兔妊娠期及围产期免疫功能动态的研究

采用ConA诱导的T淋巴细胞转化试验和LPS诱导的B淋巴细胞转化试验,测定了12只母兔妊娠期及围产期的淋巴细胞转化值。结果表明:自配种至妊娠20d,T淋巴细胞的转化值一直维持较低的水平,B淋巴细胞的转化值呈上升趋势但幅度不大。说明该时期孕兔细胞免疫功能低下。分娩前5d,T淋巴细胞转化值开始回升,至分娩当天达到最高,而B淋巴细胞的转化值则有不同程度的降低,说明母体细胞免疫功能显著增强,体液免疫有所降低。产后1dT淋巴细胞的转化值迅速下降,B淋巴细胞的转化值则升高,说明分娩后母体的细胞免疫功能有短暂的降低,而体液免疫增强。随后T、B细胞转化值逐渐与对照组接近,提示分娩后母兔免疫功能基本恢复正常。     

Putting endotoxin to work for us: Monophosphoryl lipid A as a safe and effective vaccine adjuvant

The development of non-infectious subunit vaccines greatly increases the safety of prophylactic immunization, but also reinforces the need for a new generation of immunostimulatory adjuvants. Because adverse effects are a paramount concern in prophylactic immunization, few new adjuvants have received approval for use anywhere in the developed world. The vaccine adjuvant monophosphoryl lipid A is a detoxified form of the endotoxin lipopolysaccharide, and is among the first of a new generation of Toll-like receptor agonists likely to be used as vaccine adjuvants on a mass scale in human populations. Much remains to be learned about this compound’s mechanism of action, but recent developments have made clear that it is unlikely to be simply a weak version of lipopolysaccharide. Instead, monophosphoryl lipid A’s structure seems to have fortuitously retained several functions needed for stimulation of adaptive immune responses, while shedding those associated with pro-inflammatory side effects. Received 25 April 2008; received after revision 05 June 2008; accepted 10 June 2008     

A cold-active salmon goose-type lysozyme with high heat tolerance

The Atlantic salmon (Salmo salar) goose-type lysozyme gene was isolated and revealed alternative splicing within exon 2 affecting the signal peptide-encoding region. The lysozyme was produced in Escherichia coli, and the recombinant enzyme showed a high specific lytic activity that was stimulated by low or moderate concentrations of mono- or divalent cations. Relative lytic activities of 70 and 100% were measured at 4°C and 22°C, respectively, and there was no detectable activity at 60°C. However, 30% activity was retained after heating the enzyme for 3 h at 90°C. This unique combination of thermal properties was surprising since the salmon goose-type lysozyme contains no cysteines for protein structure stabilization through disulphide bond formation. The results point to a rapid reversal of inactivation, probably due to instant protein refolding. Received 14 August 2007; received after revision 07 September 2007; accepted 12 September 2007     

Hitting malaria before it hurts: attenuated <Emphasis>Plasmodium</Emphasis> liver stages

Continuous natural exposure to Plasmodium transmission by infectious Anopheles mosquitoes leads to a gradual acquisition of immunological competence against malaria. The partial immunity, observed in adolescents and adults living in endemic areas, reduces morbidity and mortality without preventing parasite infection. In experimental animal models, long-lasting sterilizing immunity can be achieved with genetically attenuated Plasmodium liver stages. Can these findings be translated to accomplish sterile protection against natural malaria transmission in the high-risk group, young infants in sub-Saharan Africa?     

The translocation motif of hepatitis B virus improves protein vaccination

Cell-penetrating peptides (CPPs) have been shown to improve antigen loading of dendritic cell vaccines. Here we asked whether fusion of a CPP to a protein improves its immunogenicity when this fusion protein is directly applied as vaccine. We used the cell-penetrating translocation motif (TLM) derived from the hepatitis B virus, because no size limitation of cargos has been observed. Increased immunogenicity was observed when TLM was fused to ovalbumin (TLM-ova). TLM-ova was found to be superior to ova in inducing proliferation and cytotoxicity of ova-specific CD8+ T cells in vitro and in vivo. Using ovalbumin-expressing thymoma cells (EG7-ova), an improved anti-tumor immune response was observed for TLM-ova vaccination versus vaccination with ova. Moreover, TLM-ova vaccination induced a higher titer of anti-ovalbumin IgG2a antibodies compared to ova. These data demonstrate that CPP-protein vaccines can improve cellular as well as humoral immune responses. Received 16 November 2005; received after revision 12 December 2005; accepted 10 January 2006 †These authors contributed equally to this work     

The function of apolipoproteins L

The function of the proteins of the apolipoprotein L (apoL) family is largely unknown. These proteins are classically thought to be involved in lipid transport and metabolism, mainly due to the initial discovery that a secreted member of the family, apoL-I, is associated with high-density lipoprotein particles. However, the other members of the family are believed to be intracellular. The recent unravelling of the mechanism by which apoL-I kills African trypanosomes, as well as the increasing evidence for modulation of apoL expression in various pathological processes, provides new insights about the functions of these proteins. ApoLs share structural and functional similarities with proteins of the Bcl-2 family. Based on the activity of apoL-I in trypanosomes and the comparison with Bcl-2 proteins, we propose that apoLs could function as ion channels of intracellular membranes and be involved in mechanisms triggering programmed cell death. Received 28 February 2006; received after revision 18 May 2006; accepted 2 June 2006     

家鸽红细胞血型的初步研究

采用2种方法对家鸽的红细胞血型进行了初步研究．方法一：血清平板凝集试验．取家鸽的红细胞分别与家兔以及其它家鸽的血清进行混合,结果有些家鸽的红细胞与有些家兔的血清发生了凝集反应,而另一些则不发生;家鸽的不同个体之间也存在红细胞凝集现象．这表明家鸽的红细胞表面存在凝集原．方法二：异种动物免疫．将家鸽的红细胞注射到家兔体内,然后取家兔产生的免疫血清与该家鸽的红细胞混合,结果发生了凝集反应．这进一步表明家鸽的红细胞表面存在凝集原,即家鸽具有红细胞血型．     

一类传染病动力学模型的同伦映射解法

应用同伦理论来求解一类具有潜伏期的无免疫型传染病动力学模型,构造该非线性系统的近似解表达式,进而分析该传染病的传播性态和规律。结果表明,同伦映射法可以简单有效地解决这个问题。     

电子设备电磁抗扰度预测试平台的建立

通过对标准电磁兼容测试方法的分析研究,以现有电磁兼容测试设备为基础,建立了适用范围广泛的电磁抗扰度预测试平台.该平台可在一般的实验室条件下对多种电子设备进行电磁兼容性测试,利用该电磁抗扰度预测试平台对电子系统中常用电子设备进行测试,说明该预测试平台的功能,并验证其实用性和有效性.     

体外诱导骨肉瘤特异性抗肿瘤的免疫实验

采用分离骨肉瘤患者外周血单核细胞体外诱导DC细胞,Trizol法提取患者骨肉瘤细胞总RNA,用总RNA转染DC并诱导特异性CTL的扩增,用MTT法检测淋巴细胞的增殖和CTL的杀伤活性。探讨骨肉瘤细胞总RNA转染的DC疫苗体外诱导特异性抗肿瘤免疫的能力。经骨肉瘤细胞总RNA转染的DC特异性表面标志及功能相关分子表达均上调,转染后的DC可显著刺激自体T淋巴细胞增殖,诱导的特异性CTL对靶细胞的杀伤率显著高于单纯淋巴细胞和未经转染的DC。说明骨肉瘤细胞总RNA转染的DC疫苗可在体外诱导出特异性抗肿瘤免疫。