Mycoplasma pneumoniae (M. pneumoniae)-associated community-acquired pneumonia (CAP) is common in children. Cytomegalovirus (CMV) is frequently detected in respiratory samples in this patient population. We aimed to explore the clinical implications of positive CMV DNA in bronchoalveolar lavage fluid (BALF) from immunocompetent children with M. pneumoniae-associated CAP. A retrospective cohort study was conducted for M. pneumoniae-associated CAP children under two years old with CMV DNA test in BALF between January 1, 2022 and September 30, 2025. These children were assigned to the BALF CMV DNA positive group or negative group. Then, the inter-group characteristics were compared. Among the 66 children, 28 and 38 children were assigned to the CMV DNA positive and negative groups, respectively. Children in the BALF CMV DNA positive group were more likely to experience duration of fever ≥ 3 days, had a higher incidence of severe M. pneumoniae-associated CAP at admission, and required longer hospital stays. However, these children had a lower incidence of wheezing, when compared to children in the BALF CMV DNA negative group. Furthermore, virus co-infection was common in the BALF CMV DNA negative group, when compared to the BALF CMV DNA positive group (60.5

Background Severe pneumonia is a leading cause of mortality in children under 5 years old, and there is currently a lack of reliable biomarkers for early warning of adverse outcomes in the ICU. This study aimed to explore effective prognostic biomarkers for severe pneumonia and apply a deep learning model to predict in-hospital mortality in children with severe pneumonia, thereby supporting clinical decision-making. Methods This retrospective prognostic study analyzed clinical data from children under 5 years of age with severe pneumonia from the Pediatric Intensive Care (PIC) database. Patients were categorized according to in-hospital mortality status. Dynamic biomarker screening was performed from longitudinal laboratory data, and a CNN-BiLSTM-based prediction model was subsequently constructed using the selected biomarkers. Results Eleven key predictive indicators were identified from the laboratory parameters. The CNN-BiLSTM model achieved an area under the curve (AUC) of 0.956 on an independent test set, with a sensitivity of 85.7% and a specificity of 92.7%. Interpretability analysis revealed that lactate, partial pressure of carbon dioxide (pCO2), and pH were the most influential predictors. Conclusion This study provides an effective tool for dynamic risk stratification in children with severe pneumonia, offering support for timely clinical decision-making in the ICU. Future multi-center studies are still needed to validate the effectiveness of this model.

Background:Gastric cancer (GC) exhibits significant immunological heterogeneity, posing a major challenge for achieving durable responses to immunotherapy. Robust immune biomarkers for predicting treatment efficacy need to be identified. T-cell receptor (TCR) repertoire profiling has emerged as a promising approach for characterizing anti-tumor immune dynamics and therapeutic responsiveness. The aim of this study was to characterize immune heterogeneity in gastric cancer by high-throughput TCR sequencing and identify predictive clonotypes and functional signatures. Methods:High-throughput single-cell T-cell receptor beta (TCRβ) sequencing was performed on 89 longitudinal peripheral blood samples collected from 23 GC patients undergoing immunotherapy. TCR repertoire features, including diversity indices, clonal architecture, V-J gene usage, and complementarity-determining region 3 (CDR3) sequence characteristics, were systematically analyzed. The patients were stratified based on dynamic changes in TCR diversity during treatment. Results:Based on TCR diversity dynamics, the patients were classified into three TCR diversity dynamic patterns: sustained high-diversity, diversity-declining pattern, and fluctuating-diversity pattern. An early decline in clonal richness, as measured by the Chao1 index, was associated with subsequent treatment resistance. The responders showed pronounced oligoclonal T-cell expansion, while the non-responders showed polyclonal dispersion. A conserved V-J gene pairing (TRBV20-1/TRBJ2-7) was observed across patients at the repertoire level. Additionally, a shared public CDR3 sequence (CASSIGLAGFNTGELFF), associated with the TRBV19/TRBJ2-2 combination in the clone-level longitudinal analysis, was detected in more than half of the cohort and was correlated with favorable immune features, including glycine enrichment in CDR3 regions and enhanced clonal expansion. This clone-level specificity should be distinguished from the most prevalent repertoire-wide V-J pairing, TRBV20-1/TRBJ2-7. Conclusions:Distinct TCR repertoire characteristics are closely associated with immunotherapy outcomes in GC. Early changes in TCR diversity and the presence of public clonotype-like features may represent candidate biomarkers of therapeutic efficacy that warrant validation in larger cohorts. These findings provide an exploratory basis for future development of TCR-based response monitoring strategies and for further investigation of personalized immunotherapeutic approaches.

Background:Although randomized controlled trials (RCTs) have confirmed the mucolytic efficacy of ambroxol hydrochloride solution for inhalation (AHSI) in selected cohorts, their stringent exclusion criteria often omit children with comorbidities and complex presentations encountered in routine practice. Consequently, real-world evidence is needed to evaluate the effectiveness and safety of AHSI in a broader, clinically representative pediatric population with acute lower respiratory tract infections (ALRTIs). This study therefore aimed to assess the real-world effectiveness, safety, and nebulizer compatibility of a 7-day AHSI regimen added to standard care in a large, multicenter cohort of hospitalized pediatric patients with ALRTI. Methods:This real-world, multicenter, open-label, single-arm study enrolled hospitalized patients aged ≥6 months with ALRTI (acute bronchitis, bronchiolitis, or pneumonia) and symptom duration <7 days across 62 centers in China (April 2021-April 2022). Key inclusion criteria included a cough score ≥2 (0-4 scale), tenacious sputum, and difficulty expectorating. Major exclusions comprised severe pneumonia, bronchial asthma, interstitial lung disease, significant hepatic or renal dysfunction [alanine aminotransferase (ALT) >1.5× upper limit of normal (ULN), total bilirubin (TBil) or serum creatinine (Scr) > ULN], other severe comorbidities, known hypersensitivity to ambroxol, or recent trial participation. Participants received weight-based doses of nebulized AHSI twice daily for 7 days as add-on to standard care. Follow-up visits occurred at day 4 and day 7 (end of treatment). Primary endpoints were the cough improvement rate (defined by a reduction in cough score) and the overall clinical response rate (investigator-assessed improvement). Secondary endpoints included changes from baseline in cough, throat rales, and pulmonary auscultation scores. Safety assessments comprised monitoring of adverse events (AEs) (coded with MedDRA), vital signs, and laboratory tests (hematology, biochemistry, urinalysis) at baseline and day 7. Results:A total of 2,599 children were enrolled [full analysis set (FAS)]. At baseline, mean age was 3.60±2.50 years, 57.6% were male, and symptom scores were: cough 2.10±0.30, throat sputum 1.65±0.59, lung auscultation 1.44±0.70. In the FAS, the cough improvement rate was 96.73% [95% confidence interval (CI): 96.05-97.41] and the clinical response rate was 94.73% (95% CI: 93.87-95.59). All symptom scores decreased significantly from baseline to day 7 (P<0.001). Drug-related AEs (DRAEs) occurred in 0.39% of patients, predominantly mild-to-moderate rash, transient liver enzyme elevations, and gastrointestinal events; no serious DRAEs were reported. Outcomes were consistent across pneumonia and bronchitis subgroups and across various nebulizer types. Conclusions:This large real-world study demonstrated that a 7-day course of AHSI, added to standard care, was associated with clinically meaningful improvements in respiratory symptoms and a favorable safety profile in children with ALRTI. The consistent effects across disease subtypes and nebulizer devices underscore the practical utility of AHSI in diverse pediatric settings. While the single-arm design limits causal inference, these findings provide robust real-world evidence supporting AHSI as an effective expectorant option. Prospective confirmation through RCTs will further define its role in first-line therapy.

Introduction:PD-1/PD-L1 inhibitors lack evidence-based support in patients aged ≥75 years due to their frequent exclusion from clinical trials. This study aimed to evaluate the safety and efficacy of PRaG therapy-combining PD-1/PD-L1 inhibitors with radiotherapy-specifically in this elderly demographic. Materials and methods:Data were collected from patients aged ≥75 years who received PRaG therapy at our center between 1 January 2019, and 31 December 2024. Eligible patients were required to have at least one post-baseline efficacy evaluation. Tumor response was evaluated according to RECIST v1.1, and adverse events were graded using CTCAE v5.0. Results:A total of 36 elderly patients aged ≥75 years were included, with a median age of 77 years (range: 75-93). The objective response rate (ORR) was 23.5%, and the disease control rate (DCR) was 70.6%. After a median follow-up of 46.3 months, the median progression-free survival (mPFS) was 7.0 months (95% CI: 2.4-11.6 months) and the median overall survival (mOS) was 11.1 months (95% CI: 5.3-16.9 months). The Geriatric Nutritional Risk Index (GNRI) was associated with the efficacy of PRaG therapy, as well as PFS and OS. Any-grade treatment-related adverse events (TRAEs) occurred in 34 patients (94.4%), with 3 patients (8.3%) experiencing ≥Grade 3 TRAEs. No Grade 5 TRAEs were observed. Conclusion:The PRaG regimen appears feasible and tolerable in selected elderly patients with advanced cancer. Given the retrospective nature of this small cohort, an ongoing prospective trial (NCT06112041) will further validate these findings. Combining PRaG with robust nutritional support represents a rational hypothesis for future investigation.

IntroductionCarbapenem-resistant Enterobacteriaceae (CRE) is the most common clinical pathogens. Investigating the antimicrobial resistance, hypervirulence and clinical characteristics of CRE isolated from children is helpful to guide for anti-infection treatments.MethodsNonduplicated CRE clinical strains were isolated and mass spectrometry was applied to identify clinical isolated strains. VITEK 2 Compact system and Kirby-Bauer method were used to analyze the antimicrobial susceptibility. Besides, the drug resistance and hypervirulence associated genes were detected by polymerase chain reaction (PCR) and sequencing.ResultsA total of 281 non-duplicated CRE strains were identified in this study. Klebsiella pneumoniae (55.87%), Escherichia coli (36.65%) and Klebsiella aerogenes (3.20%) were the top 3 CRE strains. These strains showed high resistance to most of antimicrobial agents and carried carbapenemase genes, including blaOXA-232 (38.08%), blaKPC-2 (20.28%), blaOXA-1 (17.08%), blaNDM-5 (10.32%) and blaNDM-1 (8.90%). In addition, blaTEM-1 (98.93%), blaCTX-M-14 (88.61%) and blaSHV-11 (87.54%) were the prevalent extended-spectrum β-lactamase (ESBL) genes in these strains, while the detection rate of AmpC cephalosporinase genes were not high. Besides, 45 (28.66%) carbapenem-resistant Klebsiella pneumoniae (CRKP) strains carried hypervirulence associated genes iucA (24.84%), prmpA (17.83%), peg-344 (17.20%), and prmpA2 (9.55%). Among them, 22 (14.01%) CRKP strains were also identified as carbapenem-resistant and hypervirulent Klebsiella pneumoniae (CR-HVKP). What’s worse, the patients infected with CR-HVKP had a worse prognosis overall.ConclusionThis study revealed the drug resistance, hypervirulence and epidemiology of CRE strains in pediatric patients in Suzhou of eastern China. Unfortunately, CR-HVKP strains with more several infection were also identified, which should be of great concern to clinicians.

2516 Background: Treatment-related lymphopenia and inadequate anti-tumor immune activation remains major barriers to improving outcomes of combination immunoradiotherapy, especially for advanced refractory solid tumors. PRaG 5.0 innovatively integrates personalized thymosin alpha-1 (Tα-1) into the PRaG regimen (PD-1 inhibitor + radiotherapy + GM-CSF) to preserve lymphocytes and enhance anti-tumor immunity. We report updated efficacy and safety data of PRaG 5.0 in advanced refractory solid tumors. Methods: This is a prospective, single-armed, phase II study enrolled 43 heavily pretreated patients. Eligible patients were stratified by baseline T-lymphocyte counts to receive personalized Tα-1 dosing: 7-day loading dose for low baseline T-lymphocyte counts, and maintenance Ta-1 (1.6 mg, thrice weekly) for those with normal counts. Tα-1 was combined with the PRaG regimen for at least 2 cycles. After PRaG cycles, patients continued PD-1 inhibitor plus Tα-1 until disease progression or intolerable toxicity. The primary endpoint was objective response rate (ORR) per RECIST v1.1. Secondary endpoints included median progression-free survival (mPFS), disease control rate (DCR), safety, and immune cell dynamics (assessed by flow cytometry, single-cell sequencing, and TCR sequencing). Results: Among the 43 screened subjects, 39 received treatment, of whom 30 required loading dose thymosin α1 (Tα1) therapy, 36 were treated with PRaG regimen and 17 entered the maintenance phase with PD-1 inhibitor combined with Tα1. The objective response rate (ORR) of the 39 patients was 30.8% (95%CI 17.0%, 47.6%), including 4 cases of complete response (CR) and 8 cases of partial response (PR); the median progression-free survival (PFS) was 4.2 months (95%CI 2.3, 6.9). No Grade 3 or above TRAE was reported. Immune analysis revealed significant increases in CD8+ T cells, NK cells, and CD4+TEM cells post-Tα-1 loading, with a notable decrease in Tregs (p = 0.001). Single-cell sequencing demonstrated higher clonality in GZMK-CD8+T in responders, while TRDV2-CD8+T cells expanded in non-responders. Conclusions: Integrating of Tα-1 into the PRaG regimen is a promising therapeutic strategy, offering enhanced efficacy and a favorable safety profile. Detailed immune profiling identified distinct T-cell dynamics associated with treatment response, highlighting potential biomarkers for clinical application. Further validation in larger cohorts is warranted. Clinical trial information: NCT05790447 .

Type I interferons (IFN-I) are essential for antiviral immunity, and precise regulation of IFN-I production is crucial to balance viral clearance and immunopathology. Here, we demonstrate that the interferon-stimulated gene TOR3A negatively regulates type I IFN signalling during respiratory syncytial virus (RSV) infection. TOR3A expression was upregulated in macrophages and RSV-infected patients, and its deficiency enhanced antiviral responses, leading to reduced viral load. Mechanistically, RSV infection induced TOR3A expression through the IFN-STAT1 pathway, which in turn suppressed IFN-I production. Furthermore, TOR3A recruited the E3 ubiquitin ligase STUB1 to mediate K48-linked ubiquitination and proteasomal degradation of RIG-I at lysine 146, thereby promoting RSV immune evasion. Our study identifies TOR3A as a novel suppressor of antiviral immunity and uncovers a mechanism by which RSV exploits host ISGs to dampen IFN-I responses, providing new insights into viral pathogenesis and potential therapeutic strategies.

Introduction This study aims to investigate the effectiveness and safety of combining the antibody-drug conjugate (ADC) disitamab vedotin (RC48) with the established PRaG regimen (PD-1 inhibitor, Radiotherapy, and GM-CSF) for treating HER2-expressing (IHC 3+, 2+, or 1+) advanced solid tumors. This novel PRaG3.0 regimen is hypothesized to leverage the tumor radiosensitizing and immunogenic cell death properties of ADCs to amplify the synergistic antitumor effects of radioimmunotherapy, offering a potential paradigm for pan-cancer therapy. Methods This study is a prospective, single-arm, open-label, multi-center clinical trial. Patients enrolled have confirmed HER2-expressing solid tumors (IHC 3+, 2+, or 1+) that have progressed after standard treatment or were intolerant to it. Patients received RC48 (2 mg/kg) via intravenous injection on day 1, followed by subcutaneous GM-CSF at 200 µg from days 3 to 7 and interleukin-2 (IL-2) at 2 million IU from days 8 to 12. Radiotherapy was initiated on day 3, targeting one lesion with hypofractionated radiotherapy (2-3 fractions of 5 or 8 Gy). PD-1/PD-L1 antibodies were administered within one week after completing radiotherapy. Treatment was repeated every three weeks, and if there were no target lesions, radiotherapy could be discontinued, with RC48 given for at least six cycles. After achieving a complete tumor response, maintenance therapy with PD-1/PD-L1 antibodies continued until disease progression or intolerable toxicity occurred. The primary endpoint was the objective response rate (ORR). Results The study is currently in the recruitment phase (Registration No: NCT05115500). The primary endpoint is the objective response rate (ORR). Secondary endpoints include progression-free survival (PFS), overall survival (OS), disease control rate (DCR), safety, and QoL. Planned enrollment is 62 patients. Conclusion The PRaG3.0 protocol represents an innovative approach combining ADC therapy with radioimmunotherapy to address HER2-expressing cancers, including those with HER2-low expression. If successful, this regimen could establish a highly effective combination strategy.

Introduction: “Immune age” quantifies the immune system’s aging status, offering a new perspective for predicting disease risk and guiding health management. Although advanced technologies such as genomics have been used to develop immune age models, their high cost and complexity hinder their widespread application in healthy populations. Objective: To establish reference intervals for circulating immune cells in healthy young and middle-aged adults, and to explore and construct an immune age prediction model using machine learning. Methods: A study involving 124 healthy individuals measured 36 circulating immune cell parameters to establish population-based reference intervals. Six machine learning regression models were evaluated to identify the optimal model for predicting immune age. An open-source, visually enhanced web-based user interface was subsequently developed to improve model interpretability and provide a user-friendly experience. Results: This study established preliminary reference intervals for 36 circulating immune cell parameters and identified significant age-related correlations in several of them. With increasing age, both the percentage and the absolute count of naive T cells declined significantly, whereas the percentage and absolute count of terminally differentiated T cells increased significantly. These changes are consistent with the established hallmarks of immunosenescence. Among six prediction models, the gradient boosting regressor demonstrated the best performance, achieving a mean absolute error of 6.295 years and a coefficient of determination of 0.491 on an independent test set. This indicates the model has preliminary predictive potential. Furthermore, this study exploratorily developed a web-based visualized tool for predicting immune age. Conclusion: This study has preliminarily established reference intervals for circulating immune cells and exploratorily built an immune age prediction model for healthy young and middle-aged adults.

Immune Checkpoint Inhibitors (ICIs) have become a mainstay in the treatment of various solid tumors. At present, commonly used predictive biomarkers include tumor mutation burden, programed death-ligand 1 expression levels, and microsatellite instability. However, these biomarkers face inherent limitations, such as the challenges associated with tumor tissue sampling and the inability to provide dynamic monitoring. In recent years, significant efforts have been undertaken for the precise characterization of circulating T-lymphocyte subsets, with their classification offering the potential to reflect the functional state of T cells and predict responses to ICI therapy. Its advantages in terms of sampling convenience and minimally invasive nature further highlight its feasibility as a dynamic monitoring tool. This review expounds on current research progress on the use of "circulating" T-lymphocyte subsets as predictors of ICI efficacy and discusses their reliability and potential as predictive tools.

MicroRNAs (miRNAs) have emerged as critical epigenetic regulators in the pathogenesis of childhood bronchial asthma. This study employed high-throughput sequencing to explore miRNA expression profiles in an asthma cohort, with a focus on elucidating the functional mechanisms of key miRNAs. Notably, among the miRNAs validated by RT-qPCR, miR-31-5p exhibited the largest area under the curve (AUC) value and demonstrated significant anti-inflammatory effects in an OVA-induced allergic inflammation mouse model. Bioinformatics analysis and dual-luciferase reporter assays confirmed that TBXA2R is a direct target of miR-31-5p. Mechanistically, stimulation with house dust mite (HDM) and IL-4 downregulated miR-31-5p expression in A549 cells, accompanied by elevated levels of TBXA2R and eotaxins (CCL11, CCL24, CCL26). Conversely, overexpression of miR-31-5p suppressed TBXA2R-mediated eotaxin production. These findings highlight the significant role of miR-31-5p in peripheral blood mononuclear cells (PBMCs) of asthmatic children, suggesting its potential involvement in upregulating eotaxin expression in A549 cells through negative regulation of TBXA2R.

Mycoplasma pneumoniae pneumonia (MPP) is a common pediatric respiratory infection linked to excessive immune-inflammatory responses. This study investigated the role of the Notch ligand DLL4 in the immunopathogenesis of MPP by assessing its expression in peripheral blood mononuclear cells of affected children. A total of 128 children with MPP and 35 controls were recruited. PBMCs were analyzed for the expression of Notch ligands (Jagged1, Jagged2, DLL1, DLL4) using real-time PCR. Lymphocyte subsets were assessed via flow cytometry, and cytokine levels were measured using ELISA. Clinical data were compared between severe and mild MPP cases, and correlations between DLL4 expression and immune indicators were evaluated. DLL4 expression was significantly higher in the MPP and severe MPP groups than in controls (P < 0.01). MPP patients showed lower CD3+ and CD3+CD4+ lymphocyte levels, and higher CD3+CD8+ and CD3-CD19+ levels compared with controls (P < 0.001). Plasma levels of IFN-γ, IL-17, and IL-36α were elevated in MPP patients (P < 0.001), whereas IL-4 and IL-10 levels were reduced (P < 0.01). Severe cases had higher IFN-γ, IL-17, and IL-36α levels than mild cases (P < 0.05). DLL4 expression positively correlated with plasma IFN-γ and IL-17 levels in MPP patients (P < 0.05). Elevated DLL4 expression in MPP patients, particularly in severe cases, suggests its role in enhancing Th1/Th17-mediated immune responses while suppressing Th2 pathways. Such findings implicate the Notch signaling pathway, via DLL4, in the immunopathogenesis of MPP and highlight its potential as a therapeutic target for modulating immune responses in severe MPP.

Objective Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy with a dismal prognosis, largely due to late diagnosis at an unresectable stage. Neoadjuvant therapy aims to downstage tumors to achieve surgical resectability, but efficacy is limited. The immunosuppressive tumor microenvironment (TME) of PDAC renders it resistant to conventional immunotherapy. To evaluate the safety and efficacy of a novel neoadjuvant regimen (the NeoPRAG protocol) for patients with locally PDAC. The primary goal is to determine the regimen's safety in Phase I and the 1-year overall survival rate in Phase II, with the ultimate aim of improving surgical resectability and survival outcomes. Methods The NeoPRAG study is a prospective single-center, open-label, Phase I/II clinical trial designed to evaluate a neoadjuvant regimen in patients with locally advanced (borderline resectable or unresectable) PDAC. The treatment strategy combines the “PRaG” concept (hypofractionated Radiotherapy and Granulocyte-Macrophage Colony-Stimulating Factor [GM-CSF]) with dual checkpoint blockade and chemotherapy. The Phase I portion will determine the safety, tolerability, and recommended Phase II dose (RP2D) of the radiotherapy component using a 3 + 3 dose-escalation design. The Phase II portion will assess the preliminary efficacy of the regimen, with the primary endpoint being the 1-year overall survival (OS) rate. Secondary endpoints include objective response rate (ORR), R0 resection rate, progression-free survival (PFS), and a comprehensive panel of translational biomarkers. The study is planned to commence in December 2023. Patient enrollment and follow-up are expected to be completed by November 2026, with final data analysis scheduled for December 2026. Conclusion The NeoPRAG protocol outlines an innovative, multi-modal strategy that confronts the immunological barriers of pancreatic cancer. It is hypothesized that this combination will synergistically remodel the TME, induce a potent anti-tumor immune response, and ultimately improve the survival landscape for this devastating disease by increasing conversion to resectability.

The Casitas B-lineage lymphoma (Cbl) family proteins are E3 ubiquitin ligases implicated in the regulation of various immune cells. However, their function in macrophages remains unclear. Here, we identify both Cbl-b and c-Cbl (Cbls) as inhibitors of macrophage proliferation and promoters of macrophage apoptosis. Mechanically, we identify that Cbls functions upstream of AKT and Erk to mediate the ubiquitination and degradation of M-CSFR. M-CSF stimulation promotes dimerization and autophosphorylation activation of M-CSFR on the macrophage membrane, thereby activating downstream PI3K-AKT and Erk signaling pathways, leading to different biological effects such as macrophage proliferation and survival. At the same time, the Y559 site of the M-CSFR undergoes autophosphorylation, which can promote receptor recruitment and phosphorylation of Cbls. This promotes Cbls to induce K63-linked polyubiquitination at the K791 site of M-CSFR, leading to internalization and degradation of M-CSFR through lysosomal pathways, preventing excessive activation of the signaling pathway. Furthermore, Cbls deficiency results in increased proliferation and decreased apoptosis of macrophages in vitro and in vivo and dKO mice spontaneously develop a macrophage-dominated pulmonary enlargement. Together, these data demonstrate that Cbls play critical roles in the regulation of macrophage homeostasis by inhibiting M-CSFR-mediated AKT and Erk activation.

Background: Current evidence from evidence-based medicine is limited regarding the efficacy and safety of immunotherapy in elderly patients aged 75 years and older with malignant solid tumors. PRaG therapy, which combines PD-1/PD-L1 inhibitors, radiotherapy, and granulocyte-macrophage colony-stimulating factor (GM-CSF), aims to treat patients with advanced, refractory tumors. Preliminary findings indicate that patients aged 75 years and older can benefit from this treatment and can tolerate it well. Objective: This study aims to evaluate the efficacy and safety of the PRaG regimen in elderly patients with advanced malignant solid tumors to provide evidence-based support for immunotherapy in this population. Methods and Analysis: This study involves a multicenter, prospective, single-arm phase II clinical trial designed to enroll 29 patients aged 75 years and older with either newly diagnosed or recurrent metastatic advanced solid tumors that are histologically confirmed. All of the eligible patients will have had to receive at least two cycles of PRaG therapy until disease progression or intolerable adverse effects occurred. The study protocol was approved on September 12, 2023, by the Ethics Committee of the Second Affiliated Hospital of Soochow University (JD-LK-2023-082-I01) and by the ethics committees of all of the participating centers (Trial Registration Number: NCT06112041).

Background:Radiotherapy combined with immunotherapy shows increasing efficacy in treating metastatic malignancies; however, positive outcomes may be negatively impacted by lymphocytopenia. Previous studies suggest thymosin α1 (Tα1) may mitigate radiation-induced lymphocytopenia. This study retrospectively evaluated the effects of a Tα1 loading dose on peripheral blood lymphocyte counts and assessed the safety and efficacy of radiotherapy combined with of PD-1 inhibitors in patients with advanced or refractory cancers. Methods:A total of 48 patients received a 7-day loading dose of Tα1 (1.6 or 3.2 mg, once daily) followed by hypofractionated radiotherapy and PD-1 inhibitors. Peripheral blood T cells, B cells, and natural killer cells were quantified by flow cytometry before and after Tα1 treatment. The primary endpoint was the change from baseline in lymphocyte subset counts. Secondary endpoints included adverse events, objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS). Results:The median follow-up was 13.7 months. Tα1 treatment for 7 days significantly increased the median counts of peripheral blood total T cells (422.5/μL to 614.0 /μL, P<0.001), CD4+ T cells (244.5/μL to 284.5/μL, P<0.001), and CD8+ T cells (159.0/μL to 222.5/μL, P<0.001). Among the 36 patients with evaluable data, the ORR was 19.4% and DCR was 69.4%. The median PFS and OS were 5.1 months and 9.6 months, respectively. Two patients (4.2%) experienced grade ≥3 treatment-related adverse events. Conclusion:A 7-day loading dose of Tα1 elevated lymphocyte counts in advanced cancer patients and was accompanied by satisfactory safety and efficacy profiles. It should be noted that the median follow-up of 13.7 months may be insufficient to fully assess long-term survival outcomes and the potential for late-onset toxicities. As this was an exploratory analysis across multiple tumor types, these findings warrant validation in larger, randomized studies with more homogenous cohorts.

Human parainfluenza virus type 3 (HPIV3) is a major cause of severe pediatric respiratory infections in infants, but its association with meteorological factors is not fully understood. This study compared clinical features of HPIV3 and respiratory syncytial virus (RSV) infections and used distributed lag nonlinear models (DLNMs) to identify environmental determinants of HPIV3 transmission. HPIV3 was most prevalent in infants, causing significantly less wheeze, tachypnea (both p < 0.001) and dyspnea (p = 0.044) than RSV. Seasonal prevalence showed a summer peak (46.4%) and a winter minimum (5.9%). High temperatures immediately increased the relative risk (RR) of HPIV3 (RR = 4.258, 95% CI 1.387-13.074), while low temperatures increased the RR after a four-month lag (RR = 3.958, 95% CI 1.858-8.430). PM10 exposure at 140 μg/m3 had the greatest immediate impact (lag 0, RR = 3.335, 95% CI 1.236-8.999). Delayed effects were observed for gaseous pollutants (SO2 and NO2) after five months (SO2: RR = 2.047, 95% CI 1.247-3.362; NO2: RR = 2.596, 95% CI 1.577-4.273). These findings indicate that HPIV3 shows distinct clinical features and differential environmental sensitivity, with acute responses to heat and particulates and delayed responses to cold and gaseous pollutants. These results support season-focused prevention strategies for vulnerable infants during high-risk periods.

Mycoplasma pneumoniae (MP) infection in children has recently re-emerged with a higher rate of hospitalization in the post-COVID-19 period. However, understanding of how the adaptive immunity plays a role in the bacterial pneumonia is often restrained by recurrent infection and complex co-infection with M. pneumoniae. Herein, we took advantage of the single-cell RNA sequencing (scRNA-seq) and high-dimensional flow cytometry to characterize the impairment of peripheral T and B lymphocytes in pediatric patients with mild Mycoplasma pneumonia (MMPP). These patients were M. pneumoniae mono-infected at hospitalization, and showed an expansion of both effector and memory CD8+ T cells, with exhausted KLRG1hi CD8+ T compartments prevailed. Moreover, they exhibited a hyperactivation of IgM+ plasma cells and unswitched memory B cells, which could partly explain the IgM seroconversion routinely diagnosed in MMPP. Therefore, the hypo-functional CD8+ T cells and polarization of IgM secreting cells might help explain the ill-controlled bacterial replication in MMPP. Furthermore, compared to the healthy controls, IL-17A producing Th17 cells were reduced in MMPP, but cytotoxic granzymes increased significantly. Reduced IL-17A would suggest elevated M. pneumoniae colonization and reduced bacterial clearance in the respiratory tract, whereas cytotoxic property of this pathogenic Th17 cells might play a role in the pulmonary hyper inflammation. Therefore, this work managed to characterize the landscape of dysfunctional T and B lymphocytes that associates with the immune evasion and immunopathogenesis of MMPP.

E3 ubiquitin ligases are key molecules in regulating the innate immune responses against virus. They catalyze the activation or degradation of various signaling proteins involved in the innate immune responses. Herein, we found the regulatory role of RNF149 in the host's innate immune responses against viral infection. Virus infection induced the expression of RNF149. Overexpression of RNF149 was associated with reduced production of IFN-β and enhanced viral replication. Mechanically, RNF149 interacted with IRF3 and downregulated its protein level. As an E3 ubiquitin ligase, RNF149 promoted the K27-linked ubiquitination of IRF3 at K409 and K33-linked ubiquitination at K366 and K409, which promoted IRF3 degradation through the proteasome pathway. Our results revealed the regulatory mechanism of RNF149 during viral infection and provided new insights into host cells responding to viral infection. Downregulating the expression of RNF149 may help enhance the antiviral ability of host cells and inhibit viral replication, thus providing a new strategy for the treatment of viral infection.