动物铁过负荷的临床和实验室诊断技术

为动物铁过负荷建立简单、快捷的临床和实验室诊断技术,利用临床自然病例,采用病理解剖学、组织学和组织化学染色技术,对病猪及病犬的淋巴结、脾脏、肺脏、肝脏和肾脏进行了病理解剖学和组织病理学观察和研究.结果表明,随着铁过负荷的程度不同,富含巨噬细胞的淋巴结呈现出由棕黄色至棕褐色的不同色泽;在H.E染色的组织学标本中,可见巨噬细胞内含有数量不等的棕黄色含铁血黄素颗粒;在普鲁氏蓝染色的组织学标本中,含铁血黄素颗粒则呈蓝色.动物发生铁过负荷时,过剩的铁主要沉积在单核巨噬细胞系统的胞浆内,其次是肝细胞的胞浆内.     

Identification of genes required for the fitness of Rhodococcus equi during the infection of mice via signature-tagged transposon mutagenesis

Rhodococcus equi is a Gram-positive facultative intracellular bacterium that causes pyogranulomatous pneumonia in foals and immunocompromised people. In the present study, signature-tagged transposon mutagenesis was applied for the negative selection of R. equi mutants that cannot survive in vivo. Twenty-five distinguishable plasmid-transposon (plasposon) vectors by polymerase chain reaction (PCR), each containing a unique oligonucleotide tag, were constructed and used to select the transposon mutants that have in vivo fitness defects using a mouse systemic infection model. Of the 4,560 transposon mutants, 102 mutants were isolated via a real-time PCR-based screening as the mutants were unable to survive in the mouse model. Finally, 50 single transposon insertion sites were determined via the self-cloning strategy. The insertion of the transposon was seen on the virulence plasmid in 15 of the 50 mutants, whereas the remaining 35 mutants had the insertion of transposon on the chromosome. The chromosomal mutants contained transposon insertions in genes involved in cellular metabolism, DNA repair and recombination, gene regulation, non-ribosomal peptide synthesis, and unknown functions. Additionally, seven of the chromosomal mutants showed a reduced ability to multiply in the macrophages in vitro. In this study, we have identified several biosynthetic pathways as fitness factors associated with the growth within macrophages and survival in mice.     

PCV2感染对猪肺泡巨噬细胞Fc受体数量和吞噬功能的影响

将猪圆环病毒2型(PCV2)BF株经口、鼻接种40日龄健康普通仔猪,在接种后不同时间宰杀,收集肺泡巨噬细胞(PAM),同时设立对照组。用EA花环试验测定Fc受体数目,用吞噬鸡红细胞试验测定吞噬功能,来分析PCV2感染对PAM某些生物学活性的影响。结果显示,PAM表面Fc受体数和吞噬鸡红细胞数的变化规律一致,与对照组相比,两者数量在接种后3 d时下降至最低,之后回升,14 d时基本恢复正常。本研究表明,PCV2感染可引起PAM吞噬和清除病原的能力出现短暂下降。     

猪圆环病毒2型感染不会诱发猪肺泡巨噬细胞凋亡

将猪圆环病毒2型(PCV2)BF株经口、鼻接种40日龄健康普通仔猪,在接种后不同时相宰杀,收集肺泡巨噬细胞,用流式细胞术和琼脂糖凝胶电泳检测其凋亡现象,分析PCV2感染对猪肺泡巨噬细胞凋亡的影响。结果显示,在整个试验期内,与对照组相比,两种方法均未检测到攻毒组肺泡巨噬细胞出现凋亡上升现象,表明PCV2感染不会诱发猪肺泡巨噬细胞凋亡。     

重组真菌免疫调节蛋白对巨噬细胞RAW 264.7激活应答的研究

真菌免疫调节蛋白(fugal immunomodulatory proteins,FIPs)是一类从高等大型真菌中分离的、具有生物活性的小分子蛋白质。在之前的研究中,通过基因改组技术,对来自赤芝(Ganoderma lucidum)和紫芝(G.sinense)的FIP进行了重组改造,获得了具有333bp的FIP突变体FIP-SN15。本研究通过原核表达系统获得了重组FIP-SN15(rFIP-SN15),并利用荧光定量PCR(quantitative real-time PCR,qRT-PCR)技术在转录水平上对rFIP-SN15诱导巨噬细胞TNF-α的功能及其机制进行研究。结果表明,rFIP-SN15在原核表达系统中的产量约为35.31mg/L;rFIP-SN15处理细胞后,TNF-α的转录水平显著上调(P0.05),并且Akt的转录水平上调极其显著(P0.01)。此外,ARG1和mTOR的mRNA水平上调显著(P0.05)。因此,rFIPSN15能够激活小鼠腹腔巨噬细胞RAW 264.7。本研究为进一步验证FIP-SN15的生物学功能提供了有益的参考。     

塑化剂DEHP暴露对小鼠巨噬细胞的免疫毒性作用

为了研究邻苯二甲酸二乙基己酯(DEHP)对巨噬细胞的免疫毒性,采用不同浓度剂量DEHP处理小鼠巨噬细胞株RAW264.7细胞和腹腔巨噬细胞,通过检测细胞吞噬、细胞因子分泌及活性氧水平变化探讨DEHP暴露对免疫系统的毒性作用。结果表明:高浓度(20、40、80 mg·L-1)DEHP处理48 h后对RAW264.7细胞可造成急性损伤。低浓度(1、5、10 mg·L-1)DEHP连续染毒处理10代后,RAW264.7细胞吞噬红细胞百分率及吞噬指数显著抑制(P0.05)。RAW264.7细胞分泌TNF-α、IL-12和IL-23等细胞因子能力明显降低,并表现出一定的剂量-效应关系。随着DEHP暴露浓度的增加,DEHP染毒造成RAW264.7细胞内活性氧产生,受损加剧。除此之外,DEHP暴露还能明显抑制小鼠腹腔巨噬细胞对红细胞的吞噬能力(P0.05)。以上结果表明,DEHP暴露对巨噬细胞具有免疫抑制作用,损伤了巨噬细胞正常免疫功能发挥。     

大豆卵磷脂增强免疫活性的研究

为了研究大豆卵磷脂对机体免疫作用,进行了不同剂量大豆卵磷脂对小鼠脾指数、巨噬细胞吞噬能力和溶血素产生能力的试验。结果表明：大豆卵磷脂能显著提高巨噬细胞吞噬能力和溶血素产生能力。大豆卵磷脂具有增强免疫的作用。     

Neutrophil recruitment in endotoxin-induced murine mastitis is strictly dependent on mammary alveolar macrophages

Mastitis, inflammation of the mammary tissue, is a common disease in dairy animals and mammary pathogenic Escherichia coli (MPEC) is a leading cause of the disease. Lipopolysaccharide (LPS) is an important virulence factor of MPEC and inoculation of the mammary glands with bacterial LPS is sufficient to induce an inflammatory response. We previously showed using adoptive transfer of normal macrophages into the mammary gland of TLR4-deficient C3H/HeJ mice that LPS/TLR4 signaling on mammary alveolar macrophages is sufficient to elicit neutrophil recruitment into the alveolar space. Here we show that TLR4-normal C3H/HeN mice, depleted of alveolar macrophages, were completely refractory to LPS intramammary challenge. These results indicate that alveolar macrophages are both sufficient and essential for neutrophil recruitment elicited by LPS/TLR4 signaling in the mammary gland. Using TNFα gene-knockout mice and adoptive transfer of wild-type macrophages, we show here that TNFα produced by mammary alveolar macrophages in response to LPS/TLR4 signaling is an essential mediator eliciting blood neutrophil recruitment into the milk spaces. Furthermore, using the IL8 receptor or IL1 receptor gene-knockout mice we observed abrogated recruitment of neutrophils into the mammary gland and their entrapment on the basal side of the alveolar epithelium in response to intramammary LPS challenge. Adoptive transfer of wild-type neutrophils to IL1 receptor knockout mice, just before LPS challenge, restored normal neutrophil recruitment into the milk spaces. We conclude that neutrophil recruitment to the milk spaces is: (i) mediated through TNFα, which is produced by alveolar macrophages in response to LPS/TLR4 signaling and (ii) is dependent on IL8 and IL1β signaling and regulated by iNOS-derived NO.     

大黄鱼刺激隐核虫病组织中巨噬细胞移动抑制因子的检测分析

由刺激隐核虫(Cryptocaryon irritans)感染引发的"白点病"为大黄鱼(Larimichthys crocea)养殖业带来重大损失,但仍未找到安全、有效的治疗方法。本研究应用免疫组织化学方法,对健康大黄鱼和患刺激隐核虫病大黄鱼肠、脾、头肾与肝组织中巨噬细胞移动抑制因子(macrophage migration inhibitory factor,MIF)蛋白进行检测,研究刺激隐核虫病大黄鱼组织中MIF的表达情况及其对预后的影响。结果表明,MIF在健康大黄鱼肠、脾、头肾、肝各组织中均无表达;MIF在刺激隐核虫病大黄鱼各组织中高表达,表达强度从弱到强依次是肠、肝、脾、头肾,MIF表达阳性率分别为54%、80%、86%、90%。推测MIF在大黄鱼刺激隐核虫病发病过程中发挥作用。     

水牛肺泡巨噬细胞的分离、培养及鉴定

为了深入研究水牛巨噬细胞（Macrophage,Mφ）的生物学特性,探索一种简便的水牛肺泡巨噬细胞（Alveolarmacrophage,AM）分离、培养方法,采用肺气管冷PBS灌洗法分离获得水牛肺泡细胞,并进行鉴定和功能检测。结果表明,采用肺气管冷PBS灌洗法可获得大量贴壁细胞,经光学显微镜和电子显微镜观察,其形态具备巨噬细胞的典型特征;酸性磷酸酶和非特异性酯酶阳性率分别为（89.4±3.5）%和（83.6±3.4）%;细胞表面抗原MHCⅡ阳性率为（96.6±1.3）%;鸡红细胞吞噬率为（23.6±4.2）%,墨汁吞噬率为（92.3±0.6）%。可见,肺气管冷PBS灌洗法是一种获取水牛肺泡巨噬细胞的可行方法。