Mutations in the 3'-PPT Lead to HIV-1 Replication without Integration.

Integration of the reverse-transcribed genome is a critical step of the retroviral life cycle. Strand-transfer inhibitors (INSTIs) used for antiretroviral therapy inhibit integration but can lead to resistance mutations in the integrase gene, the enzyme involved in this reaction. A significant proportion of INSTI treatment failures, particularly those with second-generation INSTIs, show no mutation in the integrase gene. Here, we show that replication of a selected dolutegravir-resistant virus with mutations in the 3'-PPT (polypurine tract) was effective, although no integrated viral DNA was detected, due to the accumulation of unintegrated viral DNA present as 1-LTR circles. Our results show that mutation in the 3'-PPT leads to 1-LTR circles and not linear DNA as classically reported. In conclusion, our data provide a molecular basis to explain a new mechanism of resistance to INSTIs, without mutation of the integrase gene and highlights the importance of unintegrated viral DNA in HIV-1 replication. IMPORTANCE Our work highlights the role of HIV-1 unintegrated viral DNA in viral replication. A virus, resistant to strand-transfer inhibitors, has been selected in vitro. This virus highlights a mutation in the 3'PPT region and not in the integrase gene. This mutation modifies the reverse transcription step leading to the accumulation of 1-LTR circles and not the linear DNA. This accumulation of 1-LTR circles leads to viral replication without integration of the viral genome.

In vitro analysis of the replicative capacity and phenotypic susceptibility to integrase inhibitors of HIV-2 mutants with integrase insertions.

BACKGROUND: HIV-2 resistance to integrase strand-transfer inhibitors (INSTIs) is characterized by two main pathways: (i) mutations at codons 143, 148 and155; and (ii) amino acid insertion after integrase codon 231 (231ins). OBJECTIVES: To complete INSTI resistance data on HIV-2 by determining the viral replicative capacity and INSTI phenotypic susceptibility of integrase mutants obtained through site-directed mutagenesis. METHODS: Site-directed mutants (SDMs) were constructed and viral stocks produced. Viral replicative capacity was assessed by measuring HIV-2 viral load at days 3, 7 and 14. In vitro phenotypic susceptibility was measured using the ANRS PBMC assay. RESULTS: Viruses bearing 231ins did not present impaired replicative capacity, except the 231ins GIRGK mutant. A 231ins GK SDM was resistant to raltegravir and cabotegravir, but remained susceptible to dolutegravir and bictegravir. SDMs harbouring a 5 amino acid insertion (GYKGK or SREGK) were both resistant to all INSTIs. The SDM with T97A+N155H, with or without E92Q, was resistant to all INSTIs, except bictegravir. CONCLUSIONS: These first data on the newly described resistance pathway 231ins, using site-directed mutagenesis, showed no measurable impact on viral fitness and confirmed the decreased susceptibility to a first-generation INSTI (raltegravir) and cabotegravir. Resistance to second-generation INSTIs (dolutegravir and bictegravir) occurred for mutants with a 5 amino acid 231ins.

Limited HIV-2 reservoirs in central-memory CD4 T-cells associated to CXCR6 co-receptor expression in attenuated HIV-2 infection.

The low pathogenicity and replicative potential of HIV-2 are still poorly understood. We investigated whether HIV-2 reservoirs might follow the peculiar distribution reported in models of attenuated HIV-1/SIV infections, i.e. limited infection of central-memory CD4 T lymphocytes (TCM). Antiretroviral-naive HIV-2 infected individuals from the ANRS-CO5 (12 non-progressors, 2 progressors) were prospectively included. Peripheral blood mononuclear cells (PBMCs) were sorted into monocytes and resting CD4 T-cell subsets (naive [TN], central- [TCM], transitional- [TTM] and effector-memory [TEM]). Reactivation of HIV-2 was tested in 30-day cultures of CD8-depleted PBMCs. HIV-2 DNA was quantified by real-time PCR. Cell surface markers, co-receptors and restriction factors were analyzed by flow-cytometry and multiplex transcriptomic study. HIV-2 DNA was undetectable in monocytes from all individuals and was quantifiable in TTM from 4 individuals (median: 2.25 log10 copies/106 cells [IQR: 1.99-2.94]) but in TCM from only 1 individual (1.75 log10 copies/106 cells). HIV-2 DNA levels in PBMCs (median: 1.94 log10 copies/106 PBMC [IQR = 1.53-2.13]) positively correlated with those in TTM (r = 0.66, p = 0.01) but not TCM. HIV-2 reactivation was observed in the cells from only 3 individuals. The CCR5 co-receptor was distributed similarly in cell populations from individuals and donors. TCM had a lower expression of CXCR6 transcripts (p = 0.002) than TTM confirmed by FACS analysis, and a higher expression of TRIM5 transcripts (p = 0.004). Thus the low HIV-2 reservoirs differ from HIV-1 reservoirs by the lack of monocytic infection and a limited infection of TCM associated to a lower expression of a potential alternative HIV-2 co-receptor, CXCR6 and a higher expression of a restriction factor, TRIM5. These findings shed new light on the low pathogenicity of HIV-2 infection suggesting mechanisms close to those reported in other models of attenuated HIV/SIV infection models.

Evaluation of the QIAstat-Dx Respiratory SARS-CoV-2 Panel, the First Rapid Multiplex PCR Commercial Assay for SARS-CoV-2 Detection.

In the race to contain severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), efficient detection and triage of infected patients must rely on rapid and reliable testing. In this work, we performed the first evaluation of the QIAstat-Dx respiratory SARS-CoV-2 panel (QIAstat-SARS) for SARS-CoV-2 detection. This assay is the first rapid multiplex PCR (mPCR) assay, including SARS-CoV-2 detection, and is fully compatible with a non-PCR-trained laboratory or point-of-care (PoC) testing. This evaluation was performed using 69 primary clinical samples (66 nasopharyngeal swabs [NPS], 1 bronchoalveolar lavage fluid sample [BAL], 1 tracheal aspirate sample, and 1 bronchial aspirate sample) comparing SARS-CoV-2 detection with the currently WHO-recommended reverse transcription-PCR (RT-PCR) (WHO-RT-PCR) workflow. Additionally, a comparative limit of detection (LoD) assessment was performed for QIAstat-SARS and WHO-RT-PCR using a quantified clinical sample. Compatibility of sample pretreatment for viral neutralization or viscous samples with the QIAstat-SARS system were also tested. The QIAstat-Dx respiratory SARS-CoV-2 panel demonstrated a sensitivity comparable to that of the WHO-recommended assay with a limit of detection at 1,000 copies/ml. The overall percent agreement between QIAstat-Dx SARS and WHO-RT-PCR on 69 clinical samples was 97% with a sensitivity of 100% (40/40) and specificity at 93% (27/29). No cross-reaction was encountered for any other respiratory viruses or bacteria included in the panel. The QIAstat-SARS rapid multiplex PCR panel provides a highly sensitive, robust, and accurate assay for rapid detection of SARS-CoV-2. This assay allows rapid decisions even in non-PCR-trained laboratory or point-of-care testing, allowing innovative organization.

Pharmacovirological analyses of blood and male genital compartment in patients receiving dolutegravir + lamivudine dual therapy as a switch strategy (ANRS 167 LAMIDOL trial).

OBJECTIVES: To describe plasma residual HIV viraemia, cellular HIV reservoir size, blood plasma drug concentrations and their male genital tract penetration during the maintenance dual therapy dolutegravir + lamivudine. PATIENTS AND METHODS: ANRS167 LAMIDOL enrolled 104 virologically suppressed patients to switch to dolutegravir + lamivudine. In this pharmacovirological substudy, ultrasensitive plasma viral load (USpVL) and plasma drug concentrations were measured at Day 0 (D0), Week 24 (W24) and W48 of dolutegravir + lamivudine, and HIV-DNA was measured at W-8 and W48. Semen samples were collected at D0 and W24 from 18 participants. Total and unbound blood and seminal plasma drug concentrations were measured using UPLC-MS/MS. RESULTS: Median HIV-DNA was 2.5 log10 copies/106 PBMC (IQR = 2.2-3.0, n = 100) at W-8 and 2.4 log10 copies/106 PBMC (IQR = 2.1-2.9, n = 100) at W48 (P = 0.17). The proportion of patients with undetected USpVL was 38% (n = 98), 43% (n = 98) and 49% (n = 97) at D0, W24 and W48, respectively (P = 0.08). Total and unbound plasma dolutegravir concentrations were stable between timepoints (P = 0.13) and all total plasma dolutegravir concentrations except one were adequate. Median free fraction of dolutegravir in plasma was 0.21%. Median blood plasma and seminal plasma concentrations of total dolutegravir at 24 h were 1812 ng/mL and 206 ng/mL, respectively. Median seminal plasma/blood plasma total concentration ratios were 11.6% and 2478% for dolutegravir and lamivudine, respectively. HIV-RNA (365 to 475 copies/mL) was detected in seminal plasma of one patient at D0 (5.9%) and of two patients at W24 (11.8%). CONCLUSIONS: These findings add further important information regarding the effectiveness of dolutegravir + lamivudine maintenance dual therapy in terms of plasma residual viraemia, cellular reservoir size and drug penetration in the male genital tract.

Prevalence of Human Papillomavirus, Human Immunodeficiency Virus, and Other Sexually Transmitted Infections Among Men Who Have Sex With Men in Togo: A National Cross-sectional Survey.

BACKGROUND: Sub-Saharan Africa is a region of both high human immunodeficiency virus (HIV) and anal cancer incidence. We conducted the first national study in Togo to assess human papillomavirus (HPV), HIV, and other sexually transmitted infection (STI) prevalence among men who have sex with men (MSM). METHODS: A multicentric cross-sectional study was conducted among MSM recruited in 4 Togolese cities. Anal swabs were collected to test HPV, herpes simplex virus (HSV), and 7 STIs. RESULTS: Among the 207 MSM, HIV and high-risk HPV (hrHPV) overall prevalence were 26.1% and 44.9%, respectively. The most common hrHPV types were HPV-35 (15.0%) and HPV-16 (13.0%). Prevalence of hrHPV and multiple HPV infections were higher among HIV-infected than among HIV-uninfected MSM (85.2% vs 30.7%, P < 10-5 and 85.2% vs 28.7%, P < 10-5, respectively). Other STIs, except hepatitis B virus, were also more prevalent among HIV-infected MSM (Neisseria gonorrhoeae, P = .03; Mycoplasma genitalium, P = .04; HSV-2, P = .001; and a trend for Chlamydia trachomatis, P = .06). In multivariate analysis (adjusted odds ratio [95% confidence interval]), HIV (10.1 [4.0-25.6]), living in Lomé (2.8 [1.1-7.1]), HSV-2 excretion (26.7 [2.9-244.3]), C. trachomatis (11.7 [2.3-58.9]), and M. genitalium infection (9.6 [3.1-29.9]) were associated with increased risk of hrHPV infection. CONCLUSIONS: We report a high burden of anal STIs with an unusual hrHPV type distribution among MSM, highlighting the critical need of implementation of a national strategy regarding prevention of STIs and vaccination against HPV.

A New Mechanism of Resistance of Human Immunodeficiency Virus Type 2 to Integrase Inhibitors: A 5-Amino-Acid Insertion in the Integrase C-Terminal Domain.

BACKGROUND: Integrase strand transfer inhibitors (INSTIs) are crucial for the treatment of human immunodeficiency virus (HIV) type 2 infection, due to limited available therapeutic options. Recently, bictegravir has been approved for HIV-1, but no data are currently available for HIV-2. METHODS: We assessed the phenotypic susceptibility of 12 HIV-2 clinical isolates, obtained from 2 antiretroviral-naive and 10 antiretroviral-experienced patients, to 5 INSTIs (bictegravir, cabotegravir, dolutegravir, elvitegravir, and raltegravir) at the virological failure of an INSTI-based regimen. The 50% inhibitory concentrations (IC50s) were determined. Phenotypic inhibitory quotients were determined using trough INSTI plasma concentrations. RESULTS: Wild-type viruses were susceptible to the 5 INSTIs, with IC50s in the nanomolar range. Bictegravir had a lower IC50 than the other INSTIs on those HIV-2 isolates bearing major, resistance-associated mutations (codons 143, 148, and 155). We identified a new resistance profile-a 5-amino-acid insertion at codon 231 of the HIV-2 integrase (231INS)-in 6 patients at the virological failure of a raltegravir-based regimen. Those patients had adequate raltegravir concentrations, but harbored multiresistant viruses with low genotypic susceptibility scores (median = 1.5). This insertion rendered isolates highly resistant to raltegravir and elvitegravir, and moderately resistant to dolutegravir and cabotegravir. Regarding bictegravir, 2 isolates remained susceptible and 2 had a slight increase in IC50 (3- to 5-fold change). CONCLUSIONS: Our results confirm the potency of INSTI on HIV-2 clinical isolates with wild-type integrase. In addition, we identified a new resistance pathway, 231INS, selected in antiretroviral-experienced patients with multiresistant HIV-2 viruses. This highlights the need of close follow-up of those patients initiating an INSTI-based regimen.

Presence of Human Papillomavirus (HPV) Apolipoprotein B Messenger RNA Editing, Catalytic Polypeptide-Like 3 (APOBEC)-Related Minority Variants in HPV-16 Genomes From Anal and Cervical Samples but Not in HPV-52 and HPV-58.

Background: The aim of this study was to investigate the presence of minority variants (MVs) in high-risk human papillomavirus (HPV) types (HPV-16, -52, and -58) from cervical and anal smears. Methods: Whole HPV genome ultra-deep sequencing (UDS) was performed on cervical and anal smears collected during patient follow-up. Bioinformatics analyses were performed using Bowtie2 (Geneious). Results: We assessed 55 HPV-16-positive, 20 HPV-52-positive, and 17 HPV-58-positive samples, with significant differences in patient characteristics for the 2 anatomic sites. HPV-16 MVs were detected in 20 samples (36%), with no difference between cervical and anal samples. We did not find an association between the presence of MVs and cytovirological parameters. Seven HPV-16 genomes (13%) were apolipoprotein B messenger RNA editing, catalytic polypeptide-like 3 (APOBEC) edited. Among the cervical HPV-16-positive samples, most MVs (55%) resulted from APOBEC-related mutations. MVs were detected in 10 HPV-52-positive (50%) and 12 HPV-58-positive (71%) samples, with no difference between cervical and anal samples. No APOBEC-related mutations were found on HPV-58 or HPV-52 genomes. Conclusions: Overall, high-risk HPV MVs were found in about half of all cases in both anal and cervical samples. Interestingly, we reported for the first time a differential impact of APOBEC3 mutagenic activity depending on high-risk HPV type.

Minority resistant variants are also present in HIV-2-infected antiretroviral-naive patients.

Objectives: To assess the prevalence of minority resistant variants (MRV) and X4-tropic minority variants in ART-naive HIV-2-infected patients. Patients and methods: ART-naive HIV-2-infected patients with detectable plasma viral load (>100 copies/mL) included in the ANRS HIV-2 CO5 Cohort were assessed. We performed ultra-deep sequencing (UDS) of protease, RT, integrase and gp105 regions. Only mutations in the HIV-2 ANRS list >1% were considered. HIV-2 tropism was assessed by V3 loop region UDS, and each read was interpreted with determinants of CXCR4-coreceptor use. Results: Among the 47 patients assessed, three displayed plasma viruses with a resistance-associated mutation (RAM) above the 20% detection threshold, all in RT, resulting in a prevalence of transmitted drug resistance for NRTI of 7.9% (95% CI 0.0%-16.5%). No RAM above the 20% detection threshold was found in protease or integrase. At the 1% detection threshold the transmitted drug resistance prevalence was 9.8% (95% CI 0.6%-19.0%), 13.2% (95% CI 3.5%-22.9%) and 4.5% (95% CI 0%-17.5%) for PI, NRTI and integrase inhibitors. The most prevalent MRV was the PI RAM I50V detected in three samples. Tropism analysis showed that 21% of patients (4 of 19) exhibited X4-tropic viruses: two in majority proportion and two in minority proportions (1.5% and 1.9%). Conclusions: In this first study assessing the prevalence of MRV in HIV-2 infection among ART-naive patients, we observed a 2-3-fold higher prevalence of RAM when a 1% detection threshold of mutations was used compared with a 20% threshold. Similarly, the proportion of patients with X4-tropic viruses was twice as high when UDS was used.

New sensitive one-step real-time duplex PCR method for group A and B HIV-2 RNA load.

The Agence Nationale de Recherche sur le Sida et les hépatites virales (ANRS) previously developed a widely used method for HIV-1 RNA quantification (Biocentric). Here, we report the development of a new specific and sensitive method for HIV-2 RNA quantification, based on an adaptation of the existing HIV-1 protocol. The new test is based on TaqMan one-step reverse transcription-quantitative PCR (qRT-PCR) targeting two conserved consensus regions of HIV-2 (long terminal repeat [LTR] and gag). Analytic performances were determined in three laboratories. Clinical performances were evaluated on 100 plasma samples from HIV-2-infected patients (groups A, B, and H) by comparison with the assay currently used for the ANRS HIV-2 cohort. The specificity was 100%. Sensitivity was 50 copies/ml (cp/ml) and was optimized to 10 cp/ml. The within-run coefficients of variation in the three laboratories varied from 0.54% to 1.61% at 4 log10 copies/ml and from 7.24% to 14.32% at 2 log10 cp/ml. The between-run coefficients of variation varied from 2.28% to 6.43%. Of the 39 clinical samples below 2 log10 in the current assay, the new test improved the detection or quantification of 17 samples, including eight group B samples. For quantifiable samples, similar loads were obtained with the two assays for group A samples. The median difference between the two assays for group B samples was +0.18 but with greater heterogeneity than for group A. The HIV-2 group H sample had similar results with the two assays. This new assay is highly sensitive and accurately quantifies the most prevalent HIV-2 groups. This test will be useful for monitoring low viral loads in HIV-2-infected patients.

Molecular determinants of HIV-2 R5-X4 tropism in the V3 loop: development of a new genotypic tool.

OBJECTIVE: The use of CCR5 inhibitors requires a tool to predict human immunodeficiency virus type 2 (HIV-2) tropism, as established in HIV-1. The aim of our study was to identify genotypic determinants of HIV-2 tropism located in the gp105 V3 loop. METHODS: HIV-2 tropism phenotypic assays were performed on 53 HIV-2 clinical isolates using GFP expressing human osteosarcoma T4 [GHOST(3)] cell lines expressing CD4 and CCR5 or CXCR4 coreceptors. The gp105 V3 loop was sequenced and analyzed. RESULTS: Thirty-four HIV-2 isolates were classified as R5, 7 as X4, and 12 as X4/R5 (dual). Substitution at residue 18 was always associated with a dual/X4 tropism (P < .00001). The following determinants were associated with dual/X4 tropism: a global net charge of more than +6 (P < .00001), V19K/R mutation (P < .00001), S22A/F/Y mutation (P < .002), Q23R mutation (P < .00001), and insertions at residue 24 (P < .00001), I25L/Y (P < .0004), R28K (P < .0004), and R30K (P < .014). These mutations were not found in R5 isolates, except R28K and R30K, which were detected in 4 and 5 R5 isolates, respectively. The 4 major genotypic determinants of dual/X4 tropism were mutation at residue 18, V19 K/R mutation, insertions at residue 24, and V3 global net charge. CONCLUSIONS: We established a strong association between HIV-2 phenotypic tropism and V3-loop sequences, allowing for the prediction of R5- and/or X4-tropic viruses in HIV-2 infection.

Temporal dynamics of RSV shedding and genetic diversity in adults during the COVID-19 pandemic in a French hospital, early 2021.

Human respiratory syncytial virus (RSV) is responsible of lower respiratory tract infections which may be severe in infants, elderly and immunocompromised adults. Europe and North-American countries have observed a massive reduction of RSV incidence during the 2020-2021 winter season. Using a systematic RSV detection coupled to SARS-CoV-2 for all adult patients admitted at the Foch hospital (Suresnes, France) between January and March 2021 (n = 11,324), only eight RSV infections in patients with prolonged RNA shedding were diagnosed. RSV whole-genome sequencing revealed that six and two patients were infected by RSV groups A and B, respectively. RSV carriage lasted from 7 to at least 30 days disregarding of RSV lineage. The most prolonged RSV shedding was observed in an asymptomatic patient. We detected novel patient-specific non-synonymous mutations in the G glycoprotein gene, including a double identical mutation in the repeated region for one patient. No additional mutation occurred in the RSV genome over the course of infection in the four patients tested for. In conclusion, our results suggest that the temporal shift in the RSV epidemic is not likely to be explained by the emergence of a high frequency, unreported variant. Moreover, prolonged RSV carriages in asymptomatic patients could play a role in virus spread.

Association of soluble CD14 and inflammatory biomarkers with HIV-2 disease progression.

BACKGROUND: Human immunodeficiency virus type 2 (HIV-2) infection is characterized by a slower progression than HIV type 1. It is not known whether markers of inflammation such as high-sensitivity C-reactive protein (hsCRP), interleukin 6 (IL-6), and soluble CD14 (sCD14) may predict disease progression among HIV-2 patients. METHODS: We performed longitudinal retrospective analysis using 384 samples from 71 patients included in the HIV-2 French cohort ANRS CO5 and followed for a median of 8 years. Baseline was the time of the first available measurement. Disease progression was defined by the occurrence of death, Centers for Disease Control and Prevention B/C stage HIV-related event, drop in CD4 <350 cells/µL, and HIV-2 RNA detection. Cox regression models and mixed models were used for statistical analyses. RESULTS: At baseline, 75% of patients were asymptomatic, 34% were treated; 30% had detectable HIV-2 RNA load, and median CD4 cell count was 415/µL. The 3 biomarkers were positively related to each other. In adjusted analyses, sCD14 was the main factor explaining variation of hsCRP and IL-6 (P < .001). Lower CD4, older age, and advanced clinical stage were associated with higher sCD14. The biomarkers were correlated with HIV-2 RNA in unadjusted analyses only. Patients with baseline levels above either the median values (hsCRP = 1.38 mg/L; IL-6 = 1.97 pg/mL) or the highest quartile (sCD14 = 1.74 µg/mL) had a higher risk of disease progression (all P < .003). After adjustment for CD4 count, only sCD14 remained significantly associated with disease progression (hazard ratio, 3.59; P = .004). CONCLUSIONS: In this cohort of HIV-2-infected patients, sCD14 represents a better predictive biomarker of disease progression than hsCRP or IL-6, independent of CD4.

Long-term outcome of primary non-responders to tenofovir therapy in HIV/HBV-co-infected patients: impact of HBV genotype G.

AIM: To evaluate the early virological response (EVR) to combined tenofovir-lamivudine or emtricitabine regimen in HBV/HIV-co-infected patients and the long-term efficacy of tenofovir. METHODS: In this retrospective monocentric study, among the 166 HIV/HBV-co-infected patients regularly followed from 2003 to 2008 at Bichat Claude Bernard Hospital, 61 patients had received, either de novo combination therapy with tenofovir and lamivudine or emtricitabine (group I, n = 15) or add-on tenofovir to lamivudine therapy (group II, n = 46). The HBV polymerase region was sequenced and analysed for all patients with available samples. RESULTS: All 15 group I patients achieved EVR vs 32 (82%) of group II patients (P = 0.15). Seven adherent group II patients met criteria for primary non-response, but achieved delayed response (DR) to therapy. In these seven patients, when compared with the 39 group II patients, there was a trend to longer duration of lamivudine pre-treatment and to higher rate of lamivudine-resistant mutants; and HBV genotype-G proportion was higher (P = 0.026). No virological breakthrough occurred after a median of 46 months follow up. CONCLUSION: In these HBV/HIV-co-infected patients, first-line HBV therapy with tenofovir and emtricitabine or lamivudine was associated with EVR. However, DR to tenofovir was observed in 15% of patients who added tenofovir to lamivudine therapy, of whom four of seven (57%) had genotype G-HBV infection. No resistance was evidenced after 46 months of therapy even in patients with DR to tenofovir. At last, a good renal safety profile of TDF was observed after a median follow-up of 4 years of therapy.

Ibalizumab shows in-vitro activity against group A and group B HIV-2 clinical isolates.

OBJECTIVE: Treatment of multidrug-resistant HIV-2 is an emerging issue, because of the rapid selection of mutations at time of virological failure and the low number of antiretrovirals active on HIV-2. The aim of this study was to determine the susceptibility of HIV-2 primary isolates to ibalizumab, a long-acting monoclonal antibody that binds to CD4 that is approved for the treatment of MDR HIV-1. METHODS: In-vitro phenotypic susceptibility of 16 HIV-2 primary isolates was measured using a modified version of the ANRS peripheral blood mononuclear cells (PBMC) assay. Susceptibility to ibalizumab was assessed through 50% inhibitory concentrations and maximum percentage inhibitions (MPI), and gp105 was sequenced to look for determinants of reduced susceptibility. RESULTS: Ibalizumab inhibited viral replication of all 16 isolates, with a median IC 50 value of 0.027 µg/ml (range = 0.001-0.506 µg/ml), and a median MPI of 93%. Although two isolates presented higher IC 50 (above 0.1 µg/ml), they did not exhibit a loss of potential N-linked glycosylation sites in V5 loop, as reported in HIV-1 strains with reduced susceptibility. However, both presented shorter V1 and V2 loops than the HIV-2 reference strain. CONCLUSION: Ibalizumab inhibits HIV-2 replication, with IC 50 and MPI in the range of those reported for HIV-1. These in vitro data support the use of ibalizumab in patients with MDR HIV-2, in combination with an optimized background regimen.

Efficacy of Severe Acute Respiratory Syndrome Coronavirus-2 Vaccine in Patients With Thoracic Cancer: A Prospective Study Supporting a Third Dose in Patients With Minimal Serologic Response After Two Vaccine Doses.

INTRODUCTION: Coronavirus disease 2019 resulted in a 30% mortality rate in patients with thoracic cancer. Given that patients with cancer were excluded from serum antisevere acute respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccine registration trials, it is still unknown whether they would develop a protective antispike antibody response after vaccination. This prospective vaccine monitoring study primarily aimed to assess humoral responses to the SARS-CoV-2 vaccine in patients with thoracic cancer. METHODS: SARS-CoV-2-spike antibodies were measured using the Abbot Architect SARS-CoV-2 immunoglobulin G immunoassay before the first injection of BNT162b2 mRNA vaccine, at week 4, and 2 to 16 weeks after the second vaccine dose administration. The factors associated with antibody response were analyzed. RESULTS: Overall, 306 patients, with a median age of 67.0 years (interquartile range: 58-74), were vaccinated. Of these, 283 patients received two vaccine doses at 28-day intervals. After a 6.7-month median follow-up, eight patients (2.6%) contracted proven symptomatic SARS-CoV-2 infection, with rapid favorable evolution. Of the 269 serologic results available beyond day 14 after the second vaccine dose administration, 17 patients (6.3%) were still negative (<50 arbitrary units/mL, whereas 34 (11%) were less than 300 arbitrary units/mL (12.5th percentile). In multivariate analysis, only age (p < 0.01) and long-term corticosteroid treatment (p = 0.01) were significantly associated with a lack of immunization. A total of 30 patients received a third vaccine dose, with only three patients showing persistently negative serology thereafter, whereas the others exhibited clear seroconversion. CONCLUSIONS: SARS-CoV2 vaccines were found to be efficient in patients with thoracic cancer, most of them being immunized after two doses. A third shot given to 1% of patients with persistent low antibody titers resulted in an 88% immunization rate.

G140S/Q148R and N155H mutations render HIV-2 Integrase resistant to raltegravir whereas Y143C does not.

BACKGROUND: HIV-2 is endemic in West Africa and has spread throughout Europe. However, the alternatives for HIV-2-infected patients are more limited than for HIV-1. Raltegravir, an integrase inhibitor, is active against wild-type HIV-2, with a susceptibility to this drug similar to that of HIV-1, and is therefore a promising option for use in the treatment of HIV-2-infected patients. Recent studies have shown that HIV-2 resistance to raltegravir involves one of three resistance mutations, N155H, Q148R/H and Y143C, previously identified as resistance determinants in the HIV-1 integrase coding sequence. The resistance of HIV-1 IN has been confirmed in vitro for mutated enzymes harboring these mutations, but no such confirmation has yet been obtained for HIV-2. RESULTS: The integrase coding sequence was amplified from plasma samples collected from ten patients infected with HIV-2 viruses, of whom three RAL-naïve and seven on RAL-based treatment at the time of virological failure. The genomes of the resistant strains were cloned and three patterns involving N155H, G140S/Q148R or Y143C mutations were identified. Study of the susceptibility of integrases, either amplified from clinical isolates or obtained by mutagenesis demonstrated that mutations at positions 155 and 148 render the integrase resistant to RAL. The G140S mutation conferred little resistance, but compensated for the catalytic defect due to the Q148R mutation. Conversely, Y143C alone did not confer resistance to RAL unless E92Q is also present. Furthermore, the introduction of the Y143C mutation into the N155H resistant background decreased the resistance level of enzymes containing the N155H mutation. CONCLUSION: This study confirms that HIV-2 resistance to RAL is due to the N155H, G140S/Q148R or E92Q/Y143C mutations. The N155H and G140S/Q148R mutations make similar contributions to resistance in both HIV-1 and HIV-2, but Y143C is not sufficient to account for the resistance of HIV-2 genomes harboring this mutation. For Y143C to confer resistance in vitro, it must be accompanied by E92Q, which therefore plays a more important role in the HIV-2 context than in the HIV-1 context. Finally, the Y143C mutation counteracts the resistance conferred by the N155H mutation, probably accounting for the lack of detection of these mutations together in a single genome.