Peptide-drug conjugates (PDCs) have emerged as a promising modality in precision oncology, enabling targeted delivery of cytotoxic payloads while minimizing off-target toxicity. The integration of covalent warheads, such as those based on sulfur(VI) fluoride exchange (SuFEx) chemistry, enhances drug-target residence time and tumor accumulation. However, existing screening methods for covalent peptide (CP) libraries require post-translational warhead conjugation, limiting throughput. Here, we present an integrated mRNA display platform that incorporates covalent warheads during ribosomal synthesis, enabling efficient screening of ultra-diverse covalent macrocyclic peptide libraries (>10¹³ variants). This approach, using site-specific incorporation of N-chloroacetyl-d-phenylalanine and fluorosulfate-l-tyrosine, accelerated the discovery of irreversibly binding (K _i = 3.58 μmol/L) Nectin-4-targeting peptide CP-N1-N₃ via proximity-triggered SuFEx. The peptide was further conjugated to cytotoxic payloads, yielding the covalent PDC CP-N1-MMAE with potent cytotoxicity (IC₅₀ ≈ 43 nmol/L) against MDA-MB-468 cells. This platform establishes a new paradigm for precision covalent drug discovery.

Objective To evaluate the molluscicidal effect of spraying different formulations of niclosamide ethanolamine salt with drones against Oncomelania hupensis in ditches. Methods A semi-dry and semi-wet ditch with O. hupensis snails was selected in the second branch field of Jiangbei Farm, Jiangling County, Hubei Province in May 2023, and divided into 4 experimental areas, named groups A1, A2, B1 and B2. Environmental cleaning was performed in groups A1 and B2, and was not conducted in groups A2 or B2. Then, 50% wettable powder of niclosamide ethanolamine salt was sprayed with drones at an effective dose of 2 g/m² in groups A1 and A2, and 5% niclosamide ethanolamine salt granule was sprayed with drones at an effective dose of 2 g/m² in groups B1 and B2. O. hupensis snails were surveyed using the systematic sampling method 1, 3, 5, 7, 14 days after spraying, and the natural mortality and corrected mortality of O. hupensis snails were calculated. Results The occurrence of frames with living snails, mean density of living snails and natural mortality of snails were 97.50% (117/120), 6.30 snails/0.1 m² and 1.18% (9/765) in the test ditch before spraying, respectively. There were significant differences in the mortality of snails among four groups 1, 3, 5, 7 and 14 days after spraying niclosamide formulations with drones (χ² = 17.230, 51.707, 65.184, 204.050 and 34.435, all P values < 0.01). The overall mortality rates of snails were 94.51% (1 051/1 112), 79.44% (908/1 143), 96.54% (977/1 012) and 88.55% (1 021/1 153) in groups A1, A2, B1 and B2 (χ² = 207.773, P < 0.05), respectively. In addition, there was no significant difference in the overall snail mortality between groups A1 and B1 (P > 0.05), and the snail mortality in groups A1 and B1 were both statistically different from that in groups A2 and B2 (all P values < 0.05). Conclusion Both 50% wettlable powder of niclosamide ethanolamine salt and 5% niclosamide ethanolamine salt granule sprayed with drones are active against O. hupensis snails in ditches, and environmental cleaning may improve the molluscicidal effect.

Objective To investigate the effect of E2 signaling in myofibers on muscular macrophage efferocytosis in mice with cardiotoxin-induced acute skeletal muscle injury.Methods Female wild-type C57BL/6 mice with and without ovariectomy and male C57BL/6 mice were given a CTX injection into the anterior tibial muscle to induce acute muscle injury,followed by intramuscular injection of β-estradiol(E2)or 4-hydroxytamoxifen(4-OHT).The changes in serum E2 of the mice were detected using ELISA,and the number,phenotypes,and efferocytosis of the macrophages in the inflammatory exudates and myofiber regeneration and repair were evaluated using immunofluorescence staining and flow cytometry.C2C12 cells were induced to differentiate into mature myotubes,which were treated with IFN-γ for 24 before treatment with β-Estradiol or 4-OHT.The treated myotubes were co-cultured with mouse peritoneal macrophages in a 1:2 ratio,followed by addition of PKH67-labeled apoptotic mouse mononuclear spleen cells induced by UV irradiation,and macrophage efferocytosis was observed using immunofluorescence staining and flow cytometry.Results Compared with the control mice,the female mice with ovariectomy showed significantly increased mononuclear macrophages in the inflammatory exudates,with increased M1 cell percentage,reduced M2 cell percentage and macrophage efferocytosis in the injured muscle,and obviously delayed myofiber regeneration and repair.In the cell co-culture systems,treatment of the myotubes with β-estradiol significantly increased the number and proportion of M2 macrophages and macrophage efferocytosis,while 4-OHT treatment resulted in the opposite changes.Conclusion In injured mouse skeletal muscles,myofiber E2 signaling promotes M1 to M2 transition to increase macrophage efferocytosis,thereby relieving inflammation and promoting muscle regeneration and repair.

Objective:To investigate respiratory virus infection in children with septic shock in pediatric care units (PICU) in China and its influence on clinical outcomes.Methods:The clinical data of children with septic shock in children′s PICU from January 2018 to December 2019 in 10 Chinese hospitals were retrospectively collected. They were divided into the pre-COVID-19 and post-COVID-19 groups according to the onset of disease, and the characteristics and composition of respiratory virus in the 2 groups were compared. Matching age, malignant underlying diseases, bacteria, fungi and other viruses, a new database was generated using 1∶1 propensity score matching method. The children were divided into the respiratory virus group and non-respiratory virus group according to the presence or absence of respiratory virus infection; their clinical characteristics, diagnosis, and treatment were compared by t-test, rank sum test and Chi-square test. The correlation between respiratory virus infection and the clinical outcomes was analyzed by logistic regression. Results:A total of 1 247 children with septic shock were included in the study, of them 748 were male; the age was 37 (11, 105) months. In the pre-and post-COVID-19 groups, there were 530 and 717 cases of septic shock, respectively; the positive rate of respiratory virus was 14.9% (79 cases) and 9.8% (70 cases); the seasonal distribution of septic shock was 28.9% (153/530) and 25.9% (185/717) in autumn, and 30.3% (161/530) and 28.3% (203/717) in winter, respectively, and the corresponding positive rates of respiratory viruses were 19.6% (30/153) and 15.7% (29/185) in autumn, and 21.1% (34/161) and 15.3% (31/203) in winter, respectively. The positive rates of influenza virus and adenovirus in the post-COVID-19 group were lower than those in the pre-COVID-19 group (2.1% (15/717) vs. 7.5% (40/530), and 0.7% (5/717) vs. 3.2% (17/530), χ2=21.51 and 11.08, respectively; all P<0.05). Rhinovirus virus were higher than those in the pre-Covid-19 group (1.7% (12/717) vs. 0.2% (1/530), χ2=6.51, P=0.011). After propensity score matching, there were 147 cases in both the respiratory virus group and the non-respiratory virus group. Rate of respiratory failure, acute respiratory distress, rate of disseminated coagulation dysfunction, and immunoglobulin usage of the respiratory virus group were higher than those of non-respiratory virus group (77.6% (114/147) vs. 59.2% (87/147), 17.7% (26/147) vs. 4.1% (6/147), 15.6% (25/147) vs. 4.1% (7/147), and 35.4% (52/147) vs. 21.4% (32/147); χ2=11.07, 14.02, 11.06 and 6.67, all P<0.05); and PICU hospitalization of the former was longer than that of the later (7 (3, 16) vs. 3 (1, 7)d, Z=5.01, P<0.001). Univariate logistic regression analysis showed that the presence of respiratory viral infection was associated with respiratory failure, disseminated coagulation dysfunction, the use of mechanical ventilation, and the use of immunoglobulin and anti-respiratory viral drugs ( OR=2.42, 0.22, 0.25, 0.56 and 1.12, all P<0.05). Conclusions:The composition of respiratory virus infection in children with septic shock is different between pre and post-COVID-19. Respiratory viral infection is associated with organ dysfunction in children with septic shock. Decreasing respiratory viral infection through respiratory protection may improve the clinical outcome of these children.

Objective:To investigate the clinical features, pathogen composition, and prognosis of septic shock in pediatric intensive care units (PICU) in China.Methods:A multicenter retrospective cohort study. A retrospective analysis was conducted on the clinical data of children with septic shock from 10 hospitals in China between January 2018 and December 2021. The clinical features, pathogen composition, and outcomes were collected. Patients were categorized into malignant tumor and non-malignant tumor groups, as well as survival and mortality groups. T test, Mann Whitney U test or Chi square test were used respectively for comparing clinical characteristics and prognosis between 2 groups. Multiple Logistic regression was used to identify risk factors for mortality. Results:A total of 1 247 children with septic shock were included, with 748 males (59.9%) and the age of 3.1 (0.9, 8.8) years. The in-patient mortality rate was 23.2% (289 cases). The overall pathogen positive rate was 68.2% (851 cases), with 1 229 pathogens identified. Bacterial accounted for 61.4% (754 strains) and virus for 24.8% (305 strains). Among all bacterium, Gram negative bacteria constituted 64.2% (484 strains), with Pseudomonas aeruginosa and Enterobacter being the most common; Gram positive bacteria comprised 35.8% (270 strains), primarily Streptococcus and Staphylococcus species. Influenza virus (86 strains (28.2%)), Epstein-Barr virus (53 strains (17.4%)), and respiratory syncytial virus (46 strains (17.1%)) were the top three viruses. Children with malignant tumors were older and had higher pediatric risk of mortality (PRISM) Ⅲ score, paediatric sequential organ failure assessment (pSOFA) score (7.9 (4.3, 11.8) vs. 2.3 (0.8, 7.5) years old, 22 (16, 26) vs. 16 (10, 24) points, 10 (5, 14) vs. 8 (4, 12) points, Z=11.32, 0.87, 4.00, all P<0.05), and higher pathogen positive rate, and in-hospital mortality (77.7% (240/309) vs. 65.1% (611/938), 29.7% (92/309) vs. 21.0% (197/938), χ2=16.84, 10.04, both P<0.05) compared to the non-tumor group. In the death group, the score of PRISM Ⅲ, pSOFA (16 (22, 29) vs. 14 (10, 20) points, 8 (12, 15) vs. 6 (3, 9) points, Z=4.92, 11.88, both P<0.05) were all higher, and presence of neoplastic disease, positive rate of pathogen and proportion of invasive mechanical ventilation in death group were also all higher than those in survival group (29.7% (87/289) vs. 23.2% (222/958), 77.8% (225/289) vs. 65.4% (626/958), 73.7% (213/289) vs. 50.6% (485/958), χ2=5.72, 16.03, 49.98, all P<0.05). Multiple Logistic regression showed that PRISM Ⅲ, pSOFA, and malignant tumor were the independent risk factors for mortality ( OR=1.04, 1.09, 0.67, 95% CI 1.01-1.05, 1.04-1.12, 0.47-0.94, all P<0.05). Conclusions:Bacterial infection are predominant in pediatric septic shock, but viral infection are also significant. Children with malignancies are more severe and resource consumptive. The overall mortality rate for pediatric septic shock remains high, and mortality are associated with malignant tumor, PRISM Ⅲ and pSOFA scores.

Objective To investigate the effect of E2 signaling in myofibers on muscular macrophage efferocytosis in mice with cardiotoxin-induced acute skeletal muscle injury.Methods Female wild-type C57BL/6 mice with and without ovariectomy and male C57BL/6 mice were given a CTX injection into the anterior tibial muscle to induce acute muscle injury,followed by intramuscular injection of β-estradiol(E2)or 4-hydroxytamoxifen(4-OHT).The changes in serum E2 of the mice were detected using ELISA,and the number,phenotypes,and efferocytosis of the macrophages in the inflammatory exudates and myofiber regeneration and repair were evaluated using immunofluorescence staining and flow cytometry.C2C12 cells were induced to differentiate into mature myotubes,which were treated with IFN-γ for 24 before treatment with β-Estradiol or 4-OHT.The treated myotubes were co-cultured with mouse peritoneal macrophages in a 1:2 ratio,followed by addition of PKH67-labeled apoptotic mouse mononuclear spleen cells induced by UV irradiation,and macrophage efferocytosis was observed using immunofluorescence staining and flow cytometry.Results Compared with the control mice,the female mice with ovariectomy showed significantly increased mononuclear macrophages in the inflammatory exudates,with increased M1 cell percentage,reduced M2 cell percentage and macrophage efferocytosis in the injured muscle,and obviously delayed myofiber regeneration and repair.In the cell co-culture systems,treatment of the myotubes with β-estradiol significantly increased the number and proportion of M2 macrophages and macrophage efferocytosis,while 4-OHT treatment resulted in the opposite changes.Conclusion In injured mouse skeletal muscles,myofiber E2 signaling promotes M1 to M2 transition to increase macrophage efferocytosis,thereby relieving inflammation and promoting muscle regeneration and repair.

BACKGROUND: T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif domains (TIGIT), an inhibitory receptor expressed on T cells, plays a dysfunctional role in antiviral infection and antitumor activity. However, it is unknown whether TIGIT expression on T cells influences the immunological effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inactivated vaccines. METHODS: Forty-five people living with HIV (PLWH) on antiretroviral therapy (ART) for more than two years and 31 healthy controls (HCs), all received a third dose of a SARS-CoV-2 inactivated vaccine, were enrolled in this study. The amounts, activation, proportion of cell subsets, and magnitude of the SARS-CoV-2-specific immune response of TIGIT + CD4 + and TIGIT + CD8 + T cells were investigated before the third dose but 6 months after the second vaccine dose (0W), 4 weeks (4W) and 12 weeks (12W) after the third dose. RESULTS: Compared to that in HCs, the frequency of TIGIT + CD8 + T cells in the peripheral blood of PLWH increased at 12W after the third dose of the inactivated vaccine, and the immune activation of TIGIT + CD8 + T cells also increased. A decrease in the ratio of both T naïve (T N ) and central memory (T CM ) cells among TIGIT + CD8 + T cells and an increase in the ratio of the effector memory (T EM ) subpopulation were observed at 12W in PLWH. Interestingly, particularly at 12W, a higher proportion of TIGIT + CD8 + T cells expressing CD137 and CD69 simultaneously was observed in HCs than in PLWH based on the activation-induced marker assay. Compared with 0W, SARS-CoV-2-specific TIGIT + CD8 + T-cell responses in PLWH were not enhanced at 12W but were enhanced in HCs. Additionally, at all time points, the SARS-CoV-2-specific responses of TIGIT + CD8 + T cells in PLWH were significantly weaker than those of TIGIT - CD8 + T cells. However, in HCs, the difference in the SARS-CoV-2-specific responses induced between TIGIT + CD8 + T cells and TIGIT - CD8 + T cells was insignificant at 4W and 12W, except at 0W. CONCLUSIONS TIGIT expression on CD8 + T cells may hinder the T-cell immune response to a booster dose of an inactivated SARS-CoV-2 vaccine, suggesting weakened resistance to SARS-CoV-2 infection, especially in PLWH. Furthermore, TIGIT may be used as a potential target to increase the production of SARS-CoV-2-specific CD8 + T cells, thereby enhancing the effectiveness of vaccination.
Humans ; Antibodies, Viral ; CD8-Positive T-Lymphocytes ; COVID-19/complications* ; COVID-19 Vaccines/immunology* ; HIV Infections/complications* ; Receptors, Immunologic ; SARS-CoV-2

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine can induce a potent cellular and humoral immune response to protect against SARS-CoV-2 infection. However, it was unknown whether SARS-CoV-2 vaccination can induce effective natural killer (NK) cell response in people living with human immunodeficiency virus (PLWH) and healthy individuals. METHODS: Forty-seven PLWH and thirty healthy controls (HCs) inoculated with SARS-CoV-2 inactivated vaccine were enrolled from Beijing Youan Hospital in this study. The effect of SARS-CoV-2 vaccine on NK cell frequency, phenotype, and function in PLWH and HCs was evaluated by flow cytometry, and the response of NK cells to SARS-CoV-2 Omicron Spike (SARS-2-OS) protein stimulation was also evaluated. RESULTS: SARS-CoV-2 vaccine inoculation elicited activation and degranulation of NK cells in PLWH, which peaked at 2 weeks and then decreased to a minimum at 12 weeks after the third dose of vaccine. However, in vitro stimulation of the corresponding peripheral blood monocular cells from PLWH with SARS-2-OS protein did not upregulate the expression of the aforementioned markers. Additionally, the frequencies of NK cells expressing the activation markers CD25 and CD69 in PLWH were significantly lower than those in HCs at 0, 4 and 12 weeks, but the percentage of CD16 + NK cells in PLWH was significantly higher than that in HCs at 2, 4 and 12 weeks after the third dose of vaccine. Interestingly, the frequency of CD16 + NK cells was significantly negatively correlated with the proportion of CD107a + NK cells in PLWH at each time point after the third dose. Similarly, this phenomenon was also observed in HCs at 0, 2, and 4 weeks after the third dose. Finally, regardless of whether NK cells were stimulated with SARS-2-OS or not, we did not observe any differences in the expression of NK cell degranulation markers between PLWH and HCs. CONCLUSION s:SARS-CoV-2 vaccine elicited activation and degranulation of NK cells, indicating that the inoculation of SARS-CoV-2 vaccine enhances NK cell immune response.
Humans ; COVID-19 Vaccines/therapeutic use* ; COVID-19 ; SARS-CoV-2 ; Killer Cells, Natural ; HIV Infections ; Antibodies, Viral

Objective: To investigate the specificity of endogenous metabolic profile in plasma of patients with occupational acute methyl acetate poisoning using non-targeted metabolomics. Methods: A total of six patients with occupational acute methyl acetate poisoning were selected as the poisoning group, while 10 healthy workers without occupational exposure history of chemical hazards in the same industry were selected as the control group using the judgment sampling method. Metabolites in patient plasma of the two groups were detected using ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry, and non-targeted metabolomics analysis was performed. Principal component analysis and partial least squares discriminant analysis were used to identify differential metabolites and analyze their metabolic pathways. Results: There were significant differences in metabolite profiles in patient plasma between poisoning group and control group. A total of 195 differentially expressed metabolites were screened in plasma of patients in poisoning group, including 119 upregulated and 76 downregulated metabolites. Lipid substances (lipids and lipid-like molecules) accounted for the highest proportion (21.5%). The differential metabolites of poisoning group were related to folate biosynthesis, amino acid metabolism, pyrimidine metabolism, sphingolipid biosynthesis and other metabolic pathways in plasma compared with the control group (all P<0.05). Conclusion: Occupational acute methyl acetate poisoning affects metabolism of the body. The folic acid biosynthesis, amino acid and lipid metabolism and other pathways may be involved in the occurrence and development of poisoning.

Objective    To explore the safety and effectiveness of different interventional approaches for the treatment of patent ductus arteriosus (PDA) in children. Methods    The children (≤7 years) who underwent interventional treatment for PDA from 2019 to 2020 in our hospital were retrospectively included. The patients were divided into 3 groups according to the procedures: a conventional arteriovenous approach group, a simple venous approach group, and a retrograde femoral artery approach group. The clinical efficacy of the patients was compared. Results     A total of 220 patients were included. There were 78 males and 142 females, with an average age of 3.21±1.73 years, weight of 14.99±5.35 kg, and height of 96.19±15.77 cm. The average diameter of the PDA was 3.35±1.34 mm. A total of 85 patients received a conventional arteriovenous approach, 104 patients received a simple venous approach, and 31 patients received a retrograde femoral artery approach. The diameter of PDA in the retrograde femoral artery group was smaller than that in the other two groups (3.44±1.43 mm vs. 1.99±0.55 mm; 3.69±1.17 mm vs. 1.99±0.55 mm, P<0.001); the contrast medium usage [40 (30, 50) mL vs. 20 (20, 30) mL; 35 (25, 50) mL vs. 20 (20, 30) mL, P≤0.001] and operation time [32 (26, 44) min vs. 25 (23, 30) min; 29 (25, 38) min vs. 25 (23, 30) min, P<0.05] in the simple venous approach group were significantly less or shorter than those in the other two groups; the length of hospital stay of the conventional arteriovenous group was longer than that in the other two groups [3 (3, 5) d vs. 4 (3, 6) d; 4 (3, 5) d vs. 4 (3, 6) d, P<0.05]. There was no significant difference in postoperative complications. Conclusion    It is safe and effective to close PDA through simple venous approach. The retrograde femoral artery approach has the advantage of simplifying the surgical procedure for PDA with small diameters.