Background： Vascular endothelial growth factor （VEGF） in the thymus was mainly produced by the thymic epithelial cells （TECs）, the predominant component of the thymic microenvironment. The progression of TECs and...Background： Vascular endothelial growth factor （VEGF） in the thymus was mainly produced by the thymic epithelial cells （TECs）, the predominant component of the thymic microenvironment. The progression of TECs and the roles of VEGF in the neonatal thymus during sepsis have not been reported. This study aimed to explore the alterations of TECs and VEGF level in the neonatal thymus involution and to explore the possible mechanisms at the cellular level. Methods： By establishing a model of clinical sepsis, the changes of TECs were measured by hematoxylin-eosin staining. confocal microscopy, and flow cytometry. Moreover, the levels of VEGF in serum and thymus were assessed based on enzyme-linked immunosorbent assay and Western blotting. Results： The number ofthymocytes and TECs was significantly decreased 2411 after lipopolysaccharide （LPS） challenge. （2.40 ± 0,46）× 10^7 vs. （3.93 ± 0.66）× 10^7 and （1.16 ± 0.14）× 10^5 vs. （2.20 ± 0.19）× 10^5, P 〈 0.05, respectively. Cortical TECs and medullary TECs in the LPS-treated mice were decreased 1.5-fold and 3.9-fold, P 〈 0.05, respectively, lower than those in the controls. The number of thymic epithelial progenitors was also decreased. VEGF expression in TECs was down-regulated in a time-dependent manner. Conclusion： VEGF in thymic cells subsets might contribute to the development of TECs in neonatal sepsis.展开更多
Background and aims:Cancer cachexia is prevalent in various cancers and is associated with chemotherapy toxicity.However,limited data exist on the relationship between cachexia and immune-related adverse events(irAEs)...Background and aims:Cancer cachexia is prevalent in various cancers and is associated with chemotherapy toxicity.However,limited data exist on the relationship between cachexia and immune-related adverse events(irAEs).The aim of this study is to explore the correlation between cancer cachexia and irAEs and its possible mechanism.-Methods:A murine model of orthotopic hepatocellular carcinoma(HCC)with cachexia was developed to evaluate the impact of T-cell infiltration into multiple tumor-free organs on the occurrence of irAEs.Single-cell RNA sequencing of thymic stromal cells was performed.Additionally,patients with advanced cancers receiving anti-programmed cell death protein 1/ligand 1(PD-1/L1)antibody treatment were followed to investigate the relationship between cachexia and irAEs.Results:Inflammatory cell infiltration was observed in multiple tumor-free organs of cachexic HCC mice but not in non-cachexic controls.Immunofluorescence confirmed that the infiltrating cells included CD4^(+)and CD8^(+)T cells.Morphological assessment and hematoxylin-eosin staining revealed thymic atrophy in cachexic HCC mice.Single-cell RNA sequencing of thymic stromal cells showed a reduction in medullary thymic epithelial cells(mTECs)Ⅱ and Ⅲ in cachexic mice.Autoimmune regulator(Aire)downregulation was accompanied by decreased expression of tissue-restricted antigens in mTECs.T cells from cachexic HCC mice induced organ-specific inflammation and T-cell infiltration in multiple organs of tumor-free mice.Following anti-mouse PD-1 antibody treatment,the incidence of inflammation in multiple organs markedly increased in cachexic HCC mice and in tumor-free mice that had received T cells from the cachexic HCC mice.Flow cytometry and immunofluorescence analyses revealed enrichment of thymic monocytic myeloid-derived suppressor cells(M-MDSCs)in cachexic HCC mice.M-MDSCs infiltrated the thymus in cachexic mice with cancer,and they induced apoptosis of mTECs from tumor-free mice in vitro via nitric oxide production.Transfer of M-MDSCs led to inflammatory cell infiltration in multiple organs and thymic involution in tumor-free mice without affecting body weight.Sixty-four patients with advanced cancer receiving anti-PD-1/L1 therapy were enrolled.Patients who developed irAEs had higher levels of circulating M-MDSCs than those who did not.Moreover,patients with cachexia(body mass index(BMI)<20 kg/m^(2) or≥5% weight loss over the past 6 months)had elevated M-MDSC levels.Patients with both high M-MDSC levels and low BMI or weight loss≥5% experienced more irAEs(hazard ratio:2.333;95% confidence interval:1.231-4.423).Conclusions:M-MDSCs in cachexic mice induced mTEC apoptosis through nitric oxide production,impairing T-cell negative selection and promoting autoimmune T-cell infiltration into tumor-free organs.Cancer cachexia-related M-MDSCs may serve as predictive biomarkers for irAEs in patients with advanced cancer.展开更多
文摘Background： Vascular endothelial growth factor （VEGF） in the thymus was mainly produced by the thymic epithelial cells （TECs）, the predominant component of the thymic microenvironment. The progression of TECs and the roles of VEGF in the neonatal thymus during sepsis have not been reported. This study aimed to explore the alterations of TECs and VEGF level in the neonatal thymus involution and to explore the possible mechanisms at the cellular level. Methods： By establishing a model of clinical sepsis, the changes of TECs were measured by hematoxylin-eosin staining. confocal microscopy, and flow cytometry. Moreover, the levels of VEGF in serum and thymus were assessed based on enzyme-linked immunosorbent assay and Western blotting. Results： The number ofthymocytes and TECs was significantly decreased 2411 after lipopolysaccharide （LPS） challenge. （2.40 ± 0,46）× 10^7 vs. （3.93 ± 0.66）× 10^7 and （1.16 ± 0.14）× 10^5 vs. （2.20 ± 0.19）× 10^5, P 〈 0.05, respectively. Cortical TECs and medullary TECs in the LPS-treated mice were decreased 1.5-fold and 3.9-fold, P 〈 0.05, respectively, lower than those in the controls. The number of thymic epithelial progenitors was also decreased. VEGF expression in TECs was down-regulated in a time-dependent manner. Conclusion： VEGF in thymic cells subsets might contribute to the development of TECs in neonatal sepsis.
基金supported by the National Natural Science Foundation of China(No.82170749)the Guangdong Basic and Applied Basic Research Foundation(No.2022A1515010465 and 2022A1515012659)+1 种基金Guangzhou Science and Technology Program Key Projects(No.2023B01J1007)the Traditional Chinese Medicine Bureau of Guangdong Province,China(No.20241045).
文摘Background and aims:Cancer cachexia is prevalent in various cancers and is associated with chemotherapy toxicity.However,limited data exist on the relationship between cachexia and immune-related adverse events(irAEs).The aim of this study is to explore the correlation between cancer cachexia and irAEs and its possible mechanism.-Methods:A murine model of orthotopic hepatocellular carcinoma(HCC)with cachexia was developed to evaluate the impact of T-cell infiltration into multiple tumor-free organs on the occurrence of irAEs.Single-cell RNA sequencing of thymic stromal cells was performed.Additionally,patients with advanced cancers receiving anti-programmed cell death protein 1/ligand 1(PD-1/L1)antibody treatment were followed to investigate the relationship between cachexia and irAEs.Results:Inflammatory cell infiltration was observed in multiple tumor-free organs of cachexic HCC mice but not in non-cachexic controls.Immunofluorescence confirmed that the infiltrating cells included CD4^(+)and CD8^(+)T cells.Morphological assessment and hematoxylin-eosin staining revealed thymic atrophy in cachexic HCC mice.Single-cell RNA sequencing of thymic stromal cells showed a reduction in medullary thymic epithelial cells(mTECs)Ⅱ and Ⅲ in cachexic mice.Autoimmune regulator(Aire)downregulation was accompanied by decreased expression of tissue-restricted antigens in mTECs.T cells from cachexic HCC mice induced organ-specific inflammation and T-cell infiltration in multiple organs of tumor-free mice.Following anti-mouse PD-1 antibody treatment,the incidence of inflammation in multiple organs markedly increased in cachexic HCC mice and in tumor-free mice that had received T cells from the cachexic HCC mice.Flow cytometry and immunofluorescence analyses revealed enrichment of thymic monocytic myeloid-derived suppressor cells(M-MDSCs)in cachexic HCC mice.M-MDSCs infiltrated the thymus in cachexic mice with cancer,and they induced apoptosis of mTECs from tumor-free mice in vitro via nitric oxide production.Transfer of M-MDSCs led to inflammatory cell infiltration in multiple organs and thymic involution in tumor-free mice without affecting body weight.Sixty-four patients with advanced cancer receiving anti-PD-1/L1 therapy were enrolled.Patients who developed irAEs had higher levels of circulating M-MDSCs than those who did not.Moreover,patients with cachexia(body mass index(BMI)<20 kg/m^(2) or≥5% weight loss over the past 6 months)had elevated M-MDSC levels.Patients with both high M-MDSC levels and low BMI or weight loss≥5% experienced more irAEs(hazard ratio:2.333;95% confidence interval:1.231-4.423).Conclusions:M-MDSCs in cachexic mice induced mTEC apoptosis through nitric oxide production,impairing T-cell negative selection and promoting autoimmune T-cell infiltration into tumor-free organs.Cancer cachexia-related M-MDSCs may serve as predictive biomarkers for irAEs in patients with advanced cancer.
