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ObjectiveTo observe the effect of Tongxie Yaofang on the function of tumor-related natural killer （NK） cells under chronic stress and explore the possible molecular mechanism. MethodFifty SPF-grade BABL/C male mice were randomized into normal， model， and low-， medium-， and high-dose （6.825， 13.65， and 27.3 g·kg-1， respectively） Tongxie Yaofang groups， with 10 mice in each group. Other groups except the blank group were subjected to 7 days of chronic restraint stress， and then forced swimming and tail suspension tests were carried out to evaluate the modeling performance. After the successful modeling， rats in Tongxie Yaofang groups were administrated with low-， medium-， and high-doses of Tongxie Yaofang by gavage， while those in the other groups were administrated with normal saline by gavage. After 14 days， each group of mice was inoculated with subcutaneous colon cancer to establish the model of colon cancer under chronic stress. The pathological changes of the tumor tissue in each group of mice were observed using hematoxylin-eosin （HE） staining. The content of CD49b-positive cells in the peripheral blood and tumor tissue of mice was measured by flow cytometry. Enzyme-linked immunosorbent assay （ELISA） was employed to measure the content of molecules associated with NK cell activation in the peripheral blood. Western blot was employed to determine the protein levels of major histocompatibility complex class Ⅰ polypeptide-related sequences A and B （MICA+MICB） and UL-16-binding protein 1 （ULBP1） in the tumor tissue. ResultCompared with the normal group， the model group showed a decrease in 5-hydroxytryptamine （5-HT） content and an increase in corticosterone （CORT） content in the serum （P<0.05）. Compared with the model group， Tongxie Yaofang increased the 5-HT content and decreased the CORT content （P<0.05， P<0.01）. Compared with the normal group， the modeling increased the tumor volume and weight （P<0.05）， while Tongxie Yaofang inhibited such increases with no statistical significance. The tumor cells in the model group presented neat arrangement， irregular shape， uneven size， obvious atypia， common nuclear division， and small necrotic area， and blood vessels were abundant surrounding the tumor cells. Compared with the model group， Tongxie Yaofang groups showed sparse arrangement of tumor cells， different degrees of patchy necrosis areas in the tumor， and karyorrhexis， dissolution， and nuclear debris in the necrotic part. Compared with the normal group， the model group showed reduced CD49b-positive cells in the peripheral blood and tumor tissue （P<0.01）. Compared with the model group， Tongxie Yaofang increased CD49b-positive cells （medium dose P<0.01， high dose P<0.05， P<0.01）. Compared with the normal group， the modeling lowered the serum levels of granzymes-B （Gzms-B）， perforin （PF）， interferon （IFN）-γ， and tumor necrosis factor （TNF）-α （P<0.05， P<0.01）. Compared with the model group， low-dose Tongxie Yaofang elevated the serum levels of PF， Gzms-B， and TNF-α （P<0.05， P<0.01）， and medium-dose Tongxie Yaofang elevated the serum levels of Gzms-B， PF， IFN-γ， and TNF-α （P<0.05， P<0.01）. In addition， high-dose Tongxie Yaofang elevated the serum levels of PF， IFN-γ， and TNF-α （P<0.01）. Compared with the normal group， the model group presented down-regulated protein level of ULBP1 （P<0.05）. Compared with the model group， low-， medium-， and high-dose Tongxie Yaofang up-regulated the protein level of ULBP1 （P<0.05， P<0.01）， and medium- and high-dose Tongxie Yaofang up-regulated the protein level of MICA+MICB （P<0.05， P<0.01）. ConclusionTongxie Yaofang may promote NK cell activation by up-regulating the expression of MICA+MICB and ULBP1， thereby delaying the progression of colon cancer under chronic stress.
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ObjectiveTo explore the mechanism of Si Junzitang in regulating the expression of NKG2A to affect the anti-colon cancer function of natural killer （NK） cells. MethodNK cells isolated from healthy honors were cultured and used to construct the three incubation models of NK cells， human colon cancer HCT116 cells， and NK cells + HCT116 cells （co-incubation）. real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was conducted to determine the mRNA levels of natural killer group 2 member A （NKG2A） and interleukin （IL）-15 in NK cells， as well as the mRNA level of histocompatibility leucocyte antigen E （HLA-E） in HCT116 cells. The secretion of IL-15 was detected by enzyme-linked immunosorbent assay （ELISA）. Methyl thiazolyl tetrazolium （MTT） assay was employed to determine the applicable concentration of IL-15 and test the effects of Si Junzitang and IL-15 on the activities of NK cells and the HCT116 cells in the co-incubation model. The effects of Si Junzitang and IL-15 on the mRNA levels of NKG2A in NK cells and HLA-E in HCT116 cells were detected by Real-time PCR. Monalizumab （M， anti-NKG2A mab） was used to block the NKG2A-HLA-E pathway in co-incubation model， and then the proliferation of HCT116 cells was detected by MTT assay. ResultThe interaction of NK cells and HCT116 cells up-regulated the mRNA levels of NKG2A in NK cells and HLA-E in HCT116 cells （P<0.05）， as well as the expression level and secretion of IL-15 （P<0.05）. Compared with the blank group， Si Junzitang and Si Junzitang + IL-15 promoted the proliferation and improved the anti-colon cancer function of NK cells （P<0.01）. Furthermore， they down-regulated the mRNA levels of NKG2A in NK cells and HLA-E in the HCT116 cells co-incubated with NK cells （P<0.01）. M and IL-15 + M inhibited the proliferation of HCT116 cells compared with the groups without M （P<0.01）. ConclusionThe interaction of NK cells and HCT116 cells can induce activation of NKG2A-HLA-E pathway to impair NK cell function. Si Junzitang can inhibit the activation of NKG2A-HLA-E pathway to restore the anti-colon cancer function of NK cells.
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Natural killer (NK) cells are among the first in defense of the innate immune system by eliminating a variety of abnormal or stressed cells such as cancer cells or virus-infected cells. Individuals who exhibit low cytolytic NK cell activity are believed to be at higher risk of viral infection, tumorigenesis, and various other diseases of the immune system. Therefore, restoration of impaired NK cell function might be an essential step in immunostimulatory therapy of immunocompromised patients. Bacillus firmus is a non-pathogenic gram-positive bacterium of the environment, which possesses various immunomodulatory properties in vitro and in vivo. This retrospective study reports on the effect of B. firmus on the activity of NK cells in vitro. Basal cytolytic NK cell activity against tumor cells among peripheral blood mononuclear cells (PBMCs) of routine patients was determined in a standardized NK cell cytotoxicity assay. The impact of cultivation of PBMCs with B. firmus preparation Bacillus firmus e volumine ex muris cellulae (Bacillus firmus (evc)) 6x on tumor cell killing by NK cells was monitored in relation to basal NK cell activity. This study showed that stimulation of PBMCs with Bacillus firmus (evc) 6x in vitro led to a significant increase in NK cell function. Substantial improvement in cytolytic NK cell activity (more than 1.3-fold of basal activity) was much more pronounced for patients with compromised NK cell function. Due to its immunostimulatory mode of action, Bacillus firmus (evc) may be of particular importance in therapy of patients with NK cell deficiency.
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Células Asesinas Naturales , Células K562 , Bacillus firmus/inmunologíaRESUMEN
Human tumors, including those of the hepatobiliary system, express a number of specific antigens that can be recognized by T cells, and may provide potential targets for cancer immunotherapy. Dendritic cells (DCs) are rare leucocytes that are uniquely potent in their ability to capture, process and present antigens to T cells. The ability to culture sufficient numbers of DCs from human bone marrow or blood progenitors has attracted a great deal of interest in their potential utilization in human tumor vaccination. CD34+ peripheral blood stem cells (PBSCs) were obtained from a patient with a hepatocellular carcinoma. The PBSCs were cultured in the X-VIVO 20 medium supplemented with the Flt-3 Ligand (FL), GM-CSF, IL-4 and TNF-alpha for 12 days. The morphology and functions of the cells were examined. The generated cells had the typical morphology of DCs. When the DCs were reinjected into the same patient, an augmentation of the cytotoxic T lymphocyte (CTL) activity was observed. Concomitantly, an increase in the natural killer (NK) cell activity was also detected in the patient. These results suggest that DCs-based cancer immunotherapy may become an important treatment option for cancer patients in the future.