珍奥酵母核酸对环磷酰胺致小鼠免疫功能低下的影响

目的 通过环磷酰胺致小鼠免疫功能低下,建立BALB/C小鼠免疫功能低下模型,评价珍奥酵母核酸对小鼠免疫功能低下的作用.方法 选用BALB/C小鼠,随机分组,分别给予相应的处理,选择T淋巴细胞亚群CD69+/CD3+比值、NK细胞亚群CD69+/NKG2D+比值、淋巴细胞转化率及血清IL-2含量作为细胞免疫的指标.结果 核酸各剂量组和添加剂组均可使免疫低下小鼠外周血和脾的T淋巴细胞亚群CD69+/CD3+比值、NK细胞亚群CD69+/NKG2D+比值提高,同时可提高免疫低下小鼠淋巴细胞转化率及IL-2水平,尤以高、中剂量核酸组和添加剂组明显(P＜0.05).结论 珍奥酵母核酸可以提高免疫低下小鼠的免疫功能,以其为珍奥酵母核酸的临床应用及提高机体免疫力提供了实验依据.     

免疫活性地龙肽的制备及其对小鼠巨噬细胞活性的影响

分离纯化免疫活性地龙肽并研究其对小鼠巨噬细胞活性的影响.通过抽提、离心、超滤及色谱等步骤提取小分子量免疫活性地龙肽;通过体外实验测定其对巨噬细胞吞噬活性的影响.结果表明,一定浓度的3种免疫活性地龙肽在体外均可明显增强小鼠巨噬细胞的吞噬活性,提示其具有免疫调节功能.     

乳酸L-68型粪肠球菌对肉鸡生产性能和免疫功能的影响

目的研究乳酸L-68粪肠球菌对肉鸡的生产性能和免疫功能的影响。方法选用3000羽1日龄的艾维菌肉用仔鸡,随机分为两个处理组,每组1500羽。对照组饲喂基础日粮,实验组饲喂基础日粮并在饮水中加入微生态制剂乳酸L-68粪肠球菌,实验期为42d。通过检测平均周增重、料肉比、鸡群的健康状况、抗体水平和器官指数探索该制剂对肉鸡的促生长和免疫增强作用。结果微生态制剂实验组鸡的周增重、料肉比、抗NDV的HI效价、免疫器官指数均优于对照组鸡,差异有显著性（P〈0．05）。结论肉鸡饮水中添加乳酸L-68粪肠球菌,能促进免疫器官的生长发育,提高免疫器官指数;能明显提高循环抗体的水平,因而能促进仔鸡的生长发育,降低料肉比。     

牛磺酸对化疗荷瘤小鼠增效减毒作用的研究

目的:探讨牛磺酸对化疗荷瘤小鼠的增效减毒作用.方法:采用小鼠H22移植瘤动物模型,观察不同荆量牛磺酸(taurine,Tau)与环磷酰胺(cyclophosphamide,CTX)联合用药的抗肿瘤作用;检测外周血白细胞数,骨髓有核细胞数;测定脾指数,胸腺指数;采用MTT法检测NK细胞活性和脾淋巴细胞转化率.结果:Tau增强CTX的抗肿瘤作用;拮抗CTX对白细胞和骨髓有核细胞的抑制;提高免疫器官指数,促进淋巴细胞增殖,增强NK细胞活性.结论:Tau对荷瘤小鼠化疗具有增效减毒作用.     

Effect of rabbit interferon on immune responses

Rabbit interferon was found to inhibit partially the proliferative response of rabbit lymph node cells to antigen. In contrast, neither the primary humoral immune response to sheep erythrocytes in vivo nor the secondary antibody response of lymph node fragments in vitro to diphtheria toxoid was significantly inhibited by interferon.It is suggested that the inhibition of lymphoid-cell proliferation by interferon is an expression of a more general tendency to inhibit mitotic activity.     

Dietary nucleosides and nucleotides reduce Cryptosporidium parvum infection in dexamethasone immunosuppressed adult mice.

Numerous studies have demonstrated that dietary sources of nucleosides and nucleotides are important for the maintenance of cellular and humoral immune responses. To determine the immunological effects of feeding a nucleoside-nucleotide mixture to dexamethasone-immunosuppressed C57BL/6 adult mice infected with Cryptosporidium parvum, we examined fecal oocyst shedding, lymphoproliferative responses to concanavalin (Con) A, and C. parvum antigen, interleukin (IL-2), and gamma-interferon (IFN-gamma) production by cultured spleen cells. Mice were fed a nucleotide-free 20% casein diet (control group) or this diet supplemented with a 0. 5% nucleoside-nucleotide mixture before and after inoculation with C. parvum. Spleens from mice receiving the supplemented diet had higher (P < 0.05) Con A and antigen-specific induced cell proliferation than those from control mice. In addition to the increased cell proliferation, the spleen cells from the supplemented mice produced significantly more IL-2 (P < 0.002) and significantly more IFN-gamma (P <; 0.004) than cells from the control mice. Mice fed the supplemented diet excreted fewer (P < 0.05) C. parvum oocysts in the feces than control mice. The cumulative survival rate in the nucleoside-nucleotide mixture-fed group was higher compared with the control group (P < 0.05). We conclude that nucleosides and nucleotides may partially counteract the immunosuppressive effects of dexamethasone in C. parvum-challenged mice.     

双歧杆菌脂磷壁酸对化疗荷瘤小鼠免疫功能的影响

目的探讨双歧杆菌脂磷壁酸对5-氟尿嘧啶（5-FU）化疗肝癌H22荷瘤小鼠免疫的影响及其作用机制。方法双歧杆菌脂磷壁酸处理5-Fu化疗的H纶荷瘤Balb／c小鼠,MTT法检测NK细胞和CTL细胞杀伤活性;采用流式细胞仪检测荷瘤小鼠脾细胞中T亚群比例;用RT-PCR和Western Not方法分别检测荷瘤小鼠肿瘤组织Foxp3和TIM-3mRNA及蛋白的表达变化。结果荷瘤小鼠脾细胞中CD4^＋ CD25^＋Tmg比例高,并存在Foxp3和TIM-3 mRNA及蛋白的高表达,经双歧杆菌LTA和5．Fu处理后CD4^＋CD25^＋Tmg比例下降,Foxp3和TIM-3mRNA及蛋白表达水平也均呈下调趋势,但5-FU单独处理后的荷瘤小鼠脾细胞中CD4^＋细胞比例也减少,NK细胞和CTL杀伤率均降低,而双歧杆菌LTA处理后CD4^＋细胞比例,NK细胞和CTL杀伤率却明显增加。二者联合处理也能增加CD^＋细胞比例及NK细胞和CTL杀伤率。结论双歧杆菌脂磷壁酸联合5-FU可通过增强NK细胞和CTL杀伤能力,同时抑制TIM-3／TIM-3L途径,降低CD4^＋CD25^＋Tmg的免疫抑制活性,增强机体细胞免疫来提高化疗抗肿瘤效果,减轻化疗副作用,增强宿主对化疗的耐受性,从而提高抗肿瘤作用。     

Stimulation of humoral immune responses to a thymic-independent antigen in mice immunosuppressed by a graft-versus-host reaction.

The immunosuppressive effect of the graft-versus-host (GVH) reaction was studied in CBA × A F₁ (CAF₁) mice which had been rendered immunologically unresponsive by the injection of parental A-strain lymphoid cells (GVH mice). When challenged with a single injection of either sheep red blood cells or Escherichia coli lipopolysaccharide (LPS), GVH mice failed to produce a significant number of plaque-forming cells (PFC) or a significant level of antibody against either the thymic-dependent or the thymic-independent antigen. Multiple challenges with SRBC also failed to stimulate a significant humoral immune response to the thymic-dependent antigen. Multiple challenges with LPS, however, resulted in the production of a significant number of LPS-specific PFC and a high titer of anti-LPS hemagglutinating antibodies. These results suggest that GVH-induced suppression of humoral immune responses is directed partly at B-cell activity and partly at the activity of helper T cells.     

长双歧杆菌完整肽聚糖对小鼠免疫功能的影响

目的比较长双歧杆菌及其完整肽聚糖的免疫调节作用。方法通过研究长双歧杆菌完整肽聚糖对植瘤小鼠淋巴细胞的转化、抑瘤率、生命延长期以及对细胞Bcl-2和Bax表达的影响来探讨它们对小鼠细胞免疫的调节作用。结果与对照组相比,完整肽聚糖使淋巴细胞转化增加、抑瘤率提高、延长生命期增加、Bcl-2阳性表达率减小而Bax基因表达增加。结论长双歧杆菌与其完整肽聚糖均有抑制S180肿瘤的作用,但完整肽聚糖的效果优于长双歧杆菌。     

Effect of dexamethasone on moesin gene expression in rabbit bone marrow stromal cells

The influence of dexamethasone on rabbit bone marrow stromal cells differentiation was studied by screening the action of dexamethasone on gene expression. Using differential display, we observed some differential amplifications. The use of five of thirteen different primers combination allowed to identify one or more differential bands. One of them was identified as moesin gene. Real-time PCR confirmed a significant reduction of moesin gene expression following dexamethasone treatment. The decrease of expression for this protein, involved in cytoskeletal organization, could explain the effects of dexamethasone treatment on bone marrow stromal cells differentiation.     

Effect of neutrophilokines on the immune response in mice

The influence of different peptide fractions obtained from the intact and latex-stimulated neutrophils on the immune response was studied. It was demonstrated that neutrophils after stimulation synthesize the factors activating immune response, the intact neutrophils synthesize the suppressor factors of peptide nature.