一种抗原递呈细胞--树突状细胞

树突状细胞 ( Dendritic cell,DC)是抗原递呈细胞 ( APC)的一种 ,它可以将抗原物质递呈给 TH细胞。树突状细胞在机体的免疫应答中发挥着重要的作用[2 ] 。最近的研究表明 ,树突状细胞可以递呈肿瘤抗原 ,提高肿瘤病人的免疫能力 [8] 。还有研究表明 ,树突状细胞可以携带 HIV- I,并递呈给抗原反应性 T细胞 ,还可以诱导广泛的淋巴细胞死亡[10 ] 。因此 ,对树突状细胞的研究 ,对基础医学和临床治疗都具有重要意义。树突状细胞的特征是具有树突状外形 ,突起的长度、粗细、数量因不同的树突状细胞而有所不同[1] 。DC起源于骨髓干细胞 ,血液…     

黄芪多糖对树突状细胞形态和功能影响研究进展

树突状细胞(DC)是目前发现功能最强的一类抗原递呈细胞(APC),因其在机体免疫应答及免疫功能发挥中担当重要角色,成为免疫学研究热点。多糖是中药黄芪的重要有效成分,由己糖醛酸、果糖、阿拉伯糖、半乳糖醛酸等组成,具有免疫调节、抗肿瘤、抗应激和抗氧化等作用。黄芪多糖的免疫调节一直是人们研究的重点,研究发现其可通过促进DC成熟而发挥免疫调节作用。论文从DC的形态和功能变化、DC的成熟和DC表面标志CD80、CD86、CD83和相关细胞因子表达等方面,综合分析了黄芪多糖对DC抗原递呈能力的影响。     

鸡胚肝脏发育过程中增殖细胞核抗原及核仁组织区的免疫组化观察

肝脏是机体的重要器官,功能复杂,发挥着巨大的作用.在动物增殖发育的报道多集中在小鼠[1-3],检测NOR的研究多见于区别于某些肿瘤的良恶性、分级和分型以及对预后判断[4-6].在鸡的肝脏发育方面的研究报道较少[7],本试验运用常规的H.E.染色方法和增殖细胞核抗原(PCNA)免疫组织化学方法,嗜银蛋白(NOR)染色对其进行了研究,探讨其在发育过程中的规律.     

树突状细胞潜在功能的研究进展

1、免疫应答中DC的主要功能 　　DC可以看做是专门将抗原提呈给T细胞的一个细胞体系.它们是最强大的APC,在启动幼龄动物的免疫应答中是必需的.DC由骨髓样或淋巴样的前体演化而来,在许多组织中是微量的,但在体表下(如皮肤、气管、肠管)明显的形成网络,在此捕获抗原,然后迁移到输出淋巴结,提呈加工过的抗原.DC可以通过其特殊的形态和在组织中的定位来鉴别.……     

痤疮丙酸杆菌对动物的免疫调节作用及应用

痤疮丙酸杆菌(PA)是人类皮肤和自然环境中的常见微生物,具有非特异性免疫增强作用,可激活多种免疫相关细胞,具有诱生干扰素、提高体液免疫水平、上调细胞TLR-2和TLR-4的表达等多种生物学活性。PA具有显著的活化抗原递呈细胞的作用,常被用于动物的非特异性免疫刺激剂,PA制剂可提高外周血单核细胞中IFN-γ和自然杀伤细胞裂解酶水平及上调抗菌肽的表达,提高动物对病原细菌的抵抗力,胸膜肺炎放线杆菌与PA具有交叉免疫保护反应,在开发相关疫苗过程中具有潜在作用。     

Toll样受体的研究进展

Toll样受体(TLRs)在机体的先天性免疫和获得性免疫中作为重要的调节器对病原体的识别发挥着非常重要的作用.TLRs作为一类病原模式识别受体在免疫应答和炎症反应中发挥着重要作用,TLRs信号失调会引起多种疾病.在机体的免疫系统中,先天性免疫作为免疫应答的始动环节,通过抗原递呈细胞（APC）主要以MHC2抗原肽复合物的形式递呈给T细胞来启动获得性免疫应答.获得性免疫应答的启动需要双信号,即特异性抗原的刺激和来自APC的共刺激信号.通过疾病模型发现,TLR信号级联的靶向作用将会给传染性疾病带来新的治疗方案.文章就TLRs与先天性免疫的关系、TLRs的配位子及TLRs在传染性疾病治疗中的靶向作用进行了简单概述.     

硬骨鱼类黏膜免疫机理研究概况

鱼类黏膜是抗原、病原等异己物质进入机体的屏障,在免疫反应中占有重要的地位。文章总结了硬骨鱼类黏膜免疫研究所涉及的组织器官,如皮肤、鳃和肠道等,以及在这些组织器官中与黏膜免疫功能相关的细胞;描述了黏膜免疫反应中的抗原在黏膜表面被抗原递呈细胞和MHC分子摄取、递呈给效应位点淋巴细胞,引起免疫应答,发生免疫保护记忆的过程;从鱼类血清和黏液中的免疫球蛋白结构、黏液抗体的峰值以及来源等方面,讨论了黏膜免疫和系统免疫之间的关系,分析了存在观点分歧的原因,并提出了鱼类黏膜免疫的研究方向。     

MicroRNAs对巨噬细胞的调节作用

<正>巨噬细胞是一种抗原递呈细胞,同时具有很强的吞噬和消化异物抗原的能力,是固有免疫系统的主要效应细胞之一。巨噬细胞存在于机体的各个组织内,几乎参与机体的每一个生物过程,从发育、稳态到对病原体的免疫应答[1],在抗炎、抗纤维化、抗癌的治疗方面起着重要的作用。miRNA一种微小的未编码的RNA,可以对基因表达进行调控,直接抑制目的基因mRNA的表达,参与各种生物功能的调节,包括免疫细胞的分化、成熟、维持免疫内环     

哺乳动物毛囊形态发生诱导和抑制因子

动物的毛囊产生毛发,而且有调节体温、感觉外界环境、避免损伤皮肤、社会交往等功能,绵羊和山羊还能为人类提供羊毛和羊绒.毛囊发育是表皮角质化细胞向毛发特异性分化和形成毛乳头的真皮成纤维细胞群之间发生的表皮-真皮相互作用的结果.毛囊的形态发生涉及多个信号途径的调节,阐明这些信号途径发生作用的过程对于理解皮肤中毛囊的特征是非常关键的.文章综合了有关动物毛囊发育调节分子机理的一些最新研究进展.     

动物肠道黏膜免疫细胞

肠道黏膜免疫系统作为相对独立的免疫系统,是由大量的独特的免疫分子和独特的细胞群构成。根据其分布的位置不同,肠道黏膜免疫细胞可分为诱导免疫细胞和效应免疫细胞。前者主要是指肠上皮细胞、微皱褶细胞和专职抗原递呈细胞(专职APC),后者主要指上皮内淋巴细胞(IEL)和固有层淋     

Heartworm in dogs in Canada in 1984

In late December 1984, 1853 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1984 and 35% of them responded. Veterinarians reported that 97,794 dogs were blood-tested to check for microfilariae and 1417 dogs (1.45% of those tested) were found with heartworm. Another 34 dogs were amicrofilaremic, but were diagnosed as having heartworm disease, to give the total number diagnosed in 1984 as 1451 (1.48%). Heartworm was reported from all provinces except Prince Edward Island and Newfoundland but most (1310) of the cases were in Ontario. In Quebec, 126 cases were reported mostly from west of Montreal.

Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 27% of the cases were observed with clinical signs of heartworm disease and 72% had a history of not having left Canada. Southwestern Ontario continued to be the primary focus of the infection.

     

Heartworm in dogs in Canada in 1983

In late December 1983, 2 800 veterinarians across Canada were sent a questionnaire in order to assess the status of heartworm disease in Canada in 1983 and 26% of them responded. Veterinarians reported that 59 504 dogs were blood-tested to check for microfilariae and 771 dogs (1.30% of those tested) were found with Dirofilaria immitis. Heartworm disease was diagnosed in all provinces except New Brunswick and Newfoundland but most (733) of the cases were in Ontario.

Heartworm disease was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 31% of the cases were observed with clinical signs of heartworm disease and 64% had a history of not having left Canada. Southwestern Ontario continues to be the focus of the infection and most of the dogs there had not left the province previously.

     

Heartworm in dogs in Canada in 1991

In late November 1991, 1883 clinics in Canada were sent a questionnaire to assess the status of Dirofilaria immitis in dogs in 1991 and there was a 60.0% response. There were 344,031 dogs tested for heart-worm (HW), 627 were found infected and the prevalence of HW infection was 0.18%. There were 417 dogs with HW in Ontario, 116 in Manitoba, 38 in Quebec, 53 in British Columbia, three in Alberta, and one in Nova Scotia. In British Columbia, all of the infected dogs but one were from the Okanagan valley which, as from 1991, is a new focus of infection in Canada. Most dogs with HW had not been on preventive medication in 1990, and the prevalence among dogs tested and unprotected was 0.59%. That prevalence was considerably higher in endemic areas. Companion dogs, over three years of age and maintained primarily outdoors in rural areas, were most frequently infected. One cat was diagnosed with D. immitis and 33 dogs had Dipetalonema reconditium.     

Heartworm in dogs in Canada in 1985

In late December 1985, 1485 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1985 and 44% of them responded. Veterinarians reported that 137,300 dogs were blood-tested to check for microfilariae and 1210 dogs were found with heartworm. Another 36 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number diagnosed in 1985 as 1247 (0.91%).

Heartworm was reported from all provinces except Prince Edward Island, Newfoundland and Saskatchewan but most (1126) of the cases were in Ontario. Southwestern Ontario continued to be the primary focus of the infection in Canada. From Quebec, 91 cases were reported mostly from and around Montreal. From Manitoba, 19 cases were reported from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 28% of the cases were observed with clinical signs of heartworm disease and 78% had a history of not having left Canada.

     

Heartworm in dogs in Canada in 1988

In late November 1988, 1581 small and mixed animal clinics and institutional veterinarians across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1988, and 46% of them responded. Veterinarians reported that 181,577 dogs were blood-tested for heartworm disease and 367 dogs were found with D. immitis microfilariae. Another 60 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1988 as 441 (0.24%).     

Heartworm in dogs in Canada in 1989

In late November 1989, 1732 clinics and institutional veterinarians were sent a questionnaire to assess the status of Dirofilaria immitis, and 51.7% responded. Of 247,716 dogs tested, 394 had D. immitis microfilariae and 51 were amicrofilaremic for a total of 445 cases and heartworm prevalence of 0.17%. Most (408) of these dogs had no preventive medication and the prevalence among dogs tested and unprotected was 1.01%. That prevalence was considerably higher in endemic areas. Thirty-seven dogs with heartworm had preventive medication. Heartworm was most frequent in companion dogs over three years of age maintained outdoors in rural areas. About 75% of the cases had never left Canada, 26% had clinical signs and 125 were not treated.

Heartworm was reported from British Columbia, Manitoba, Ontario, Quebec, Nova Scotia and Newfoundland, but 383 cases were in Ontario. South-western Ontario was the primary focus of infection. There were 33 cases in Quebec and 24 in Manitoba, mainly found in and around Metropolitan Montreal and Winnipeg respectively.

     

Heartworm in dogs in Canada in 1987

In late November 1987, 1246 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1987, and 50% of them responded. Veterinarians reported that 165,428 dogs were blood tested for heartworm disease and 511 dogs were found with D. immitis microfilariae. Another 78 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1987 as 589 (0.35%).     

Heartworm in dogs in Canada in 1986

In late December 1986, 1224 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1986; 46% of them responded. Veterinarians reported that 150,989 dogs were blood-tested for microfilariae and 869 dogs were found with heartworm. Another 65 dogs were amicrofilaremic but diagnosed with heartworm disease and one was found with heartworm at necropsy to give the total number diagnosed in 1986 as 935 (0.62%).

Heartworm was reported from Manitoba, New Brunswick, Ontario and Quebec, but most (810) of the cases were from Ontario. South-western Ontario continued to be the primary focus of the infection in Canada. There were 103 cases reported from Quebec, mostly from and around Montreal, and 21 cases from Manitoba, from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 33% of the cases were observed with clinical signs of heartworm disease and 81% had a history of not having left Canada.