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1.
In homologous and heterologous challenge trials using calves 相似文献
2.
An enzyme-linked immunospot (ELISPOT) has been developed to detect porcine epidemic diarrhea virus (PEDV)-specific antibody secreting cells (ASC) in gut associated lymphoid tissues (duodenum and ileum lamina propria and mesenteric lymph nodes) and systemic locations (spleen and blood) of conventional pigs so as to characterise the mucosal and systemic antibody response generated by the infection with PEDV. A total number of 28 eleven-day-old conventional pigs were orally inoculated with the field isolate of the PEDV strain CV-777. Diarrhea was observed in 32% of the pigs and virus shedding was demonstrated in 100% between postinoculation day (PID) 1 and 8. Serum IgG and IgA antibodies to PEDV were detected by isotype ELISA from PID 12 and 15, respectively, reaching maximum values at PID 32 (IgG) and 21 (IgA). PEDV specific IgM ASC occurred in all the tissues between PID 4 and 7, with the strongest response in the intestinal lamina propria. IgA and IgG ASC responses were evident in the intestinal lymphoid tissues from PID 21, the highest number of specific ASC corresponded to the duodenum lamina propria. In the systemic lymphoid tissues the number of IgG and IgA ASC detected were lower than in the mucosal tissues, however, in the blood, presence of IgA ASC was constantly detected from PID 14 until the end of the experiment. Memory antibody response to the PEDV was also studied by secondary in vitro stimulation of the mononuclear cells (MNC) isolated from mesenteric lymph nodes, spleen and blood. The memory B cell response was prominent at PID 21 and 25 and consisted in IgG and IgA ASC. To our knowledge, this is the first report to research into the presence and distribution of specific ASC in different locations of the systemic and the gut associated lymphoid tissues after a PEDV infection as well as the presence of memory B cells. 相似文献
3.
Induction of mucosal immune responses and protection against enteric viruses: rotavirus infection of gnotobiotic pigs as a model 总被引：4，自引：0，他引：4
Enteric viruses are a major cause of diarrhea in animals and humans. Among them, rotaviruses are one of the most important causes of diarrhea in young animals and human infants. A lack of understanding of mechanisms to induce intestinal immunity and the correlates of protective immunity in neonates has impaired development of safe and effective vaccines against enteric viruses. Studies of candidate vaccines using an adult mouse model of subclinical enteric viral infections often do not predict vaccine efficacy against disease evaluated in neonatal large animals. A series of studies have been conducted using a neonatal gnotobiotic pig model of rotavirus infection and diarrhea to identify correlates of protective immunity and to evaluate traditional and novel vaccine approaches for the induction of mucosal immune responses and protection to enteric viruses. Gnotobiotic pigs recovered from infection with virulent Wa human rotavirus (HRV) (mimic natural infection) had high numbers of intestinal IgA rotavirus-specific primary antibody-secreting cells (ASCs) and memory B-cells (to recall antigen) measured by ELISPOT assay, which correlated with complete protection against rotavirus challenge. Most short-term IgA memory B-cells were resident in the ileum, the major site of rotavirus replication. Spleen, not the bone marrow, was the major resident site for longer-term IgG memory B-cells. Candidate rotavirus vaccines evaluated in pigs for their ability to induce intestinal or systemic ASC and protection against rotavirus infection and diarrhea included attenuated live virus, inactivated virus, and baculovirus-expressed double-layered rotavirus-like particles (2/6-VLPs). In combination with those candidate vaccines, various adjuvants, delivery systems, and immunization routes were tested, including incomplete Freund's adjuvant for i.m. immunization, and a mutant Escherichia coli heat labile enterotoxin R192G (mLT) for i.n. immunization. It was shown that orally administered replicating vaccines were most effective for priming for intestinal IgA ASC and memory B-cell responses, but i.n. administered non-replicating 2/6-VLPs plus mLT were effective as booster vaccines. We conclude that protective immunity depends on the magnitude, location, viral protein-specificity, and isotype of the antibody responses induced by vaccination. Therefore highly effective enteric viral vaccines should: (i) induce sufficient levels of intestinal IgA antibodies; (ii) include viral antigens that induce neutralizing antibodies; and (iii) require the use of effective mucosal adjuvants or antigen delivery systems for non-replicating oral or i.n. vaccines. 相似文献
4.
In seeking to develop a safe fowl typhoid (FT) vaccine, a novel candidate lacking cpxR, lon, and asd Salmonella Gallinarum (SG) genes was constructed with the plasmid-containing araC::P(araBAD)::asd system. A balanced-lethal host-vector system based on the essential bacterial gene for aspartate beta-semialdehyde dehydrogenase (asd) was used to construct the SG mutant strain. A plasmid (p15A ori) with an araC::P(araBAD)::asd cassette was introduced into an auxotrophic mutant to prevent ex vivo survival. The safety, immunity, and protective properties of the SG mutant were evaluated. Inoculation of the mutant at 10(6) colony-forming units (CFU) did not result in recovery in feces and internal organs, whereas inoculation at 10(8) and 10(10) CFU resulted in moderate bacterial recovery from feces and organs. Birds immunized with the mutant were challenged with a virulent SG strain at day 14 postimmunization; significantly reduced mortality and induced plasma immunoglobulin (Ig)G and mucosal IgA responses were noted. Cellular immune responses as evaluated by a peripheral lymphocyte proliferation assay were also significantly induced. The balanced-lethal host-vector system for construction of SG mutants is an effective and improved approach for safe vaccine construction against FT. 相似文献
5.
Crouch CF Daly J Henley W Hannant D Wilkins J Francis MJ 《Veterinary immunology and immunopathology》2005,108(3-4):345-355
In horses, natural infection confers long lasting protective immunity characterised by mucosal IgA and humoral IgGa and IgGb responses. In order to investigate the potential of locally administered vaccine to induce a protective IgA response, responses generated by vaccination with an immunostimulating complex (ISCOM)-based vaccine for equine influenza (EQUIP F) containing A/eq/Newmarket/77 (H7N7), A/eq/Borl?nge/91 (H3N8) and A/eq/Kentucky/98 (H3N8) using a systemic prime/mucosal boost strategy were studied. Seven ponies in the vaccine group received EQUIP F vaccine intranasally 6 weeks after an initial intramuscular immunisation. Following intranasal boosting a transient increase in virus-specific IgA was detected in nasal wash secretions. Aerosol challenge with the A/eq/Newmarket/1/93 reference strain 4 weeks after the intranasal booster resulted in clinical signs of infection and viral shedding in seven of seven influenza-naive control animals whereas the seven vaccinated ponies had statistically significantly reduced clinical signs and duration of virus excretion. Furthermore, following this challenge, significantly enhanced levels of virus-specific IgA were detected in the nasal washes from vaccinated ponies compared with the unvaccinated control animals. These data indicate that the intranasal administration of EQUIP F vaccine primes the mucosal system for an enhanced IgA response following exposure to live influenza virus. 相似文献
6.
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。 相似文献
7.
Salmon H 《Veterinary immunology and immunopathology》1999,72(1-2):143-155
The passive mucosal protection of neonate mammals is dependent on the continuous supply until weaning of maternally dimeric IgA (monogastric) and IgG1 (ruminants). This lactogenic (humoral) immunity is linked to the gut, the so-called entero-mammary link, because of the translocation of Ig (IgA and IgG1) or the emigration of IgA lymphoblasts from the gut into the mammary gland (MG); on the other hand, studies on the lymphocyte subsets in the MG of artiodactyls sustained the view of a true local immune response, depending on the MG stage development. Accordingly, the increase of the lactogenic immunity may focus on (1) inductor sites (gut and, possibly, the MG), (2) increase in cell traffic from the gut into the MG, and (3) enhancement at the effector site of the Ig production and excretion in milk. A specific mucosal environment (interleukins and hormones) is responsible for IgM/IgA switch, the induction of mucosal homing receptor onto lymphoblasts and mucosal vascular addressins; very few data are available for the mechanism of lymphoblasts recruitment, either IgA or IgG1, although lactogenic hormones have been implicated in the IgA-blasts homing into the mice MG. After weaning, the neonate is able to mount a gut immune response, but the shortage of the suckling period did not seem to be detrimental for its onset. In soyabean allergy, both piglet and calf exhibited gut villus atrophy, gut accumulation of IgA (swine) and IgG1 (cattle) immunocytes, sustaining the view that a specific environment in ruminant is responsible for both IgA and IgG1 production. 相似文献
8.
Enhancement of mucosal immune responses by intranasal co-delivery of Newcastle disease vaccine plus CpG oligonucleotide in SPF chickens in vivo 总被引：2，自引：0，他引：2
Immunostimulatory CpG oligodeoxynucleotides (ODN) have been tested as immunoadjuvants for various vaccines in mice and human. Findings from previous reports suggest that CpG ODN can be used to enhance magnitude and balance of an immune response while reducing undesirable side effects of commercial vaccine, when delivered by parenteral route. Recently, it has been showed that CpG ODN is a promising mucosal adjuvant in mice, but data on mucosal immune responses induced by CpG ODN in other animals, especially in chickens, are scarce. Herein, we evaluated intranasal (IN) delivery of CpG ODN with newcastle disease (ND) vaccine (NDV) to determine its potential as a mucosal adjuvant to a commercial vaccine. CpG ODN augmented systemic (IgG in serum, T cell proliferation) and mucosal (IgA in intestinal washings and feces) immune responses against antigen. CpG ODN stimulated effectively both systemic and mucosal immune responses when delivered intranasally. Results from this study indicate that stimulatory CpG ODN is a potential effective mucosal adjuvant for the NDV in SPF chickens and may be applicable to husbandry animals. 相似文献
9.
《Research in veterinary science》2009,86(3):495-502
Immunostimulatory CpG oligodeoxynucleotides (ODN) have been tested as immunoadjuvants for various vaccines in mice and human. Findings from previous reports suggest that CpG ODN can be used to enhance magnitude and balance of an immune response while reducing undesirable side effects of commercial vaccine, when delivered by parenteral route. Recently, it has been showed that CpG ODN is a promising mucosal adjuvant in mice, but data on mucosal immune responses induced by CpG ODN in other animals, especially in chickens, are scarce. Herein, we evaluated intranasal (IN) delivery of CpG ODN with newcastle disease (ND) vaccine (NDV) to determine its potential as a mucosal adjuvant to a commercial vaccine. CpG ODN augmented systemic (IgG in serum, T cell proliferation) and mucosal (IgA in intestinal washings and feces) immune responses against antigen. CpG ODN stimulated effectively both systemic and mucosal immune responses when delivered intranasally. Results from this study indicate that stimulatory CpG ODN is a potential effective mucosal adjuvant for the NDV in SPF chickens and may be applicable to husbandry animals. 相似文献
10.
Xuefeng Qi Xiaoyan Yang Anchun Cheng Mingshu Wang Dekang Zhu Renyong Jia Qihui Luo Xiaoyue Chen 《Research in veterinary science》2009,87(2):218-225
Duck virus enteritis (DVE) is an acute and contagious herpes virus infection of duck, geese and swans with high morbidity and mortality. The development of specific mucosal immune system against duck enteritis virus (DEV) infection for ducks has been hindered by a lack of knowledge concerning the purification of immunoglobulin A (IgA) of duck. In the present work, the method for purification of duck immunoglobulin A was developed, and the induction of intestinal mucosal immune responses against DEV was studied by orally infected ducklings with virulent DEV. The results showed that a continuous increased DEV DNA levels were observed in blood and various organs examined of orally infected ducklings throughout the infection, which was accompanied by the development of infection in ducklings from mild progressed to severe pathological lesions. Furthermore, a marked increased level of DEV-specific IgA and IgG antibodies in bile, serum and the intestinal tract, as well as the density of IgA+ cells in intestine were detected between 1 and 12 days p.i., followed by a drastic reduction of the antibody levels and the density of IgA+ cells at 15 days p.i. The results indicate that the DVE infection can stimulate both IgA-dominated antibody immune responses in the intestinal tract, and IgG-dominated antibody systemic immunity in the serum of ducklings orally inoculated with virulent DEV. The severe lesions of the villus epithelial cells and the lymphoid organs can suppress the intestinal mucosal immune responses. 相似文献
11.
枯草芽孢杆菌属于革兰氏阳性菌,非致病菌,其芽孢是其一种休眠体,能抵御外界恶劣的环境条件。该菌细胞壁不含内毒素,具有单层细胞外膜,动物肠道中枯草芽孢能直接分泌蛋白质到胞外。枯草芽孢杆菌是一种存在于动物的肠道中的有益菌,参与维持肠道内环境的平衡与稳定,且可刺激机体释放分泌型免疫球蛋白,有利于肠道黏膜的局部免疫,进而增强机体免疫力。因其对体液免疫和细胞免疫的特性,其菌体成为当今制备黏膜免疫疫苗的一种理想的疫苗载体。枯草芽孢杆菌具有独特的优势,使其能作为便于推广的疫苗载体进行研究。文章主要对枯草芽孢杆菌的黏膜免疫机制及其作为疫苗载体研究和应用前景进行阐述。 相似文献
12.
Picherot M Oswald IP Cote M Noeckler K Le Guerhier F Boireau P Vallée I 《Veterinary parasitology》2007,143(2):122-130
The immune protective response developed by swine against Trichinella spiralis is not yet fully understood, particularly at the mucosal level. This study aimed to characterise intestinal immunity to T. spiralis by comparison with the systemic response in specifically pathogen-free pigs. For this purpose, the kinetics of cytokine and antibody production were assessed in the intestinal mucosa and serum of swine infected with T. spiralis for up to 60 days post-infection (dpi). An ex vivo model of jejunum mucosa culture was used to collect the supernatant as a source of antibodies (Abs). Mucosal antibodies were observed by Western blot from 15 dpi, while serum antibodies were expressed from 20 dpi. Both sources of antibodies initially recognized a 110 kDa protein, followed by the identification of 35, 43/46 and 55/59 kDa proteins. IgG1 and IgA antibodies were strongly expressed within the mucosa. The expression levels of Type 1 (IFN-gamma, IL-12), Type 2 (IL-4, IL-6), pro-inflammatory (TNF-alpha) and regulatory (IL-10, TGF-beta) cytokines were assessed by RT-PCR in the intestinal mucosa and spleen. Both IL-10 and IFN-gamma mRNA levels were increased in mucosa, whereas IL-6 and IL-12 mRNA were expressed in spleen. Taken together, these results demonstrated a mixed Type 1/Type 2 profile, the Type 2 profile being dominant in the mucosa. 相似文献
13.
Husband AJ 《Veterinary immunology and immunopathology》2002,87(3-4):131-136
The maintenance of IgA antibody responses at mucosal surfaces is the outcome of influences on IgA precursor cell dissemination from the mucosal inductive sites, such as the intestinal Peyer's patches, their selective extravasation at mucosal effector sites and the retention and local proliferation of these cell populations under local influences. Examination of these local post-extravasational effects has implicated cytokines as major regulatory elements in this process. This paper will address the role of cytokines in induction and expression of IgA responses and the differential requirements for cytokine signals among IgA-committed B cell subsets in both rodent and domestic livestock species. The way in which cytokines influence local immunity in the gut with respect to microbial and parasitic challenge and comparative cytokine effects in extra-intestinal sites, particularly the eye, will be presented, and opportunities for therapeutic interventions to modify cytokine expression will be discussed. 相似文献
14.
Short term tissue biopsy cultures and paired, sera, bile and gastric and intestinal contents from Helicobacter pylori-infected gnotobiotic piglets were tested for the synthesis of H. pylori-specific immunoglobulin (Ig) isotype production by antigen-specific ELISA from post-infection days (PIDs) 2-28. Serum antibody levels in all three Ig isotypes were elevated from baseline values by PID 14, serum IgM levels reached peak levels on PID 14 and by PID 28 bile was strongly positive for IgA and IgG.Intestinal, but not gastric contents from infected piglets, contained IgA-specific antibody from PID 14 onward. Gastric mucosal epithelia adjacent to areas of inflammation in infected but not uninfected control piglets produced readily detectable amounts of porcine secretory component (SC); IgA-positive plasma cells were identified in gastric submucosa and lamina propria in these areas. Culture fluid supernatants, collected from explanted gastric cardia and antra and intestinal ilea of H. pylori-infected piglets had trace amounts of IgA as early as PID 2 in some animals, and strong IgA reactivity in all by PID 28. Supernatants also contained H. pylori-specific IgG by PID 14. A strong gastric lymph node IgA response contrasted with moderate IgA production in mesenteric lymph nodes and spleen. Mucosal biopsy production of H. pylori-specific IgG was more evenly distributed throughout the lymphoid system. These data support the contention that the Ig response to H. pylori is initiated within the gastric compartment and matures over time to a generalized IgA-dominated mucosal and IgG-dominated nonmucosal humoral immune response. 相似文献
15.
饲用益生菌对动物肠道免疫调节的作用机理 总被引：1，自引：0，他引：1
益生菌即一类以活菌为主的新型饲料添加剂,其活菌能在动物肠道内定植,维护肠道菌群平衡,并刺激肠黏膜免疫系统,引起体液免疫和细胞免疫应答,从而增强机体抗病力.本文对益生菌的免疫刺激及其作用机理进行综述. 相似文献
16.
给10头8周龄仔猪经口感染猪流行性腹泻肠管毒,于感染后5、15、25、35和45d各扑杀2头,采取胃及各段肠管标本,用免疫过氧化物酶技术(间接法)检查胃肠粘膜固有层中IgA、IgM和IgG产生细胞数;收集血液及胃、各段肠管分泌液,应用ELISA双抗体夹心法测定IgA、IgM和IgG含量。结果:实验猪感染后第15d,空肠下段、回肠和回盲口处粘膜固有层中IgA和IgM产生细胞明显增多,肠管分泌液中IgA含量与IgA产生细胞数呈正相关,肠道局部免疫反应的高峰比全身性(系统性)免疫出现得早,且周期短。本试验提示,肠道粘膜积极参与了该病的免疫过程;胃肠道对猪流行性腹泻病毒(PEDV)免疫反应的主要部位在空肠下段、回肠和回盲目;参与胃肠道免疫反应的免疫球蛋白产生细胞主要是IgA和IgM产生细胞。 相似文献
17.
Studies on local immunity to transmissible coronaviral enteritis of turkeys (bluecomb) was made. Intestinal secretions and bile from affected birds contained secretory immunoglobulins against coronaviral antigen throughout the 6 months' duration of the experiment. Attempts to purify and to characterize the globulins in intestinal secretions and bile of the affected birds were made, using the techniques of gel filtration, DEAE chromatography, and immunoelectrophoresis. Class-specific anti-turkey IgA antiserum in the agar gel precipitin test further established the presence of IgA in the intestinal secretions and bile. 相似文献
18.
猪支原体肺炎活疫苗（168株）肺内免疫机制研究 总被引：1，自引：0，他引：1
为研究猪支原体肺炎活疫苗(168株)的免疫机制,通过肺内接种免疫5 ～ 10日龄仔猪,并于免疫后不同时间点检测血清中IgG抗体效价、全血中淋巴细胞转化效率、呼吸道局部的IFN-γ浓度和特异性SIgA滴度,于免疫后28 d剖杀采集呼吸道上皮组织,通过扫描电镜法与原位杂交检测法观察疫苗株在呼吸道的存留以及对纤毛的影响情况.结果发现,免疫后猪血液中淋巴细胞转化增强1.52～2.01倍,支气管表面IFN-γ浓度和特异性SIgA滴度持续增加,但血清抗体一直未检测到.扫描电镜与原位杂交检测结果发现疫苗株能有效地黏附在支气管纤毛上皮细胞上,但对纤毛的影响较小.由此表明,猪支原体肺炎活疫苗(168株)通过肺内免疫可有效激活全身细胞免疫及呼吸道局部的黏膜免疫与细胞免疫反应,而且还可以通过黏附支气管纤毛上皮细胞产生占位效应而对上皮组织不产生损伤. 相似文献
19.
肠道黏膜免疫研究进展 总被引：1，自引：0，他引：1
黏膜免疫是当前免疫学领域的研究热点,尤其是肠道黏膜免疫越来越被人们重视.近年来国内外学者分别探讨了肠道黏膜组织结构、肠道菌群及黏膜疫苗对黏膜免疫的作用及影响,研究表明,肠道黏膜组织结构中主要是M细胞、树突状细胞和巨噬细胞进行抗原摄取和转运,对起始黏膜免疫起着重要的作用.肠道菌群在免疫过程中主要是促进抗原的分泌和调节各种细胞因子的产生.合适的黏膜疫苗能够有效地激发黏膜免疫反应,具有方便、快捷、安全、有效、持续等优点.文章重点阐述了肠道菌群对黏膜免疫的影响及黏膜免疫的优点,并指出了制约黏膜免疫发展的关键因素、存在的问题及其发展前景. 相似文献
20.
雏鸡服用益生素后免疫器官指数及局部体液免疫球蛋白相对含量的动态变化 总被引：18，自引：0，他引：18
用商品益生素和自制益生素分别灌服1日龄雏鸡，灌服益生素后1、4、7、10、18d测定胸腺、脾脏、法氏囊的器官指数动态变化，用间接酶联免疫吸附试验(ELISA)方法测定泪液、气管液、胆汁和肠液的IgA、IgM、IgG相对含量的动态变化，结果发现服用商品益生素的雏鸡免疫器官指数在第7天高于未服用益生素的对照雏鸡，上述4种体液的IgA、IgM、IgG相对含量在服用益生素后7～10d高于未服用益生素的对照雏鸡，服用自制益生素的雏鸡上述4种体液的IgA、IgM、IgG相对含量在服用益生素后4～7d高于未服用益生素的对照雏鸡。表明益生素对雏鸡的免疫系统有一定的影响，能够促进免疫器官的生长发育，提高雏鸡呼吸道和消化道局部体液的免疫球蛋白相对含量。 相似文献