Alterations of intestinal immune function and regulatory effects of L-arginine in experimental severe acute pancreatitis rats

ABM: To discuss the changes of intestinal mucosal immune function in rats with experimental severe acute pancreatitis (SAP) and the regulatory effect of L-arginine. METHODS: Male adult Wistar rats were randomly divided into pancreatitis group, sham-operation group, and L-arginine treatment group. Animals were killed at 24, 48, and 72 h after SAP models were developed and specimens were harvested. Endotoxin concentration in portal vein was determined by limulus endotoxin analysis kit. CD3+, CD4+, CD8+ T lymphocytes in intestinal mucosal lamina propria were examined by immunohistochemistry. Secretory immunoglobulin A (SIgA) in cecum feces was examined by radioimmunoassay. RESULTS: Compared to the control group, plasma endotoxin concentration in the portal vein increased, percentage of CD3+ and CD4+ T lymphocyte subsets in the end of intestinal mucosal lamina propria reduced significantly, CD4+/CD8+ ratio decreased, and SIgA concentrations in cecum feces reduced at 24, 48, and 72 h after SAP developed. Compared to SAP group, the L-arginine treatment group had a lower level of plasma endotoxin concentration in the portal vein, a higher CD3+ and CD4+ T lymphocyte percentage in the end of intestinal mucosal lamina propria, an increased ratio of CD4+/CD8+ and a higher SIgA concentration in cecum feces. CONCLUSION: Intestinal immune suppression occurs in the early stage of SAP rats, which may be the main reason for bacterial and endotoxin translocation. L-arginine can improve the intestinal immunity and reduce bacterial and endotoxin translocation in SAP rats.     

Blueprint for schistosomiasis vaccine development

A number of different schistosome antigens are capable of partially protecting experimental animals from challenge infection. More than 100 such antigens have been identified, about 15% of which are strongly protective and deemed promising though they do not reach the level close to sterile immunity seen after vaccination with irradiated cercariae. Studies of human correlate reactions, i.e. serological reactions and cytokine responses to schistosomiasis antigens, in individuals living in areas endemic for schistosomiasis have shown associations between certain antigen-specific immune responses and lack of re-infection over time. This approach was applied in Brazil and Egypt where it was possible to epidemiologically follow cohorts of individuals in endemic areas for extended periods of time correlating infection status with immune responses against a panel of well-researched, highly purified vaccine candidates. The immune correlates found were unique to each antigen and could be either positive or negative, i.e. associated with resistance or with susceptibility to re-infection. However, few antigens were clear-cut in this respect, i.e. the majority of them induced ambiguous responses. For example, a single antigen might have a significant positive correlation when antigen-driven interferon (INF)-gamma production is measured but also show a significant negative correlation with respect to the IgG1 titre induced. These observations suggest that there are desirable, antigen-specific immune responses that would be valuable in a vaccine but they also indicate that there are responses that must be avoided. The insights gained should be useful not only for antigen selection but also for vaccine formulation prior to Phase I/II trials in humans. It would be of great value if similar independent, long-term human correlate studies could also be undertaken in areas endemic for Schistosoma japonicum.     

Live porcine reproductive and respiratory syndrome virus vaccines: Current status and future direction

Porcine reproductive and respiratory syndrome (PRRS) caused by PRRS virus (PRRSV) was reported in the late 1980s. PRRS still is a huge economic concern to the global pig industry with a current annual loss estimated at one billion US dollars in North America alone. It has been 20 years since the first modified live-attenuated PRRSV vaccine (PRRSV-MLV) became commercially available. PRRSV-MLVs provide homologous protection and help in reducing shedding of heterologous viruses, but they do not completely protect pigs against heterologous field strains. There have been many advances in understanding the biology and ecology of PRRSV; however, the complexities of virus-host interaction and PRRSV vaccinology are not yet completely understood leaving a significant gap for improving breadth of immunity against diverse PRRS isolates. This review provides insights on immunization efforts using infectious PRRSV-based vaccines since the 1990s, beginning with live PRRSV immunization, development and commercialization of PRRSV-MLV, and strategies to overcome the deficiencies of PRRSV-MLV through use of replicating viral vectors expressing multiple PRRSV membrane proteins. Finally, powerful reverse genetics systems (infectious cDNA clones) generated from more than 20 PRRSV isolates of both genotypes 1 and 2 viruses have provided a great resource for exploring many innovative strategies to improve the safety and cross-protective efficacy of live PRRSV vaccines. Examples include vaccines with diminished ability to down-regulate the immune system, positive and negative marker vaccines, multivalent vaccines incorporating antigens from other porcine pathogens, vaccines that carry their own cytokine adjuvants, and chimeric vaccine viruses with the potential for broad cross-protection against heterologous strains. To combat this devastating pig disease in the future, evaluation and commercialization of such improved live PRRSV vaccines is a shared goal among PRRSV researchers, pork producers and biologics companies.     

甘草酸在肝外疾病中的研究进展

异甘草酸镁是常用的护肝降酶药物,其主要成分由甘草酸制备而得,后者具有抗炎、抗氧化、抗病毒感染的作用。近年研究证实,甘草酸可能对缺血-再灌注损伤、神经系统损伤、多种炎症、免疫相关疾病、内分泌疾病和肿瘤有治疗作用,有广阔的应用前景。本文系统总结近年来甘草酸在肝外疾病中的研究进展,概括甘草酸治疗上述疾病的可能机制,并对未来的研究方向做前瞻性的展望。     

前S2合成肽对肝癌组织中浸润T淋巴细胞亚群表达的影响

目的通过前S2合成肽对肝细胞癌(HCC)组织中浸润T淋巴细胞亚群表达状况的分析,探讨前S2合成肽是否能改变乙型肝炎病毒(HBV)导致的HCC组织中浸润T淋巴细胞亚群表达的百分数和CD4+/CD8+比值,达到特异性治疗HCC. 方法用Merrifield固相化学合成法合成HBV中前S2抗原性最强的P120～146多肽段.测序后,用0.01mol/L磷酸盐缓冲液溶解除菌后作为抗原.选择12例术后病理诊断为HCC,术前血清经酶联免疫吸附法测得HBsAg、HBeAg、抗-HBC阳性和HBV DNA阳性,且HBsAg在HCC组织中表达为阳性病例作为研究对象.在96孔培养板上,每孔加入经密梯度离心获得的单个核细胞悬液100μl(1×106细胞),设每孔含量为1μg、5μg、10μg、白细胞介素-2 500U和阴性对照共5组,每组均设3复孔,作用7d后制片,采用APAAP法观察CD3+、CD4+、CD8+的百分数和CD4+/CD8+的比值变化. 结果 发现在含有前S2合成肽5μg/孔组中,CD4+表达明显增加(34.1±3.2),与自身对照(29.3±3.5)相比差异有显著性 (t＝3.508,P<0.01),CD4+/CD8+比值(1.19±0.43)与自身对照(0.81±0.41)相比差异有显著性(t＝2.235,P＜0.05).在白细胞介素-2组中,CD3+表达有增加,与自身对照相比有差异,其它各组T淋巴细胞亚群几乎处于不变化的状态. 结论在适当的剂量下,前S2合成肽能够改变HCC组织中T淋巴细胞亚群的表达,使CD4+增加,并能改变CD8+静息状态,使二者互为达到杀伤肿瘤细胞的目的,为特异性运用前S2蛋白提供客观依据.     

Immune responses of poultry to Newcastle disease virus

Newcastle disease (ND) remains a constant threat to poultry producers worldwide, in spite of the availability and global employment of ND vaccinations since the 1950s. Strains of Newcastle disease virus (NDV) belong to the order Mononegavirales, family Paramyxoviridae, and genus Avulavirus, are contained in one serotype and are also known as avian paramyxovirus serotype-1 (APMV-1). They are pleomorphic in shape and are single-stranded, non-segmented, negative sense RNA viruses. The virus has been reported to infect most orders of birds and thus has a wide host range. Isolates are characterized by virulence in chickens and the presence of basic amino acids at the fusion protein cleavage site. Low virulent NDV typically produce subclinical disease with some morbidity, whereas virulent isolates can result in rapid, high mortality of birds. Virulent NDV are listed pathogens that require immediate notification to the Office of International Epizootics and outbreaks typically result in trade embargos. Protection against NDV is through the use of vaccines generated with low virulent NDV strains. Immunity is derived from neutralizing antibodies formed against the viral hemagglutinin and fusion glycoproteins, which are responsible for attachment and spread of the virus. However, new techniques and technologies have also allowed for more in depth analysis of the innate and cell-mediated immunity of poultry to NDV. Gene profiling experiments have led to the discovery of novel host genes modulated immediately after infection. Differences in virus virulence alter host gene response patterns have been demonstrated. Furthermore, the timing and contributions of cell-mediated immune responses appear to decrease disease and transmission potential. In view of recent reports of vaccine failure from many countries on the ability of classical NDV vaccines to stop spread of disease, renewed interest in a more complete understanding of the global immune response of poultry to NDV will be critical to developing new control strategies and intervention programs for the future.     

Attachment style and immunity: A 1-year longitudinal study

Previous cross-sectional studies suggested an association between attachment-related avoidance and altered immune function. We aimed at testing this hypothesis with longitudinal data. A random sample of 65 female nurses provided a blood sample and completed measures of perceived stress, social support, alexithymia, and attachment style. Immune assays included lymphocyte proliferative response (LPR) to Phytohemagglutinin and NK cell cytotoxicity (NKCC). State measures (perceived stress and support) and immune measures were collected again after 4, 8, and 12 months. Linear mixed effects models were used to examine the relationship between attachment and immunity. While low to moderate levels of attachment-related avoidance were not associated with NKCC, there was a significant negative association (beta −.35; p = .005) between high levels of avoidance and NKCC. No association was observed between NKCC and attachment-related anxiety, and between LPR and both attachment dimensions. While our findings should be interpreted with caution due to study limitations such as the relatively small sample size and the inclusion of only female participants, they corroborate the notion that attachment is linked to physiology and health.     

靶向纳米级免疫偶联物诱导检查点抑制剂抗体治疗颅内胶质瘤的可行性实验研究

目的 探讨靶向纳米级免疫偶联物(Nanoscale immunoconjugates,NCI)诱导检查点抑制剂抗体治疗颅内胶质瘤的可行性。方法 无特定病原体级(Specific pathogen free,SPF)级、雌性大鼠168只,随机分为磷酸缓冲盐溶液(Phosphate buffer saline,PBS)组(24只),游离组(72只)及NIC组(72只); 所有大鼠均进行颅内胶质瘤细胞植入,构建颅内胶质瘤大鼠模型; PBS组不进行治疗; 游离组给予T淋巴细胞相关抗原4(Cytotoxic T lymphocyte associated antigen-4,a-CTLA-4)和程序性细胞死亡1(Anti programmed cell death protein-1,a-PD-1)及两者联合注射,每种各24只; NCI组给予纳米级免疫偶联物诱导检查点抑制剂抗体[分别为聚苹果酸/ T淋巴细胞相关抗原4(Polymalic malic acid/ Cytotoxic T lymphocyte associated antigen-4,P/a-CTLA-4)、聚苹果酸/程序性细胞死亡1(Polymalic malic acid/Anti programmed cell death protein-1,P/a-PD-1)及两盒联合注射]注射,每种各24只; 使用荧光素标记法观察不同组大鼠药物血脑屏障穿透效率,比较不同治疗方式大鼠治疗后CD3+T细胞(CD3+Pan T Cells,CD3+)、CD4+,CD8+、调节性T细胞(Regulatory T cells,Treg)、巨噬细胞(MΦ)、自然杀伤细胞(Natural killer cell,NK)细胞、自然杀伤T细胞(Natural killer T cell,NKT)细胞、干扰素γ(Interferon-γ,IFNγ)水平及大鼠CD4+,CD8+增殖活跃程度、生存期。结果 荧光实验显示,NIC组各治疗方式大鼠脑部荧光面积均显著高于游离组及PBS组; NCI各组CD3+、CD4+、CD8+、Treg、CD4+ki67、CD8+ki67、MΦ、M1MΦ、M2MΦ、NK细胞、NKT细胞、IFNγ每孔计数及总体生存期显著高于游离组及PBS组(P<0.05)。结论 NCI诱导检查点抑制剂抗体能促进药物透过血脑屏障,刺激大脑驻留的免疫系统,促使CD8+ T细胞增殖并触发多种免疫细胞因子的释放,增加M1型巨噬细胞的产生,从而协调针对GBM的免疫反应,提高颅内胶质瘤大鼠存活时间。     

Prophylactic Dose of Neem (Azadirachta indica) Leaf Preparation Restricting Murine Tumor Growth is Nontoxic,Hematostimulatory and Immunostimulatory

Significant restriction of growth of Ehrlich's carcinoma was observed following prophylactic treatment on Swiss albino mice with neem leaf preparation (NLP-1 unit) once weekly for four weeks. Toxic effects of this particular dose (1 unit), along with 0.5 unit and 2 units of NLP doses, were evaluated on different murine physiological systems. One hundred percent of mice could tolerate 4 injections of 0.5 and 1 unit NLP doses. Body weight, different organ-body weight ratios and physical behavior of treated mice remained completely unchanged during treatment with different NLP doses. All of these NLP doses were observed to stimulate hematological systems as evidenced by the increase in total count of RBC, WBC and platelets and hemoglobin percentage. As histological changes as well as elevation in serum alkaline phosphatase, SGOT, SGPT were not observed in mice treated with three different doses of NLP, the nonhepatotoxic nature of NLP was proved. The level of serum urea remained unaltered and normal architecture of the cortical and medullary parts of the kidney were also preserved after NLP treatment. Increased antibody production against B16 melanoma antigen was detected in mice immunized with 0.5 unit and 1 unit of NLP. Number of splenic T lymphocytes (CD4+ and CD8+) and NK cells were also observed to be increased in mice injected with 0.5 unit and 1 unit of NLP. However, NLP dose of 2 units could not exhibit such immunostimulatory changes; NLP mediated immunostimulation was correlated well with the growth restriction of murine carcinoma. In other words, tumor growth restriction was observed only when mice were injected with immunostimulatory doses of NLP (0.5 unit and 1 unit).