Daily Respiratory Research Analysis
Analyzed 109 papers and selected 3 impactful papers.
Summary
Three high-impact respiratory studies stood out: a translational Nature Communications paper shows amphotericin B paradoxically enhances influenza and SARS-CoV-2 entry via endosomal ceramide remodeling and is linked to higher subsequent viral infections clinically; a JCI Insight mechanistic study identifies neonatal virus-primed Th2 tissue-resident memory T cells as drivers of asthma-like disease; and a BMC Medicine longitudinal cohort defines age-specific RSV Prefusion F antibody kinetics and correlates of protection.
Research Themes
- Antifungal–viral interactions and iatrogenic risk in respiratory infections
- Early-life viral imprinting and tissue-resident memory T cells in asthma pathogenesis
- Age-specific correlates of protection and antibody durability for RSV
Selected Articles
1. Amphotericin B promotes respiratory viral entry by enhancing late endosomal maturation and fusion via glucocerebrosidase-mediated ceramide remodeling.
Amphotericin B directly activates glucocerebrosidase, drives ceramide accumulation, and accelerates late endosomal maturation/fusion, thereby facilitating influenza A and SARS-CoV-2 entry. In vivo, AmB worsened viral disease, and in a propensity score–matched IPA cohort AmB use was associated with higher subsequent viral infections (21.55% vs 7.76%; adjusted OR 3.45).
Impact: This study reveals a previously unrecognized iatrogenic risk of a cornerstone antifungal by uncovering a concrete mechanism that enhances respiratory viral entry and validating the signal in animal models and a human cohort.
Clinical Implications: Clinicians should weigh alternative antifungals (e.g., azoles, echinocandins) when high risk of respiratory viral exposure exists, reinforce viral surveillance in patients on systemic amphotericin B, and consider infection prevention measures during influenza/COVID-19 surges.
Key Findings
- Amphotericin B binds and activates glucocerebrosidase, increasing ceramide and RAB7 in late endosomes to promote viral entry.
- Amphotericin B enhanced influenza A and SARS-CoV-2 infection severity in mouse and hamster models.
- Systemic amphotericin B was associated with higher subsequent viral infection incidence versus other antifungals in a PS-matched IPA cohort (21.55% vs 7.76%, adjusted OR 3.45).
Methodological Strengths
- Convergent mechanistic validation across in vitro assays, two animal models, and a propensity score–matched human cohort.
- Clear molecular pathway elucidation (glucocerebrosidase–ceramide–RAB7 axis) linking drug action to viral entry.
Limitations
- Observational clinical component may have residual confounding and is limited to IPA populations.
- Translational gap remains regarding dose, timing, and patient heterogeneity beyond study contexts.
Future Directions: Assess risk-benefit of amphotericin B versus alternatives in randomized or pragmatic trials during influenza/COVID-19 seasons; test pharmacologic blockade of the GCase–ceramide pathway to mitigate viral entry.
Respiratory viral infections, such as influenza and COVID-19, pose significant global health challenges. For patients with invasive pulmonary aspergillosis, a subsequent viral infection can lead to markedly worse clinical outcomes. Although amphotericin B (AmB) remains a cornerstone antifungal therapy, our investigation demonstrates that it paradoxically enhances the entry of influenza A virus and SARS-CoV-2. Mechanistically, AmB directly binds to and activates glucocerebrosidase, leading to ceramide accumulation and RAB7 upregulation in the late endosomes, thereby enhancing late endosomal maturation and fusion with viruses. In animal models, AmB treatment enhances viral infection in both influenza A virus-infected mice and SARS-CoV-2-challenged hamsters, resulting in accelerated weight loss, higher viral loads, and aggravated tissue damage. Consistently, in our propensity score-matched cohort of patients with culture-confirmed invasive pulmonary aspergillosis (2016-2025, n = 1,072), systemic use of AmB is associated with a significantly higher incidence of subsequent viral infection compared to other antifungals (21.55% vs. 7.76%, P = 0.003), which is further supported by multivariable analysis confirming AmB as an independent risk factor (adjusted OR = 3.45, 95% CI 2.20-5.41, P = 7.174 × 10
2. Early life viral infection generates pathologic tissue resident memory cells that contribute to asthma-like disease.
Neonatal HMPV infection imprints Th2-skewed, clonally expanded lung TRM that are absent after adult infection and drive asthma-like mucus hypersecretion, eosinophilia, and airway hyperresponsiveness upon re-challenge. Blocking lymphocyte trafficking (FTY720), depleting lung CD4+ T cells, or inhibiting JAK2 mitigated pathology.
Impact: Identifies a causal, targetable cellular mechanism linking early-life viral infection to Th2-driven asthma, advancing pathogenesis and potential preventive/therapeutic strategies.
Clinical Implications: Supports preventing severe early-life viral infections and suggests that targeting TRM/Th2 pathways or JAK2 signaling could mitigate established virus-primed airway disease.
Key Findings
- Neonatal, but not adult, HMPV infection generated Th2-biased, clonally expanded lung TRM cells.
- Upon re-challenge 6 weeks later, neonatal-primed mice developed mucus hypersecretion, eosinophilia, and airway hyperresponsiveness.
- FTY720 lymphocyte trafficking blockade, local lung CD4+ T cell depletion, and JAK2 inhibition reduced pathological responses.
Methodological Strengths
- Direct neonatal versus adult infection comparison with re-challenge at a fixed interval (6 weeks).
- Multiple orthogonal interventions (FTY720, CD4+ depletion, JAK2 inhibition) to probe causality.
Limitations
- Mouse model findings require validation in human tissues and cohorts.
- Specificity to HMPV and generalizability to other early-life viral pathogens remain to be defined.
Future Directions: Define TRM phenotypes in pediatric airways post-viral infection, explore JAK2/TRM-targeted interventions, and assess interactions with current biologics for eosinophilic asthma.
Viral lower respiratory tract infections are common early in life and are associated with long-term development of asthma, a chronic condition defined by reversible airflow obstruction secondary to inflammation. Understanding the immunologic mechanism connecting these two pathologies observed early in life becomes imperative to guide therapeutic measures. To investigate this connection, neonatal (day of life 4-6) or adult mice were infected with human metapneumovirus (HMPV) followed by a secondary HMPV infection 6 weeks later. Mice initially infected as neonates demonstrate increased mucus production, eosinophil recruitment, airway hyperresponsiveness, and Th2 T-cell differentiation following re-challenge compared to adult mice rechallenged with HMPV. Neonatal HMPV infection led to formation of Th2 clonally expanded tissue resident memory (TRM) T cells that were absent after adult HMPV. FTY720-mediated disruption of lymphocyte circulation demonstrated TRMs contribute to pathology. Local depletion of lung CD4+ T cells and JAK2-inhibition mitigated pathology. These findings suggest TRMs uniquely generated after early life viral infection can contribute to Th2-driven asthma pathology.
3. Kinetics of antibodies and risk of respiratory syncytial virus infection: a longitudinal cohort in Taizhou City, eastern China.
In a 508-participant longitudinal cohort, two RSV waves produced seasonal infection rates of 4–7%. Post-infection Prefusion F antibody boosts were strongest in ≤5-year-olds and waned rapidly (fourfold rise sustained ~128 days on average). Prefusion F titres predicted protection well in young children but poorly in older adults.
Impact: Provides age-stratified correlates of protection and durability for RSV, directly informing vaccine and monoclonal antibody strategies and booster timing in different age groups.
Clinical Implications: Young children may benefit from targeted timing of prophylaxis/boosters aligned with short-lived boosts, whereas older adults may require alternative or complementary correlates and strategies beyond Prefusion F titres.
Key Findings
- Two RSV waves with community infection rates of 4–7% were observed between 2023–2024.
- Post-infection Prefusion F antibody fold-rise peaked at 29.4× in ≤5-year-olds and 5.4× in ≥75-year-olds, with fourfold rises sustained ~128 days on average.
- Higher Prefusion F titres correlated with lower infection risk; predictive performance was strong in young children but weak in older adults.
Methodological Strengths
- Prospective longitudinal sampling with repeated Prefusion F titres across age strata.
- Bayesian reversible-jump MCMC to reconstruct infection histories and estimate correlates of protection.
Limitations
- Neutralization assays were performed in a subset, and Prefusion F correlates showed limited discrimination in older adults.
- Community-based cohort from a single region may limit generalizability; non-randomized design.
Future Directions: Integrate mucosal immunity and cellular responses to refine correlates in older adults; evaluate optimal booster/prophylaxis schedules informed by waning kinetics.
BACKGROUND: Respiratory syncytial virus (RSV) causes recurrent infections throughout life. Yet, the form and durability of antibody-mediated protection induced by infection remained poorly understood. METHODS: We conducted a longitudinal cohort study in Taizhou City, China. Participant age distribution approximately reflected the age structure of population in Taizhou. Blood samples were collected at baseline (March 12, 2023) and four follow-up visits (May 7-26, 2023, August 13-23, 2023, November 12, 2023, and June 2-3, 2024). Serum-specific RSV pre-fusion F (PreF) protein antibody titres were measured for all samples, and neutralising antibodies against RSV strain A2 and RSV strain B were assessed in a subset. Using a Bayesian inference framework and reversible-jump Markov Chain Monte Carlo, we recovered individual infection histories, estimated population-level RSV incidence, and characterised antibody dynamics from longitudinal PreF titres. We also estimated the correlates of protection (COP) by quantifying the relationship between PreF antibody titres and infection risk. RESULTS: A total of 508 individuals were included. Over the study period, two RSV epidemic waves were observed: the first wave between May and November 2023 and the second from February to May 2024. We estimated seasonal RSV infection rates of 4-7% in the community-based population. Post-infection immunity responses were most robust in young children ≤ 5 years and weakest in adults ≥ 75 years, with peak fold rises in antibody titres of 29.4 and 5.4, respectively. The post-infection antibody titres declined substantially, with fourfold rises sustained for an average of 128 days (95% credible interval of 21-281). The probability of protection given exposure increased with higher PreF titres across all age groups. However, the predictive performance of PreF titres as a COP varied markedly by age: titres strongly predicted protection in young children but showed weaker discrimination in older children and adults, and minimal predictive value in the oldest adults. CONCLUSIONS: These results revealed age-related differences in the durability and protective value of natural infection-elicited RSV PreF antibody responses, emphasising the importance of age-specific prevention strategies.