Association of bovine secretory immunoglobulins with milk fat globule membranes

Milk IgA was seen to be largely associated with milk fat globules ( of the sIgA in whole milk). Isolated fat globules became agglutinated by anti-IgA and to a lesser degree by anti-IgM but not by anti-IgG₁ or anti-IgG₂ (microscopic plate agglutination). Absorption studies using anti-bovine sIgA showed that the cream contained some 16 times more IgA than the repective whey. Isolated milk fat globule membranes released IgA and SC when treated by Triton X 100 as demonstrated by double gel diffusion. IgA was the only membrane-associated component showing cross-reactivity with serum proteins in immunoelectrophoresis. An antiserum prepared against fat globule membranes showed strong anti-IgA activity. IgA from whey became absorbed into washed cream. The specificity of MFGM associated immunity was demonstrated by analysing the capacity of cream, isolated from mastitic cows, to bind homologous labelled bacteria (cream-rising test).     

猪乳中抗猪瘟IgA、IgG、IgM抗体动态变化规律研究

以猪瘟弱毒疫苗免疫空怀母猪,待母猪分娩后,分别收集10 d内的乳汁,以建立的间接ELISA方法检测猪瘟IgA、IgG、IgM水平,并观察各种抗体动态变化规律。试验结果表明,猪初乳中的IgA、IgG、IgM抗体效价均在分娩当天达到最高值,随后迅速下降,7 d后抗体水平与常乳基本一致。对照组母猪仅在分娩当天检测到较低的抗体水平。     

商品长白杂交猪IgA H链CH1-CH3区基因的克隆与表达

在猪IgA重链CH1-CH3区设计一对引物,用RT-PCR方法从地方杂交品种长白猪肠系膜淋巴结组织中扩增出预期大小的片断,插入pGEM-Teasy载体,测序并与约克夏猪、人及其他动物的IgA进行序列比较。随后,将该序列酶切后引入到pQE-30表达载体相应位点,转化JM109大肠杆菌,经IPTG诱导表达后,进行SDS-PAGE分析。结果显示,本研究克隆了猪IgA重链恒定区部分CH1亚区及完整的CH2-CH3亚区基因序列,全长822bp,编码274个氨基酸,该序列与GenBank上登录的约克夏猪参考序列核苷酸序列同源率为99.8%,有2处核苷酸变异,氨基酸序列的同源率为100%。但与人及其他动物显示从84%～51%不等的同源性;在大肠杆菌表达出约31ku的蛋白条带,表达量约占菌体总蛋白的32.3%。本试验为今后的IgA免疫功能研究及基因工程化检测试剂开发打下了基础。     

禽流感灭活抗原与佐剂配合鼻腔免疫对鸽呼吸道抗体分泌细胞的影响

通过禽流感灭活抗原配合黏膜免疫佐剂鼻腔免疫乳鸽,研究鸽呼吸道各段抗体分泌细胞的分布和数量。结果显示,首免后第3、5周,应用CpG免疫后肺IgG分泌细胞面积显著高于对照组（P〈0.05）,首免后第5,7周,应用CpG免疫后肺IgA分泌细胞面积显著高于对照组（P〈0.05）;首免后第3、5、7周,应用灭活禽流感抗原免疫后,鸽呼吸道各部位IgG分泌细胞和IgA分泌细胞面积与对照组无显著差异;应用禽流感抗原配合CpG和胆酸钠免疫后鸽呼吸道各部位单位面积中IgA分泌细胞和IgG分泌细胞面积均显著或极显著高于对照组（P〈0.01,P〈0.05）。结果表明,灭活禽流感抗原配合黏膜免疫佐剂通过鼻腔免疫能够提高呼吸道中IgA分泌细胞和IgG分泌细胞的面积,增强局部呼吸道体液免疫应答水平。     

分泌型IgA对肠道黏膜免疫的研究进展

分泌型IgA(secretory IgA,SIgA)作为一种包被于肠道黏膜的抗体,能保护肠道免受病原微生物和毒素的攻击而不引起炎症反应,对激活黏膜免疫和维持肠道内环境稳态起到重要作用。在动物肠腔中,SIgA能通过调节肠道上皮细胞受体的识别能力,阻断病原微生物侵入黏膜相关淋巴组织,随后在肠道蠕动和黏液绒毛的协助运动下,最终将病原微生物清除;且最近也有报道揭示SIgA在肠上皮胞吞转运作用下的新机制。因此,作者主要阐述SIgA在肠道黏膜免疫及其内环境方面发挥关键的生物学特征和功能,以及探讨胞吞转运机制下SIgA的潜在作用。     

芪蓝四君子汤对雏鸡小肠IgA分泌细胞和SIgA(分泌型IgA)的影响

雏鸡在新城疫La Sota系冻干苗进行口腔免疫时,分别按0.125,0.250,0.500 g/mL 3个剂量灌服芪蓝四君子汤1 mL,连续10 d。于20,40,60日龄时剖杀摘取各段肠管,免疫组织化学方法检测十二指肠、空肠、Peyer's斑单位面积IgA分泌细胞的变化,同时通过ELISA方法测定空肠中SIgA的含量。结果表明,与对照组相比,芪蓝四君子汤能显著提高雏鸡小肠IgA分泌细胞的阳性表达率及空肠SIgA抗体水平,揭示芪蓝四君子汤能提高新城疫的免疫原性,增强雏鸡的黏膜免疫力,是有效的口服佐剂。     

Effect of heat killed Mycobacterium phlei on body weight gain and management of caecal coccidiosis in broiler chickens

The objective of this study was to evaluate the immunotherapeutic potential of heat killed Mycobacterium phlei in broiler chicken against experimentally produced Eimeria tenella infection. The selected dose of E. tenella oocyst (5 × 10³ sporulated oocysts per bird) was capable of producing a mild form of caecal coccidiosis as observed by significant difference in body weight gain, clinical findings and caecal lesion score. Heat killed M. phlei was fed orally at 10 mg per bird with sterile PBS vehicle at alternate day for four doses. Our study reveals that per day body weight gain was significantly (p < 0.01) higher for healthy control compared to coccidia infected group. The group fed M. phlei along with coccidial challenge showed significantly (p < 0.05) higher body weight gain than infected control group. Heat killed M. phlei feeding also found effective to reduce the caecal lesion score significantly (p < 0.05) in comparison to E. tenella infected untreated group. IgA concentrations in serum and bile at 7-day post challenge of coccidial oocyst was also significantly (p < 0.01) higher in M. phlei fed group when compared to coccidia infected and healthy control group. We concluded that use of heat killed M. phlei has a beneficial role as an immunostimulant against caecal coccidiosis in broiler chicken.     

Serum concentrations of IgG, IgA, and IgM in retired racing Greyhound dogs

Background: Greyhound dogs have significant physiologic, hematologic, and biochemical differences when compared with other breeds, including significantly lower serum globulin concentration owing to decreases in the α‐ and β‐globulin fractions. The specific proteins that account for differences in globulin concentrations are not known, but IgA and IgM, both β‐globulins, are potential candidates. Objectives: The aims of this study were to measure serum IgG, IgA, and IgM in clinically healthy retired racing Greyhounds and compare the results with those of age‐ and sex‐matched non‐Greyhound dogs. Methods: Study animals included 25 Greyhound and 20 non‐Greyhound dogs. Total protein, albumin, and total globulin concentrations were determined. IgG, IgA, and IgM concentrations were measured using a commercially available radial immunodiffusion kit. The Student t‐test assuming equal variances was used to compare concentrations of immunoglobulins between groups. Results: Serum concentrations of IgA and IgM in Greyhounds (IgA=49±20 mg/dL; IgM=132±47 mg/dL) were significantly lower than concentrations in non‐Greyound dogs (IgA=70±39 mg/dL; Ig M=212±78 mg/dL). Concentrations of IgG did not differ between groups. Conclusions: Mean serum IgA and IgM concentrations in Greyhounds were lower than those in non‐Greyhound dogs. This may contribute to low serum concentrations of β‐globulins in Greyhounds. Specific reference intervals are recommended for Greyhounds to avoid possible misdiagnosis of IgA or IgM deficiency.     

Serum and skin IgA concentrations in normal and atopic dogs

Objective To compare serum and skin surface IgA concentrations from atopic and normal dogs.
Procedure IgA concentrations in sera and skin washings of 20 clinically normal dogs that had no history of pruritus or skin disease were compared to those obtained in 20 dogs with a diagnosis of atopy determined by history, clinical examination and positive intradermal skin test.
Results There was no significant difference in the mean serum IgA concentration in normal dogs (252 ± 187 mg/L) versus atopic animals (314 ± 327). When skin washings from all sites in both groups were compared, atopic dogs had significantly greater concentrations of IgA in their skin washings than normal dogs as evaluated by an enzyme-linked immunoassay (P < 0.001). However, there was no significant difference between the individual sites of the skin washings of atopic and normal dogs.
Conclusion IgA concentrations of skin washings in atopic dogs were greater than in normal dogs. Further investigations need to determine if the greater concentrations were caused by nonspecific inflammation or by secretion of allergen-specific IgA onto the skin surface.     

Retracted: Isolation,characterization, and effect of administration in vivo,a novel probiotic strain from pig feces

From porcine rectal swabs or feces, we isolated lactic acid bacteria and used porcine Peyer's patch cells to select them for inducibility of IgA production as an indicator of probiotic effects. The strain selected as a new probiotic was named ‘Enterococcus faecium NHRD IHARA‘. To verify the probiotic effects of this strain in vivo, 536 piglets at age 25 days were assigned to either the trial group, which administrated the strain, or the control group. An increase in IgA in the feces was observed at age 45 days (P < 0.05 compared with the control group); a significant increase in serum IgA was also observed at the end of the study (P < 0.01) in the trial group. In addition, significant differences between the groups in terms of body weight (P < 0.05) and average daily gain (P < 0.01) were observed. The rate of detection of swine‐pathogenic Escherichia coli gene in the feces tended to be lower in the trial group than in the controls. The novel probiotic strain; E. faecium NHRD IHARA may have beneficial effects on swine growth by inducing IgA production and reducing rates of colonization by pathogens in the body.