Quer, J. (Josep)

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    Characterization of hepatitis B virus X gene quasispecies complexity in mono-infection and hepatitis delta virus superinfection
    (Baishideng Publishing Group Inc., 2019) González-Aseguinolaza, G. (Gloria); Rando, A. (Ariadna); Quer, J. (Josep); González, C. (Carolina); López-Martínez, R. (Rosa); Yll, M. (Marçal); Gregori, J. (Josep); Cortese, M.F. (Maria Francesca); Riveiro-Barciela, M. (Mar); Esteban, R. (Rafael); Buti, M. (Maria); Casillas, R. (Rosario); Sopena, S. (Sara); Godoy, C. (Cristina); Tabernero, D. (David); Rodríguez-Frías, F. (Francisco)
    BACKGROUND Hepatitis delta virus (HDV) seems to strongly suppress hepatitis B virus (HBV) replication, although little is known about the mechanism of this interaction. Both these viruses show a dynamic distribution of mutants, resulting in viral quasispecies. Next-generation sequencing is a viable approach for analyzing the composition of these mutant spectra. As the regulatory hepatitis B X protein (HBx) is essential for HBV replication, determination of HBV X gene (HBX) quasispecies complexity in HBV/HDV infection compared to HBV monoinfection may provide information on the interactions between these two viruses.AIM To compare HBV quasispecies complexity in the HBX 5’ region between chronic hepatitis delta (CHD) and chronic HBV mono-infected patients. METHODS Twenty-four untreated patients were included: 7/24 (29.2%) with HBeAgnegative chronic HBV infection (CI, previously termed inactive carriers), 8/24 (33.3%) with HBeAg-negative chronic hepatitis B (CHB) and 9/24 (37.5%) with CHD. A serum sample from each patient was first tested for HBV DNA levels. The HBX 5’ region [nucleotides (nt) 1255-1611] was then PCR-amplified for subsequent next-generation sequencing (MiSeq, Illumina, United States). HBV quasispecies complexity in the region analyzed was evaluated using incidencebased indices (number of haplotypes and number of mutations), abundancebased indices (Hill numbers of order 1 and 2), and functional indices (mutation frequency and nucleotide diversity). We also evaluated the pattern of nucleotide changes to investigate which of them could be the cause of the quasispecies complexity. RESULTS CHB patients showed higher median HBV-DNA levels [5.4 logIU/mL, interquartile range (IQR) 3.5-7.9] than CHD (3.4 logIU/mL, IQR 3-7.6) (P = n.s.) or CI (3.2 logIU/mL, IQR 2.3-3.5) (P < 0.01) patients. The incidence and abundance indices indicated that HBV quasispecies complexity was significantly greater in CI than CHB. A similar trend was observed in CHD patients, although only Hill numbers of order 2 showed statistically significant differences (CHB 2.81, IQR 1.11-4.57 vs CHD 8.87, 6.56-11.18, P = 0.038). There were no significant differences in the functional indices, but CI and CHD patients also showed a trend towards greater complexity than CHB. No differences were found for any HBV quasispecies complexity indices between CHD and CI patients. G-to-A and C-to-T nucleotide changes, characteristic of APOBEC3G, were higher in CHD and CI than in CHB in genotype A haplotypes, but not in genotype D. The proportion of nt G-to-A vs A-to-G changes and C-to-T vs T-to-C changes in genotype A and D haplotypes in CHD patients showed no significant differences. In CHB and CI the results of these comparisons were dependent on HBV genotype. CONCLUSION The lower-replication CHD and CI groups show a trend to higher quasispecies complexity than the higher-replication CHB group. The mechanisms associated with this greater complexity require elucidation.
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    Induction of potent and long-lasting CD4 and CD8 T-cell responses against hepatitis C virus by immunization with viral antigens plus poly(I:C) and anti-CD40
    (Elsevier masson, 2007) Dotor, J. (Javier); Zabaleta, A. (Aintzane); Borras-Cuesta, F. (Francisco); Quer, J. (Josep); Esteban, J.I. (Juan Ignacio); Prieto, J. (Jesús); Llopiz, D. (Diana); Vayreda, F. (Francesc); Sarobe, P. (Pablo); Arribillaga, L. (Laura); Lasarte, J.J. (Juan José)
    Development of vaccination strategies against hepatitis C virus (HCV) is of paramount importance. With this aim, we tested the ability of dendritic cell-activating reagents polyinosinic-polycytidylic acid (poly(I:C)) and anti-CD40, as adjuvants to induce T-cell responses against HCV. Immunization of mice with these adjuvants induced dendritic cell maturation in vivo. Also, joint administration of poly(I:C) and anti-CD40 plus HCV antigens had a synergistic effect on the induction of anti-HCV T-cell responses. CD4 responses displayed a Th1 cytokine profile, and CD8 responses could be induced by immunization with a minimal CD8 epitope. Addition of a low amount of NS3 protein (as a source of Th epitopes) to the immunization mixture enhanced CD8 responses, whereas immunization with higher doses of NS3 induced both CD4 and CD8 responses. Surprisingly, immunization with NS3 protein but not with CD8 epitopes was able to induce CD8 responses and able to recognize cells expressing HCV antigens endogenously. Moreover, immunization with these adjuvants activated NK cells, which in turn helped to induce Th1 responses. Finally, this combined immunization protocol afforded long-lasting T-cell responses, suggesting that this strategy may prove to be useful in vaccination and/or treatment of HCV infection.