| Immunity is the ability of body to defense against pathogenic invaders and to guard against the uncontrolled growth of cells into neoplasms or tumours,maintaining the homeostasis of body.The genesis and development of lots of diseases are associated with the disturbance of immune system or dysfunction of immunity,hence it is taken seriously starting with modulating the immunol function to treat diseases. Accordingly, the exploitage of immunomodulators attracted more attention from medical professors.There is rich bioactive substance in ocean.It is a new field of immunopharmacology to exploit specific, novel and effective immunomodulator from marine organisms and their metabolites.Polypeptides from Chlamys Farreri(PCF),the micromolecular and water-soluble polypeptides,was isolated and purified from Chlamys Farreri. The previous studies have demonstrated that PCF possessed the activity of protecting immunocytes from the damage of Ultraviolet or 60Co,and reducing the inhibition of the lymphocytes proliferation induced by E2.In our experiment,we further investaged the effects of PCF on the cellular immunity and the nonspecific immunity and its mechanism both in vitro and in v/vo.Dexamethasone (DEX) is a widely used immunosuppressor in clinic,we useflit to establish the immunosuppressed models . The thymus and spleens-of mice were weighed and their morphological changes were observed by haematoxylin and eosin staining(H.E staining). The proliferative response of lymphocytes to ConA was measured with MTT method. The percentages of mouse thymocytes subpopulations and T lymphocytes subpopulations of spleen(of peripheral blood in vivo) were analysed by flow cytometer. The cytotoxicity of splenic natural killer cells was measured with lactate dehydrogenase (LDH) release method. The phagocytic capacity of peritoneal macrophages was measured with neutral red method( with phagocytosing chicken erythrocytes method in vivo) and the Bcl-2 expression of macrophages in vitro was detected withimmunocytochemical staining.The results of our research are as follows:CCF showed a slight raise of the thymus weights and spleen weights of normal mice and mice treated with DEX,but there is no statistic difference among them (P>0. 05; P>0. 05). H.E staining showed that PCF could antagonize the atrophy of the white pulps of mice spleens caused by DEX ,but could not antagonize the atrophy of mice thymuses caused by DEX. (2) PCF could enhance the lymphocytes proliferation induced by ConA(P<0.01; P<0.05) ,and reduce the inhibition of the lymphocytes proliferation caused by DEX both in vitro and in vivo (P<0.01; P<0.01). (3)PCF could decrease the percentages of mouse, thymic L3T4~Lyt-2~ cells and Lyt-2+ cells and splenic Ly.t-2+ cells (P<0.05; P<0.05; P<0.05), and significantly increase the percentage of mouse splenic L3T4+ cells in vitro(P<0.01). PCF treatment exhibited no influence on the percentages of thymocytes subpopulations of normal mice or. mice treated with DEX ,but an increase of the percentages of both L3T4+ cells and Lyt-2+ cells in the peripheral blood of DEX-treated mice in vivo(P<0.05; P<0.05). (4) PCF could enhance the NK cytotoxicity (P<0.01; P<0.05),and resist thie inhibition of NK cytotoxicity caused by DEX both in vitro and in v/vo(P<0.01; P<0.01).(5) PCF could increase the phagocytosis of rat peritoneal macraphage and the Bcl-2 expression ofmacrophages ,and decreasing the downregulation of boJ-2 expression caused by DEX in vitro(P<0.01; P<0.05; P<0.05). PCF could reduce the inhibition of the phagocytosis of peritoneal macrophages induced by DEX (P<0.01),but had no effect on the phagocytosis of macrophages in normal mice in vivo. These indicated that PCF had the ability to upregulate the immunity suppressed by DEX .The mechanism of these effects of PCF may be mediated by promoting the lymphocytes proliferation,enhancing the cytotoxicity of NK cells and the phagocytosis of macrophages ,and increasing the expression of Bcl-2 protein to inhibit the apoptosis of macrophages induced by DEX.Zhang CaiMei(P... |
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