Whole exome HBV DNA integration is independent of the intrahepatic HBV reservoir in HBeAg-negative chronic hepatitis B.

OBJECTIVE: The involvement of HBV DNA integration in promoting hepatocarcinogenesis and the extent to which the intrahepatic HBV reservoir modulates liver disease progression remains poorly understood. We examined the intrahepatic HBV reservoir, the occurrence of HBV DNA integration and its impact on the hepatocyte transcriptome in hepatitis B 'e' antigen (HBeAg)-negative chronic hepatitis B (CHB). DESIGN: Liver tissue from 84 HBeAg-negative patients with CHB with low (n=12), moderate (n=25) and high (n=47) serum HBV DNA was analysed. Covalently closed circular DNA (cccDNA), pregenomic RNA (pgRNA) were evaluated by quantitative PCR, whole exome and transcriptome sequencing was performed by Illumina, and the burden of HBV DNA integrations was evaluated by digital droplet PCR. RESULTS: Patients with low and moderate serum HBV DNA displayed comparable intrahepatic cccDNA and pgRNA, significantly lower than in patients with high HBV DNA, while hepatitis B core-related antigen correlated strongly with the intrahepatic HBV reservoir, reflecting cccDNA quantity. Whole exome integration was detected in a significant number of patients (55.6%, 14.3% and 25% in high, moderate and low viraemic patients, respectively), at a frequency ranging from 0.5 to 157 integrations/1000 hepatocytes. Hepatitis B surface antigen >5000 IU/mL predicted integration within the exome and these integrations localised in genes involved in hepatocarcinogenesis, regulation of lipid/drug metabolism and antiviral/inflammatory responses. Transcript levels of specific genes, including the proto-oncogene hRAS, were higher in patients with HBV DNA integration, supporting an underlying oncogenic risk in patients with low-level to moderate-level viraemia. CONCLUSIONS: HBV DNA integration occurs across all HBeAg-negative patients with CHB, including those with a limited HBV reservoir; localising in genes involved in carcinogenesis and altering the hepatocyte transcriptome.

Pre-ART HIV-1 DNA in CD4+ T cells correlates with baseline viro-immunological status and outcome in patients under first-line ART.

Objectives: We evaluated the association between pre-ART HIV DNA and HIV-infected participant characteristics at baseline as well as with their response to first-line ART. Methods: Four hundred and thirty-three patients from the ICONA cohort, starting first-line ART after the year 2000, were analysed. Pre-ART HIV DNA was quantified with the modified COBAS TaqMan HIV-1 Test and normalized by CD4+ T cells. Linear correlation between pre-ART HIV DNA and other continuous markers (HIV RNA, CD4 count, markers of inflammation and coagulation) at baseline was evaluated by means of Pearson correlation coefficient and a linear regression model. Survival analyses and Cox regression models were used to study the association between pre-ART HIV DNA and time to viro-immunoclinical events. Results: Pre-ART HIV DNA [median (IQR): 10 702 (3397-36 632) copies/106 CD4+ T cells] was correlated with pre-ART HIV RNA [R2 = +0.44, (P < 0.0001)], CD4+ T cells [R2 = -0.58, (P < 0.0001)] and CD4/CD8 ratio [R2 = -0.48, (P < 0.0001)], while weaker correlations were observed with CD8+ T cells (R2 = -0.20, P = 0.01), IL-6 (R2 = +0.16, P = 0.002) and soluble CD14 (R2 = +0.09, P = 0.05). Patients with higher pre-ART HIV DNA showed lower rate and delayed virological response (defined as HIV RNA ≤50 copies/mL), compared with those having lower HIV DNA (67.2% for >10 000, 81.1% for 1000-10 000 and 86.4% for 10-1000 copies/106 CD4+ T cells; P = 0.0004). Higher pre-ART HIV DNA was also correlated with increased risk of virological rebound (defined as HIV RNA >50 copies/mL) by 24 months (17.2% for >10 000, 7.4% for 1000-10 000 and 4.3% for 10-1000 copies/106 CD4+ T cells; P = 0.0048). Adjusted HRs of all virological rebound definitions confirmed these findings (P ≤ 0.02). Conclusions: Pre-ART HIV DNA, along with HIV RNA and CD4+ T cell count, should be considered as a new staging marker to better identify people at lower (or higher) risk of viral rebound following achievement of virological suppression (≤50 copies/mL).

Genetic diseases and aneuploidies can be detected with a single blastocyst biopsy: a successful clinical approach.

STUDY QUESTION: Can simultaneous detection of aneuploidies and genetic diseases or chromosomal aberrations in blastocysts reduce the chance of transferring embryos with low implantation potential, guaranteeing good clinical outcomes? SUMMARY ANSWER: The screening for chromosomal aneuploidies revealed that 50.6% of blastocysts diagnosed free of genetic disease or balanced, were aneuploid, therefore avoiding the transfer of blastocysts potentially resulting in implantation failures, miscarriages, or in some cases, in health affected live births. WHAT IS KNOWN ALREADY: PGD is applied in patients at risk of transmitting genetically inheritable diseases to their offspring. It has been demonstrated that aneuploidies can involve chromosomes other than those investigated with PGD, affecting embryo implantation competence. Performing the biopsy at blastocyst level produces higher clinical outcomes allowing a more accurate diagnosis, compared to blastomere biopsy. STUDY DESIGN, SIZE, DURATION: This consecutive case series study was performed from October 2011 to May 2016. Clinical and biological outcomes from 1122 blastocysts obtained in 304 PGD cycles for monogenic diseases (N = 163) or chromosomal rearrangements (N = 141) were analyzed. When the blastocyst resulted transferable after the PGD analysis or chromosomal rearrangement analysis, its ploidy status by mean of preimplantation genetic screening (PGS) was also detected using the same biopsy sample. Mean female age was 35.4 ± 4.2 years old. All biopsies were performed at blastocyst stage and analyzed by Whole Genome Amplification (WGA) followed by PCR for monogenic diseases, and by array-comparative genotype hybridization (array-CGH) for all cycles. PARTICIPANTS/MATERIALS, SETTING, METHOD: All mature oocytes retrieved were injected and cultured individually until the blastocyst stage at 37°C, 6% CO2, 5% O2. When the blastocyst was formed, it was biopsied and vitrified, awaiting the genetic results. The frozen-thawed embryo transfer was performed in a subsequent cycle. In some cases, when the blastocyst was obtained within the morning of Day 5 of culture, it had been maintained in culture and transferred on Day 6, after receiving the genetic report. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 2809 (2718 fresh and 91 frozen-thawed) mature oocytes were injected with a fertilization rate of 75.5% (N = 2120), leading to the development of 2102 embryos. A further 24 frozen embryos, previously vitrified without any genetic testing, were successfully warmed for genetic screening. A total of 2126 embryos were cultured with a blastocyst formation rate of 52.8% (N = 1122); all of them were biopsied from Day 4 to Day 7 of culture. After the genetic analysis, 309 (27.5%) blastocysts resulted transferable, both for monogenic disease or translocation and for their ploidy status, 42 were diploid/aneuploid mosaic, 55 were no result and 716 were not transferable, due to genetic disease or chromosomal rearrangement and/or for their ploidy status. Of note, 316 (50.6% of transferable blastocysts after PGD and 28.2% of total number of biopsied blastocysts) of the blastocysts resulted healthy for the genetic disease or chromosomal rearrangement were aneuploid. Out of 304 PGD/PGS cycles performed, 28.6% (N = 87) resulted in no-transferable blastocysts after only PGD analysis; this percentage increased to 39.8% (N = 121) when also PGS was carried out (Mc Nemar test P < 0.001). A total of 202 embryo-transfers were performed, 53 fresh and 149 cryopreserved, in which 218 healthy or carrier euploid blastocysts were transferred. Clinical pregnancy, implantation and miscarriage rates were 49.0, 47.7 and 9.9%, respectively. To date, 66 deliveries occurred with 70 healthy babies born and 13 pregnancies are still ongoing. Finally, 91 euploid healthy blastocysts are still cryopreserved waiting to be transferred. LIMITATIONS, REASONS FOR CAUTION: A higher than expected cycle cancellation rate could be found due to the double genetic analysis performed. For this reason, particular care should be taken in drafting and explaining informed consent, in order to avoid patient drop out. WIDER IMPLICATIONS OF THE FINDINGS: When the biopsy has to be performed in order to prevent the transmission of an inheritable disease, it should be mandatory to analyze also the genetic status of the blastocyst, avoiding useless embryo-transfers in this particular category of patients. In our study, 316 aneuploid healthy blastocysts could have been transferred without performing PGS, leading to implantation failures, miscarriages, or in some cases, to live births affected by different syndromes. STUDY FUNDING/COMPETING INTEREST(S): No specific funding was obtained for this study. None of the authors have any competing interests to declare. TRIAL REGISTRATION NUMBER: Not applicable.

Hepatitis B surface antigen genetic elements critical for immune escape correlate with hepatitis B virus reactivation upon immunosuppression.

UNLABELLED: Hepatitis B virus (HBV) reactivation during immunosuppression can lead to severe acute hepatitis, fulminant liver failure, and death. Here, we investigated hepatitis B surface antigen (HBsAg) genetic features underlying this phenomenon by analyzing 93 patients: 29 developing HBV reactivation and 64 consecutive patients with chronic HBV infection (as control). HBsAg genetic diversity was analyzed by population-based and ultradeep sequencing (UDS). Before HBV reactivation, 51.7% of patients were isolated hepatitis B core antibody (anti-HBc) positive, 31.0% inactive carriers, 6.9% anti-HBc/anti-HBs (hepatitis B surface antibody) positive, 6.9% isolated anti-HBs positive, and 3.4% had an overt HBV infection. Of HBV-reactivated patients, 51.7% were treated with rituximab, 34.5% with different chemotherapeutics, and 13.8% with corticosteroids only for inflammatory diseases. In total, 75.9% of HBV-reactivated patients (vs. 3.1% of control patients; P<0.001) carried HBsAg mutations localized in immune-active HBsAg regions. Of the 13 HBsAg mutations found in these patients, 8 of 13 (M103I-L109I-T118K-P120A-Y134H-S143L-D144E-S171F) reside in a major hydrophilic loop (target of neutralizing antibodies [Abs]); some of them are already known to hamper HBsAg recognition by humoral response. The remaining five (C48G-V96A-L175S-G185E-V190A) are localized in class I/II-restricted T-cell epitopes, suggesting a role in HBV escape from T-cell-mediated responses. By UDS, these mutations occurred in HBV-reactivated patients with a median intrapatient prevalence of 73.3% (range, 27.6%-100%) supporting their fixation in the viral population as a predominant species. In control patients carrying such mutations, their median intrapatient prevalence was 4.6% (range, 2.5%-11.3%; P<0.001). Finally, additional N-linked glycosylation (NLG) sites within the major hydrophilic loop were found in 24.1% of HBV-reactivated patients (vs. 0% of chronic patients; P<0.001); 5 of 7 patients carrying these sites remained HBsAg negative despite HBV reactivation. NLG can mask immunogenic epitopes, abrogating HBsAg recognition by Abs. CONCLUSION: HBV reactivation occurs in a wide variety of clinical settings requiring immune-suppressive therapy, and correlates with HBsAg mutations endowed with enhanced capability to evade immune response. This highlights the need for careful patient monitoring in all immunosuppressive settings at reactivation risk and of establishing a prompt therapy to prevent HBV-related clinical complications.

Incomplete APOBEC3G/F Neutralization by HIV-1 Vif Mutants Facilitates the Genetic Evolution from CCR5 to CXCR4 Usage.

Incomplete APOBEC3G/F neutralization by a defective HIV-1Vif protein can promote genetic diversification by inducing G-to-A mutations in the HIV-1 genome. The HIV-1 Env V3 loop, critical for coreceptor usage, contains several putative APOBEC3G/F target sites. Here, we determined if APOBEC3G/F, in the presence of Vif-defective HIV-1 virus, can induce G-to-A mutations at V3 positions critical to modulation of CXCR4 usage. Peripheral blood mononuclear cells (PBMC) and monocyte-derived macrophages (MDM) from 2 HIV-1-negative donors were infected with CCR5-using 81.A-VifWT virus (i.e., with wild-type [WT] Vif protein), 81.A-VifE45G, or 81.A-VifK22E (known to incompletely/partially neutralize APOBEC3G/F). The rate of G-toA mutations was zero or extremely low in 81.A-VifWT- and 81.A-VifE45G-infected PBMC from both donors. Conversely, G-to-A enrichment was detected in 81.A-VifK22E-infected PBMC (prevalence ranging from 2.18% at 7 days postinfection [dpi] to 3.07% at 21 dpi in donor 1 and from 10.49% at 7 dpi to 8.69% at 21 dpi in donor 2). A similar scenario was found in MDM. G-to-A mutations occurred at 8 V3 positions, resulting in nonsynonymous amino acid substitutions. Of them, G24E and E25K strongly correlated with phenotypically/genotypically defined CXCR4-using viruses (P = 0.04 and 5.5e-7, respectively) and increased the CXCR4 N-terminal binding affinity for V3 (WT, -40.1 kcal/mol; G24E, -510 kcal/mol; E25K, -522 kcal/mol). The analysis of paired V3 and Vif DNA sequences from 84 HIV-1-infected patients showed that the presence of a Vif-defective virus correlated with CXCR4 usage in proviral DNA (P = 0.04). In conclusion, incomplete APOBEC3G/F neutralization by a single Vif amino acid substitution seeds a CXCR4-using proviral reservoir. This can have implications for the success of CCR5 antagonist-based therapy, as well as for the risk of disease progression.

Comparative replication capacity of raltegravir-resistant strains and antiviral activity of the new-generation integrase inhibitor dolutegravir in human primary macrophages and lymphocytes.

OBJECTIVES: To evaluate the replication capacity and phenotypic susceptibility to dolutegravir and raltegravir of wild-type and raltegravir-resistant HIV-1 strains in several cellular systems. METHODS: The antiviral activities of dolutegravir and raltegravir were evaluated in human primary monocyte-derived macrophages (MDMs), peripheral blood mononuclear cells (PBMCs) and C8166 T lymphocytic cells. The following raltegravir resistance mutations were analysed: N155H, Y143C, N155H + Y143C and G140S+Q148H. RESULTS: In the absence of drug, the replication capacity of raltegravir-resistant viruses was strongly reduced compared with wild-type in all cellular models analysed. In MDMs and PBMCs, a dramatic decrease in viral replication was observed for the double mutants N155H + Y143C and G140S + Q148H (ranging from 0.1% to 2.5% compared with wild-type). In MDMs, dolutegravir exhibited high potency, with EC50 and EC90 values of 1.1 ± 0.9 and 5.5 ± 3.4 nM, respectively (comparable to raltegravir). These values (particularly for EC90) were significantly lower than those observed in PBMCs (EC50: 2.7 ± 1.5 nM; EC90: 14.8 ± 0.9 nM) and C8166 cells (EC50: 5.5 ± 0.8 nM; EC90: 64.8 ± 5.8 nM). In all cellular models analysed, dolutegravir showed full efficacy against N155H and Y143C mutants (dolutegravir fold-change resistance ranging from 0.1 to 1.4; raltegravir fold-change resistance ranging from 0.1 to 10.3). In C8166 (the only cell model in which replication capacity was sufficient to perform the test) dolutegravir showed full efficacy against mutations N155H + Y143C (dolutegravir fold-change resistance: 0.6) and a slightly lower activity against G140S+Q148H (dolutegravir fold-change resistance: 2.1). CONCLUSIONS: Dolutegravir is effective in different HIV cellular targets and against raltegravir-resistant mutants. The high efficacy of dolutegravir in MDMs (cells with limited metabolism) has relevant clinical implications in light of the role of MDMs in the transmission of HIV infection and dissemination in different body compartments.

Cross-Validation of Next-Generation Sequencing Technologies for Diagnosis of Chromosomal Mosaicism and Segmental Aneuploidies in Preimplantation Embryos Model.

Detection of mosaic embryos is crucial to offer more possibilities of success to women undergoing in vitro fertilization (IVF) treatment. Next Generation Sequencing (NGS)-based preimplantation genetic testing are increasingly used for this purpose since their higher capability to detect chromosomal mosaicism in human embryos. In the recent years, new NGS systems were released, however their performance for chromosomal mosaicism are variable. We performed a cross-validation analysis of two different NGS platforms in order to assess the feasibility of these techniques and provide standard parameters for the detection of such aneuploidies. The study evaluated the performance of MiseqTM Veriseq (Illumina, San Diego, CA, USA) and Ion Torrent Personal Genome Machine PGMTM ReproSeq (Thermo Fisher, Waltham, MA, USA) for the detection of whole and segmental mosaic aneuploidies. Reconstructed samples with known percentage of mosaicism were analyzed with both platforms and sensitivity and specificity were determined. Both platforms had high level of specificity and sensitivity with a Limit Of Detection (LOD) at ≥30% of mosaicism and a showed a ≥5.0 Mb resolution for segmental abnormalities. Our findings demonstrated that NGS methodologies are capable of accurately detecting chromosomal mosaicism and segmental aneuploidies. The knowledge of LOD for each NGS platform has the potential to reduce false-negative and false-positive diagnoses when applied to detect chromosomal mosaicism in a clinical setting.

An Increase in the Levels of Middle Surface Antigen Characterizes Patients Developing HBV-Driven Liver Cancer Despite Prolonged Virological Suppression.

Hepatitis B virus (HBV) contains three surface glycoproteins-Large-HBs (L-HBs), Middle-HBs (M-HBs), and Small-HBs (S-HBs), known to contribute to HBV-driven pro-oncogenic properties. Here, we examined the kinetics of HBs-isoforms in virologically-suppressed patients who developed or did not develop hepatocellular carcinoma (HCC). This study enrolled 30 chronically HBV-infected cirrhotic patients under fully-suppressive anti-HBV treatment. Among them, 13 patients developed HCC. Serum samples were collected at enrolment (T0) and at HCC diagnosis or at the last control for non-HCC patients (median (range) follow-up: 38 (12-48) months). Ad-hoc ELISAs were designed to quantify L-HBs, M-HBs and S-HBs (Beacle). At T0, median (IQR) levels of S-HBs, M-HBs and L-HBs were 3140 (457-6995), 220 (31-433) and 0.2 (0-1.7) ng/mL. No significant differences in the fraction of the three HBs-isoforms were noticed between patients who developed or did not develop HCC at T0. On treatment, S-HBs showed a >25% decline or remained stable in a similar proportion of HCC and non-HCC patients (58.3% of HCC- vs. 47.1% of non-HCC patients, p = 0.6; 25% of HCC vs. 29.4% of non-HCC, p = 0.8, respectively). Conversely, M-HBs showed a >25% increase in a higher proportion of HCC compared to non-HCC patients (50% vs. 11.8%, p = 0.02), in line with M-HBs pro-oncogenic role reported in in vitro studies. No difference in L-HBs kinetics was observed in HCC and non-HCC patients. In conclusion, an increase in M-HBs levels characterizes a significant fraction of HCC-patients while under prolonged HBV suppression and stable/reduced total-HBs. The role of M-HBs kinetics in identifying patients at higher HCC risk deserves further investigation.

Different kinetics of viral replication and DNA integration in the main HIV-1 cellular reservoirs in the presence and absence of integrase inhibitors.

To compare the kinetics of integration, p24 production and equilibrium of the different HIV-DNA forms in human primary cells in the presence/absence of integrase-inhibitors (INIs) in vitro. Monocyte-derived-macrophages (MDMs), CD4+ T-cells and peripheral blood mononuclear cells (PBMCs) were infected with HIV-1 in the presence/absence of raltegravir and dolutegravir. HIV-DNA levels and p24 production were measured by qPCR and ELISA assays, respectively. In the absence of INIs, levels of HIV-DNA forms were initially very low, with an increase in the integration process starting at 3 dpi. HIV-DNA increased more slowly in MDMs than it did in CD4+ T-cells and PMBCs peaking at 21 dpi with a mean of 1580 (±890) and 615 (±37) copies/103 cells for proviral and unintegrated HIV-DNA, and 455,972 (±213,255) pg/mL of p24 at the same time point. In CD4+ T-cells the proviral HIV-DNA increased together with unintegrated HIV-DNA peaking at 7 dpi (583 ±â€¯261 and 338 ±â€¯254 copies/103 cells) when the p24 was 218,000 (±75,600) pg/mL. A similar trend was observed in PBMCs (494 ±â€¯361 and 350 ±â€¯123 copies/103 cells for proviral and unintegrated HIV-DNA, and p24 production of 149,400 ±â€¯131,800 pg/mL). Both INIs inhibited viral replication and integration in all the cell types that were tested, especially starting at 3 dpi. However, a small but measurable amount of HIV-DNA (<5 copies/103 cells) was still observed in treated-MDMs up to 30 dpi. In conclusion, our study showed differences in HIV-DNA kinetic integration between CD4+ T-cells and MDMs, which could explain the divergent kinetics of viral-replication. Both INIs inhibited HIV-1 integration and replication with no difference found between CD4+ T-cells and MDMs. However, residual HIV-DNA remained detectable up to 30 dpi in INI-treated MDMs although complete inhibition of HIV replication was achieved. The clinical significance of this minor DNA persistence deserves further investigation considering the role of macrophages as reservoirs.

Novel HBsAg mutations correlate with hepatocellular carcinoma, hamper HBsAg secretion and promote cell proliferation in vitro.

BACKGROUND: An impaired HBsAg-secretion can increase HBV oncogenic-properties. Here, we investigate genetic-determinants in HBsAg correlated with HBV-induced hepatocellular carcinoma (HCC), and their impact on HBsAg-secretion and cell-proliferation. METHODS: This study included 128 chronically HBV-infected patients: 23 with HCC (73.9% D; 26.1% A HBV-genotype), and 105 without cirrhosis/HCC (72.4% D, 27.6% A) as reference-group. The impact of mutations on HBsAg-secretion was assessed by measuring the ratio [secreted/intracellular HBsAg] until day 5 post-transfection. The impact of mutations on cell-cycle advancement was assessed by flow-cytometry. RESULTS: Two HBsAg mutations significantly correlated with HCC: P203Q (17.4% [4/23] in HCC vs 1.0% [1/105] in non-HCC, P=0.004); S210R (34.8% [8/23] in HCC vs 3.8% [4/105] in non-HCC, P <0.001); P203Q+S210R (17.4% [4/23] in HCC vs 0% [0/110] in non-HCC, P=0.001). Both mutations reside in trans-membrane C-terminal domain critical for HBsAg-secretion. In in-vitro experiments, P203Q, S210R and P203Q+S210R significantly reduced the ratio [secreted/intracellular HBsAg] compared to wt at each time-point analysed (P <0.05), supporting an impaired HBsAg-secretion. Furthermore, P203Q and P203Q+S210R increased the percentage of cells in S-phase compared to wt, indicating cell-cycle progression (P203Q:26±13%; P203Q+S210R:29±14%; wt:18%±9, P <0.01. Additionally, S210R increased the percentage of cells in G2/M-phase (26±8% for wt versus 33±6% for S210R, P <0.001). CONCLUSIONS: Specific mutations in HBsAg C-terminus significantly correlate with HBV-induced HCC. They hamper HBsAg-secretion and are associated with increased cellular proliferation, supporting their involvement in HCC-development. The identification of viral genetic markers associated with HCC is critical to identify patients at higher HCC-risk that may deserve intensive liver monitoring, and/or early anti-HBV therapy.

The HIV-1 reverse transcriptase polymorphism A98S improves the response to tenofovir disoproxil fumarate+emtricitabine-containing HAART both in vivo and in vitro.

The impact of baseline HIV-1 reverse transcriptase (RT) polymorphisms on response to first-line modern HAART containing tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) was evaluated. The impact of each RT polymorphism on virological success (VS) was evaluated in 604 HIV-1 subtype B-infected patients starting TDF+FTC-containing HAART. TDF and FTC antiviral activity was also tested in PBMCs infected by mutagenised HIV. Structural analysis based on docking simulations was performed. A98S was the only mutation significantly correlated with an increased proportion of patients achieving VS at 24 weeks (94.0% vs. 84.3%; P=0.03). Multivariate regression and Cox model analyses confirmed this result. At concentrations close to the minimal concentration achieved in patient plasma, TDF and FTC exhibited higher potency in the presence of A98S-mutated virus compared with wild-type (IC90,TDF, 8.6±1.1 vs. 19.3±3.5nM; and IC90,FTC, 12.4±7.7 vs. 16.8±9.8nM, respectively). The efficacy of FTC, abrogated by M184V, was partially restored by A98S (IC90,FTC, 5169±5931nM for A98S+M184V vs. 18477±12478nM for M184V alone). Docking analysis showed the higher potency of TDF and FTC in the presence of A98S-mutated virus was mainly due to higher binding affinity between drugs and mutated RT compared with wild-type. In the presence of FTC, A98S also partially restored the RT binding affinity impaired by M184V alone. A98S polymorphism improves virological response to TDF+FTC-containing HAART. This may help clinicians in the choice of the optimal NRTI backbone aimed at achieving maximal virological inhibition.

Specific mutations in the C-terminus domain of HBV surface antigen significantly correlate with low level of serum HBV-DNA in patients with chronic HBV infection.

BACKGROUND: To define HBsAg-mutations correlated with different serum HBV-DNA levels in HBV chronically-infected drug-naive patients. METHODS: This study included 187 patients stratified into the following ranges of serum HBV-DNA:12-2000 IU/ml, 2000-100,000 IU/ml, and >100,000 IU/ml. HBsAg-mutations were associated with HBV-DNA levels by applying a Bayesian-Partitional-Model and Fisher-exact test. Mutant and wild-type HBV genotype-D genomes were expressed in Huh7 cells and HBsAg-production was determined in cell-supernatants at 3 days-post-transfection. RESULTS: Specific HBsAg-mutations (M197T,-S204N-Y206C/H-F220L) were significantly correlated with serum HBV-DNA <2000 IU/ml (posterior-probability>90%, P < 0.05). The presence of Y206C/H and/or F220L was also associated with lower median (IQR) HBsAg-levels and lower median (IQR) transaminases (for HBsAg:250[115-840] IU/ml for Y206C/H and/or F220L versus 4300[640-11,838] IU/ml for wild-type, P = 0.023; for ALT:28[21-40] IU/ml versus 53[34-90] IU/ml, P < 0.001). These mutations were localized in the HBsAg C-terminus, known to be involved in virion and/or HBsAg secretion. The co-occurrence of Y206C + F220L was found significant by cluster-analysis, (P = 0.02). In addition, in an in-vitro model Y206C + F220L determined a 2.8-3.3 fold-reduction of HBsAg-amount released in supernatants compared to single mutants and wt (Y206C + F220L = 5,679 IU/ml; Y206H = 16,305 IU/ml; F220L = 18,368 IU/ml; Y206C = 18,680 IU/ml; wt = 14,280 IU/ml, P < 0.05). CONCLUSIONS: Specific HBsAg-mutations (compartmentalized in the HBsAg C-terminus) correlated with low-serum HBV-DNA and HBsAg-levels. These findings can be important to understand mechanisms underlying low HBV replicative potential including the inactive-carrier state.

Inhibition of dual/mixed tropic HIV-1 isolates by CCR5-inhibitors in primary lymphocytes and macrophages.

BACKGROUND: Dual/mixed-tropic HIV-1 strains are predominant in a significant proportion of patients, though little information is available regarding their replication-capacity and susceptibility against CCR5-antagonists in-vitro. The aim of the study was to analyze the replication-capacity and susceptibility to maraviroc of HIV-1 clinical isolates with different tropism characteristics in primary monocyte-derived-macrophages (MDM), peripheral-blood-mononuclear-cells (PBMC), and CD4(+) T-lymphocytes. METHODS: Twenty-three HIV-1 isolates were phenotipically and genotipically characterized as R5, X4 or dual (discriminated as R5(+)/X4, R5/X4, R5/X4(+)). Phenotypic-tropism was evaluated by multiple-cycles-assay on U87MG-CD4(+)-CCR5(+)-/CXCR4(+)-expressing cells. Genotypic-tropism prediction was obtained using Geno2Pheno-algorithm (false-positive-rate [FPR] = 10%). Replication-capacity and susceptibility to maraviroc were investigated in human-primary MDM, PBMC and CD4(+) T-cells. AMD3100 was used as CXCR4-inhibitor. Infectivity of R5/Dual/X4-viruses in presence/absence of maraviroc was assessed also by total HIV-DNA, quantified by real-time polymerase-chain-reaction. RESULTS: Among 23 HIV-1 clinical isolates, phenotypic-tropism-assay distinguished 4, 17 and 2 viruses with R5-tropic, dual/mixed-, and X4-tropic characteristics, respectively. Overall, viruses defined as R5(+)/X4-tropic were found with the highest prevalence (10/23, 43.5%). The majority of isolates efficiently replicated in both PBMC and CD4(+) T-cells, regardless of their tropism, while MDM mainly sustained replication of R5- or R5(+)/X4-tropic isolates; strong correlation between viral-replication and genotypic-FPR-values was observed in MDM (rho = 0.710;p-value = 1.4e-4). In all primary cells, maraviroc inhibited viral-replication of isolates not only with pure R5- but also with dual/mixed tropism (mainly R5(+)/X4 and, to a lesser extent R5/X4 and R5/X4(+)). Finally, no main differences by comparing the total HIV-DNA with the p24-production in presence/absence of maraviroc were found. CONCLUSIONS: Maraviroc is effective in-vitro against viruses with dual-characteristics in both MDM and lymphocytes, despite the potential X4-mediated escape. This suggests that the concept of HIV-entry through one of the two coreceptors "separately" may require revision, and that the use of CCR5-antagonists in patients with dual/mixed-tropic viruses may be a therapeutic-option that deserves further investigations in different clinical settings.

Comparative antiviral activity of integrase inhibitors in human monocyte-derived macrophages and lymphocytes.

The activity of raltegravir and 4 other integrase inhibitors (MK-2048, L870,810, IN2, and IN5) was investigated in primary human macrophages, PBMC and C8166-lymphocytic T cells, in order to determine their relative potency and efficacy in different cellular systems of HIV infection. Raltegravir showed better protective efficacy in all cell types; MK-2048, L870,810 and IN5 showed a potent anti-HIV-1 activity in macrophages, while in lymphocytes only MK-2048 and L870,810 showed an inhibitory effect comparable to raltegravir. IN2 was a poorly effective anti-HIV-1 compound in all cellular systems. All effective integrase inhibitors exhibited a potent antiviral activity against both X4 and R5 HIV-1 strains. In general, raltegravir, MK-2048, L870,810 and IN5 showed anti HIV activity similar or slightly higher in macrophages compared to PBMC and C8166 T cells: for MK-2048, the EC(50) was 0.4, 0.9, 11.5 nM in macrophages, in PBMCs and T cells, respectively; for L870,810, the EC(50) was 1.5, 14.3, and 10.6 nM, respectively; for IN5 the EC(50) was 0.5, 13.7, and 5.7 nM, respectively.

HIV-1 dual/mixed tropic isolates show different genetic and phenotypic characteristics and response to maraviroc in vitro.

Dual/mixed-tropic HIV-1 strains are predominant in a significative proportion of patients, though few information is available regarding the genetic characteristics, quasispecies composition, and susceptibility against CCR5-antagonists of the primary-isolates. For this reason, we investigated in deep details, both phenotypically and genotypically, the characteristics of 54 HIV-1 primary-isolates obtained from HIV-infected patients. Tropism was assessed by multiple-cycles phenotypic-assay on U87MG-CD4(+)-CCR5(+)-/CXCR4(+)-expressing cells. In vitro selection in PBMCs of X4-tropic viral strains following maraviroc-treatment was also performed. Phenotypic-assay reported pure R5-tropic viruses in 31 (57.4%) isolates, dual/mixed-tropic viruses in 22 (40.7%), and pure X4-tropic virus in only 1 (1.8%). Among dual/mixed-tropic isolates, 12 showed a remarkably higher replication-efficacy in CCR5-expressing cells (R5(+)/X4), and 2 in CXCR4-expressing cells (R5/X4(+)). Genotypic-tropism testing showed a correlation between PSSM-scores, geno2pheno false-positive-rate, and V3-net-charge with both CCR5-usage and syncytium-inducing ability. Moreover, specific gp120- and gp41-mutations were significantly associated with tropism and/or syncytium-inducing ability. Ultra-deep V3-pyrosequencing showed the presence of a swarm of genetically distinct species with a preference for CCR5-coreceptor not only in all pure R5-isolates, but also in 6/7 R5(+)/X4-tropic isolates. In both pure-X4 and R5/X4(+)-isolates, we observed extensive prevalence of X4-using species. In vitro selection-experiments with CCR5-inhibitor maraviroc (up to 2 months) showed no-emergence of X4-tropic variants for all R5- and R5(+)/X4-isolates tested (while X4-virus remained fully-resistant). In conclusion, our study shows that dual/mixed-tropic viruses are constituted by different species, whereby those with characteristics R5(+)/X4 are genotypically and phenotypically similar to the pure-R5 isolates; thus the use of CCR5-antagonists in patients with R5(+)/X4-tropic viruses may be a therapeutic-option that deserves further investigations.