BACKGROUND:Individuals with HIV remain at higher risk of non-communicable diseases associated with interleukin-6-specific (IL-6) inflammation compared to the background population. Despite antiretroviral therapy, some individuals exhibit persistent hyperinflammation. We characterise these understudied longitudinal profiles and distinguish the predictors of chronic versus acute inflammation. METHODS:A subset from the Strategic Timing of Antiretroviral Treatment (START) trial with up to seven years of biomarker follow-up was included. Inflammatory states were defined based on plasma IL-6 levels, measured at randomisation, months eight, 12, and annually until 84. Hyperinflammation was defined as IL-6>1.8 pg/mL; ≥2 consecutive elevated measurements defined persistent hyperinflammation and a single elevated bracketed by non-elevated measurements defined IL-6 blips. Variables associated with these outcomes were analysed by generalized estimating equations. RESULTS:Among 2,102 individuals with a median of 5 (IQR: 4-6) measurements, 861 (41%) had persistent hyperinflammation whereas 575 (27%) had blips. Participants with BMI≥40 versus 18.5 to <25 (OR: 5.49, 95%CI: 4.18-7.20) and females with black ethnicity versus white males (2.58, 2.17-3.06) had increased risk of persistent hyperinflammation but not blips. Other persistent hyperinflammation predictors included higher white blood cell (WBC) counts, HIV-1 RNA, total cholesterol to high-density lipoprotein ratio >5, older age, smoking and diabetes. Of these only higher WBCs were also associated with blips. CONCLUSIONS:Persistent hyperinflammation is strongly associated with demographic characteristics, comorbidities, and HIV-1 RNA, whereas blips were associated with markers of immune activation. Longitudinal IL-6 measurements are needed to distinguish persistent hyperinflammation from blips, which can lead to establishing a "high-risk phenotype" to target for clinical intervention.
BACKGROUND:CD8+ T cell responses are thought to be critical for spontaneous control of human immunodeficiency virus (HIV) but findings supporting their role in post-intervention control have been mixed. We hypothesized that HIV-specific T cell proliferation, interferon-γ (IFN-γ) and granzyme B response prior to analytical treatment interruption (ATI) were associated with time to viral rebound. METHODS:We pooled data from six different HIV cure trials including people living with HIV receiving antiretroviral therapy (ART) alone or combined with latency reversing agents, Toll-Like receptor 9 agonists or broadly neutralizing antibodies. Pre-ATI blood samples were analysed by IFN-γ ELISpot and lymphocyte proliferation assay (LPA). RESULTS:We included 91 participants (90% male, median age 45 years). Compared to participants without virologic control (two consecutive measurements >1000 copies of HIV RNA/mL or ART restart), participants with virologic control at day 28 post-ATI (n=49) had higher Gag-specific IFN-γ (210 vs. 50 SFC/106 PBMCs, p=0.03) and CD8+ T cell proliferation (0.48% vs. 0.16%, p=0.03) responses pre-ATI. The median duration of virologic control was 28 vs. 21 days in people with high vs low Gag-specific IFN-γ response (p<0.01) or CD8+ T cell proliferation (p=0.03). ELISpot and LPA responses were not associated with time to first plasma HIV RNA of >50 copies/mL. CONCLUSIONS:These findings indicate that high pre-ATI Gag-specific IFN-γ and CD8+ T cell proliferation responses were associated with an increase in the duration of virological control after stopping ART, supporting a role for CD8+ T cells in sustaining virological control.
BACKGROUND:Endogenous human herpesvirus 6 (eHHV-6), in which the entire viral genome is integrated into human chromosomes, is present in approximately 1% of the population and has been associated with various clinical conditions, including neurological disorders. However, its biological significance remains unclear due to the lack of appropriate experimental models. METHODS:We established a patient-derived induced pluripotent stem cell (iPSC)-based tissue culture model using lymphoblastoid cell lines from individuals with eHHV-6B. iPSCs retaining the integrated viral genome were generated and subsequently differentiated into neural stem cells (NSCs). Viral gene expression was evaluated by RT-qPCR under basal conditions and following chemical stimulation. RESULTS:The integrated HHV-6B genome was transcriptionally silent in iPSCs but exhibited spontaneous low-level expression of the immediate-early gene U90 and the late gene U100 in NSCs. Chemical stimulation further enhanced U90 expression, whereas induction of U100 did not reach statistical significance. These findings indicate preferential activation of early viral transcriptional programs in neural lineage cells. CONCLUSIONS:Neural lineage cells provide a permissive environment for expression of eHHV-6B transcripts. This patient-derived iPSC-based model provides a platform for investigating the biological significance of neural lineage-specific eHHV-6 transcripts and may facilitate interpretation of HHV-6 DNA detection in patients with eHHV-6 by enabling studies of cell type-dependent viral transcription.
BACKGROUND:Human herpesvirus 6B (HHV-6B) infection causes clinically distinct diseases in primary infection or viral reactivation. Primary infection manifests as exanthem subitum (ES), a common childhood febrile exanthem; whereas reactivation is associated with drug reaction with eosinophilia and systemic symptoms (DRESS), a severe cutaneous adverse reaction. The immune mechanisms underlying these divergent outcomes remain poorly understood. METHODS:We performed single-cell RNA sequencing of peripheral blood mononuclear cells from patients with ES and DRESS. Comparative analysis of immune cell populations and transcriptional programs during the acute and recovery phases revealed distinct immune interaction networks. RESULTS:Primary HHV-6B infection was characterized by marked expansion of proliferating natural killer (NK) cells, which expressed cytotoxic effector genes including GNLY and NKG7. Cell-cell communication analysis predicted strong communication between proliferating NK cells and inflammatory monocytes during acute ES. In contrast, HHV-6B reactivation in DRESS was associated with expansion of proliferating CD4+ T cells with inflammatory transcriptional signatures that showed predicted communication with CD14+ monocytes. Despite these differences, monocytes occupied a prominent position within the predicted interaction networks in both conditions. Complementary protein-level analysis identified CXCL10 as a shared systemic inflammatory marker in active HHV-6B infection. CONCLUSIONS:HHV-6B infection exhibits distinct immune interaction networks depending on the clinical context, characterized by proliferating NK cell-monocyte interactions during primary infection and proliferating CD4+ T cell-monocyte interactions during viral reactivation.
BACKGROUND:Virus-specific CD8+ T-cells play an important part in HIV cure/remission in adults, yet their role in paediatric immune control is limited by tolerogenic early-life immunity. Very-early ART initiation, while effective in restricting viral reservoir size, also prevents antigenic exposure and, thereby, the induction of HIV-specific CD8+ T-cell responses. Analytical treatment interruption (ATI) is an established tool in cure/remission studies for assessing time to viral rebound and viral setpoint off ART yet the impact of ATI on HIV-specific immune responses and plasma viral load (pVL) remains understudied in paediatric populations. METHODS:We evaluated a historical randomised cohort of early ART-treated children in South Africa. Infants with HIV were randomized to either Arm-1, receiving an initial course of ART followed by three short, pVL-guided treatment interruptions, or Arm-2, receiving continuous ART. Both arms then underwent an extended ATI in the second year of life. Virological outcomes, viral sequencing, and HIV-specific T-cell responses were assessed longitudinally. RESULTS:During the extended ATI, Arm-1 participants, following multiple treatment interruptions, demonstrated a lower peak and set-point pVL compared to Arm-2, alongside an early induction of HIV-specific CD8+ T-cell responses. One Arm-1 participant achieved undetectable pVL for 1.5 months during the extended ATI, before losing immune control associated with viral escape within dominant Gag CD8+ T-cell epitopes. CONCLUSIONS:Short-term viral exposure from serial ATIs is associated with the induction and/or boosting of HIV-specific CD8+ T-cell responses and enhanced immune control of HIV in early ART-treated children.
BACKGROUND:No reliable markers exist for parasitological cure in adult patients with chronic Chagas disease. We assessed whether a serological multiplex immunoassay for Trypanosoma cruzi, MultiCruzi, could differentiate the outcomes of treatment regimens. METHODS:This analysis included adults with indeterminate Chagas disease from a randomized trial of E1224. Serum samples at baseline, 6, and 12 months post-treatment with Benznidazole, E1224 regimens, or placebo were tested at three dilutions using MultiCruzi. We calculated the dilution factor at which 50% of reactivity remained (DF50) and used mixed-effects models to assess antibody decline. Log2DF50 slopes compared Benznidazole and E1224 regimens, and pooled data from the BENDITA trials helped define a cut-off for treatment response. FINDINGS:Within six months after treatment, participants exhibited a significantly greater rate of decline in antibody levels compared to the placebo group, contrasting with results from T. cruzi conventional ELISA tests. Our analysis showed a difference in response to benznidazole and to E1224 regimens after twelve months' follow-up, confirming results for benznidazole from BENDITA. Combining data from both trials allowed discrimination of benznidazole and E1224 treatment regimens after six months' follow-up. CONCLUSION:MultiCruzi enables the early assessment of treatment-associated biological responses in adults with Chagas disease, with antibody decline serving as an exploratory pharmacodynamic marker.
BACKGROUND:Prior dengue virus (DENV) infection is common in regions affected by Zika virus (ZIKV) and may shape immune responses to subsequent ZIKV infection. Although cross-reactive neutralizing and disease-enhancing antibodies have been extensively studied, the effect of prior DENV immunity on antibody-dependent cellular cytotoxicity (ADCC) responses to ZIKV remains unclear. METHODS:Longitudinal serum samples were obtained and analyzed from a prospective cohort of 46 PCR-confirmed ZIKV cases enrolled at two U.S. sites between 2016-2018 (follow-up visits 6-409 days). ZIKV cases were classified as DENV-experienced (n=13) or DENV-naïve groups (n=33) based on detection of DENV neutralizing antibodies at baseline. ZIKV-specific ADCC activity was measured using a natural killer cell cytotoxicity assay. RESULTS:DENV-experienced individuals had significantly higher peak ZIKV-specific ADCC responses (geometric mean titers [GMT] 15,104 vs 1,819; P<0.0001) and greater cumulative ADCC responses during early (≤80 days, AUC 918,540 vs 42,752; P = 0.0012) and late convalescent phases (>80 days, AUC 953,694 vs 182,004; P=0.0037). Peak ZIKV ADCC magnitude did not correlate with peak DENV or ZIKV antibody neutralizing titers, and ZIKV neutralization efficiency at the time of peak ZIKV ADCC did not differ between groups. However, ZIKV ADCC normalized to ZIKV IgG was significantly higher among DENV-experienced individuals (GMT 2,230 vs 735.6; P=0.0107). CONCLUSIONS:Prior DENV infection was associated with greater ZIKV-specific ADCC magnitude, despite similar ZIKV neutralization, suggesting that prior DENV exposure shapes Fc-mediated flavivirus immunity beyond neutralization. Future studies are needed to assess the clinical implications of these antibodies in immunopathology and protection.
BACKGROUND:The study uses spatial analysis to identify factors associated with human immunodeficiency virus (HIV) detectable viremia in dolutegravir (DTG)-based first-line antiretroviral therapy (ART), which is crucial for targeted interventions to sustain epidemic control in Botswana. METHODS:This was a longitudinal observational cohort utilizing a dataset of 42 546 people with HIV on DTG-based first-line ART from June 2016 to December 2022 enrolled in the Botswana National Treatment Program. Detectable viremia was defined as viral load (VL) >50 copies/mL and further classified into low-level viremia (LLV; VL from 51 to 999 copies/mL) and virologic failure (VF; VL ≥1000 copies/mL). The rates of detectable viremia, LLV, and VF were stratified by year from 2017 to 2022 and mapped by districts in Botswana. Generalized estimating equation (GEE) models were utilized to evaluate odds of detectable viremia. RESULTS:There was an overall trend of increasing detectable viremia, with rates of 6.7% (2017), 5.6% (2018), 4.7% (2019), 7.1% (2020), 13.5% (2021), and 11.2% (2022) (P < .001). The linear annual trend showed that each additional year from 2017 was associated with 23% increased odds of detectable viremia and 50% increase in the odds of LLV, while odds of VF decreased by 6% per year. Repeated-measures GEE models showed that male sex (adjusted odds ratio [aOR], 1.36 [95% confidence interval {CI}, 1.30-1.43]) and rural residence (aOR, 1.10 [95% CI, 1.05-1.16]) were consistently associated with higher odds of detectable viremia, LLV, and VF over follow-up. CONCLUSIONS:While VF is declining, LLV is increasing. We observed spatial heterogeneity in detectable viremia, and higher odds in males, those with rural residence, and young individuals (18-35 years). Targeted interventions are necessary for high-risk groups and regions to further suppress viremia and achieve sustained epidemic control beyond the UNAIDS 95-95-95 targets.
The anal canal represents the primary site of HIV-1 acquisition in men-who-have-sex-with-men (MSM), while MSM-living-with-HIV (MLWH) have the highest anal cancer incidence. Since HPV16-infection and low-nadir CD4-T-cell counts predict anal cancer risk, we developed an assay to identify and characterize HPV16-specific T-cell responses in MLWH. 40% of acutely and 81% of chronically infected MLWH had HPV16-specific CD4-T-cells, which harbored higher levels of HIV-1 DNA/RNA than non-HPV16-specific CD4-T-cells. T-cell-receptor (TCR) sequencing revealed a less diverse and more restricted TCR-repertoire in HPV16-specific CD4-T-cells. HPV16-specific CD4-T-cells represent an early-established preferential HIV-1 reservoir and a potential novel immunologic correlate of anal cancer-risk in MLWH.
BACKGROUND:Despite continued control efforts, malaria due to Plasmodium vivax and P. falciparum remains endemic across the Amazon Basin. Here, we sought to understand how malaria parasites spread between sources and sinks within the upper Juruá Valley region of northwestern Brazil, the country's main residual transmission hotspot, to inform more effective control and elimination strategies. METHODS:We combined the analysis of nearly 70,000 case notifications between 2018 and 2021 with high-resolution molecular genotyping data from 207 P. vivax and 117 P. falciparum isolates to map malaria parasite movement across the Juruá Valley hotspot. We introduce the C50 metric to estimate parasite connectivity within clusters of genetically related parasites, or molecular clusters. RESULTS:We found that 16-18% of infections were acquired outside participants' localities of residence. Genotyping of P. vivax and P. falciparum revealed large molecular clusters comprising parasites of each species collected across rural-urban boundaries over four years, with some pairs of genetically related parasites originating from distant localities within Juruá Valley. We found a large variation in C50 values, with a few parasites serving as main hubs within large molecular clusters. Imported P. vivax isolates were significantly more connected than locally acquired infections. CONCLUSIONS:We suggest that the combined use of routine epidemiological surveillance data and molecular genotyping can help to map human mobility and parasite lineage dispersal across space and time, aiming to inform specific interventions tailored for local populations that move malaria parasites between source and sink localities in residual transmission settings in the Amazon.
BACKGROUND:Preterm infants are at higher risk of severe RSV infection, partially because of reduced placental transfer of maternal antibodies (Abs). Increased risk of severe infection persists in the first year of life. This study evaluates the postnatal kinetics of RSV neutralizing antibodies in preterm and full-term infants born to unvaccinated mothers. METHODS:We enrolled infants with a gestational age (GA) of 24-42 weeks born in hospital from RSV-unvaccinated mothers. Serum was collected at birth (cord blood), 1-2 weeks, and 4-8 weeks. Linear mixed-effects models were used to estimate half-lives of RSV-neutralizing Abs in relation to GA and cord blood titer. Analyses were repeated for total serum IgG1 to confirm the robustness of our findings. RESULTS:Of 169 infants, 95 were born preterm (<37 weeks GA, including 53 neonates <32 weeks GA). Premature birth was related to prolonged half-life of RSV-neutralizing Abs (∼79 days very preterm to ∼30 days in term infants). The inverse association between gestational age and antibody half-life was largely accounted for by an inverse association between cord blood Ab levels and Ab half-life. A doubling in cord blood titers led to a reduction in half-life of ∼20% for RSV neutralizing Abs and ∼32% for IgG1. CONCLUSIONS:Postnatal antibody half-life depends on starting levels: higher titers decline faster. If our observation would be replicated for vaccine-induced Abs, the difference in vaccine protection between preterm and term infants may be smaller than anticipated.
BACKGROUND:Regulation of transcription is essential for the pathoadaptation of non-typeable Haemophilus influenzae(NTHi). We identified FabR as a previously unrecognized transcriptional regulator in NTHi through its binding to the promoter region of ompP5 and investigated its contribution to bacterial virulence and physiology. METHODS:A fabR deletion mutant (ΔfabR) was generated in NTHi strain 3655. The mutant was compared with the wild-type strain in assays of host cell adherence, serum resistance, immunoglobulin G (IgG) deposition, vitronectin binding, murine nasopharyngeal colonization, protein expression, membrane fatty acid composition, and metabolic activity. Metabolic activity was also evaluated in ΔfabR mutants generated in additional NTHi strains. RESULTS:Deletion of fabR reduced host cell adherence, increased serum sensitivity, enhanced IgG deposition, and decreased vitronectin binding compared with the wild-type strain. The ΔfabR mutant also exhibited impaired colonization of the murine nasopharynx. Proteomic analyses demonstrated altered expression of metabolic proteins, accompanied by an increased unsaturated-to-saturated fatty acid ratio. Furthermore, ΔfabR mutants from multiple NTHi strains showed increased metabolic activity, indicating a conserved role for FabR in metabolic regulation. CONCLUSIONS:FabR is a novel transcriptional regulator that may contribute to NTHi virulence. By modulating bacterial metabolism and membrane lipid composition, FabR may influence outer membrane architecture, thereby affecting host interaction, immune evasion, and colonization.
Tuberculosis (TB) causes profound systemic illness, and many survivors experience long-term sequelae associated with disability and premature mortality. Current TB severity indicators capture isolated aspects of disease and may not reflect the integrated physiological impact of infection on the host. Frailty, a multidimensional syndrome characterized by reduced physiological reserve and increased vulnerability to stressors, predicts adverse outcomes and guides clinical management in geriatrics. We propose frailty as an integrative framework for understanding the systemic effects of TB across the life course, encompassing disease severity, recovery, and long-term sequelae. We discuss biological mechanisms through which Mycobacterium tuberculosis infection may erode physiological reserve and promote frailty, including inflammation and metabolic and endocrine dysregulation. We further consider how frailty assessment could improve risk stratification and guide individualized supportive care to mitigate post-TB sequelae. Unlike aging-related frailty, TB-associated frailty may provide a unique opportunity to study mechanisms of resilience and recovery following severe infection.
BACKGROUND:Clofazimine is commonly included in multidrug regimens for children with multidrug-resistant and rifampicin-resistant tuberculosis (MDR/RR-TB), but accurate pediatric dosing has been limited by 100-mg soft-gel capsules that cannot be reliably divided. We evaluated the exposure and safety of a novel 50-mg clofazimine tablet using revised once-daily weight-banded dosing informed by a previous study (Clofazimine PK1). METHODS:Children <18 years weighing <30 kg receiving MDR/RR-TB treatment, including clofazimine, were enrolled. Sparse and semi-intensive pharmacokinetic sampling was completed at baseline and at weeks 2 and 12. Model-predicted weekly steady-state area-under-the-curve (wAUCss) was compared with an adult target of 111.79 mg·h/L. Safety monitoring included clinical, laboratory, and electrocardiogram (ECG) monitoring. RESULTS:Twelve children were included (median age 2.8 years; range 0.6-8.2). Median predicted wAUCss was 106 mg·h/L (range 76.9-274), within 25% of target. Two grade 3 adverse events (drug-induced liver injury and skin hyperpigmentation) possibly related to clofazimine, but no other clofazimine-related serious adverse events, were observed, The Fridericia corrected QT (QTcF) interval typically increased with 0.042 ms per1-µg/L increase in clofazimine concentration; five QTcF prolongations (>460-480 ms) occurred in three participants. CONCLUSIONS:The revised once-daily dosing with the 50-mg clofazimine tablet achieved the predefined exposure target. Clinically important adverse events support cautious use with ECG and laboratory monitoring and further evaluation before broad adoption. CLINICAL TRIALS REGISTRATION:South African National Clinical Trials Register (https://sanctr.samrc.ac.za/; DOH-27-0620-6415).
BACKGROUND:Seborrheic dermatitis (SD) is characterized by limited therapeutic options and high recurrence rates, and the efficacy and mechanism of ozone hydrotherapy for SD remain unclear, especially its potential role in regulating metabolic pathways of keratinocytes. METHODS:We performed a single-arm, open-label, self-controlled before-and-after study of ozone hydrotherapy in 24 SD patients, evaluating clinical symptoms and analyzing scalp microbiome. A Malassezia-induced guinea pig model of SD-like lesions and a Malassezia-infected HaCaT cell model were used to explore barrier repair, anti-inflammatory effects and the potential involvement of mitochondrial lactate shuttle. RESULTS:Ozone hydrotherapy significantly alleviated erythema, scaling and pruritus during the 3-week treatment period in SD patients. Treatment was well tolerated with no serious adverse events observed. It decreased the abundance of Malassezia and Staphylococcus, increased skin microbial Shannon diversity, and reshaped the structure of scalp fungal and bacterial communities. In guinea pigs, ozone water upregulated barrier-related genes and suppressed inflammatory cytokines. In HaCaT cells, ozone water restored mitochondrial lactate shuttle function, reversed the abnormal expression and localization of MCT1, MCT4 and LDHB, reduced lactate accumulation and pro-inflammatory factor release. CONCLUSION:Ozone hydrotherapy may improve SD symptoms by regulating scalp microbial homeostasis, mechanistic studies further suggest that it may alleviate inflammation by reversing Malassezia-induced mitochondrial lactate shuttle abnormalities in keratinocytes. Ozone hydrotherapy represents a promising candidate intervention for SD symptom management, pending validation in controlled clinical trials.
Bacille Calmette-Guérin (BCG) provides limited protection against tuberculosis relapse. We investigated whether adjunctive immunotherapy targeting B cells enhances BCG-mediated protection in a murine model of latent tuberculosis. While BCG alone had modest effects, adjunctive immunotherapy with recombinant APRIL significantly reduced relapse. Protection was associated with selective remodeling and activation of marginal-zone B cell compartments, whereas effects on T cell populations were comparatively modest. These findings support further investigation of B cell-targeted immunomodulation to improve durable immune control and reduce tuberculosis relapse.
