Summary： Human interleukin-15 （hIL-15） is an important cytokine to activate endothelial cells and can be regulated by many other cytokines. The aim of this study is to examine the ability of interferon-γ （IFN-γ...Summary： Human interleukin-15 （hIL-15） is an important cytokine to activate endothelial cells and can be regulated by many other cytokines. The aim of this study is to examine the ability of interferon-γ （IFN-γ）, and tumor necrosis factor-or （TNF-α to induce the production of human interleukin-15 （hIL-15） and IL-15 receptor （IL-15Rα by human umbilical vein endothelial cells （HUVECs）. The data are summarized as follows： 1. Northern blot revealed that IL-15 mRNA was up-regulated by IFN-γ and TNF-α 2. Intracellular IL-15 protein was visualized by fluorescence microscopy, whereas the expression of IL-15 on the surface of HUVECs was detected by fluorescence activated cell sorting （FACS）, and no detectable IL-15 in the medium was verified by ELISA. 3. IL-15Rα was detected on the surface of HUVECs by FACS after IFN-α and TNF-α stimulation, whereas Western blotting revealed that the elevated expression on surface IL-15Rα was not due to the increased protein expression. The conclusion demonstrated from our results is that IFN-α and TNF-α play an important role in regulating the expression of IL-15 and IL-15Rα on the surface of HUVECs.展开更多
Neonatal hypoxic-ischemic encephalopathy is often associated with permanent cerebral palsy,neurosensory impairments,and cognitive deficits,and there is no effective treatment for complications related to hypoxic-ische...Neonatal hypoxic-ischemic encephalopathy is often associated with permanent cerebral palsy,neurosensory impairments,and cognitive deficits,and there is no effective treatment for complications related to hypoxic-ischemic encephalopathy.The therapeutic potential of human placental chorionic plate-derived mesenchymal stem cells for various diseases has been explored.However,the potential use of human placental chorionic plate-derived mesenchymal stem cells for the treatment of neonatal hypoxic-ischemic encephalopathy has not yet been investigated.In this study,we injected human placental chorionic plate-derived mesenchymal stem cells into the lateral ventricle of a neonatal hypoxic-ischemic encephalopathy rat model and observed significant improvements in both cognitive and motor function.Protein chip analysis showed that interleukin-3 expression was significantly elevated in neonatal hypoxic-ischemic encephalopathy model rats.Following transplantation of human placental chorionic plate-derived mesenchymal stem cells,interleukin-3 expression was downregulated.To further investigate the role of interleukin-3 in neonatal hypoxic-ischemic encephalopathy,we established an in vitro SH-SY5Y cell model of hypoxic-ischemic injury through oxygen-glucose deprivation and silenced interleukin-3 expression using small interfering RNA.We found that the activity and proliferation of SH-SY5Y cells subjected to oxygen-glucose deprivation were further suppressed by interleukin-3 knockdown.Furthermore,interleukin-3 knockout exacerbated neuronal damage and cognitive and motor function impairment in rat models of hypoxic-ischemic encephalopathy.The findings suggest that transplantation of hpcMSCs ameliorated behavioral impairments in a rat model of hypoxic-ischemic encephalopathy,and this effect was mediated by interleukin-3-dependent neurological function.展开更多
Human interleukin-15 （IL-15） is a proinflammatory cytokine to suppress neutrophil apoptosis, which is a potential therapeutic agent. The modulatory effect of TNFα was investigated in IL-15-induced suppression of hu...Human interleukin-15 （IL-15） is a proinflammatory cytokine to suppress neutrophil apoptosis, which is a potential therapeutic agent. The modulatory effect of TNFα was investigated in IL-15-induced suppression of human neutrophil apoptosis. TNFa was shown to reverse the ability of IL-15 to delay neutrophil apoptosis within certain time course. Moreover, this reverse effect by TNFα might be associated with a reduction of the expression of the anti-apoptotic Bcl-XI protein detected by Western blotting. It is concluded that TNFα can be used to modulate IL- 15-induced suppression of neutrophil apoptosis within certain time course.展开更多
AIM To evaluate the treatment effects of recombinant human interleukin-12(rh IL-12) on radiotherapy complications, such as severe myelosuppression or pancytopenia, the decline or imbalance of immune function, etc.METH...AIM To evaluate the treatment effects of recombinant human interleukin-12(rh IL-12) on radiotherapy complications, such as severe myelosuppression or pancytopenia, the decline or imbalance of immune function, etc.METHODS The patients received high-dose and short-course precise radiotherapy, such as Cyber knife and image-guided radiotherapy(IGRT), which can cause myelosuppression or pancytopenia and immune function decline within a short time. One-hundred subjects were enrolled in the study, and 50 were randomized to a treatment group which used rh IL-12 and 50 were randomized to a control group which used symptomatic and supportive therapy after radiotherapy. The 50 subjects in the treatment group were further divided into five subgroups and intervenedwith rh IL-12 at a dose of 50, 100, 150, 200 or 250 ng/kg respectively. The dose-effect relationship was observed. RESULTS Rh IL-12 significantly attenuated the decrease of peripheral blood cells in the treatment group, and immune function was improved after treatment. Due to the different radiation doses, there was a fluctuation within 12 h after treatment but mostly showing an increasing trend. As to the clinical manifestations, 2 patients in the 250 ng/kg subgroup showed low fever after administration, 1 patient in the 200 ng/kg subgroup and 2 patients in the 250 ng/kg subgroup showed mild impairment of liver function during the observation period.CONCLUSION Rh IL-12 has effective therapeutic and protective effects on complications following radiotherapy, such as the decline of blood cells, myelosuppression and the decline or imbalance of immune function, which indicated good prospects for development and application.展开更多
Human IL15 cDNA fragment, which contains all codons encoding the human IL15 mature protein and signal peptide was transducted into the human lung squmouse cancer cells(PG cells) and murine lung adenocarcinoma cells(LA...Human IL15 cDNA fragment, which contains all codons encoding the human IL15 mature protein and signal peptide was transducted into the human lung squmouse cancer cells(PG cells) and murine lung adenocarcinoma cells(LA795 cell lines). Two IL15 highly expressed cell clones PG1 and LA795A were used to inoculate the nude mice and the T739 syngeneic mice respectively. PG1 cell express higher level of class ⅠMHC molecule on their surface than PG cells. It was shown that the modified LA795A tumor cells grew slowly in T739 mice and induced high levels of CTL/NK/LAK activity in vivo as well, compared with the case of inoculation with LA795 or LA795neo. No significant difference in the tumor growth was observed in groups of the nude mice inoculated by PG1, PG and PGneo cells respectively, except the gene modified cells could not show the lung metastasis of tumors. The supernatants derived from the LA795A cell culture could promote CTL/NK/LAK activity from the whole splenocytes and the CD4/CD8deleted splenic cells in vitro. The results indicated that the IL15 gene transfected tumor cells play important roles in the process of antitumor or antitumor metastasis.展开更多
Intraperitoneal injection of recombinant human interleukin-2（rhIL-2）inhibits neuronal apoptosis in the chronic ocular hypertension retinal ganglion cell layer.Intravitreous injection was performed on retinal ganglio...Intraperitoneal injection of recombinant human interleukin-2（rhIL-2）inhibits neuronal apoptosis in the chronic ocular hypertension retinal ganglion cell layer.Intravitreous injection was performed on retinal ganglion cells in a Wistar rat model of chronically elevated intraocular pressure to observe the effects of LY294002 and AG490 on retinal ganglion cell survival,macrophage activation,and PI3K/Akt and JAK/STAT activation.The number of retinal ganglion cells in the rhIL-2 treatment group was much greater than in the normal control and phosphate-buffered saline groups.Western blot analysis revealed low Akt and STAT3 protein expression in the retina after 3-hour intravitreous injections of rhIL-2.However,protein expression was increased at 12 hours,but decreased again at 24 hours,with very low expression at 96 hours.LY294002 and AG490,which are inhibitors of the PI3K/Akt and JAK/STAT3 signal pathways,prevented upregulation of Akt and STAT3 protein expression in the retina,respectively.Intravitreous injection of rhIL-2 exhibited neuroprotective effects by decreasing retinal ganglion cell layer damage in a rat model of chronic glaucoma.These results suggest that intravitreal injection of rhIL-2 could induce the PI3K/Akt and JAK/STAT3 signaling pathways to protect retinal ganglion cells in chronically elevated intraocular pressure models.展开更多
Studies have shown that human hair keratin(HHK) has no antigenicity and excellent mechanical properties. Schwann cells, as unique glial cells in the peripheral nervous system, can be induced by interleukin-1β to secr...Studies have shown that human hair keratin(HHK) has no antigenicity and excellent mechanical properties. Schwann cells, as unique glial cells in the peripheral nervous system, can be induced by interleukin-1β to secrete nerve growth factor, which promotes neural regeneration. Therefore, HHK with Schwann cells may be a more effective approach to repair nerve defects than HHK without Schwann cells. In this study, we established an artificial nerve graft by loading an HHK skeleton with activated Schwann cells. We found that the longitudinal HHK microfilament structure provided adhesion medium, space and direction for Schwann cells, and promoted Schwann cell growth and nerve fiber regeneration. In addition, interleukin-1β not only activates Schwann cells, but also strengthens their activity and increases the expression of nerve growth factors. Activated Schwann cells activate macrophages, and activated macrophages secrete interleukin-1β, which maintains the activity of Schwann cells. Thus, a beneficial cycle forms and promotes nerve repair. Furthermore, our studies have found that the newly constructed artificial nerve graft promotes the improvements in nerve conduction function and motor function in rats with sciatic nerve injury, and increases the expression of nerve injury repair factors fibroblast growth factor 2 and human transforming growth factor B receptor 2. These findings suggest that this artificial nerve graft effectively repairs peripheral nerve injury.展开更多
BACKGROUND： Studies of several animal models of central nervous system diseases have shown that neural progenitor cells （NPCs） can migrate to injured tissues. Stromal cell-derived factor 1 alpha （SDF-la）, and its...BACKGROUND： Studies of several animal models of central nervous system diseases have shown that neural progenitor cells （NPCs） can migrate to injured tissues. Stromal cell-derived factor 1 alpha （SDF-la）, and its primary physiological receptor CXCR4, have been shown to contribute to this process. OBJECTIVE： To investigate migration efficacy of human NPCs toward a SDF-1α gradient, and the regulatory roles of tumor necrosis factor-α （TNF-α） and interleukin-8 （IL-8） in SDF-1α/CXCR4 axis-induced migration of NPCs. DESIGN, TIME AND SETTING： An in vitro, randomized, controlled, cellular and molecular biology study was performed at the Laboratory of Department of Cell Biology, Medical College of Soochow University between October 2005 and November 2007. MATERIALS： SDF-1α and mouse anti-human CXCR4 fusion antibody were purchased from R＆D Systems, USA. TNF-αwas purchased from Biomyx Technology, USA and IL-8 was kindly provided by the Biotechnology Research Institute of Soochow University. METHODS： NPCs isolated from forebrain tissue of 9 to 10-week-old human fetuses were cultured in vitro. The cells were incubated with 0, 20, and 40 ng/mL TNF-α, or 0, 20, and 40 ng/mL IL-8, for 48 hours prior to migration assay. For antibody-blocking experiments, cells were further pretreated with 0, 20, and 40 μg/mL mouse anti-human CXCR4 fusion antibody for 2 hours. Subsequently, the transwell assay and CXCR4 blockade experiments were performed to evaluate migration of human NPCs toward a SDF-1α gradient. Serum-free culture medium without SDF-1α served as the negative control. MAIN OUTCOME MEASURES： The transwell assay was performed to evaluate migration of human NPCs toward a SDF-1α gradient, which was blocked by fusion antibody against CXCR4. In addition, CXCR4 expression in human NPCs stimulated by TNF-α and IL-8 was measured by flow cytometry. RESULTS： Results from the transwell assay demonstrated that SDF-1α was a strong chemoattractant for human NPCs （P 〈 0.01）, and 20 ng/mL produced the highest levels of migration. Anti-human CXCR4 fusion antibody significantly blocked the chemotactic effect （P 〈 0.05）. Flow cytometry results showed that treatment with TNF-α and IL-8 resulted in increased CXCR4 expression and greater chemotaxis efficiency of NPCs towards SDF-1α（P 〈 0.01）. CONCLUSION： These results demonstrated that SDF-la significantly attracted NPCs in vitro, and neutralizing anti-CXCR4 antibody could block part of this chemotactic function. TNF-α and IL-8 increased chemotaxis efficiency of NPCs towards the SDF-1αgradient by upregulating CXCR4 expression in NPCs.展开更多
Using cytotoxicity and thymidine uptake assays, we investigated the effects of human recombinant in-terleukin-2 (rIL-2) on the induction of lympholine-activated killer (LAK) activity and cellular proliferation in sple...Using cytotoxicity and thymidine uptake assays, we investigated the effects of human recombinant in-terleukin-2 (rIL-2) on the induction of lympholine-activated killer (LAK) activity and cellular proliferation in splenocytes and thymocytes from human fetuses (18-22 weeks). We observed that fetal splenocytes and thymocytes incubated with low doses of rIL-2 (10-100 U ml) developed broad antitumor activity (LAK activity) although the kinetics and magnitudes of the responses were different. It indicated the LAK precursors are present in fetal spleen and thymus. Further, rIL-2 induced a strong proliferative response in splenocytes, but not in thymocytes. On the basis of the findings, we conclude that the responses of fetal splenocytes and thymocytes to IL-2 are different.展开更多
文摘Summary： Human interleukin-15 （hIL-15） is an important cytokine to activate endothelial cells and can be regulated by many other cytokines. The aim of this study is to examine the ability of interferon-γ （IFN-γ）, and tumor necrosis factor-or （TNF-α to induce the production of human interleukin-15 （hIL-15） and IL-15 receptor （IL-15Rα by human umbilical vein endothelial cells （HUVECs）. The data are summarized as follows： 1. Northern blot revealed that IL-15 mRNA was up-regulated by IFN-γ and TNF-α 2. Intracellular IL-15 protein was visualized by fluorescence microscopy, whereas the expression of IL-15 on the surface of HUVECs was detected by fluorescence activated cell sorting （FACS）, and no detectable IL-15 in the medium was verified by ELISA. 3. IL-15Rα was detected on the surface of HUVECs by FACS after IFN-α and TNF-α stimulation, whereas Western blotting revealed that the elevated expression on surface IL-15Rα was not due to the increased protein expression. The conclusion demonstrated from our results is that IFN-α and TNF-α play an important role in regulating the expression of IL-15 and IL-15Rα on the surface of HUVECs.
基金supported by the National Natural Science Foundation of China,No.82001604Guizhou Provincial Higher Education Science and Technology Innovation Team,No.[2023]072+1 种基金Guizhou Province Distinguished Young Scientific and Technological Talent Program,No.YQK[2023]040Guizhou Provincial Basic Research Program(Natural Science),No.ZK[2021]-368(all to LXiong),and Zunyi City Innovative Talent Team Training Plan,No.[2022]-2.
文摘Neonatal hypoxic-ischemic encephalopathy is often associated with permanent cerebral palsy,neurosensory impairments,and cognitive deficits,and there is no effective treatment for complications related to hypoxic-ischemic encephalopathy.The therapeutic potential of human placental chorionic plate-derived mesenchymal stem cells for various diseases has been explored.However,the potential use of human placental chorionic plate-derived mesenchymal stem cells for the treatment of neonatal hypoxic-ischemic encephalopathy has not yet been investigated.In this study,we injected human placental chorionic plate-derived mesenchymal stem cells into the lateral ventricle of a neonatal hypoxic-ischemic encephalopathy rat model and observed significant improvements in both cognitive and motor function.Protein chip analysis showed that interleukin-3 expression was significantly elevated in neonatal hypoxic-ischemic encephalopathy model rats.Following transplantation of human placental chorionic plate-derived mesenchymal stem cells,interleukin-3 expression was downregulated.To further investigate the role of interleukin-3 in neonatal hypoxic-ischemic encephalopathy,we established an in vitro SH-SY5Y cell model of hypoxic-ischemic injury through oxygen-glucose deprivation and silenced interleukin-3 expression using small interfering RNA.We found that the activity and proliferation of SH-SY5Y cells subjected to oxygen-glucose deprivation were further suppressed by interleukin-3 knockdown.Furthermore,interleukin-3 knockout exacerbated neuronal damage and cognitive and motor function impairment in rat models of hypoxic-ischemic encephalopathy.The findings suggest that transplantation of hpcMSCs ameliorated behavioral impairments in a rat model of hypoxic-ischemic encephalopathy,and this effect was mediated by interleukin-3-dependent neurological function.
基金This project was supported by a grant from NIH foundation of USA
文摘Human interleukin-15 （IL-15） is a proinflammatory cytokine to suppress neutrophil apoptosis, which is a potential therapeutic agent. The modulatory effect of TNFα was investigated in IL-15-induced suppression of human neutrophil apoptosis. TNFa was shown to reverse the ability of IL-15 to delay neutrophil apoptosis within certain time course. Moreover, this reverse effect by TNFα might be associated with a reduction of the expression of the anti-apoptotic Bcl-XI protein detected by Western blotting. It is concluded that TNFα can be used to modulate IL- 15-induced suppression of neutrophil apoptosis within certain time course.
文摘AIM To evaluate the treatment effects of recombinant human interleukin-12(rh IL-12) on radiotherapy complications, such as severe myelosuppression or pancytopenia, the decline or imbalance of immune function, etc.METHODS The patients received high-dose and short-course precise radiotherapy, such as Cyber knife and image-guided radiotherapy(IGRT), which can cause myelosuppression or pancytopenia and immune function decline within a short time. One-hundred subjects were enrolled in the study, and 50 were randomized to a treatment group which used rh IL-12 and 50 were randomized to a control group which used symptomatic and supportive therapy after radiotherapy. The 50 subjects in the treatment group were further divided into five subgroups and intervenedwith rh IL-12 at a dose of 50, 100, 150, 200 or 250 ng/kg respectively. The dose-effect relationship was observed. RESULTS Rh IL-12 significantly attenuated the decrease of peripheral blood cells in the treatment group, and immune function was improved after treatment. Due to the different radiation doses, there was a fluctuation within 12 h after treatment but mostly showing an increasing trend. As to the clinical manifestations, 2 patients in the 250 ng/kg subgroup showed low fever after administration, 1 patient in the 200 ng/kg subgroup and 2 patients in the 250 ng/kg subgroup showed mild impairment of liver function during the observation period.CONCLUSION Rh IL-12 has effective therapeutic and protective effects on complications following radiotherapy, such as the decline of blood cells, myelosuppression and the decline or imbalance of immune function, which indicated good prospects for development and application.
文摘Human IL15 cDNA fragment, which contains all codons encoding the human IL15 mature protein and signal peptide was transducted into the human lung squmouse cancer cells(PG cells) and murine lung adenocarcinoma cells(LA795 cell lines). Two IL15 highly expressed cell clones PG1 and LA795A were used to inoculate the nude mice and the T739 syngeneic mice respectively. PG1 cell express higher level of class ⅠMHC molecule on their surface than PG cells. It was shown that the modified LA795A tumor cells grew slowly in T739 mice and induced high levels of CTL/NK/LAK activity in vivo as well, compared with the case of inoculation with LA795 or LA795neo. No significant difference in the tumor growth was observed in groups of the nude mice inoculated by PG1, PG and PGneo cells respectively, except the gene modified cells could not show the lung metastasis of tumors. The supernatants derived from the LA795A cell culture could promote CTL/NK/LAK activity from the whole splenocytes and the CD4/CD8deleted splenic cells in vitro. The results indicated that the IL15 gene transfected tumor cells play important roles in the process of antitumor or antitumor metastasis.
基金the New Century Excellent Talents Project Grant by the Ministry of Education of China,No.NCET-06-0677the Natural Science Foundation of Hu-nan Province,No.05JJ30051
文摘Intraperitoneal injection of recombinant human interleukin-2（rhIL-2）inhibits neuronal apoptosis in the chronic ocular hypertension retinal ganglion cell layer.Intravitreous injection was performed on retinal ganglion cells in a Wistar rat model of chronically elevated intraocular pressure to observe the effects of LY294002 and AG490 on retinal ganglion cell survival,macrophage activation,and PI3K/Akt and JAK/STAT activation.The number of retinal ganglion cells in the rhIL-2 treatment group was much greater than in the normal control and phosphate-buffered saline groups.Western blot analysis revealed low Akt and STAT3 protein expression in the retina after 3-hour intravitreous injections of rhIL-2.However,protein expression was increased at 12 hours,but decreased again at 24 hours,with very low expression at 96 hours.LY294002 and AG490,which are inhibitors of the PI3K/Akt and JAK/STAT3 signal pathways,prevented upregulation of Akt and STAT3 protein expression in the retina,respectively.Intravitreous injection of rhIL-2 exhibited neuroprotective effects by decreasing retinal ganglion cell layer damage in a rat model of chronic glaucoma.These results suggest that intravitreal injection of rhIL-2 could induce the PI3K/Akt and JAK/STAT3 signaling pathways to protect retinal ganglion cells in chronically elevated intraocular pressure models.
基金supported by Military Medical Science&Technology Youth Training Program,No. 19QNP005President Foundation of Nanfang Hospital,Southern Medical University,No. 2020B028 (both to JY)。
文摘Studies have shown that human hair keratin(HHK) has no antigenicity and excellent mechanical properties. Schwann cells, as unique glial cells in the peripheral nervous system, can be induced by interleukin-1β to secrete nerve growth factor, which promotes neural regeneration. Therefore, HHK with Schwann cells may be a more effective approach to repair nerve defects than HHK without Schwann cells. In this study, we established an artificial nerve graft by loading an HHK skeleton with activated Schwann cells. We found that the longitudinal HHK microfilament structure provided adhesion medium, space and direction for Schwann cells, and promoted Schwann cell growth and nerve fiber regeneration. In addition, interleukin-1β not only activates Schwann cells, but also strengthens their activity and increases the expression of nerve growth factors. Activated Schwann cells activate macrophages, and activated macrophages secrete interleukin-1β, which maintains the activity of Schwann cells. Thus, a beneficial cycle forms and promotes nerve repair. Furthermore, our studies have found that the newly constructed artificial nerve graft promotes the improvements in nerve conduction function and motor function in rats with sciatic nerve injury, and increases the expression of nerve injury repair factors fibroblast growth factor 2 and human transforming growth factor B receptor 2. These findings suggest that this artificial nerve graft effectively repairs peripheral nerve injury.
基金the National Natural Science Foundation of China,No.30671041the National Basic Research Program of China(973 Program),No. 2005CB623902
文摘BACKGROUND： Studies of several animal models of central nervous system diseases have shown that neural progenitor cells （NPCs） can migrate to injured tissues. Stromal cell-derived factor 1 alpha （SDF-la）, and its primary physiological receptor CXCR4, have been shown to contribute to this process. OBJECTIVE： To investigate migration efficacy of human NPCs toward a SDF-1α gradient, and the regulatory roles of tumor necrosis factor-α （TNF-α） and interleukin-8 （IL-8） in SDF-1α/CXCR4 axis-induced migration of NPCs. DESIGN, TIME AND SETTING： An in vitro, randomized, controlled, cellular and molecular biology study was performed at the Laboratory of Department of Cell Biology, Medical College of Soochow University between October 2005 and November 2007. MATERIALS： SDF-1α and mouse anti-human CXCR4 fusion antibody were purchased from R＆D Systems, USA. TNF-αwas purchased from Biomyx Technology, USA and IL-8 was kindly provided by the Biotechnology Research Institute of Soochow University. METHODS： NPCs isolated from forebrain tissue of 9 to 10-week-old human fetuses were cultured in vitro. The cells were incubated with 0, 20, and 40 ng/mL TNF-α, or 0, 20, and 40 ng/mL IL-8, for 48 hours prior to migration assay. For antibody-blocking experiments, cells were further pretreated with 0, 20, and 40 μg/mL mouse anti-human CXCR4 fusion antibody for 2 hours. Subsequently, the transwell assay and CXCR4 blockade experiments were performed to evaluate migration of human NPCs toward a SDF-1α gradient. Serum-free culture medium without SDF-1α served as the negative control. MAIN OUTCOME MEASURES： The transwell assay was performed to evaluate migration of human NPCs toward a SDF-1α gradient, which was blocked by fusion antibody against CXCR4. In addition, CXCR4 expression in human NPCs stimulated by TNF-α and IL-8 was measured by flow cytometry. RESULTS： Results from the transwell assay demonstrated that SDF-1α was a strong chemoattractant for human NPCs （P 〈 0.01）, and 20 ng/mL produced the highest levels of migration. Anti-human CXCR4 fusion antibody significantly blocked the chemotactic effect （P 〈 0.05）. Flow cytometry results showed that treatment with TNF-α and IL-8 resulted in increased CXCR4 expression and greater chemotaxis efficiency of NPCs towards SDF-1α（P 〈 0.01）. CONCLUSION： These results demonstrated that SDF-la significantly attracted NPCs in vitro, and neutralizing anti-CXCR4 antibody could block part of this chemotactic function. TNF-α and IL-8 increased chemotaxis efficiency of NPCs towards the SDF-1αgradient by upregulating CXCR4 expression in NPCs.
文摘Using cytotoxicity and thymidine uptake assays, we investigated the effects of human recombinant in-terleukin-2 (rIL-2) on the induction of lympholine-activated killer (LAK) activity and cellular proliferation in splenocytes and thymocytes from human fetuses (18-22 weeks). We observed that fetal splenocytes and thymocytes incubated with low doses of rIL-2 (10-100 U ml) developed broad antitumor activity (LAK activity) although the kinetics and magnitudes of the responses were different. It indicated the LAK precursors are present in fetal spleen and thymus. Further, rIL-2 induced a strong proliferative response in splenocytes, but not in thymocytes. On the basis of the findings, we conclude that the responses of fetal splenocytes and thymocytes to IL-2 are different.
