牛磺酸对有丝分裂原刺激的小鼠免疫细胞功能的影响

为探讨牛磺酸对有丝分裂原刺激的小鼠免疫细胞功能的影响,本实验体外设计了终浓度为0.5、5、50、和500μg/mL四个浓度梯度。开展了Tau对有丝分裂原刺激的小鼠腹腔巨噬细胞和脾淋巴细胞功能影响的研究。结果Tau对LPS刺激的腹腔巨噬细胞分泌IL-1β具有免疫增强作用;对LPS刺激的小鼠腹腔巨噬细胞的增殖反应无显著作用。Tau对LPS刺激的脾淋巴细胞增殖反应在一定浓度范围内无显著作用,但当浓度较高时,有显著的抑制作用;Tau对ConA刺激的脾淋巴细胞分泌IL-2具有极显著的增强和调节作用;Tau在较高浓度时对LPS刺激的脾淋巴细胞分泌IgG也具有极显著的促进作用。牛磺酸对有丝分裂原刺激的小鼠腹腔巨噬细胞和脾淋巴细胞的免疫功能具有增强和调节作用。     

皮质醇对黄颡鱼头肾巨噬细胞呼吸爆发活动的影响

用Percoll连续密度梯度离心法分离黄颡鱼头肾巨噬细胞,经含0.1%牛血清的L-15培养液中培养,在光镜和电镜下观察其形态、超微结构和吞噬作用;采用硝基四氮唑蓝（NBT）与多孔酶标仪检测细胞在佛波豆蔻酸乙酯（PMA）刺激下产生的呼吸爆发,并观察外源皮质醇对黄颡鱼体内外头肾巨噬细胞呼吸爆发活动的影响。结果表明：每尾黄颡鱼可分离出1.2-1.6 mL浓度为1×10^7cells/mL的高纯度头肾巨噬细胞;培养3-18 h后,贴壁纯化的头肾巨噬细胞达到95%-98%;分离培养的头肾巨噬细胞具有巨噬细胞的形态结构特征,对福尔马林灭活的金黄色葡萄球菌（F-SA）的吞噬率达95%以上。PMA刺激分离的头肾巨噬细胞产生显著的呼吸爆发活动。在较高浓度和较长作用时间情况下,外源皮质醇对黄颡鱼体内外头肾巨噬细胞的呼吸爆发均产生抑制作用。     

Activation of macrophages

The role of macrophages is essential in the development of a normal immune response. Not only are these cells involved in the initiation of this response by presenting antigens to lymphocytes and by producing Interleukin I, but they also participate in the various phenomena of cellular co-operation and regulation. It is also evident that macrophages can act as cytotoxic effector cells, especially against micro-organisms and tumor cells. This last function is restricted to activated macrophages. The aim of this review is to summarize our present knowledge concerning this "macrophage activation".     

淫羊藿多糖醇沉工艺优化及其对巨噬细胞释放NO的影响

旨在优化淫羊藿多糖醇沉条件并研究不同浓度乙醇醇沉的淫羊藿多糖对巨噬细胞释放NO的影响。采用乙醇沉淀法从淫羊藿多糖提取物中获得淫羊藿多糖,在单因素试验基础上,选择浓缩比、乙醇浓度、乙醇体积倍数、醇沉时间为自变量,采用L9(34)的正交试验设计,优化淫羊藿多糖最佳醇沉条件。用浓度为400、500、600、700、800mL/L乙醇醇沉的淫羊藿多糖,采用体外培养法,测定淫羊藿多糖对巨噬细胞释放NO的影响。结果表明,淫羊藿多糖最佳醇沉条件为浓缩比为1∶2,乙醇浓度为800mL/L,乙醇体积倍数为4倍,醇沉时间为12h;每个乙醇浓度醇沉的淫羊藿多糖均具有良好的活性,500mL/L乙醇醇沉的多糖活性最好。结果显示,淫羊藿多糖对巨噬细胞具有良好的刺激作用。     

Distribution of CD68‐, CD8‐, MHCI‐ and MHCII‐positive cells in the bull and ram testis and epididymis

The mammalian testis possesses a special immunological environment because of its properties of remarkable immune privilege and effective local innate immunity. The testicular immune privilege protects immunogenic germ cells from systemic immune attack, and local innate immunity is important in preventing testicular microbial infections. Thus, this study aimed to immunohistochemically demonstrate the distribution and localization of CD68‐, CD8‐, MHCI‐ and MHCII‐positive immune cells in the testes and epididymes. Negative immunoreactivity was detected in the seminiferous tubule epithelium and peritubular myoid cells of the testes upon staining in CD68, CD8 and MHC Class I. Positive CD68 immunoreaction was determined in the Sertoli cells and some Leydig cells. The detection of positive cells for CD8 clearly indicated the presence of lymphocytes. Furthermore, the staining with MHCI intensity was ascertained to vary from weak to moderate in the Sertoli and Leydig cells and connective tissue cells. MHCII‐positive immunoreactivity was determined in myoid cells and Leydig cells in the interstitial area. The epithelium of the epididymis showed positive staining for CD68 and CD8, but the stroma displayed a rather weak staining. In the ram epididymis, neither intraepithelial nor interstitial positive reaction was observed for MHCI. In the epididymis, the basal cells displayed a stronger staining for MHCII. In conclusion, these cells not only contribute to local immunity through their direct effects on the quality of fertility in males, but also contribute either directly or indirectly to immune privilege by minimizing the development of both autoimmune reactions and potentially harmful risks.     

The spreading process of Ehrlichia canis in macrophages is dependent on actin cytoskeleton,calcium and iron influx and lysosomal evasion

Ehrlichia canis is an obligate intracellular microorganism and the etiologic agent of canine monocytic ehrlichiosis. The invasion process has already been described for some bacteria in this genus, such as E. muris and E. chaffeensis, and consists of four stages: adhesion, internalisation, intracellular proliferation and intercellular spreading. However, little is known about the spreading process of E. canis. The aim of this study was to analyse the role of the actin cytoskeleton, calcium, iron and lysosomes from the host cell in the spreading of E. canis in dog macrophages in vitro. Different inhibitory drugs were used: cytochalasin D (actin polymerisation inhibitor), verapamil (calcium channel blocker) and deferoxamine (iron chelator). Our results showed a decrease in the number of bacteria in infected cells treated with all drugs when compared to controls. Lysosomes in infected cells were cytochemically labelled with acid phosphatase to allow the visualisation of phagosome-lysosome fusion and were further analysed by transmission electron microscopy. Phagosome-lysosome fusion was rarely observed in vacuoles containing viable E. canis. These data suggest that the spreading process of E. canis in vitro is dependent on cellular components analysed and lysosomal evasion.     

肝X受体激动剂抑制NLRP3炎性体活化

为探讨肝X受体激动剂对NLRP3配体ATP诱导小鼠巨噬细胞炎性复合体活化的影响,应用荧光定量PCR方法测定肝x受体激动荆对LPS诱导的Pro-IL-1β、NLRP3等基因表达的影响,并用免疫蛋白印迹的方法检测Caspase—l的活化片段。结果证明,肝X受体（LXRs）激动剂能抑制NLRP3炎性体的活化。LXRs激动剂F0901317和GW3965显著抑制LPS联合ATP诱导的Caspase-1剪切成熟和IL-lβ分泌,并且LXRs激动剂对NLRP3炎性体的抑制作用,部分源于其抑制NLRP3和IL-1β的基因转录。     

Functional impairment of PRRSV-specific peripheral CD3+CD8high cells

The replication of porcine reproductive and respiratory syndrome virus (PRRSV) in lungs and lymphoid tissues of PRRSV-infected pigs is already strongly reduced before the appearance of neutralizing antibodies, indicating that other immune mechanisms are involved in eliminating PRRSV at those sites. This study aimed to determine whether PRRSV Lelystad virus (LV)-specific cytotoxic T-lymphocytes (CTL) can efficiently eliminate PRRSV-infected alveolar macrophages. Therefore, CTL assays were performed with PRRSV-infected alveolar macrophages as target cells and autologous peripheral blood mononuclear cells (PBMC) from PRRSV-infected pigs as a source of PRRSV-specific CTL. PBMC of 3 PRRSV-infected pigs were used either directly in CTL assays, or following restimulation in vitro. CTL assays with pseudorabies virus (PRV) Begonia-infected alveolar macrophages and autologous PBMC, from 2 PRV Begonia-inoculated pigs, were performed for validation of the assays. In freshly isolated PBMC, derived from PRRSV-infected pigs, CTL activity towards PRRSV-infected macrophages was not detected until the end of the experiment (56 days post infection – dpi). Restimulating the PBMC with PRRSV in vitro resulted in proliferation of CD3⁺CD8^high cells starting from 14 dpi. Although CD3⁺CD8^high cells are generally considered to be CTL, CTL activity was not detected in PRRSV-restimulated PBMC of the 3 pigs until 49 dpi. A weak PRRSV-specific CTL activity was observed only at 56 dpi in PRRSV-restimulated PBMC of one pig. In contrast, a clear CTL activity was observed in PRV Begonia-restimulated PBMC, derived from PRV Begonia-infected pigs, starting from 21 dpi. This study indicates that PBMC of PRRSV-infected pigs contain proliferating CD3⁺CD8^high cells upon restimulation in vitro, but these PBMC fail to exert CTL activity towards PRRSV-infected alveolar macrophages.