Development of Cell-Defined Lentivirus-Based Microarray for Mammalian Cells

Kim, Hi Chul,Shum, David,Seol, Hyang Sook,Jang, Se Jin,Cho, Ssang-Goo,Kwon, Yong-Jun SAGE Publications 2017 SLAS discovery Vol.22 No.1

<P> Although reverse transfection cell microarray (RTCM) is a powerful tool for mammalian cell studies, the technique is not appropriate for cells that are difficult to transfect. The lentivirus-infected cell microarray (LICM) technique was designed to improve overall efficiency. However, LICM presents new challenges because individual lentiviral particles can spread through the cell population, leading to cross-contamination. Therefore, we designed a cell-defined lentivirus microarray (CDLM) technique using cell-friendly biomaterials that are controlled by cell attachment timing. We selected poly-l-lysine (PLL) with Matrigel as the best combination of biomaterials for cell-defined culture. We used 2 µL PLL to determine by titration the optimum concentration required (0.04% stock, 0.005% final concentration). We also determined the optimum concentration of 10 µL of lentivirus particles for maximum reverse infection efficiency (1 × 10<SUP>8</SUP> infectious units [IFU]/mL stock, 62.5% final concentration) and established the best combination of components for the lentivirus mixture (10 µL of lentivirus particles and 2 µL each of siGLO Red dye, Matrigel, and 0.04% PLL). Finally, we validated both the effect of reverse infection in various cell lines and lentivirus spot activity in CDLM by storage period. This method provides an effective lentivirus-infected cell microarray for large-scale gene function studies. </P>

Comparison of Antibody and T Cell Responses Induced by Single Doses of ChAdOx1 nCoV-19 and BNT162b2 Vaccines

김지연,배성만,박순주,권지수,임소윤,박지영,차혜희,서미현,이현정,이나경,허진영,Shum David,지영미,김성한 대한면역학회 2021 Immune Network Vol.21 No.4

There are limited data directly comparing humoral and T cell responses to the ChAdOx1 nCoV-19 and BNT162b2 vaccines. We compared Ab and T cell responses after first doses of ChAdOx1 nCoV-19 vs. BNT162b2 vaccines. We enrolled healthcare workers who received ChAdOx1 nCoV-19 or BNT162b2 vaccine in Seoul, Korea. Anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) S1 protein-specific IgG Abs (S1-IgG), neutralizing Abs (NT Abs), and SARS-CoV-2-specific T cell response were evaluated before vaccination and at 1-wk intervals for 3 wks after vaccination. A total of 76 persons, comprising 40 injected with the ChAdOx1 vaccine and 36 injected with the BNT162b2 vaccine, participated in this study. At 3 wks after vaccination, the mean levels (±SD) of S1-IgG and NT Abs in the BNT162b2 participants were significantly higher than in the ChAdOx1 participants (S1-IgG, 14.03±7.20 vs. 6.28±8.87, p<0.0001; NT Ab, 183.1±155.6 vs. 116.6±116.2, p=0.035), respectively. However, the mean values of the T cell responses in the 2 groups were comparable after 2 wks. The humoral immune response after the 1st dose of BNT162b2 developed faster and was stronger than after the 1st dose of ChAdOx1. However, the T cell responses to BNT162b2 and ChAdOx1 were similar.

Correlation between Reactogenicity and Immunogenicity after the ChAdOx1 nCoV-19 and BNT162b2 mRNA Vaccination

임소윤,김지연,박순주,권지수,박지영,차혜희,Suh Mi Hyun,이현정,Lim Joon Seo,배성만,Jung Jiwon,이나경,Kim Kideok,Shum David,Jee Youngmee,Kim Sung-Han 대한면역학회 2021 Immune Network Vol.21 No.6

Correlation between vaccine reactogenicity and immunogenicity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unclear. Thus, we investigated to determine whether the reactogenicity after coronavirus disease 2019 vaccination is associated with antibody (Ab) titers and T cell responses. This study was prospective cohort study done with 131 healthcare workers at tertiary center in Seoul, South Korea. The degrees of the local reactions after the 1st and 2nd doses of ChAdOx1 nCov-19 (ChAdOx1) vaccination were significantly associated with the S1-specific IgG Ab titers (p=0.003 and 0.01, respectively) and neutralizing Ab (p=0.04 and 0.10, respectively) in age- and sex-adjusted multivariate analysis, whereas those after the BNT162b2 vaccination did not show significant associations. T cell responses did not show significant associations with the degree of reactogenicity after the ChAdOx1 vaccination or the BNT162b2 vaccination. Thus, high degree of local reactogenicity after the ChAdOx1 vaccine may be used as an indicator of strong humoral immune responses against SARS-CoV-2.

Using the Interaction Between Staufen 1 and ncRNAs to Predict DNMTis Sensitivity in Individual AML Patients

Yongsuk KU,Joo-Hwan PARK,Ryeongeun CHO,Yongki LEE,Hyoung-Min PARK,MinA KIM,Kyunghoon HUR,Soo Young BYUN,Jun LIU,Young-suk LEE,David SHUM,Dong-Yeop SHIN,Youngil KOH,Je-Yoel CHO,Sung-Soo YOON,Junshik HO 한국생물공학회 2021 한국생물공학회 학술대회 Vol.2021 No.4

Efficient long-term amplification of hepatitis B virus isolates after infection of slow proliferating HepG2-NTCP cells

Kö,nig, Alexander,Yang, Jaewon,Jo, Eunji,Park, Kyu Ho Paul,Kim, Hyun,Than, Thoa Thi,Song, Xiyong,Qi, Xiaoxuan,Dai, Xinghong,Park, Soonju,Shum, David,Ryu, Wang-Shick,Kim, Jung-Hee,Yoon, Seung Kew,P Elsevier 2019 Journal of hepatology Vol.71 No.2

<P><B>Background & Aims</B></P> <P>As hepatitis B virus (HBV) spreads through the infected liver it is simultaneously secreted into the blood. HBV-susceptible <I>in vitro</I> infection models do not efficiently amplify viral progeny or support cell-to-cell spread. We sought to establish a cell culture system for the amplification of infectious HBV from clinical specimens.</P> <P><B>Methods</B></P> <P>An HBV-susceptible sodium-taurocholate cotransporting polypeptide-overexpressing HepG2 cell clone (HepG2-NTCPsec+) producing high titers of infectious progeny was selected. Secreted HBV progeny were characterized by native gel electrophoresis and electron microscopy. Comparative RNA-seq transcriptomics was performed to quantify the expression of host proviral and restriction factors. Viral spread routes were evaluated using HBV entry- or replication inhibitors, visualization of viral cell-to-cell spread in reporter cells, and nearest neighbor infection determination. Amplification kinetics of HBV genotypes B-D were analyzed.</P> <P><B>Results</B></P> <P>Infected HepG2-NTCPsec+ secreted high levels of large HBV surface protein-enveloped infectious HBV progeny with typical appearance under electron microscopy. RNA-seq transcriptomics revealed that HBV does not induce significant gene expression changes in HepG2-NTCPsec+, however, transcription factors favoring HBV amplification were more strongly expressed than in less permissive HepG2-NTCPsec−. Upon inoculation with HBV-containing patient sera, rates of infected cells increased from 10% initially to 70% by viral spread to adjacent cells, and viral progeny and antigens were efficiently secreted. HepG2-NTCPsec+ supported up to 1,300-fold net amplification of HBV genomes depending on the source of virus. Viral spread and amplification were abolished by entry and replication inhibitors; viral rebound was observed after inhibitor discontinuation.</P> <P><B>Conclusions</B></P> <P>The novel HepG2-NTCPsec+ cells efficiently support the complete HBV life cycle, long-term viral spread and amplification of HBV derived from patients or cell culture, resembling relevant features of HBV-infected patients.</P> <P><B>Lay summary</B></P> <P>Currently available laboratory systems are unable to reproduce the dynamics of hepatitis B virus (HBV) spread through the infected liver and release into the blood. We developed a slowly dividing liver-derived cell line which multiplies infectious viral particles upon inoculation with patient- or cell culture-derived HBV. This new infection model can improve therapy by measuring, in advance, the sensitivity of a patient’s HBV strain to specific antiviral drugs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Cell culture system that mimicks complete HBV life cycle from entry to egress. </LI> <LI> Efficient <I>in vitro</I> infection with crude HBV patient sera. </LI> <LI> Up to 50- and 1,300-fold net amplification of patient- and cell culture-derived input HBV in the supernatant. </LI> <LI> Polyethylene glycol-independent HBV spread to adjacent cells, forming infected cell clusters. </LI> <LI> Evaluation of patient- and cell culture-derived HBV amplification w/wo antivirals over 8 weeks. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>