AIM To study the role of semaphorin 4 D(Sema4 D) expression promoted by tumor-associated macrophages(TAMs) in gastric carcinoma cells and its clinical significance in the invasion and metastasis of gastric carcinoma.M...AIM To study the role of semaphorin 4 D(Sema4 D) expression promoted by tumor-associated macrophages(TAMs) in gastric carcinoma cells and its clinical significance in the invasion and metastasis of gastric carcinoma.METHODS CD68 and Sema4 D expression was analyzed in gastric carcinoma and adjacent normal tissues from 290 patients using the immunohistochemical streptavidinperoxidase method, and their relationships with clinicopathological features were evaluated. Human M2 macrophages were induced in vitro and co-cultured in non-contact with gastric carcinoma SGC-7901 cells. Changes in the secretory Sema4 D level in the SGC-7901 cell supernatant were measured using an enzymelinked immunosorbent assay. The effects of TAMs on SGC-7901 cell invasion and migration were assessed with invasion and migration assays, respectively.RESULTS CD68 and Sema4 D protein expression was significantly higher in gastric carcinoma tissues than in adjacent normal tissues(71.7% vs 33.8% and 74.5% vs 42.8%, respectively; P < 0.01). CD68 and Sema4 D protein expression was significantly associated with histological differentiation, TNM stage, and lymph node metastasis(P < 0.05), and their expression levels were positively correlated with one another(r = 0.467, P < 0.01). In the in vitro experiment, secretory Sema4 D protein expression was significantly increased in the supernatant of SGC-7901 cells co-cultured with TAMs compared with the blank control(1224.13 ± 29.43 vs 637.15 ± 33.84, P < 0.01). Cell invasion and metastasis were enhanced in the Transwell invasion and migration assays(P < 0.01).CONCLUSION TAMs promote the invasion and metastasis of gastric carcinoma cells possibly through upregulated secretory Sema4 D protein expression. Combined detection of TAM markers, CD68 and Sema4 D, in gastric carcinoma tissue shows potential to predict the trend of gastric carcinoma progression.展开更多
Background and Aims:Overexpression of IGF2BP3 is associated with the prognosis of hepatocellular carcinoma(HCC).However,its role in regulating tumor immune microenvironment(TME)is not well characterized.Here,we invest...Background and Aims:Overexpression of IGF2BP3 is associated with the prognosis of hepatocellular carcinoma(HCC).However,its role in regulating tumor immune microenvironment(TME)is not well characterized.Here,we investigated the effects of IGF2BP3 on macrophages and CD8^(+)T cells within the TME of HCC.Methods:The relationship between IGF2BP3 and immune cell infiltration was analyzed using online bioinformatics tools.Knockout of IGF2BP3 in mouse hepatoma cell line Hepa1-6 was established using CRISPR/Cas9 technology.In vitro cell coculture and subcutaneously implanted hepatoma mice model were used to explore the effects of IGF2BP3 on immune cells.Expression of CCL50l transforming growth factor beta 1(TGF-β1)was detected with quantitative real-time polymerase chain reaction,western blotting,and enzyme-linked immunosorbent assay.The binding of IGF2BP3 and its target RNA was verified by trimolecular fluorescence complementation system and RNA immunoprecipitation followed by quantitative or semiquantitative polymerase chain reaction.Results:IGF2BP3 expression was elevated in HCC and was positively correlated with macrophage infiltration.Patients with higher IGF2BP3 expression and lower macrophage infiltration had a better survival rate.We found that IGF2BP3 could bind to the mRNA of CCL5 or TGF-β1,increasing their expression,and inducing macrophage infiltration and M2 polarization while inhibiting the activation of CD8^(+)T cells.Furthermore,inhibition of IGF2BP3 combined with anti-CD47 antibody treatment significantly suppressed the growth of hepatoma in Hepa1-6 xenograft tu-mor mice.Conclusions:IGF2BP3 promoted the infiltration and M2-polarization of macrophages and suppressed CD8^(+)T activation by enhancing CCL5 and TGF-β1 expression,which facilitated the progression of Hepa1-6 xenograft tumor.展开更多
Background:Interleukin-15(IL-15)is a promising immunotherapeutic agent owing to its powerful immune-activating effects.However,the clinical benefits of these treatments are limited.Crosstalk between tumor cells and im...Background:Interleukin-15(IL-15)is a promising immunotherapeutic agent owing to its powerful immune-activating effects.However,the clinical benefits of these treatments are limited.Crosstalk between tumor cells and immune cells plays an important role in immune escape and immunotherapy drug resistance.Herein,this study aimed to obtain in-depth understanding of crosstalk in the tumor microenvironment for providing potential therapeutic strategies to prevent tumor progression.Methods:T-cell killing assays and co-culture models were developed to determine the role of crosstalk between macrophages and tumor cells in breast cancer resistant to IL-15.Western blotting,histological analysis,CRISPR-Cas9 knockout,multi-parameter flow cytometry,and tumor cell-macrophage co-injection mouse models were developed to examine the mechanism by which IL-15Rα^(+)tumor-associated macrophages(TAMs)regulate breast cancer cell resistance to IL-15.Results:We found thatmacrophages contributed to the resistance of tumor cells to IL-15,and tumor cells induced macrophages to express high levels of theαsubunit of the IL-15 receptor(IL-15Rα).Further investigation showed that IL-15Rα^(+)TAMs reduced the protein levels of chemokine CX3C chemokine ligand 1(CX3CL1)in tumor cells to inhibit the recruitment of CD8^(+)T cells by releasing the IL-15/IL-15Rαcomplex(IL-15Rc).Administration of an IL-15Rc blocking peptide markedly suppressed breast tumor growth and overcame the resistance of cancer cells to anti-programmed cell death protein 1(PD-1)antibody immunotherapy.Interestingly,Granulocyte-macrophage colony-stimulating factor(GMCSF)inducedγchain(γc)expression to promote tumor cell-macrophage crosstalk,which facilitated tumor resistance to IL-15.Additionally,we observed that the non-transcriptional regulatory function of hypoxia inducible factor-1alpha(HIF-1α)was essential for IL-15Rc to regulateCX3CL1 expression in tumor cells.Conclusions:The IL-15Rc-HIF-1α-CX3CL1 signaling pathway serves as a crosstalk between macrophages and tumor cells in the tumormicroenvironment of breast cancer.Targeting this pathway may provide a potential therapeutic strategy for enhancing the efficacy of cancer immunotherapy.展开更多
Background:Several clinical studies have uncovered a negative correlation between baseline tumor burden and the efficacy of immune checkpoint inhibitor(ICI)treatment.This study aimed to uncover the specific mechanisms...Background:Several clinical studies have uncovered a negative correlation between baseline tumor burden and the efficacy of immune checkpoint inhibitor(ICI)treatment.This study aimed to uncover the specific mechanisms underlying the difference in sensitivity to ICI treatment between tumors with high(HTB)and low(LTB)tumor burden.Methods:For in vivo studies,several mouse models of subcutaneous tumors were established,and transcriptome sequencing,immunohistochemistry,and flow cytometry assays were used to detect the immune status in these subcutaneous tumors.For in vitro experiments,co-culture models,cytokine antibody arrays,western blotting,flow cytometry,and enzyme-linked immunosorbent assays were used to explore the underlying molecular mechanisms Results:We found that MC38 or B16 subcutaneous tumors from the HTB group did not show any response to anti-programmed cell death protein-1(PD-1)therapy.Through flow cytometry assays,we found that the infiltration with CD8^(+)T cellswas significantly decreasedwhereasM2-like macrophageswere enriched in subcutaneous tumors of HTB groups compared with those of LTB group.These changes were not affected by the initial number of injected tumor cells or tumor age,nor could they be reversed by surgical tumor reduction.Intraperitoneal colony-stimulating factor 1 receptor(CSF-1R)inhibitor PLX3397 injection at different time points of tumor growth only had an effect when administered in the early tumor stage to maintain the“heat”of the tumor microenvironment during the process of tumor growth,thereby achieving a response to ICI treatment when the tumor grew to a large size.Mechanistically,we found that insulin-like growth factor binding protein 2(IGFBP2)expression levelswere significantly elevated in HTB tumor tissues.IGFBP2 promoted the programmed death-ligand 1(PD-L1)expression in M2-like macrophages by activating signal transducer and activator of transcription 3(STAT3),and PD-L1^(+)M2-likemacrophages exerted an immunosuppressive effect by inhibiting the proliferation and activation of CD8^(+)T cells in a PD-L1-dependent fashion.Conclusions:This study suggested that the low efficacy of ICI treatment in HTB tumors is mainly attributed to the intratumoral accumulation of PD-L1^(+)M2-like macrophages via the IGFBP2-STAT3-PD-L1 signaling pathway and their substantial inhibitory effects on T cell proliferation and activation.展开更多
Activin A, a multifunctional factor of the transforming growth factor-beta （TGF-β） superfamily, is mainly produced by microglia and macrophages, and its anti-inflammatory and pro-inflammatory activities are both re...Activin A, a multifunctional factor of the transforming growth factor-beta （TGF-β） superfamily, is mainly produced by microglia and macrophages, and its anti-inflammatory and pro-inflammatory activities are both related to macrophage functions. However the direct effect of activin A on the rest macrophages in vivo remains unclear. In the present study, the results showed that activin A not only increased NO and IL-1β release, but also promoted phagocytic abilities of mouse peritoneal macrophages in vitro and in vivo, whereas it did not influence MHC Ⅰ and MHC Ⅱ expression. Moreover, we found that activin A significantly upregulated the expressions of CD14 and CD68, markers of mature macrophages, on the surface of macrophages in vitro and in vivo. These data suggest that activin A can induce primary macrophage maturation in vitro and in vivo, but may not trigger the acquired immune response via regulating expression of MHC molecules involved in presentation of antigen.展开更多
AIM To investigate the influence of high salt on dextran sulfate sodium(DSS)-induced colitis in mice and explore the underlying mechanisms of this effect.METHODS DSS and NaC l were used to establish the proinflammator...AIM To investigate the influence of high salt on dextran sulfate sodium(DSS)-induced colitis in mice and explore the underlying mechanisms of this effect.METHODS DSS and NaC l were used to establish the proinflammatory animal model. We evaluated the colitis severity. Flow cytometry was employed for detecting the frequencies of Th1, macrophages and Tregs in spleen, mesenteric lymph node and lamina propria. The important role of macrophages in the promotion of DSS-induced colitis by NaCl was evaluated by depleting macrophages with clodronate liposomes. Activated peritoneal macrophages and lamina propria mononuclear cells(LPMCs) were stimulated with NaCl, and proteins were detected by western blotting. Cytokines and inflammation genes were analyzed by enzyme-linked immunosorbent assay and RT-PCR, respectively.RESULTS The study findings indicate that NaC l up-regulates the frequencies of CD11b^+ macrophages and CD4^+IFN-γ^+IL-17^+ T cells in lamina propria in DSS-treated mice. CD3^+CD4^+CD25^+Foxp^3+ T cells, which can secrete high levels of IL-10 and TGF-β, increase through feedback in NaCl-and DSS-treated mice. Furthermore, clodronate liposomes pretreatment significantly alleviated DSSinduced colitis, indicating that macrophages play a vital role in NaCl proinflammatory activity. NaCl aggravates peritoneal macrophage inflammation by promoting the expressions of interleukin(IL)-1, IL-6 and mouse inducible nitric oxide synthase. Specifically, high NaCl concentrations promote p38 phosphorylation in lipopolysaccharide-and IFN-γ-activated LPMCs mediated by SGK1. CONCLUSION Proinflammatory macrophages may play an essential role in the onset and development of NaCl-promoted inflammation in DSS-induced colitis. The underlining mechanism involves up-regulation of the p38/MAPK axis.展开更多
文摘AIM To study the role of semaphorin 4 D(Sema4 D) expression promoted by tumor-associated macrophages(TAMs) in gastric carcinoma cells and its clinical significance in the invasion and metastasis of gastric carcinoma.METHODS CD68 and Sema4 D expression was analyzed in gastric carcinoma and adjacent normal tissues from 290 patients using the immunohistochemical streptavidinperoxidase method, and their relationships with clinicopathological features were evaluated. Human M2 macrophages were induced in vitro and co-cultured in non-contact with gastric carcinoma SGC-7901 cells. Changes in the secretory Sema4 D level in the SGC-7901 cell supernatant were measured using an enzymelinked immunosorbent assay. The effects of TAMs on SGC-7901 cell invasion and migration were assessed with invasion and migration assays, respectively.RESULTS CD68 and Sema4 D protein expression was significantly higher in gastric carcinoma tissues than in adjacent normal tissues(71.7% vs 33.8% and 74.5% vs 42.8%, respectively; P < 0.01). CD68 and Sema4 D protein expression was significantly associated with histological differentiation, TNM stage, and lymph node metastasis(P < 0.05), and their expression levels were positively correlated with one another(r = 0.467, P < 0.01). In the in vitro experiment, secretory Sema4 D protein expression was significantly increased in the supernatant of SGC-7901 cells co-cultured with TAMs compared with the blank control(1224.13 ± 29.43 vs 637.15 ± 33.84, P < 0.01). Cell invasion and metastasis were enhanced in the Transwell invasion and migration assays(P < 0.01).CONCLUSION TAMs promote the invasion and metastasis of gastric carcinoma cells possibly through upregulated secretory Sema4 D protein expression. Combined detection of TAM markers, CD68 and Sema4 D, in gastric carcinoma tissue shows potential to predict the trend of gastric carcinoma progression.
基金supported by the National Natural Science Foundation of China(81601374)the Fundamental Research Funds for the Central Universities(3332022181)the Bilateral Inter-Governmental S&T Cooperation Project from the Ministry of Science and Technology of China(2018YFE0114300).
文摘Background and Aims:Overexpression of IGF2BP3 is associated with the prognosis of hepatocellular carcinoma(HCC).However,its role in regulating tumor immune microenvironment(TME)is not well characterized.Here,we investigated the effects of IGF2BP3 on macrophages and CD8^(+)T cells within the TME of HCC.Methods:The relationship between IGF2BP3 and immune cell infiltration was analyzed using online bioinformatics tools.Knockout of IGF2BP3 in mouse hepatoma cell line Hepa1-6 was established using CRISPR/Cas9 technology.In vitro cell coculture and subcutaneously implanted hepatoma mice model were used to explore the effects of IGF2BP3 on immune cells.Expression of CCL50l transforming growth factor beta 1(TGF-β1)was detected with quantitative real-time polymerase chain reaction,western blotting,and enzyme-linked immunosorbent assay.The binding of IGF2BP3 and its target RNA was verified by trimolecular fluorescence complementation system and RNA immunoprecipitation followed by quantitative or semiquantitative polymerase chain reaction.Results:IGF2BP3 expression was elevated in HCC and was positively correlated with macrophage infiltration.Patients with higher IGF2BP3 expression and lower macrophage infiltration had a better survival rate.We found that IGF2BP3 could bind to the mRNA of CCL5 or TGF-β1,increasing their expression,and inducing macrophage infiltration and M2 polarization while inhibiting the activation of CD8^(+)T cells.Furthermore,inhibition of IGF2BP3 combined with anti-CD47 antibody treatment significantly suppressed the growth of hepatoma in Hepa1-6 xenograft tu-mor mice.Conclusions:IGF2BP3 promoted the infiltration and M2-polarization of macrophages and suppressed CD8^(+)T activation by enhancing CCL5 and TGF-β1 expression,which facilitated the progression of Hepa1-6 xenograft tumor.
基金National Key Research and Development Plan,Grant/Award Number:2017YFA0506000Guangdong Basic and Applied Basic Research Foundation,Grant/Award Number:2021B1515120016+1 种基金National Natural Science Foundation of China,Grant/Award Number:82072822the Key Research and Development Program of Jiangsu Province,China-Social Development Projects,Grant/Award Number:BE2020687。
文摘Background:Interleukin-15(IL-15)is a promising immunotherapeutic agent owing to its powerful immune-activating effects.However,the clinical benefits of these treatments are limited.Crosstalk between tumor cells and immune cells plays an important role in immune escape and immunotherapy drug resistance.Herein,this study aimed to obtain in-depth understanding of crosstalk in the tumor microenvironment for providing potential therapeutic strategies to prevent tumor progression.Methods:T-cell killing assays and co-culture models were developed to determine the role of crosstalk between macrophages and tumor cells in breast cancer resistant to IL-15.Western blotting,histological analysis,CRISPR-Cas9 knockout,multi-parameter flow cytometry,and tumor cell-macrophage co-injection mouse models were developed to examine the mechanism by which IL-15Rα^(+)tumor-associated macrophages(TAMs)regulate breast cancer cell resistance to IL-15.Results:We found thatmacrophages contributed to the resistance of tumor cells to IL-15,and tumor cells induced macrophages to express high levels of theαsubunit of the IL-15 receptor(IL-15Rα).Further investigation showed that IL-15Rα^(+)TAMs reduced the protein levels of chemokine CX3C chemokine ligand 1(CX3CL1)in tumor cells to inhibit the recruitment of CD8^(+)T cells by releasing the IL-15/IL-15Rαcomplex(IL-15Rc).Administration of an IL-15Rc blocking peptide markedly suppressed breast tumor growth and overcame the resistance of cancer cells to anti-programmed cell death protein 1(PD-1)antibody immunotherapy.Interestingly,Granulocyte-macrophage colony-stimulating factor(GMCSF)inducedγchain(γc)expression to promote tumor cell-macrophage crosstalk,which facilitated tumor resistance to IL-15.Additionally,we observed that the non-transcriptional regulatory function of hypoxia inducible factor-1alpha(HIF-1α)was essential for IL-15Rc to regulateCX3CL1 expression in tumor cells.Conclusions:The IL-15Rc-HIF-1α-CX3CL1 signaling pathway serves as a crosstalk between macrophages and tumor cells in the tumormicroenvironment of breast cancer.Targeting this pathway may provide a potential therapeutic strategy for enhancing the efficacy of cancer immunotherapy.
基金National Natural Science Foundation of China,Grant/Award Numbers:82073303,82103335,82102731Science and Technology Planning Project of Guangzhou,Grant/Award Number:202201011560Natural Science Foundation of Guangdong Province of China,Grant/Award Number:2022A1515012418。
文摘Background:Several clinical studies have uncovered a negative correlation between baseline tumor burden and the efficacy of immune checkpoint inhibitor(ICI)treatment.This study aimed to uncover the specific mechanisms underlying the difference in sensitivity to ICI treatment between tumors with high(HTB)and low(LTB)tumor burden.Methods:For in vivo studies,several mouse models of subcutaneous tumors were established,and transcriptome sequencing,immunohistochemistry,and flow cytometry assays were used to detect the immune status in these subcutaneous tumors.For in vitro experiments,co-culture models,cytokine antibody arrays,western blotting,flow cytometry,and enzyme-linked immunosorbent assays were used to explore the underlying molecular mechanisms Results:We found that MC38 or B16 subcutaneous tumors from the HTB group did not show any response to anti-programmed cell death protein-1(PD-1)therapy.Through flow cytometry assays,we found that the infiltration with CD8^(+)T cellswas significantly decreasedwhereasM2-like macrophageswere enriched in subcutaneous tumors of HTB groups compared with those of LTB group.These changes were not affected by the initial number of injected tumor cells or tumor age,nor could they be reversed by surgical tumor reduction.Intraperitoneal colony-stimulating factor 1 receptor(CSF-1R)inhibitor PLX3397 injection at different time points of tumor growth only had an effect when administered in the early tumor stage to maintain the“heat”of the tumor microenvironment during the process of tumor growth,thereby achieving a response to ICI treatment when the tumor grew to a large size.Mechanistically,we found that insulin-like growth factor binding protein 2(IGFBP2)expression levelswere significantly elevated in HTB tumor tissues.IGFBP2 promoted the programmed death-ligand 1(PD-L1)expression in M2-like macrophages by activating signal transducer and activator of transcription 3(STAT3),and PD-L1^(+)M2-likemacrophages exerted an immunosuppressive effect by inhibiting the proliferation and activation of CD8^(+)T cells in a PD-L1-dependent fashion.Conclusions:This study suggested that the low efficacy of ICI treatment in HTB tumors is mainly attributed to the intratumoral accumulation of PD-L1^(+)M2-like macrophages via the IGFBP2-STAT3-PD-L1 signaling pathway and their substantial inhibitory effects on T cell proliferation and activation.
基金Acknowledgments This research was supported by grants provided by the Natural Science Foundation of China （Grant No. 30671953, 30801005 and 30901329）, Ministry of Education of China （Grant No 20070183013） and the Project of Science and Technology of Jilin Province （Grant No 20080160）.
文摘Activin A, a multifunctional factor of the transforming growth factor-beta （TGF-β） superfamily, is mainly produced by microglia and macrophages, and its anti-inflammatory and pro-inflammatory activities are both related to macrophage functions. However the direct effect of activin A on the rest macrophages in vivo remains unclear. In the present study, the results showed that activin A not only increased NO and IL-1β release, but also promoted phagocytic abilities of mouse peritoneal macrophages in vitro and in vivo, whereas it did not influence MHC Ⅰ and MHC Ⅱ expression. Moreover, we found that activin A significantly upregulated the expressions of CD14 and CD68, markers of mature macrophages, on the surface of macrophages in vitro and in vivo. These data suggest that activin A can induce primary macrophage maturation in vitro and in vivo, but may not trigger the acquired immune response via regulating expression of MHC molecules involved in presentation of antigen.
基金Supported by National Natural Science Foundation of China,No.81271813 and No.81570497
文摘AIM To investigate the influence of high salt on dextran sulfate sodium(DSS)-induced colitis in mice and explore the underlying mechanisms of this effect.METHODS DSS and NaC l were used to establish the proinflammatory animal model. We evaluated the colitis severity. Flow cytometry was employed for detecting the frequencies of Th1, macrophages and Tregs in spleen, mesenteric lymph node and lamina propria. The important role of macrophages in the promotion of DSS-induced colitis by NaCl was evaluated by depleting macrophages with clodronate liposomes. Activated peritoneal macrophages and lamina propria mononuclear cells(LPMCs) were stimulated with NaCl, and proteins were detected by western blotting. Cytokines and inflammation genes were analyzed by enzyme-linked immunosorbent assay and RT-PCR, respectively.RESULTS The study findings indicate that NaC l up-regulates the frequencies of CD11b^+ macrophages and CD4^+IFN-γ^+IL-17^+ T cells in lamina propria in DSS-treated mice. CD3^+CD4^+CD25^+Foxp^3+ T cells, which can secrete high levels of IL-10 and TGF-β, increase through feedback in NaCl-and DSS-treated mice. Furthermore, clodronate liposomes pretreatment significantly alleviated DSSinduced colitis, indicating that macrophages play a vital role in NaCl proinflammatory activity. NaCl aggravates peritoneal macrophage inflammation by promoting the expressions of interleukin(IL)-1, IL-6 and mouse inducible nitric oxide synthase. Specifically, high NaCl concentrations promote p38 phosphorylation in lipopolysaccharide-and IFN-γ-activated LPMCs mediated by SGK1. CONCLUSION Proinflammatory macrophages may play an essential role in the onset and development of NaCl-promoted inflammation in DSS-induced colitis. The underlining mechanism involves up-regulation of the p38/MAPK axis.
