一种人工合成Tuftsin类似肽大鼠组织分布和排泄研究

目的研究Tuftsin类似肽（T肽）单次皮下注射后在大鼠体内的组织分布特点和排泄情况。方法 Wistar大鼠,单次皮下注射剂量21.6 mg.kg-1T肽。采用竞争ELISA方法检测各时间点的组织器官、尿、粪和胆汁中的药物含量。结果组织分布试验结果表明,药物主要分布在大鼠的血清、肾、脾和小肠组织中,除小肠达峰时间为给药后2 h之外,其它药物含量均于给药后15 min达最高;排泄实验结果表明,0～144 h内尿和粪中排泄的原型药物分别占给药总量的2.21%和0.03%;0～96 h内大鼠胆汁中排泄的原型药物为给药总量的0.02%。结论 T肽给药后在Wistar大鼠体内广泛分布,在血清、肾和脾组织中含量较高,在粪和胆汁中检测出T肽的含量很少。     

Tuftsin的合成及对裸鼠胆管癌模型的作用

目的：用多肽合成仪固相合成Ｔｕｆｔｓｉｎ后，研究在体情况下Ｔｕｆｔｓｉｎ抗胆管癌的作用。方法：用毛细管电泳仪检测合成Ｔｕｆｔｓｉｎ的纯度。建立胆管癌裸鼠模型后，用Ｔｕｆｔｓｉｎ治疗４周，观察治疗前后的肿瘤大小与重量和肝、脾及肿瘤组织的病理变化。结果：合成Ｔｕｆｔｓｉｎ纯度在９９．９％以上；Ｔｕｆｔｓｉｎ治疗组和对照组肿瘤大小及重量差异明显，治疗组肝、脾组织内的单核吞噬细胞增生活路。结论：多肽合成仪     

Enhanced immune response induced by a potential influenza A vaccine based on branched M2e polypeptides linked to tuftsin

Vaccination is the most effective means for preventing influenza-associated morbidity and mortality. Since the influenza virus mutates frequently, the virus strains for new vaccine production should be changed according to predicted epidemic strains. The extracellular domain of matrix protein 2 (M2e) is 24 amino acids long, which is highly conserved and therefore a good target for the development of a universal vaccine which may protect against a much wider range of influenza A virus strains. However its low antigenicity and immunogenicity, which are related to its small size, poses a big challenge for vaccine development. Multiple antigen peptide system (MAP) is based on an inert core molecule of radially branching lysine dendrites onto which a number of peptide antigens are anchored. Tuftsin is an immuno-stimulant molecule peptide. Here we developed a novel peptide vaccine by connecting a tuftsin to a branched, four-copy M2e. Not only did this increase the molecular mass, but also potentiate the immunogenicity. Two branched peptides, (M2e)4-tuftsin and (M2e)4-G4(tuftsin was replaced with four glycines), and a M2e monomer were synthesized using standard solid-phase methods. In vitro and in vivo studies were performed to compare their antigenicity and immunogenicity. Experiments in BALB/c mice demonstrated that the branched M2e could induce stronger humoral and cellular immune responses than the M2e monomer, and (M2e)4-tuftsin induced stronger humoral and cellular immune response than (M2e)4-G4. After lethal challenge with influenza virus PR8 strain, up to 80% of the animals in the (M2e)4-tuftsin vaccinated group still survived, in contrast to 44% in the (M2e)4-G4 group and 30% in the M2e monomer group. The combination of branched polypeptides and tuftsin in vaccine design is presented here for the first time, and the results show that the new construct is a promising candidate for a universal vaccine against the influenza A virus.     

炎症性肠病患者血清促吞噬素水平及临床意义

目的通过研究炎症性肠病（inflammatory bowel diseases,IBD）患者血清中Tuftsin（促吞噬素）的水平和与临床表现的关系,探讨其在IBD中的作用和意义。方法选取24例溃疡性结肠炎（UC）患者和28例克罗恩病（CD）患者及30例正常对照者,应用反相-高效液相色谱法（RP-HPLC）进一步测定Tuftsin在血清中的表达水平,并分析其与临床表现之间的关系。结果 UC患者Tuftsin水平（1.50±1.04）μg/ml和CD患者Tuftsin水平（1.56±1.06）μg/ml均高于健康对照组（0.92±0.58）μg/ml,（P〈0.05）,且与临床疾病活动指数和血清C反应蛋白升高阳性率正相关（P〈0.05）,但与病变部位无关（P〉0.05）。结论 IBD患者血清中Tuftsin水平明显增高,且与临床表现有关,提示Tuftsin可能在IBD发病机制中发挥重要的免疫调节作用。     

吞噬刺激素及其抑制物对急性胰腺炎胰腺微血栓影响的实验研究

目的 :探讨在急性胰腺炎 (acutepancreatitis ,AP)病情发展过程中吞噬刺激素 (Tuftsin ,Ts)及其抑制物对胰腺微循环的影响。方法 :SD大鼠分为 4组 ,每组 18只 ,分别为对照组、AP组、AP +Ts组、AP+Ts抑制物组。胰胆管逆行注射 4%牛磺胆酸钠建立AP模型 ,Ts及其抑制物组自制模 2 0min后从股静脉注入Ts或其抑制物 75ug/kg。按随机原则在制模后 3、6、12h分批处死 ,留取胰腺 (体部 )组织甲醛固定 ,HE染色光镜观察胰腺病理改变程度 ,纤维素染色观察微血栓情况 ,在显微镜下连续观察 5 0个视野 ,计数微血栓数量。结果 :制模后各组在不同时间段微血栓数量均比对照组明显升高 ;AP组、AP +Ts组、AP +Ts抑制物组在 3、6、12h各组各时间段之间比较微血栓数量逐渐增加 ,差别均有显著性 ;AP +Ts组在制模后各时间段均较AP组微血栓数量明显增加 ;AP +Ts抑制物组在制模后 6、12h微血栓数量明显减少 ,与单纯AP组比较差异有显著性 ,制模后 3h微血栓数量无明显变化。结论 :在急性胰腺炎进展过程中Ts使胰腺微血栓数量增加 ,胰腺微循环障碍加重 ;应用Ts抑制物可使胰腺微循环状态明显改善     

Phosphorylcholine-tuftsin compound prevents development of dextransulfate-sodium-salt induced murine colitis: Implications for the treatment of human inflammatory bowel disease

Improved clinical findings of inflammatory bowel disease (IBD) upon treatment with helminthes and their ova were proven in animal models of IBD and in human clinical studies. The immunomodulatory properties of several helminthes were attributed to the phosphorylcholine (PC) molecule. We assessed the therapeutic potential of tuftsin-PC conjugate (TPC) to attenuate murine colitis. Colitis was induced by Dextransulfate-Sodium-Salt (DSS) in drinking water. TPC was given by daily oral ingestion (50 μg/0.1 ml/mouse or PBS) starting at day −2. Disease activity index (DAI) score was followed daily and histology of the colon was performed by H&E staining. Analysis of the cytokines profile in distal colon lysates was performed by immunoblot. Treatment of DSS induced colitis with TPC prevented the severity of colitis, including a reduction in the DAI score, less shortening of the colon and less inflammatory activity in histology. The immunoblot showed that the colitis preventive activity of TPC was associated with downregulation of colon pro-inflammatory IL-1β, TNFα and IL-17 cytokines expression, and enhancement of anti-inflammatory IL-10 cytokine expression. In the current study, we demonstrated that TPC treatment can prevent significantly experimental colitis induction in naïve mice. We propose the TPC as a novel potential small synthetic molecule to treat colitis.     

Analogues of muramyl dipeptide (MDP) and tuftsin limit infection and inflammation in murine model of sepsis

Pharmacological manipulation of the balance between pro- and anti-inflammatory mediators emerges as a key aspect of a successful treatment of sepsis. A murine model of septic shock was developed and chosen conjugates (1a, 1b, 8a, 8c) and analogs (T2) of muramyl dipeptide and tuftsin were tested in this model as prospective anti-bacterial drugs or adjuvants. The phagocytic activity of monocytes/macrophages was determined (flow cytometry, bacterial clearance from vital organs). To evaluate cytokines levels (TNFα, IFNγ, IL6, IL10) we used real-time PCR. The most promising immunomodulatory properties were displayed by the analogue T2 and two conjugates: 8a, 8c.     

Superior Chemotherapeutic Efficacy of Amphotericin B in Tuftsin-bearing Liposomes against Leishmania Donovani Infection in Hamsters

Chemotherapeutic efficacy of the amphotericin B (Amp B), which is the drug of choice for treatment of the leishmanial infections (kala-azar) that become resistant to the conventional chemotherapy using antimonials, has been examined in the Leishmania donovani infected hamsters after encapsulating the drug in tuftsin-free as well as tuftsin-bearing liposomes. The activity was significantly increased (p <0.05) by delivering Amp B in tuftsin-free liposomes. This antileishmanial effect of the liposomized Amp B was further increased (p <0.05) by grafting the natural macrophage-activator tetrapeptide, tuftsin (Thr-Lys-Pro-Arg), on the liposome's surface. This could possibly be attributed to both the enhanced drug tolerance after liposomization as well as to the increased uptake of tuftsin-bearing Amp B-laden liposomes by the macrophages. In addition to the increased efficacy, encapsulation of Amp B in the tuftsin-bearing liposomes also enhanced the drug accessibility to areas (e.g. bone marrow) that are otherwise inaccessible to the free drug. These results further demonstrate the usefulness of tuftsin-bearing liposomes as drug vehicles in treatment of the macrophage-based infections that have been reviewed recently (Agrawal, A.K. and Gupta, C.M. (2000). Tuftsin-bearing liposomes in treatment of macrophage-based infections, Adv. Drug Deliv. Rev., 41, 135-146).     

The temporary dynamics of inflammation-related genes expression under tuftsin analog Selank action

Previous studies have shown that synthetic tuftsin analogue Selank and its fragments cause a number of alterations in the expression of certain genes involved in inflammation in mouse spleen. In this work we studied the effect of Selank and its short fragment Gly-Pro on the temporary dynamics of C3, Casp1, Il2rg, and Xcr1 genes expression in mouse spleen after single intraperitoneal injection (100 μg/kg) of peptides using real-time PCR method. We found a significant 3-fold decrease in the C3 mRNA level just 30 min after Selank injection and similar alteration this gene mRNA level after Gly-Pro administration. A wave-like alteration in the Casp1 mRNA level was observed after Selank injection. We found a significant alteration in the mRNA level of the Il2rg gene at early time points after Selank and Gly-Pro administration and an almost equal reduction in the Xcr1 mRNA level 90 min after the administration of Selank and its fragment. Our results showed that, Selank and its short fragment Gly-Pro influence the expression of genes that mediate different types of immune responses, thereby maintaining the balance of the immune system. It should be noted that in most cases, there was a coincidence in the expression profiles of the studied genes after Selank and Gly-Pro administration. This might indicate an active contribution of the dipeptide to the final effect of Selank.