4种因素对NK细胞杀伤活性的影响

为了探讨效应细胞与靶细胞的比例(效靶比)、孵育时间、显色时间以及小牛血清浓度对NK细胞杀伤活性的影响,采用乳酸脱氢酶释放法来测定不同因素对NK细胞杀伤活性的影响,结果表明,最佳效靶比和孵育时间分别为50∶1和2 h。在最优效靶比及孵育时间的基础上,显色0.5 h,小牛血清浓度为50 mL/L时NK细胞活性最高,证明4种因素对NK细胞杀伤活性均有不同程序的影响。     

重组鸡白细胞介素18(rChIL-18)对MDV感染SPF鸡细胞免疫的影响

用马立克氏病病毒（MDV）感染5日龄SPF鸡后,取21日龄和35日龄鸡的淋巴细胞,运用3H-TdR掺入法检测T淋巴细胞对ConA和重组鸡白细胞介素18（rChIL-18）的反应,并用MTT法检测NK细胞和CTL对MD肿瘤细胞系CU147的杀伤活性及rChIL-18和IFN-γ对它们的作用。结果显示,SPF鸡感染MDV后淋转水平显著下降,NK细胞、CTL杀伤活性在感染后21日龄时升高,而在35日龄时NK细胞杀伤活性显著下降。rChIL-18对对照组和感染组SPF鸡的淋转水平和杀伤活性均有提高作用,同样IFN-γ也具有提高NK细胞和CTL杀伤活性的作用。     

动物粘膜免疫系统研究进展(续)

接上期2.3.2.2　K细胞(Killercell)是一类具杀伤作用的淋巴细胞,其表面特征和免疫效应均与T、B细胞不同。K细胞本身杀伤作用是非特异性的,但可通过抗体的特异性有目的杀死靶细胞。K细胞所杀伤的靶细胞一般较大,如不能被巨噬细胞吞噬的寄生虫、真菌、病毒感染细胞、恶性肿瘤细胞及同种移植物组织细胞等。因此,K细胞在抗感染、抗肿瘤及移植排斥反应、超敏反应、自身免疫病等的发生中均发挥一定作用。2.3.2.3　自然杀伤细胞(naturalkillercell,NK细胞)　是一类异质性、多功能性的细胞群体,它不需抗原刺激,也不需抗体参与,即能杀伤某些靶细…     

微量乳酸脱氢酶释放法检测NK细胞活性的几个主要影响因素

对乳酸脱氢酶释放法测定小鼠脾脏 NK细胞活性中的酶促反应时间、效靶细胞比例、检测波长、细胞毒试验孵育时间、维持液中小牛血清 ( FCS)浓度等 5个重要的影响因素进行了探索。结果显示 ,酶促反应时间以 1 0 min最佳 ;效靶细胞比例以 1 5∶ 1为适宜 ;最适检测波长为 570 nm,其结果线性关系好 ;细胞毒试验孵育时间以 2 h为宜 ;维持液中小牛血清以低浓度为宜 ,其结果更接近自然杀伤百分率计算公式 ,并选用 2 %为本试验小牛血清的体积分数     

华蟾毒精对小鼠免疫细胞活性的影响

为观察华蟾毒精（CBG）对小鼠免疫细胞活性的影响,本研究采用MTT法检测小鼠脾淋巴细胞的增殖情况,检测小鼠腹腔巨噬细胞的吞噬功能以及小鼠NK细胞对靶细胞的杀伤作用。结果显示,CBG在一定剂量范围内单独或者协同非特异性丝裂原（Con A或LPS）作用能够显著增强小鼠脾淋巴细胞的增殖,CBG单独作用可以显著提高小鼠腹腔巨噬细胞的吞噬功能,并能够显著提高小鼠NK细胞对靶细胞的杀伤作用,表明CBG能够提高小鼠免疫细胞的活性。     

穿孔素的研究进展

穿孔素（PFP）是主要由CTL和NK细胞产生的一种糖蛋白，通过在靶细胞膜上形成活性孔道使靶细胞渗透压改变而溶解，或者与颗粒酶协同作用而主秀导靶细胞凋亡，生物学功能以及其在抗感染免疫，免疫应答，疾病（如自身免疫疫病，肿瘤）和移植排斥反应等中所发挥的作用作一综述。     

人参总皂苷及其衍生物对小鼠淋巴细胞和NK细胞免疫活性的影响

为了提高人参总皂苷的生物学活性,对其进行了硫酸化修饰,并探讨总皂苷及其衍生物对小鼠脾T、B淋巴细胞增殖（MTT法）和NK细胞杀伤活性（乳酸脱氢酶释放法）的影响。结果表明,2种衍生物质量浓度在50～500 mg/L时可以促进小鼠脾T、B淋巴细胞的分化增殖和NK细胞对YAC-1的杀伤作用,质量浓度较高时促进作用明显优于总皂苷;衍生物质量浓度达到1 400 mg/L时,仍然可以显著促进T淋巴细胞的增殖。试验结果提示,人参皂苷的这种衍生物有可能成为一种毒副作用较小、免疫活性更强的药物。     

山羊、水牛感染肝片吸虫后淋巴细胞自然杀伤活性动态变化

自然杀伤 (NK)活性是在细胞水平反映机体天然免疫力的重要指标之一。本实验以SP2 / 0细胞为靶细胞 (即效应细胞 ) ,采用乳酸脱氢酶(LDH)短程释放法测定人工感染肝片吸虫的水牛和山羊的外周血液中淋巴细胞的NK活性动态变化。从测定结果的相对值来看 ,发现山羊在感染肝片吸虫后NK活性有 2次高峰 ,推测与虫体的发育或感染山羊的免疫状态有关 ;2个感染组 (Ⅰ ,2 0 0个囊蚴 /只 ;Ⅱ ,50 0个囊蚴 /只 )的变化趋势表明 ,感染量与NK活性无相关关系。感染水牛的NK值仅略高于对照组 ,无明显的高峰。而绝对值结果又反映出不同动物的NK活性有差异 ,水牛的NK活性比山羊高 ,说明水牛对肝片吸虫的天然免疫力比山羊强     

干扰素对自然杀伤细胞的免疫调节作用

<正>自然杀伤细胞(NK细胞)是体内一类独特的淋巴细胞亚群,缺乏表面抗原受体,无CD3/TCR复合体,无表面免疫球蛋白。NK细胞的主要功能是溶解某些肿瘤细胞和病毒感染细胞,还可通过分泌炎性介质参与T淋巴细胞的分化。NK细胞位于机体抵抗肿瘤和病毒感染的第一线,不需预先刺激即可对病毒感染或恶性转化细胞进行攻击,且不受主要组织相容性复合体限制。NK细胞表面存在识别靶细胞表面     

蒙药特润舒都乐对模型小鼠脾脏NK细胞活性的影响

目的:观察和探讨蒙药特润舒都乐对小鼠脾脏NK细胞杀伤活性的影响,了解该蒙药的生物学活性.方法:采用皮下给药的体内实验及3 H-TdR掺入抑制法检测小鼠脾脏NK细胞活性.结果:蒙药特润舒都乐能显着提高小鼠脾脏NK细胞杀伤活性,且呈剂量依赖性,其高、中、低剂量(50,25,10mg/L)各组的NK活性分别为64.39±16.53、46.21±13.28、36.09±12.26,与空白对照及阴性对照均有显着性差异(P<0.05).结论:蒙药特润舒都乐能提高NK细胞活性,并有剂量依赖性.     

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 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.