The HIV envelope glycoprotein (Env) is a trimeric protein that facilitates viral binding and fusion with target cells. As the sole viral protein on the HIV surface, Env is important both for immune responses to HIV and in vaccine designs. Targeting Env in clinical applications is challenging due to its heavy glycosylation, high genetic variability, conformational camouflage, and its low abundance on virions. Thus, there is a critical need to better understand this protein. Flow virometry (FV) is a useful methodology for phenotyping the virion surface in a high-throughput, single virion manner. To demonstrate the utility of FV to characterize Env, we stained HIV virions with a panel of 85 monoclonal antibodies targeting different regions of Env. A broad range of antibodies yielded robust staining of Env, with V3 antibodies showing the highest quantitative staining. A subset of antibodies tested in parallel on viruses produced in CD4+ T cell lines, HEK293T cells, and primary cells showed that the cellular model of virus production can impact Env detection. Finally, in addition to being able to highlight Env heterogeneity on virions, we show FV can sensitively detect differences in Env conformation when soluble CD4 is added to virions before staining.

BACKGROUND: An effective vaccine is required to end the HIV pandemic. We evaluated the safety and immunogenicity of a DNA (DNA-HIV-PT123) vaccine with low- or high-dose bivalent (TV1.C and 1086.C glycoprotein 120) subtype C envelope protein combinations, adjuvanted with MF59 or AS01B.
METHODS: HIV Vaccine Trials Network (HVTN)108 was a randomized, placebo-controlled, double-blind, phase 1/2a trial conducted in the United States and South Africa. HIV-negative adults were randomly assigned to 1 of 7 intervention arms or placebo to assess DNA prime with DNA/protein/adjuvant boosts, DNA/protein/adjuvant co-administration, and low-dose protein/adjuvant regimens. HVTN111 trial participants who received an identical regimen were also included. Outcomes included safety and immunogenicity 2 weeks and 6 months after final vaccination.
RESULTS: From June 2016 to July 2018, 400 participants were enrolled (N = 334 HVTN108, N = 66 HVTN111); 370 received vaccine and 30 received placebo. There were 48 grade 3 and 3 grade 4 reactogenicity events among 39/400 (9.8%) participants, and 32 mild/moderate-related adverse events in 23/400 (5.8%) participants. All intervention groups demonstrated high IgG response rates (>89%) and high magnitudes to HIV-1 Env gp120 and gp140 proteins; response rates for AS01B-adjuvanted groups approached 100%. V1V2 IgG magnitude, Fc-mediated functions, IgG3 Env response rates, and CD4+ T-cell response magnitudes and rates were higher in the AS01B-adjuvanted groups. The AS01B-adjuvanted low-dose protein elicited greater IgG responses than the higher protein dose.
CONCLUSIONS: The vaccine regimens were generally well tolerated. Co-administration of DNA with AS01B-adjuvanted bivalent Env gp120 elicited the strongest humoral responses; AS01B-adjuvanted regimens elicited stronger CD4+ T-cell responses, justifying further evaluation.ClinicalTrials.gov registration: NCT02915016, registered 26 September 2016.

UNASSIGNED: The HVTN 105 vaccine clinical trial tested four combinations of two immunogens - the DNA vaccine DNA-HIV-PT123, and the protein vaccine AIDSVAX B/E. All combinations induced substantial antibody and CD4+ T cell responses in many participants. We have now re-examined the intracellular cytokine staining flow cytometry data using the high-resolution SWIFT clustering algorithm, which is very effective for enumerating rare populations such as antigen-responsive T cells, and also determined correlations between the antibody and T cell responses.
UNASSIGNED: Flow cytometry samples across all the analysis batches were registered using the swiftReg registration tool, which reduces batch variation without compromising biological variation. Registered data were clustered using the SWIFT algorithm, and cluster template competition was used to identify clusters of antigen-responsive T cells and to separate these from constitutive cytokine producing cell clusters.
UNASSIGNED: Registration strongly reduced batch variation among batches analyzed across several months. This in-depth clustering analysis identified a greater proportion of responders than the original analysis. A subset of antigen-responsive clusters producing IL-21 was identified. The cytokine patterns in each vaccine group were related to the type of vaccine - protein antigens tended to induce more cells producing IL-2 but not IFN-γ, whereas DNA vaccines tended to induce more IL-2+ IFN-γ+ CD4 T cells. Several significant correlations were identified between specific antibody responses and antigen-responsive T cell clusters. The best correlations were not necessarily observed with the strongest antibody or T cell responses.
UNASSIGNED: In the complex HVTN105 dataset, alternative analysis methods increased sensitivity of the detection of antigen-specific T cells; increased the number of identified vaccine responders; identified a small IL-21-producing T cell population; and demonstrated significant correlations between specific T cell populations and serum antibody responses. Multiple analysis strategies may be valuable for extracting the most information from large, complex studies.

Acute, transient lymphocytopenia, not clinically significant was observed in the CAPRISA 012B phase 1 clinical trial following administration of broadly neutralizing antibodies (bnAb)-CAP256V2LS alone or with VRC07-523LS. Lymphocytopenia was assigned upon a > 50% decline in absolute lymphocyte counts following bnAb administration. We posited that systemic immunoglobulins (Igs), and cytokine profiles of eight women who developed lymphocytopenia were different to the 12 women without lymphocytopenia. Plasma Ig subclasses (IgG)/isotypes (IgM/IgA), and 27 cytokines were measured at enrolment (prior to bnAbs) and at days 1, 7, 28, 56 post-bnAb administration. IgG subclasses, IgM and total lymphocyte counts were significantly lower prior to bnAbs in women with gradable lymphocytopenia than those without. Gradable lymphocytopenia compared to non-lymphocytopenia women had significantly higher MIP-1β from enrolment up to day 56. TNF-α was significantly lower in gradable lymphocytopenia compared to non-lymphocytopenia women for enrolment, days 7, 28 and 56 except for day 1. Within the gradable and within the non-lymphocytopenia women, from enrolment to day 1, significantly elevated IL-6, IL-8, IP-10, MCP-1, G-CSF and IL-1RA were found. Additionally, within the gradable lymphocytopenia women, 9 additional cytokines (TNF-α, MIP-1α, MIP-1β, RANTES, Basic FGF, eotaxin, IFN-γ, IL-17A and IL-4) were significantly elevated at day 1 post-bnAbs compared to enrolment. This sub study presents preliminary findings to support the monitoring of baseline immunological markers including lymphocyte counts for assessing the development of transient lymphocytopenia. In high-risk settings conducting clinical trials testing bnAbs for HIV prevention, understanding factors that could amplify rates of lymphocytopenia, even if transient, remain undefined.

UNASSIGNED: Fostemsavir is a gp120-directed attachment inhibitor approved for heavily treatment-experienced (HTE) adults with multidrug-resistant HIV-1. We provide detailed week 240 safety results from the BRIGHTE study and evaluate the impact of immune recovery on safety outcomes.
UNASSIGNED: The phase 3 BRIGHTE trial is ongoing; data for this analysis were collected from the first participant\'s first visit (February 23, 2015) through the last participant\'s last visit for week 240 (March 22, 2021). Safety endpoints were assessed in participants who received fostemsavir + optimized background therapy. In participants with baseline CD4+ T-cell count <200 cells/mm3, exposure-adjusted adverse event (AE) rates were assessed among subgroups with or without CD4+ T-cell count ≥200 cells/mm3 at any time during 48-week analysis periods through week 192.
UNASSIGNED: Through a median of 258 weeks (range, 0.14-319) of treatment, discontinuations due to AEs occurred in 30/371 (8%) participants. Serious AEs were reported in 177/371 (48%) participants, including 16 drug-related events in 13 (4%) participants. Thirty-five (9%) deaths occurred, primarily related to AIDS or acute infections. COVID-19-related events occurred in 25 (7%) participants; all resolved without sequelae. Among participants with baseline CD4+ T-cell count <200 cells/mm3, 122/162 (75%) achieved CD4+ T-cell count ≥200 cells/mm3 at week 192. Exposure-adjusted AE rates were markedly lower among participants achieving CD4+ T-cell count ≥200 cells/mm3 at any time vs those sustaining <200 cells/mm3. No new AIDS-defining events were reported after week 48 in participants with CD4+ T-cell count ≥200 cells/mm3.
UNASSIGNED: Cumulative safety findings through the BRIGHTE 240-week interim analysis are consistent with other trials in HTE participants with advanced HIV-1 and comorbid disease. Reduced rates of AIDS-defining events and AEs were observed in participants with immunologic recovery on fostemsavir-based treatment.
UNASSIGNED: NCT02362503, https://clinicaltrials.gov/study/NCT02362503.

BACKGROUND: Allogeneic haematopoietic stem-cell transplantation (allo-HSCT) markedly reduces HIV reservoirs, but the mechanisms by which this occurs are only partly understood. In this study, we aimed to describe the dynamics of virological and immunological markers of HIV persistence after allo-HSCT.
METHODS: In this prospective observational cohort study, we analysed the viral reservoir and serological dynamics in IciStem cohort participants with HIV who had undergone allo-HSCT and were receiving antiretroviral therapy, ten of whom had received cells from donors with the CCR5Δ32 mutation. Participants from Belgium, Canada, Germany, Italy, the Netherlands, Spain, Switzerland, and the UK were included in the cohort both prospectively and retrospectively between June 1, 2014 and April 30, 2019. In the first 6 months after allo-HSCT, participants had monthly assessments, with annual assessments thereafter, with the protocol tailored to accommodate for the individual health status of each participant. HIV reservoirs were measured in blood and tissues and HIV-specific antibodies were measured in plasma. We used the Wilcoxon signed-rank test to compare data collected before and after allo-HSCT in participants for whom longitudinal data were available. When the paired test was not possible, we used the Mann-Whitney U test. We developed a mathematical model to study the factors influencing HIV reservoir reduction in people with HIV after allo-HSCT.
RESULTS: We included 30 people with HIV with haematological malignancies who received a transplant between Sept 1, 2009 and April 30, 2019 and were enrolled within the IciStem cohort and included in this analysis. HIV reservoirs in peripheral blood were reduced immediately after full donor chimerism was achieved, generally accompanied by undetectable HIV-DNA in bone marrow, ileum, lymph nodes, and cerebrospinal fluid, regardless of donor CCR5 genotype. HIV-specific antibody levels and functionality values declined more slowly than direct HIV reservoir values, decaying significantly only months after full donor chimerism. Mathematical modelling suggests that allogeneic immunity mediated by donor cells is the main viral reservoir depletion mechanism after massive reservoir reduction during conditioning chemotherapy before allo-HSCT (half-life of latently infected replication-competent cells decreased from 44 months to 1·5 months).
CONCLUSIONS: Our work provides, for the first time, data on the effects of allo-HSCT in the context of HIV infection. Additionally, we raise the question of which marker can serve as the last reporter of the residual viraemia, postulating that the absence of T-cell immune responses might be a more reliable marker than antibody decline after allo-HSCT.
BACKGROUND: amfAR (American Foundation for AIDS Research; ARCHE Program), National Institutes of Health, National Institute of Allergy and Infectious Diseases, and Dutch Aidsfonds.

OBJECTIVE: To analyse the HIV-1 subtypes and molecular transmission characteristics of HIV-infected older individuals aged 50 and above in Huzhou City, and provide a scientific basis for prevention and treatment strategies for them.
METHODS: A cross-sectional study with clustered molecular transmission network cases was performed, and basic epidemiological information was retrieved from the Chinese Centres for Disease Prevention and Control (CDC) Information System.
METHODS: A molecular epidemiological study was conducted in 899 newly diagnosed HIV-infected individuals from January 2019 and March 2023 in Huzhou city, Zhejiang province, Eastern China. Out of these, HIV sequences were successfully obtained from 673 individuals, including 274 who were older individuals aged 50 and above.
METHODS: Reverse transcription-polymerase chain reaction (PCR) and nested PCR were used to amplify the polymerase gene of HIV-1, and gene sequencing was performed. We used univariate and multivariate logistic regression to describe the association of clustered molecular transmission network cases.
RESULTS: In total, 274 valid HIV sequences of older individuals were obtained, which revealed 14 subtypes. Circulating recombinant forms (CRF) 07_BC accounted for 55.8% and CRF01_AE accounted for 20.1% of the subtypes. Data of 150 older individuals were included in the molecular transmission network, and the proportion of elderly individuals in clustered cases is 52.26% (150/287). The results of multivariable logistic regression analysis showed that the older age group (60-82 years) and CRF07_BC subtype were associated with case clustering (transmission risk).
CONCLUSIONS: The key high-risk transmission network was mainly composed of the older age group (60-82 years) and CRF07_BC subtype. It is necessary to further strengthen AIDS health promotion and education for individuals aged 60 years and above, as well as for patients with the CRF07_BC subtype, to reduce HIV transmission and clustering risk.

BACKGROUND: The HIV-1 molecular network is an innovative tool, using gene sequences to understand transmission attributes and complementing social and sexual network studies. While previous research focused on static network characteristics, recent studies\' emphasis on dynamic features enhances our understanding of real-time changes, offering insights for targeted interventions and efficient allocation of public health resources.
OBJECTIVE: This study aims to identify the dynamic changes occurring in HIV-1 molecular transmission networks and analyze the primary influencing factors driving the dynamics of HIV-1 molecular networks.
METHODS: We analyzed and compared the dynamic changes in the molecular network over a specific time period between the baseline and observed end point. The primary factors influencing the dynamic changes in the HIV-1 molecular network were identified through univariate analysis and multivariate analysis.
RESULTS: A total of 955 HIV-1 polymerase fragments were successfully amplified from 1013 specimens; CRF01_AE and CRF07_BC were the predominant subtypes, accounting for 40.8% (n=390) and 33.6% (n=321) of the specimens, respectively. Through the analysis and comparison of the basic and terminal molecular networks, it was discovered that 144 sequences constituted static molecular networks, and 487 sequences contributed to the formation of dynamic molecular networks. The findings of the multivariate analysis indicated that the factors occupation as a student, floating population, Han ethnicity, engagement in occasional or multiple sexual partnerships, participation in anal sex, and being single were independent risk factors for the dynamic changes observed in the HIV-1 molecular network, and the odds ratio (OR; 95% CIs) values were 2.63 (1.54-4.47), 1.83 (1.17-2.84), 2.91 (1.09-7.79), 1.75 (1.06-2.90), 4.12 (2.48-6.87), 5.58 (2.43-12.80), and 2.10 (1.25-3.54), respectively. Heterosexuality and homosexuality seem to exhibit protective effects when compared to bisexuality, with OR values of 0.12 (95% CI 0.05-0.32) and 0.26 (95% CI 0.11-0.64), respectively. Additionally, the National Eight-Item score and sex education experience were also identified as protective factors against dynamic changes in the HIV-1 molecular network, with OR values of 0.12 (95% CI 0.05-0.32) and 0.26 (95% CI 0.11-0.64), respectively.
CONCLUSIONS: The HIV-1 molecular network analysis showed 144 sequences in static networks and 487 in dynamic networks. Multivariate analysis revealed that occupation as a student, floating population, Han ethnicity, and risky sexual behavior were independent risk factors for dynamic changes, while heterosexuality and homosexuality were protective compared to bisexuality. A higher National Eight-Item score and sex education experience were also protective factors. The identification of HIV dynamic molecular networks has provided valuable insights into the characteristics of individuals undergoing dynamic alterations. These findings contribute to a better understanding of HIV-1 transmission dynamics and could inform targeted prevention strategies.

The susceptibility of genetically divergent HIV-1 strains (HIV-1 non-M) from groups O, N, and P to the CCR5 co-receptor antagonist, maraviroc (MVC), was investigated among a large panel of 45 clinical strains, representative of the viral genetic diversity. The results were compared to the reference strains of HIV-1 group M (HIV-1/M) with known tropism. Among the non-M strains, a wide range of phenotypic susceptibilities to MVC were observed. The large majority of HIV-1/O strains (40/42) displayed a high susceptibility to MVC, with median and mean IC50 values of 1.23 and 1.33 nM, respectively, similar to the HIV-1/M R5 strain (1.89 nM). However, the two remaining HIV-1/O strains exhibited a lower susceptibility (IC50 at 482 and 496 nM), in accordance with their dual/mixed (DM) tropism. Interestingly, the two HIV-1/N strains demonstrated varying susceptibility patterns, despite always having relatively low IC50 values (2.87 and 47.5 nM). This emphasized the complexity of determining susceptibility solely based on IC50 values. Our study examined the susceptibility of all HIV-1 non-M groups to MVC and correlated these findings with virus tropism (X4, R5, or DM). The results confirm the critical significance of tropism determination before initiating MVC treatment in patients infected with HIV-1 non-M. Furthermore, we advocate for the consideration of additional parameters, such as the slope of inhibition curves, to provide a more thorough characterization of phenotypic susceptibility profiles.
OBJECTIVE: Unlike HIV-1 group M, the scarcity of studies on HIV-1 non-M groups (O, N, and P) presents challenges in understanding their susceptibility to antiretroviral treatments, particularly due to their natural resistance to non-nucleoside reverse transcriptase inhibitors. The TROPI-CO study logically complements our prior investigations into integrase inhibitors and anti-gp120 efficacy. The largest panel of 45 non-M strains existing so far yielded valuable results on maraviroc (MVC) susceptibility. The significant variations in MVC IC50 reveal a spectrum of susceptibilities, with most strains displaying R5 tropism. Notably, the absence of MVC-resistant strains suggests a potential therapeutic avenue. The study also employs a robust novel cell-based phenotropism assay and identifies distinct groups of susceptibilities based on inhibition curve slopes. Our findings emphasize the importance of determining tropism before initiating MVC and provide crucial insights for selecting effective therapeutic strategies in the delicate context of HIV-1 non-M infections.

BACKGROUND: Randomised comparative data on efficacy and safety of second-line antiretroviral therapy (ART) after failure of non-nucleoside reverse transcriptase inhibitors (NNRTIs) across diverse geographical settings are scarce. The aim of this study was to evaluate optimal second-line ART for people with HIV.
METHODS: D2EFT is a completed international, randomised, open-label, phase 3b/4 trial evaluating three second-line ART strategies in adults (aged ≥18 years) with HIV-1 for whom first-line NNRTI therapy has failed. The study was done at 28 sites across 14 countries in Asia, Africa, and Latin America. It was originally designed to compare recommended standard of care (ritonavir-boosted darunavir [800 mg darunavir plus 100 mg ritonavir once daily] plus two nucleoside reverse transcriptase inhibitors [NRTIs; dosed once or twice daily]) with a novel nucleoside sparing regimen of dolutegravir (50 mg once daily) with ritonavir-boosted darunavir. The study was adapted during the first year to add a third arm of dolutegravir (50 mg once daily) with fixed tenofovir disoproxil fumarate (300 mg once daily) plus either lamivudine (300 mg once daily) or emtricitabine (200 mg once daily). Participants were randomly assigned with a computer-generated, blocked randomisation scheme (block size of two) stratified by site, previous tenofovir disoproxil fumarate use, and HIV viral load. The trial was designed to evaluate non-inferiority of either interventional arm against standard of care for the primary outcome of virological suppression, as determined by HIV RNA load of less than 50 copies per mL at 48 weeks. The prespecified non-inferiority margin was 12%. Comparisons were made with a modified intention-to-treat population, including all participants randomly assigned but excluding administrative withdrawals. This study is registered with ClinicalTrials.gov, NCT03017872.
RESULTS: 1190 individuals were screened; 828 participants were enrolled between Nov 1, 2017, and Dec 31, 2021. Two participants were unable to receive their assigned regimen for administrative reasons; and 826 participants were included in analyses. Median age was 39 years (IQR 33-46), and 450 (54%) participants were female. Baseline median CD4 count was 206 cells per μL (23-354) and median HIV RNA was 15 400 copies per mL (3600-65 986). The proportion of participants with HIV RNA of less than 50 copies per mL at 48 weeks was 194 (75%) of 257 in the ritonavir-boosted darunavir plus two NRTIs group, 222 (84%) of 264 in the ritonavir-boosted darunavir plus dolutegravir group, and 227 (78%) of 291 in the dolutegravir with tenofovir disoproxil fumarate plus either lamivudine or emtricitabine group. Compared with ritonavir-boosted darunavir plus two NRTIs, the difference in virological suppression was 8·6% (95% CI 1·7 to 15·5; p=0·016) for dolutegravir plus ritonavir-boosted darunavir and 6·7% (-1·2 to 14·4; p=0·093) for dolutegravir with tenofovir disoproxil fumarate plus either lamivudine or emtricitabine. Six deaths occurred, none of which were related to treatment. 19 pregnancies (11 livebirths) occurred with no congenital defects.
CONCLUSIONS: In individuals experiencing failure of an NNRTI-based first-line ART, a switch to either dolutegravir plus ritonavir-boosted darunavir or dolutegravir with tenofovir disoproxil fumarate plus either lamivudine or emtricitabine, without universal access to genotyping, was non-inferior in achieving viral suppression compared with ritonavir-boosted darunavir plus two NRTIs. These global data support the most recent WHO treatment guidelines.
BACKGROUND: UNITAID; National Institute of Allergy and Infectious Diseases, USA; National Health and Medical Research Council, Australia; ViiV Healthcare; and Janssen.