RESUMO
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.
RESUMO
El sistema inmune es capaz de realizar la detección y eliminación de células transformadas por un mecanismo fisiológico conocido como inmunovigilancia. En este proceso participa el receptor activador NKG2D presente en linfocitos T y células NK, ambos de suma relevancia en la inmunovigilancia contra el cáncer. Al reconocer el receptor NKG2D a sus ligandos (NKG2DLs) en las células que experimentan neotransformación se desencadena la respuesta lítica específica de las células linfoides citotóxicas. Asimismo, se ha descrito en diversos tipos de cáncer formas solubles de NKG2DLs que se ha demostrado son utilizadas para la evasión tumoral al saturar los receptores NKG2D presentes en las células efectoras linfoides evitando de esta manera ser reconocidas y eliminadas y, con ello escapando de la inmunovigilancia. Aunque este fenómeno de evasión inmune, donde participan algunos NKG2DLs, ha sido ya descrito y corroborado clínicamente no se ha estudiado si el receptor NKG2D está presente en las células tumorales per se ya que también podría estar implicado en subvertir la inmunovigilancia. En este trabajo se analizan evidencias recientes de que la expresión del receptor NKG2D no es exclusiva de linfocitos T y NK ya es expresado por células epiteliales tumorales tanto in vitro como in vivo. Las consecuencias de esta anómala expresión en células no linfoides tiene amplias implicaciones en la carcinogénesis que serán revisadas. También se analizan estudios clínicos recientes donde se comprueba la participación del receptor NKG2D en diferentes patologías tumorales.
The immune system is able to perform the detection and elimination of transformed cells by a mechanism known as physiological immune surveillance. This process involves the NKG2D receptor activator present in T lymphocytes and NK cells, both of paramount importance in the immune surveillance against cancer. To recognize the receptor NKG2D ligands (NKG2DLs) in cells that experience retransformation triggers the specific lithic response of the cytotoxic lymphoid cells. Also, soluble forms of NKG2DLs have been described in various types of cancer that have proven to be used for tumor evasion by saturating the NKG2D receptors present in the effector lymphoid cells thus avoiding their recognition and elimination, which makes them escape immune surveillance. Although this phenomenon of immune evasion, where some NKG2DLs participate, has already been described and corroborated, clinically, it has not been studied whether the receptor NKG2DL is present in the tumor cells per se because it could also be involved in reversing immune surveillance. This paper analyzes recent evidence that the expression of the NKG2D receptor is not lymphocyte T and NK exclusive it is already expressed by tumor epithelial cells in vitro and in vivo. Consequences of this anomalous expression in non-lymphoid cells have widespread implications in carcinogenesis, which will be revised. Recent clinical studies to prove the participation of NKG2D receptor in several tumor pathologies are analyzed.
Assuntos
Humanos , Neoplasias , Linfócitos , Citotoxinas , CarcinogêneseRESUMO
Objective To investigate the changes in cytotoxicity of DC-CIK cells to human multiple myeloma RPMI 8226 cells before and after treatment with oridonin. Methods Normal human peripheral blood mononuclear cells were isolated and induced to obtain DC-CIK cells. Cytotoxicity of DC-CIK cells against RPMI 8226 cells which were treated by oridonin was analyzed by LDH releasing assay. The variation for expression of NKG2D ligands on RPMI 8226 cells were measured by flow cytometry. Results DC-CIK cells were successfully induced from the peripheral blood mononuclear cells. At the same effector to target ratio, oridonin obviously enhanced the cytotocixity of DC-CIK cells against RPMI 8226 cells (P<0.01). Flow cytometry showed the expression of NKG2D ligands ULBP1 of RPMI8226 cells was most significantly increased as the cells were treated by oridonin [(9.19 ± 1.85) vs. (15.47 ± 0.67), P<0.01]. Correlation analysis indicated that cytotocixity was positively correlated with changes in ULBP1. Conclusions Oridonin can improve the cytotoxicity of DC-CIK cells against RPMI 8226 cells, which may be related with the increased expressions of NKG2D ligands on the tumor cell surface.