474 resultados para IgA


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中文摘要   已有的研究表明,小鼠背部携带能分泌抗原特异的IgA单克隆抗体的杂交细胞瘤,可以保护小鼠抵抗微生物和病毒等多种病原体经粘膜途径感染机体。我们利用背部携带能分泌抗精子特异抗原(LDH-C4)的IgA和IgG杂交细胞瘤、以及抗DNP的IgA骨髓细胞瘤的小鼠为动物模型,采用定量ELISA法研究了抗LDH-C4 IgA与抗DNP IgA单克隆抗体在呼吸道、肠道及生殖道内转运和分布,抗LDH-C4 IgG2b在肠道内转运和分布,以及抗LDH-C4 IgA和IgG单克隆抗体与体内抗生育作用的关系。研究结果表明,带瘤小鼠血液中含有较高水平抗原特异的IgA和IgG单克隆抗体。PA4和MOPC IgA单克隆抗体在呼吸道、肠道以及雌性生殖道分泌物内有较高的分布水平。在肠道,PA4和MOPC IgA 单克隆抗体的分布水平显著高于IgG(p < 0.01和p < 0.05)。在肠道和生殖道的不同部位,IgA抗体的分布水平不同。在肠道,结肠分泌物中的IgA单克隆抗体显著高于其它肠道部位(p < 0.01)。在生殖道,IgA单克隆抗体分布水平以子宫角分泌物中最高。雄性的前列腺也有较高的IgA抗体水平。在呼吸道、肠道以及雌性生殖道相应部位的分泌物内,PA4 IgA单克隆抗体的水平显著高于MOPC IgA单克隆抗体的分布水平(<0.05)。PA4和MOPC IgA单克隆抗体在粘膜分泌物内的分布水平差异可能与其IgA聚合形式的不同有关。另外,除气管外,在两时间点间分泌物中的IgA抗体水平没有显著差异。检测背部带瘤小鼠交配后的两细胞胚胎期,发现携带PA4或G2b杂交细胞瘤的雌雄小鼠的受精率与对照组并没有显著性差异,这表明抗LDH-C4 IgA和IgG单克隆抗体在体内不能显著抑制小鼠的精子和卵子的结合或受精过程。注射细胞后的27天,检测着床胚胎时,发现带瘤两性小鼠均携带PA4时或者只有雌性携带PA4杂交瘤时,以及雌雄性小鼠均携带G2b杂交瘤时,交配后的怀孕率与带能分泌抗DNP抗体的MOPC骨髓瘤细胞瘤的相应组别相比,显著降低(p < 0.01)。但PA4各组与G2b各组之间无显著差异(p < 0.05)。然而,雌雄小鼠均带瘤时,最高怀孕减少率也未达到100%。这些结果提示,抗LDH-C4 IgA和IgG单克隆抗体在小鼠体内不能有效地抑制小鼠的精子和卵子的结合,但能显著地抑制小鼠受精后胚胎的发育。抗LDH-C4 的IgA或者IgG单克隆抗体单独存在时,在小鼠体内均具有抗生育作用,但不能完全抑制生育。

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为了弄清生殖道内抗体,特别是IgA抗体的准确来源和它的调控因子,同时也为了弄清生殖的局部免疫与典型的粘腊免疫之间的关系,以同位素标记的针对精子特有抗原乳酸脱氢酶C4(LDH-C4)的多聚IgA单抗及其单体,与小鼠精子发生反应的IgA单抗,以及LDH-C4特异的IgG抗体,尾静脉注射给雌雄Balb/c小鼠,4小时后测定小鼠的生殖道及其分汾物,肠道、呼吸道及其分泌物,各相关淋巴组织以及其它器官内这些抗体的分布。还研究了特异抗原刺激、性激素等对这些抗体分布状况的影响。

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乳酸脱氢酶C4 (LDH-C4)是一种人和哺乳动物精子特有的乳酸脱氢酶同功酶。用纯化的小鼠LDH-C4 免疫动物,有一定的避孕效果。这种避孕效果与血清特异性抗体水平并不完全一致。这可能是由于受精过程是在生殖道内进行的,而生殖道内又有粘膜免疫因素存在。IgA抗体是生殖道内的主要抗体成分,研究抗LDH-C4 IgA抗体的抗精子作用有助于了解局部分泌性免疫系统在抗精子免疫避孕中的作用。由于足够量的特异性IgA抗体难于从动物或人粘膜分泌液中分离到,为了获得供体内外试验用的该种抗体,直接证明它在抗生育方面的作用,我们采用一种特殊的免疫方法制备了一系列的抗LDH-C4的单克隆抗体,包括6株IgA和9株IgM。这种免疫方法的主要特点是将抗原直接注射到派伊尔氏淋巴小结(PP)或小肠腔内。ELISA检测表明,按这种方法免疫后,分泌IgA的克隆出现的比例明显高于常规免疫的结果。这是因为PP是粘膜免疫的中枢,其中含有大量的IgA前体细胞,直接将抗原注射到PP内有助于刺激IgA前体细胞的分化和增殖,诱导局部分泌性免疫反应。我们用所得到的单克隆抗体研究了LDH-C4在人,小鼠和树鼩精子表面的定位。结果表明,大多数单克隆抗体可以结合到这些精子的表面;不同的单抗在同一物种的精子表面呈现不同的结合区域。这一方面说明来源于人,小鼠和树鼩的LDH-C4的抗原决定簇有很高的同源性;另一方面提示LDH-C4在精子表面不同的区域所暴露的抗原决定簇不同。初步的功能试验表明,某些抗LDH-C4的IgA单克隆抗体可以凝集或制动精子,说明生殖道内的IgA抗体可以通过凝集和制动作用来影响精子的功能,从而影响精子的受精力。

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There are many factors in mucosal secretions that contribute to innate immunity and the 'first line of defence' at mucosal surfaces. Few studies, however, have investigated the effects of exercise on many of these 'defence' factors. The aim of the present study was to determine the acute effects of prolonged exercise on salivary levels of selected antimicrobial peptides (AMP) that have not yet been studied in response to exercise (HNP1-3 and LL-37) in addition to immunoglobulin A (IgA). A secondary objective was to assess the effects of exercise on saliva antibacterial capacity. Twelve active men exercised on a cycle ergometer for 2.5 h at approximately 60% of maximal oxygen uptake. Unstimulated whole saliva samples were obtained before and after exercise. There was a significant decrease (P < 0.05) in salivary IgA:osmolality ratio, following exercise, but IgA concentration and secretion rate were unaltered. Salivary HNP1-3 and LL-37 concentrations (P < 0.01 and P < 0.05, respectively), concentration:osmolality ratios (P < 0.01) and secretion rates (P < 0.01) all increased following exercise. Salivary antibacterial capacity (against E. coli) did not change. The increased concentration of AMPs in saliva may confer some benefit to the 'first line of defence' and could result from synergistic compensation within the mucosal immune system and/or airway inflammation and epithelial damage. Further study is required to determine the significance of such changes on the overall 'defence' capacity of saliva and how this influences the overall risk for infection.

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This study investigated the effect of a fed or fasted state on the salivary immunoglobulin A (s-IgA) response to prolonged cycling. Using a randomized, crossover design, 16 active adults (8 men and 8 women) performed 2 hr of cycling on a stationary ergometer at 65% of maximal oxygen uptake on 1 occasion after an overnight fast (FAST) and on another occasion 2 hr after consuming a 2.2-MJ high-carbohydrate meal (FED). Timed, unstimulated whole saliva samples were collected immediately before ingestion of the meal, immediately preexercise, 5 min before cessation of exercise, immediately postexercise, and 1 hr postexercise. The samples were analyzed for s-IgA concentration, osmolality, and cortisol, and saliva flow rates were determined to calculate s-IgA secretion rate. Saliva flow rate decreased by 50% during exercise (p < .05), and s-IgA concentration increased by 42% (p < .05), but s-IgA secretion rate remained unchanged. There was a 37% reduction in s-IgA:osmolality postexercise (p < .05), and salivary cortisol increased by 68% (p < .05). There was no effect of FED vs. FAST on these salivary responses. The s-IgA concentration, secretion rate, and osmolality were found to be significantly lower in women than in men throughout the exercise protocol (p < .05); however, there was no difference between genders in saliva flow rate, s-IgA:osmolality ratio, or cortisol. These data demonstrate that a fed or fasted state 2 hr before exercise does not influence resting s-IgA or the response to prolonged cycling. Furthermore, these results show lower levels of s-IgA and osmolality in women than in men at rest.

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Background: Haem oxygenase-1 (HO-1) is a cytoprotective molecule that is reported to have a protective role in a variety of experimental models of renal injury. A functional dinucleotide repeat (GT)n polymorphism, within the HO-1 promoter, regulates HO-1 gene expression; a short number of repeats (S-allele <25) increases transcription. We report the first assessment of the role of this HO-1 gene promoter polymorphism in chronic kidney disease due to autosomal dominant polycystic kidney disease (ADPKD) and IgA nephropathy (IgAN).

Methods: The DNA from 160 patients (99% Caucasian) on renal replacement therapy (RRT) was genotyped. The primary renal disease was ADPKD in 100 patients and biopsy-proven IgAN in 60 patients.

Results: Overall, the mean age at commencement of RRT was not significantly different between patients with and without an S-allele (44.1 years versus 45.0 years, P = 0.64). In patients with ADPKD, the age at commencement of RRT was comparable regardless of the HO-1 genotype (47.7 years versus 46.7 years, P = 0.59). The same was true in patients with IgAN (38.3 years versus 42.2 years, P = 0.28).

Conclusion: This suggests that the functional HO-1 promoter polymorphism does not influence renal survival in CKD due to ADPKD or IgAN.

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IgA nephropathy (IgAN) is a frequent cause of end-stage renal disease (ESRD) and recurrent disease causes deterioration and graft loss in transplant recipients. No definitive management is known to reduce the risk or severity of recurrent IgAN, and the evidence to support the use of renin-angiotensin system blockade in such patients is limited.

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The immunogenicity of proteins encapsulated in poly(DL-lactide-co-glycolide) (PLG) microspheres has not been investigated to any extent in large animal models. In this study, IgG and IgA responses to ovalbumin (OVA), encapsulated in microspheres was investigated following intranasal inoculation into calves. Scanning electron microscopy and flow cytometric analysis demonstrated a uniform microsphere population with a diameter of <2.5 micrometers. Ovalbumin was released steadily from particles stored in PBS almost in a linear fashion, and after 4 weeks many particles showed cracks and fissures in their surface structure. Following intranasal inoculation of calves with different doses of encapsulated antigen, mean levels of ovalbumin-specific IgA were observed to increase steadily but significant differences in IgA levels (from the pre-inoculation level) were only observed following a second intranasal inoculation. With 0.5 and 1.0mg doses of antigen, ovalbumin-specific IgG was also detected in serum. Ovalbumin-specific IgA persisted in nasal secretions for a considerable period of time and were still detectable in four out of seven animals, 6 months after inoculation.