Notably, the in vivo half-life of rhIFN-λ1-CTPON was determined to be 3-fold higher than that of rhIFN-λ1. We also assessed the anti-hepatitis B virus activity of rhIFN-λ1-CTPON; it was able to inhibit the production of the antigens HBs-Ag and HBe-Ag and induce antiviral gene expression. In conclusion, rhIFN-λ1-CTPON has a longer half-life than rhIFN-λ1 and has similar biological activities, so rhIFN-λ1-CTPON is an appropriate substitute for rhIFN-λ1 in the further study of potential clinical applications for rhIFN- λ1.

[Experimental studies on the repair and restitution of cartilage by cartilage acellular extracellular matrix and adipose tissue-derived stem cells]

Objective: To investigate the effects of the repair and restitution of ear-shaped cartilage by adipose tissue-derived stem cells(ADSC) and cartilage acellular extracellular matrix. Methods: ADSC were extracted by digesting with collagenase type II from the adipose tissue from 32 patients with adiposity whose fats were drawn, and were cultured and subcultured in vitro. The natural biological scaffolds were prepared by acellular method using porcine ear cartilage, and then the second generation ADSC(5.0×10(7)/ml) were inoculated on the preformed natural bio-scaffold scaffold by culturing in vitro for 3 days to form a cell scaffold complex. 32 New Zealand white rabbits were randomly divided into the experimental groups, the control group A, the control group B and the control group C. All New Zealand white rabbits were modeled by ear cartilage defects. The cell scaffolds composite was implanted into the experimental group of the ear cartilage defects of rabbits, the ADSC were implanted into the control group A, the cartilage acellular extracellular matrix scaffold was implanted into the control group B and the control group C was modeled only by ear cartilage defects. After 16 weeks, the animals were sacrificed and the repair effect was observed by gross appearance and histological examinations including HE, Toluidine blue staining, Safranin O and typeⅡ collagen staining. Its were quantitatively analyzed by positive staining results of type Ⅱ collagen. Ear cartilage tissue elasticity was detected. SPSS 17.0 software was used to analyze the data. Results: The cartilage defects in the experimental group were repaired well by general shape observation and those in the control group was filled in with granulation tissue. There were significant differences between the experimental group and the control group in the wet weight(P<0.05). HE staining showed that cartilage cavities formed in articular cartilage defects, and only the fibrous tissue was filled with the ear cartilage defect in the control groups. In the repair area, Toluidine blue staining, Safranin O and type Ⅱ collagen staining were positive in the experimental group, and negative in the control groups. There was no significant difference between the experimental group and the normal ear cartilage in the ear cartilage elastic constant detection(P>0.05). Conclusions: The mechanics and histology of rabbit ear neonatal cartilage constructed by ADSC combined with cartilage acellular matrix are close to normal ear cartilage. Cartilage acellular matrix material combined with adipose-derived stem cells has good repair and reconstruction ability for ear cartilage defects, which possesses potential clinical application value.

Quantitative detection of human Malawi polyomavirus in nasopharyngeal aspirates, sera, and feces in Beijing, China, using real-time TaqMan-based PCR

Background

Human Malawi polyomavirus (MWPyV) was discovered in 2012, but its prevalence and clinical characteristics are largely unknown.

Methods

We used real-time TaqMan-based PCR to detect MWPyV in the feces (n = 174) of children with diarrhea, nasopharyngeal aspirates (n = 887) from children with respiratory infections, and sera (n = 200) from healthy adults, and analyzed its clinical characteristics statistically. All the MWPyV-positive specimens were also screened for other common respiratory viruses.

Results

Sixteen specimens were positive for MWPyV, including 13 (1.47%) respiratory samples and three (1.7%) fecal samples. The samples were all co-infected with other respiratory viruses, most commonly with influenza viruses (69.2%) and human coronaviruses (30.7%). The MWPyV-positive children were diagnosed with bronchopneumonia or viral diarrhea. They ranged in age from 12 days to 9 years, and the most frequent symptoms were cough and fever.

Conclusions

Real-time PCR is an effective tool for the detection of MWPyV in different types of samples. MWPyV infection mainly occurs in young children, and fecal–oral transmission is a possible route of its transmission.

Electronic supplementary material

The online version of this article (doi:10.1186/s12985-017-0817-2) contains supplementary material, which is available to authorized users.

Human polyomavirus type six in respiratory samples from hospitalized children with respiratory tract infections in Beijing, China

Background

HPyV6 is a novel human polyomavirus (HPyV), and neither its natural history nor its prevalence in human disease is well known. Therefore, the epidemiology and phylogenetic status of HPyV6 must be systematically characterized.

Methods

The VP1 gene of HPyV6 was detected with an established TaqMan real-time PCR from nasopharyngeal aspirate specimens collected from hospitalized children with respiratory tract infections. The HPyV6-positive specimens were screened for other common respiratory viruses with real-time PCR assays.

Results

The prevalence of HPyV6 was 1.7 % (15/887), and children ≤ 5 years of age accounted for 80 % (12/15) of cases. All 15 HPyV6-positive patients were coinfected with other respiratory viruses, of which influenza virus A (IFVA) (8/15, 53.3 %) and respiratory syncytial virus (7/15, 46.7 %) were most common. All 15 HPyV6-positive patients were diagnosed with lower respiratory tract infections, and their viral loads ranged from 1.38 to 182.42 copies/μl nasopharyngeal aspirate specimen. The most common symptoms were cough (100 %) and fever (86.7 %). The complete 4926-bp genome (BJ376 strain, GenBank accession number KM387421) was amplified and showed 100 % identity to HPyV6 strain 607a.

Conclusions

The prevalence of HPyV6 was 1.7 % in nasopharyngeal aspirate specimens from hospitalized children with respiratory tract infections, as analyzed by real-time PCR. Because the coinfection rate was high and the viral load low, it was not possible to establish a correlation between HPyV6 and respiratory diseases.

Electronic supplementary material

The online version of this article (doi:10.1186/s12985-015-0390-5) contains supplementary material, which is available to authorized users.

[The expression of interferon-lambda1 in CHO cell]

OBJECTIVE

To construct the eukaryotic expression vector PCI-dhfr-lambda1 and PCI-dhfr-SP163-lambda1 which linked the enhancer SP163 with interferon lambda1. Then express the interferon lambda1 in CHO (dhfr-) cells.

METHODS

Using PCR method to introduce the restriction enzyme sites and through the fusion PCR binding the enhancer with the interferon Lambda1. After sequenced, lambda1 and SP163-lambda1 was inserted into PCI-dhfr forming the expression vector PCI-dhfr-lambda1 and PCI-dhfr-SP163-lambda1 which was constructed successfully confirming by sequencing. Then the expressing vectors were transfected into CHO (dhfr-) cells using liposome transfection method and interferon lambda1 protein was assayed with indirect immunofluorescence and Western Blot. Using cytopathic effect inhibition evaluated the antiviral activity of interferon lambda1.

RESULTS

Successfully constructing the eukaryotic expression vectors of interferon lambda and the vectors could express interferon lambda1. The result of immunofluorescence showed the enhancer developed the expression of interferon lambda1. Detecting the interferon lambda1 in CHO (dhfr-) cells after transfecting 48 hour using Western Blot. The cytopathic effect inhibition showed the expressed interferon lambda1 has the antiviral activity.

CONCLUSION

Successfully expressed the interferon lambda1 in CHO (dhfr-) cells and the protein possesses antiviral activity, which may supply a valuable basis for building the stable cell line of interferon lambda1.

[Preparation of the monoclonal antibody against human Bocavirus VP2 protein]

OBJECTIVE

To express and purify HBoV VP2 protein, and the monoclonal antibody against HBoV VP2 protein was prepared with hybridoma technique.

METHODS

The HBoV VP2 cloned into vector pET-30a was expressed in E. coil. After purified by immobilized metal affinity chromatography, the BALB/c mouse was immunized with purified protein as antigen. The positive hybridoma cells were screened with hybridoma technique and ELISA assay. Isotype and titer of the monoclonal antibody were detected.

RESULTS

The recombinant HBoV VP2 protein was expressed and purified, and then the monoclonal antibody was obtained with hybridoma technique. The titer of the IgG monoclonal antibody was up to 1:4 x 10(5).

CONCLUSION

Monoclonal antibody against recombinant HBoV VP2 protein was prepared and the antibody titer was high. This work may provide a new method in rapid diagnosis and study of HBoV.

Differential gene expression profiling in aggressive bladder transitional cell carcinoma compared to the adjacent microscopically normal urothelium by microdissection-SMART cDNA PCR-SSH

Identifying novel and known genes that are differentially expressed in aggressive bladder transitional cell carcinoma (BTCC) has important implications in understanding the biology of bladder tumorigenesis and developing new diagnostic and therapeutic agents. In this study we identified the differential gene expression profiles comparing tumor to the adjacent microscopically normal mucosa by manual microdissection on frozen sections. The RNAs extracted from microdissected tissues were amplified by SMART cDNA PCR technology to generate forward subtractive cDNA library by suppressive subtractive hybridization (SSH). We obtained 376 positive clones, one hundred clones of aggressive BTCC subtracted cDNA library were selected at random and inserts were reamplified by PCR. After differential screening by reverse dot blotting, 73 positive clones, that contend inserts putatively upregulated in aggressive BTCC, were further analysed by DNA sequencing, GenBank and EST database searching. Sequencing results showed that 66 clones stand for 23 known genes and 7 clones for three new EST (Genbank number: DN236875, DN236874 and DN236873). In conclusion, microdissection-SMART cDNA PCR-SSH allowed for an efficient way to identify aggressive BTCC-specific differential expressed genes that may potentially be involved in the carcinogenesis and/or progression of aggressive BTCC. These differentially expressed genes may be of potential utility as therapeutic and diagnostic targets for aggressive BTCC.