CARs derived from broadly neutralizing, human monoclonal antibodies identified by single B cell sorting target hepatitis B virus-positive cells.

To design new CARs targeting hepatitis B virus (HBV), we isolated human monoclonal antibodies recognizing the HBV envelope proteins from single B cells of a patient with a resolved infection. HBV-specific memory B cells were isolated by incubating peripheral blood mononuclear cells with biotinylated hepatitis B surface antigen (HBsAg), followed by single-cell flow cytometry-based sorting of live, CD19+ IgG+ HBsAg+ cells. Amplification and sequencing of immunoglobulin genes from single memory B cells identified variable heavy and light chain sequences. Corresponding immunoglobulin chains were cloned into IgG1 expression vectors and expressed in mammalian cells. Two antibodies named 4D06 and 4D08 were found to be highly specific for HBsAg, recognized a conformational and a linear epitope, respectively, and showed broad reactivity and neutralization capacity against all major HBV genotypes. 4D06 and 4D08 variable chain fragments were cloned into a 2nd generation CAR format with CD28 and CD3zeta intracellular signaling domains. The new CAR constructs displayed a high functional avidity when expressed on primary human T cells. CAR-grafted T cells proved to be polyfunctional regarding cytokine secretion and killed HBV-positive target cells. Interestingly, background activation of the 4D08-CAR recognizing a linear instead of a conformational epitope was consistently low. In a preclinical model of chronic HBV infection, murine T cells grafted with the 4D06 and the 4D08 CAR showed on target activity indicated by a transient increase in serum transaminases, and a lower number of HBV-positive hepatocytes in the mice treated. This study demonstrates an efficient and fast approach to identifying pathogen-specific monoclonal human antibodies from small donor cell numbers for the subsequent generation of new CARs.

Virological responses to tenofovir-alafenamide-containing antiretroviral therapy in people living with HIV co-infected with lamivudine-resistant or lamivudine-susceptible hepatitis B virus.

BACKGROUND: Data on the effectiveness of tenofovir alafenamide (TAF) against lamivudine-resistant (LAM-R) hepatitis B virus (HBV) among patients co-infected with human immunodeficiency virus (HIV) and HBV are limited. METHODS: Between April and December 2018, HIV-positive patients co-infected with LAM-R or lamivudine-susceptible (LAM-S) HBV who switched from tenofovir-disoproxil-fumarate-containing antiretroviral therapy (ART) to TAF-containing ART were followed for 96 weeks. Plasma HBV and HIV loads, HBV serological markers, and liver function before and after the switch were analysed. RESULTS: In total, 182 patients co-infected with HIV and HBV were included in this study: 45 with LAM-R HBV and 137 with LAM-S HBV. At baseline, 28.9% and 7.4% of patients in the LAM-R and LAM-S groups, respectively, tested positive for hepatitis B virus envelope antigen (HBeAg) (P<0.001), and the respective percentages of patients who had achieved plasma HBV DNA <20 IU/mL were 95.5% and 97.1%. At weeks 48 and 96, 100% and 94.9% of patients in the LAM-R group, respectively, and 97.1% and 95.6% of patients in the LAM-S group, respectively, maintained plasma HBV DNA <20 IU/mL. Lamivudine resistance of HBV and baseline hepatitis B virus surface antigen (HBsAg) level were associated with HBsAg decrement at week 96 at a degree of 0.25 log10 IU/mL [95% confidence interval (CI) 0.059-0.246] and 0.22 log10 IU/mL (per 1-log10IU/mL increase, 95% CI 0.018-0.101), respectively. At week 96, 2.2% (4/182) of patients had HBsAg loss; no patients in the LAM-R group and 25.0% (2/8) of patients in the LAM-S group had HBeAg seroconversion. CONCLUSIONS: Switching to TAF-containing regimens maintained high rates of HBV viral suppression in patients co-infected with either LAM-R or LAM-S HBV. The decrease in HBsAg was minimal, and HBsAg seroconversion occurred infrequently.

Analysis on significance of HBV envelope large protein and its correlation with virus replication in patients with chronic hepatitis B / 国际检验医学杂志

Objective To analyze the relationship among serum hepatitis B virus (HBV ) envelope large protein (HBV‐LP ) , HBV‐DNA and HBV marker(HBV‐M ) for investigating the clinical significance of HBV‐LP to reflect the HBV in vivo replication in the patients with HBV infection .Methods Total 540 cases of chronic HBV infection treated in the Longgang District Hospital of Traditional Chinese Medicine from April 2013 to September 2015 were selected .The real‐time fluorescence quantitative PCR meth‐od was used to detect serum HBV‐DNA ,HBV‐LP and HBV‐M were detected by the enzyme linked immunosorbent assay (ELISA) . The correlation among HBV‐LP ,HBV‐M and HBV‐DNA were analyzed .Results The positive rate of HBV‐LP in HBeAg‐positive patients was 96 .39% ,and which of HBV‐DNA was 93 .33% ,there was no statistically significant difference between them (P>0 .05);The serum HBV‐LP level was positively related with the logarithmic value of HBV‐DNA copies ;the positive rate of HBV‐LP in HBeAg‐negative patients was 63 .33% ,and which of HBV‐DNA was 51 .11% ,the difference between them was statistically significant(P<0 .05) .Conclusion HBV‐LP can effectively reflect the HBV in vivo replication in the patients with chronic hepatitis B and its sensitivity is higher than that of HBeAg ,HBV‐LP can even more reflect the HBV in vivo replication status in patients with HBeAg‐negative chronic hepatitis B .

Construction of a liver targeting gene transfer vector using hepatitis B virus envelope particles and assessment of its function / 中国肿瘤生物治疗杂志

Objective: To construct a liver targeting gene transfer vector using hepatitis B virus envelope particles. Methods: Hepatitis B viruses were obtained from the supernatant of HepG 2.2.15 cells by a PEG8000 system and were inactivated by ?-propiolactone to prepare hepatitis B virus envelope. The hepatitis B virus envelope was used to pack 5.3 kb pIRES_2-EGFP to assess their packing ability. Subsequently, the products were studied with ELISA, PCR, SDS-PAGE, and electron microscopy. Finally, the product was used to transfect HepG2 cells and the green fluorescent protein (GFP) expression was observed under a fluorescent microscope. The rate of GFP positive cells was determined by flow cytometer.Results: The acquired hepatitis B virus envelope retained the surface protein HBsAg+pre S_1+pre S_2, but with no virus DNA. The prepared envelope had high packing ability for GFP and the packed GFP had a high transfection rate in HepG2 cell. Conclusion: Hepatitis B virus envelope has been successfully obtained from the supernatant of HepG 2.2.15 cells with a PEG8000 system and ?-propiolactone.

Whether the hepatitis B virus envelope as a gene transfer vector has targeting ability for liver cancer / 中国癌症杂志

Background and purpose:The reason for hepatitis B virus (HBV) with hepatocyte specificity is PreS1 enchased on the hepatitis B virus envelope (HBVE). So HBVE may have a potential application in liver targeting gene transfer. In this study, we investigated whether HBVE has the ability to target liver cancer cells. Methods:HBVE was obtained from the supernatant of Hep G 2.2.15 cells through PEG8000 system and ?-propiolactone method. The pIRS2-EGFP was packed with HBVE and resulted in the product HBVE-GFP. HBVE-GFP was transfected into HepG2, A549, HeLa and FB cells. The green fluorescent protein (GFP) expression was observed under a fluorescent microscope. The rate of GFP positive cells was determined by flow cytometer.Results:The GFP could be observed in the four groups, but the HepG2 group had a higher fluorescent intensity than the other 3 groups. The transfected rate of HepG2 group was (71.35?0.03)% , much higher than other groups(P

Targeting efficiency of hepatitis B virus envelope as a gene transfer vector on liver cancer cells / 中国肿瘤生物治疗杂志

Objective:To observe the transfection efficacy and targeting efficiency of hepatitis B virus envelope(HBVE) as a gene transfer vector for liver cancer cells.Methods:HBVE was obtained from the supernatant of HepG2.2.15 cells with a PEG8000 system and ?-propiolactone.The pIRS2-EGFP was packed with HBVE to obtain HBVE-GFP and was packed with liposome to obtain Liposome-GFP.HBVE-GFP and Liposome-GFP were used to transfect human hepatoblastoma cell line HepG 2 to study the transfection efficiency.HepG 2,A 549,HeLa and FB cells were transfected with HBVE-GFP to appraise the targeting ability of HBVE-GFP.GFP protein expression was observed under a fluorescent microscope and the ratio of GFP positive cells was determined by flow cytometry.Results:(1) Transfection efficiency:The GFP protein was observed in both the liposome group and the HBVE group under the fluorescent microscope;the fluorescent intensity in the HBVE group was 3-4 times that of liposome group as determined by flow cytometry(P