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Background: Evidence of lymphopoiesis, exhaustion, and premature aging in Chinese patients with human immunodeficiency virus (HIV) is very limited. Objective: To assess biological aging and immune senescence in Chinese healthy controls (HC) and ART-naïve HIV-infected men who have sex with men (MSM). Methods: This case-control study was conducted in Beijing Ditan Hospital from March 2018 to June 2019. The percentages of naïve (TN), central memory (TCM), effector memory (TEM), and terminally differentiated memory (TemRA) subsets of CD4 and CD8 T cells were studied, along with markers of senescence (CD28-CD57+) and activation (HLA-DR+). Telomere length of naïve (CD45RA+) and memory (CD45RO+) CD8 T cells were quantified by real-time PCR. Results: A total of 26 HIV-infected and 20 age-matched HC MSM were included. Compared to the HC group, the CD4/CD8 ratio of the HIV-infected group was significantly reduced (0.30 vs. 1.70, P Conclusion: HIV-infected MSM exhibit signs of accelerated immune senescence and biological aging, which particularly affects the CD8 T-cell subsets.

Background: The average lifespan of HIV-infected subjects remains shorter compared to uninfected individuals. Accelerated senescence may be responsible for this difference despite effective antiretroviral therapy (ART) with successful viral suppression. The present study aimed to assess the impact of HIV on immune and biological senescence of ART-naive HIV-infected men who have sex with men (MSM) in Beijing, China. Methods: A cross-sectional study was conducted that compared MSM HIV-infected patients and age-matched MSM HIV negative controls. Within the CD4 and CD8 population, the percentages of naive(TN), central memory(TCM), effector memory(TEM) and terminally differentiated memory(TemRA) subsets were studied and markers of senescence and activation in these cells were measured by multiparameter flow cytometry. Naive (CD45RA+) and memory (CD45RO+) CD8 T cells were purified by MACS technology. Telomere length was quantified by real-time PCR. Results: Within the CD8 T cell subsets, TN, TCM,TEM and TemRA cells showed more activation (HLA-DR+) and replicative senescence(CD28-CD57+) phenotypes in ART-naive MSM. However, in the CD4 T cell subsets, expect for TN, the percentage of senescent cells did not differ between ART-naive MSM and uninfected controls, but activated cells were upregulated in the former. The telomere length of naive and memory CD8 T cells was significantly shorter in ART-naive MSM than that of uninfected controls.Conclusion: Our results indicate that HIV-infected ART-naive MSM exhibit accelerated immune senescence with premature biological aging, which particularly affects the CD8 T-cell subsets. This highlights the strong impact of HIV on aging process of T-cell despite patient’s young age at infection and supports the importance of early control of HIV replication.

Background: In March 2020, the WHO declared the novel coronavirus (COVID-19) outbreak a global pandemic. While great success in the coronavirus disease 2019 (COVID-19) control has been achieved in China, imported cases have become a major challenge. This study aimed to describe the epidemiological and clinical characteristics of imported COVID-19 cases and to assess the effectiveness of screening strategy in Beijing, China.Methods: This retrospective study included all imported COVID-19 cases from Beijing Ditan Hospital from 29 February to 20 March 2020, who were screened by both chest computed tomography (CT) and reverse-transcriptase-polymerase chain reaction (RT-PCR) at initial presentation. Demographic, clinical and laboratory data, in addition to chest CT imaging were collected and analyzed. Results: A total of 71 imported cases were finally diagnosed with laboratory-confirmed COVID-19. The cases were mainly acquired from Europe (63cases, 88.73%). The main clinical manifestations were fever and cough, which accounted for 30 cases (42.25%) and 35 cases (49.30%), respectively. Only 4 cases (5.63%) had lymphocytopenia and 13 (18.31%) cases demonstrated elevated levels of C-reactive protein (CRP). All cases had normal serum levels of procalcitonin(PCT). 35 cases (49.30%) had abnormal CT findings at initial presentation, whereas 36 cases (50.70%) had a normal CT. Using RT-PCR, 59 cases (83.10%) were tested positive at initial presentation.Conclusions: The combination of screening tools, particularly CT and RT-PCR, could be considered to improve the diagnosis in imported COVID-19 cases. Our findings provide the important information and clinical evidence for infection control of imported COVID-19 cases.

Background In March 2020, the WHO declared the novel coronavirus outbreak a global pandemic. While great success in coronavirus disease 2019 (COVID-19) control has been achieved in China, imported cases have become a major challenge. This study aimed to describe the epidemiological and clinical characteristics of imported COVID-19 cases and to assess the effectiveness of screening strategies in Beijing, China. Methods This retrospective study included all imported cases transferred to Beijing Ditan Hospital from 29 February to 20 March 2020 who were screened by both chest computed tomography (CT) and reverse-transcriptase-polymerase chain reaction (RT-PCR) at the initial presentation. Demographic, clinical and laboratory data, in addition to chest CT imaging, were collected and analysed. Results In total, 2545 cases were included, among which 71 (2.8%) were finally diagnosed with laboratory-confirmed COVID-19. The majority 63 (88.7%) were from Europe. The most common initial symptoms were cough and fever, which accounted for 49.3% and 42.3%, respectively. Only four cases (5.6%) had lymphocytopenia, and thirteen cases (18.3%) demonstrated elevated levels of C-reactive protein (CRP). All cases had normal serum levels of procalcitonin (PCT). At initial presentation, among the 71 confirmed cases, 59 (83.1%) had a positive RT-PCR assay, and 35 (49.3%) had a positive chest CT. Twelve (16.9%) had a negative RT-PCR assay but a positive chest CT. Conclusions A combination of RT-PCR and chest CT is an effective strategy for the screening of imported COVID-19 cases. Our findings provide important information and clinical evidence about the infection control of imported COVID-19 cases.

AIM: To report the surgical result of pars plana vitrectomy (PPV) with air tamponade for rhegmatogenous retinal detachment (RRD) by ultra-widefield fundus imaging system. METHODS: Of 25 consecutive patients (25 eyes) with fresh primary RRD and causative retinal break and vitreous traction were presented. All the patients underwent PPV with air tamponade. Visual acuity (VA) was examined postoperatively and images were captured by ultra-widefield scanning laser ophthalmoscope system (Optos). RESULTS: Initial reattachment was achieved in 25 cases (100%). The air volume was >60% on the postoperative day (POD) 1. The ultra-widefield images showed that the retina was reattached in all air-filled eyes postoperatively. The retinal break and laser burns in the superior were detected in 22 of 25 eyes (88%). A missed retinal hole was found under intravitreal air bubble in 1 case (4%). The air volume was range from 40% to 60% on POD 3. A double-layered image was seen in 25 of 25 eyes with intravitreal gas. Retinal breaks and laser burns around were seen in the intravitreal air. On POD 7, small bubble without effect was seen in 6 cases (24%) and bubble was completely disappeared in 4 cases (16%). Small oval bubble in the superior area was observed in 15 cases (60%). There were no missed and new retinal breaks and no retinal detachment in all cases on the POD 14 and 1mo and last follow-up. Air disappeared completely on a mean of 9.84d postoperatively. The mean final postoperative best-corrected visual acuity (BCVA) was 0.35 logMAR. Mean final postoperative BCVA improved significantly relative to mean preoperative (P

NS1 of dengue virus (DENV) is an important non-structural protein, which plays an important role in DENV replication and dengue infection. In this study, using the phage-displayed peptide library screening method and purified anti-DENV2-NS1 polyclonal antibody immunoglobulin G (IgG) as target, which was generated from the purified recombinant expressed DENV2-NS1 protein immunization on rabbit, seven B-cell epitopes of DENV2-NS1 protein were screened. Considering the results of comprehensive bioinformatic analysis on NS1 B-cell epitopes, possible dominant B-cell epitopes are located in amino acids residues 36-45, 80-89, 103-112, 121-130, 187-196, 295-304, and 315-324 of the NS1, and two epitope-based NS1 protein dodecapeptides corresponding to the predominant epitopes (PA10: (36)PESPSKLASA(45) and AA10: (187)AIKDNRAVHA(196)) were chosen for synthesis. Results of binding assay and competitive-inhibition assays indicated the two peptides were the specific epitopes of DENV2-NS1 protein. These epitopes could be useful in understanding the pathogenesis of DENV and as dengue vaccine constituents in further study.

Dengue is currently a significant global health problem but no vaccines are available against the four dengue serotypes virus infections. The development of safe and effective vaccines has been hampered by the requirement of conferring complete protection against all four dengue serotypes and the lack of a convenient animal model. Virus-like particles (VLPs) have emerged as a promising subunit vaccine candidate. One strategy of vaccine development is to produce a tetravalent dengue subunit vaccine by mixing recombinant VLPs, corresponding to all four dengue virus serotypes. Towards this end, this study aimed to establish a Pichia pastoris (P. pastoris) expression system for production of dengue virus type 1 (DENV-1) VLPs and evaluate the humoral and cellular immune response of this particle in mice.A recombinant yeast P. pastoris clone containing prM and E genes of DENV-1 was constructed and DENV-1 VLPs expressed by this clone were analyzed by sucrose density gradient centrifugation, Western blotting, and transmission electron microscope. Groups of mice were immunized by these particles plus adjuvant formulations, then mice were tested by ELISA and neutralization assay for humoral immune response, and by lymphocyte proliferation and cytokine production assays for a cellular immune response.Our data demonstrated that recombinant DENV-1 VLPs consisting of prM and E protein were successfully expressed in the yeast P. pastoris. Sera of VLPs immunized mice were shown to contain a high-titer of antibodies and the neutralization assay suggested that those antibodies neutralized virus infection in vitro. Data from the T lymphocyte proliferation assay showed proliferation of T cell, and ELISA found elevated secretion levels of interferon IFN-γ and IL-4.P. pastoris-expressed DENV-1 VLPs can induce virus neutralizing antibodies and T cell responses in immunized mice. Using P. pastoris to produce VLPs offers a promising and economic strategy for dengue virus vaccine development.

The envelope glycoprotein (E) of flavivirus is the major structural protein on the surface of the mature virions. The complexes of premembrane (prM) and E play important roles in virus assembly and fusion modulation and in potential immunity-inducing vaccines. In the present study, the cDNA encoding prM and E proteins of dengue virus type 2 (DENV-2) was subcloned into the pGAPZalphaA vector and further integrated into the genome of Pichia pastoris under the control of the glyceraldehyde-3-phosphate dehydrogenase (GAP) constitutive promoter. The high-level constitutive expression of recombinant E antigen was achieved in P. pastoris. Both the cell lysate and the culture supernatant, examined by electron microscopy, were found to contain DENV-2 virus-like particles (VLPs) with diameters of about 30 nm. After immunization of BALB/c mice, the VLPs exhibited similar efficacies as inactivated virus in terms of antibody induction and neutralization titer. These results suggest that recombinant DENV VLPs can be efficiently produced in the GAP promoter-based P. pastoris expression system. This system may be useful for the development of effective and economic dengue subunit vaccine.

To explore the relationship between polymorphisms of natural resistance-associated macrophage protein 1 (NRAMP1) gene and genetic susceptibility of pulmonary tuberculosis (PTB) in workers exposed to silica dusts.A 1:2 case control study of 61 male workers with PTB (50 silicosis patients and 11 unsilicosis workers) as the case group and 122 male PTB-free workers (100 silicosis patients and 22 unsilicosis workers) as the control group was conducted with the frequency matched for age of +/- 5 years, the job, the silica exposure, and the condition of cigarette smoking and alcohol drinking. The polymerase chain reaction-restrained fragment length polymorphism technique (PCR-RFLP) was used to detect the single nucleotide polymorphisms (SNPs) of NRAMP1 INT4 and D543N.There was a 2.73 times (95% CI: 1.32 approximately 5.64) increased risk of silicosis for individuals with C allele of NRAMP1 INT4 compared with individuals carrying homozygote (G/G), while SNPs of NRAMP1 D543N was not associated with PTB (P0.05).The GC mutation of intron 4 of NRAMP1 gene might be a susceptible factor of silica for the workers exposed to PTB.

The dengue 2 virus (DEN-2) RNA (NGC strain) was used as a substrate to produce DNA clones of the full-length NS1 genes via reverse transcriptase synthesis of cDNA followed by polymerase chain reaction amplification of the NS1 region. Products were cloned into pPICZalphaB vector for sequencing and into Pichia pastoris for expression. A recombinant protein with a molecular size of approximately 80 KDa was secreted into the supernatant from the yeast cells when induced with methanol. The expressed protein was able to bind with mouse polyclonal antibody or NS1-specific monoclonal antibody of dengue 2 virus. Purified NS1-poly(His)-tagged fusion protein was obtained from the expressed product by passing through a metal-chelating affinity chromatographic (MCAC) column. The study also verified that our purified rNS1 protein retained its antigenicity. High-level production of the rNS1 protein up to 70 mg/l indicates that P. pastoris is an efficient expression system for dengue virus full-length NS1 glycoprotein.

Oncolytic adenovirus Ad.TERT, a novel tumor-specific proliferating virus, has been constructed by replacing normal promoter of mild-type adenovirus E1A with promoter of human telomerase reverse transcriptase (hTERT). In vitro and in vivo experiments confirmed that Ad.TERT has antitumor effect. This study was to construct Ad.TERT-TRAIL through inserting apoptosis gene trail into Ad.TERT, and explore its antitumor effect and mechanism.Plasmid pZhTERT-trail and adenovirus packaging plasmid pBHGE3 were homologously recombined in HEK293 cells to construct Ad.TERT-TRAIL. Ad.TERT-TRAIL was identified by polymerase chain reaction (PCR), and confirmed by Western blot. Killing effects of Ad.TERT-TRAIL and Ad.TERT on 3 tumor cell lines, SW620, BEL-7404 and Bcap-37, and a normal cell line NHLF were detected by crystal violet dye method or MTT assay. Expression of Caspase-3 in Ad.TERT-TRAIL-, and Ad.TERT-transfected SW620 cells was detected by Western blotu cell apoptosis was detected by flow cytometry (FCM).The 860 bp-length trail gene has been amplified by PCR. Western blot showed trail and E1A only expressed in tumor cells, which confirmed the successful construction of Ad.TERT-TRAIL. Killing effects of Ad.TERT-TRAIL on tumor cells were 10-100 times as strong as that of Ad.TERTu while both of them had little effects on normal cells. After 3 days infection (100 multiple of infection, MOI), survival rate of Ad.TERT-TRAIL-infected SW620 cells was 4%, but that of Ad.TERT-infected SW620 cells was 56%u both viruses had little effects on NHLF cells. Expression of Caspase-3 was higher in Ad.TERT-TRAIL-infected SW620 cells than in Ad.TERT-infected SW620 cells. Apoptosis rate of Ad.TERT-TRAIL-infected SW620 cells was 4 times as high as that of Ad.TERT-infected SW620 cells.Ad.TERT-TRAIL has much stronger antitumor effect than Ad.TERT. Its effect might relate with inducement effects of trail gene on expression of Caspase-3, and apoptosis of tumor cells.