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1.
Collagenous lectins such as mannan-binding lectins (MBLs), ficolins (FCNs), surfactant proteins A and D (SP-A, SP-D), conglutinin (CG), and related ruminant lectins are multimeric proteins with carbohydrate-binding domains aligned in a manner that facilitates binding to microbial surface polysaccharides. MBLs and FCNs are structurally related to C1q, but activate the lectin complement pathway via interaction with MBL-associated serine proteases (MASPs). MBLs, FCNs, and other collagenous lectins also bind to some host macromolecules and contribute to their removal. While there is evidence that some lectins and the lectin complement pathway are conserved in vertebrates, many differences in collagenous lectins have been observed among humans, rodents, and other vertebrates. For example, humans have only one MBL but three FCNs, whereas most other species express two FCNs and two MBLs. Bovidae express CG and other SP-D-related collectins that are not found in monogastric species. Some dysfunctions of human MBL are due to single nucleotide polymorphisms (SNPs) that affect its expression or structure and thereby increase susceptibility to some infections. Collagenous lectins have well-established roles in innate immunity to various microorganisms, so it is possible that some lectin genotypes or induced phenotypes influence resistance to some infectious or inflammatory diseases in animals.  相似文献   

2.
Mannose-binding lectin (MBL), a calcium-dependent collagenous lectin, plays an important role in the host immune defence against a wide range of pathogens. There are MBL1 and MBL2 genes which encode the MBL-A and MBL-C proteins, respectively. This study was carried out to investigate the relationship between the variants of the bovine MBL2 gene and milk production traits, mastitis, serum MBL-C levels and hemolytic complement activity in both classical pathway (CH50) and alternative pathway (ACH50) in Chinese Holstein cattle. Four single-nucleotide polymorphisms (SNPs) in the exon 1 of the MBL2 gene in Chinese Holstein cattle and Luxi yellow cattle were identified by the direct sequencing method. The SNP g.201 G>A was identified as a non-synonymous mutation (codon 31, Arg>Gln) at the N-terminus cysteine-rich domain and the SNPs g.234 C>A and g.235 G>A (codon 42) made Pro to Gln at the 1st Gly-X-Y repeat of the collagen-like domain, while the SNP g.244 T>C (codon 45) was identified as a synonymous mutation (Asn>Asn) at the 2th Gly-X-Y repeat of the collagen-like domain. The SNP markers (g.201 G>A, and g.234 C>A) were significantly correlated with somatic cell score (SCS) (P<0.05). The concentration of MBL-C protein in serum ranges from 0.8 to 7.4μg/mL by enzyme-linked immunosorbent assay. Six combinations of different haplotypes from the four SNPs were identified in Chinese Holstein cattle. Statistical analysis revealed that cows with the haplotype combination H4H5 exhibited the lowest SCS. The CH50 value of H4H5 and H5H5 cow are significantly higher than H2H5 haplotype combination (P<0.05). The association analysis results showed that the haplotype combination H4H5 may be used as a tolerance haplotype combination for the bovine mastitis.  相似文献   

3.
Humans have one mannan-binding lectin (MBL) in circulation but rodents, pigs, rabbits and rhesus monkeys have two, MBL-A and MBL-C. Plasma forms of these proteins have similar mannan-binding activity in vitro, but might differ in their ability to bind other microbial targets. In these studies, we compared carbohydrate-dependent binding of mouse plasma MBL-A and MBL-C to mannan-sepharose beads and to intact bacteria isolated as pathogens from mice. After incubation of mouse plasma with intact bacteria, MBL-A and MBL-C were eluted with N-acetylglucosamine (GlcNAc) and identified in nonreducing SDS-PAGE using Western blot analysis and MBL-A or MBL-C specific monoclonal antibodies. GlcNAc eluates of plasma incubated with mannan-sepharose beads, Klebsiella oxytoca and Staphylococcus aureus contained similar bands (mainly approximately 50kDa) that were immunoreactive with MBL-C antibody. Furthermore, a smaller form of MBL-C (approximately 45kDa) was detected bound to Pseudomonas aeruginosa. By comparison, immunoreactive MBL-A (a ladder of approximately 175kDa and larger bands) was identified in these GlcNAc eluates from mannan-sepharose beads, S. aureus and K. oxytoca but not P. aeruginosa. These studies demonstrate that mouse MBL-A and MBL-C in plasma are not equivalent in their ability to recognize bacteria that are pathogens for mice.  相似文献   

4.
用PCR-SSCP方法检测猪Toll样受体4(TLR4)基因外显子3的SNP   总被引:1,自引:0,他引:1  
Toll样受体(TLRs)能识别各种微生物成分并诱导免疫反应。作为TLR家族中一员的TLR4是识别革兰氏阴性菌内毒素-脂多糖(LPS)的主要受体,其多态性与动物对相关病原的免疫力有着明显的相关性。本文利用PCR-SSCP并结合PCR产物双向测序的方法,对梅山猪、新淮猪、大白猪、长白猪和杜洛克猪共203个样本TLR4基因外显子3部分片段的单核苷核多态性进行了研究。结果检测到了5个SNP,分别是T611A,G826A,G960A,G962A和C1027A,其中有4个非同义的SNP,有2个SNP的氨基酸性质发生了改变。猪TLR4的SNP出现频率在各猪种中有差异,其中T611A仅在新淮猪和大白猪中检测到,而G826A和C1027A仅分别在新淮猪和大白猪中检测到。  相似文献   

5.
根据人和小鼠TLR2基因序列设计了特异性PCR引物,优化PCR条件后扩增到中国梅山猪、欧洲约克夏猪、PIC-2系及PIC-3系商品猪的TLR2基因690 bp的基因片段,并对其进行序列分析。序列分析结果显示,猪TLR2基因多态性程度低,发现在猪TLR2基因编码区第1 255位点上存在1个单碱基突变位点。利用双向特定等位基因PCR扩增法(B i-PASA)建立了检测猪TLR2基因变异的遗传标记。利用猪TLR2基因的B i-PASA标记,分析了TLR2基因在大河乌猪、撒坝猪和黔邵花猪中的基因频率和多态性。研究建立的B i-PASA遗传标记和基因变异信息,将为进一步分析猪TLR2基因变异与疾病抵抗力及经济性状的相关分析提供基础资料。  相似文献   

6.
One hundred Hampshire x Duroc cross-bred pigs (HD) and 100 NE Index line (I) pigs were infected with porcine reproductive and respiratory syndrome (PRRS) virus and evaluated for resistance/susceptibility. Controls (100/line) were uninfected littermates to the infected pigs. Viremia, change in weight (WTdelta), and rectal temperature at 0, 4, 7, and 14 d postinfection were recorded. Lung, bronchial lymph node (BLN), and blood tissue were collected at necropsy (14 d postinfection). The first principal component from principal component analyses of all variables was used to rank the pigs for phenotypic response to PRRS virus. Low responders (low PRRS burden) had high WTdelta, low viremia, and few lung lesions; high responders (high PRRS burden) had low WTdelta, high viremia, and many lesions. The RNA was extracted from lung and BLN tissue of the 7 highest and 7 lowest responders per line and from each of their littermates. Expression of 11 innate and T helper 1 immune markers was evaluated with cDNA in a 2 x 2 x 2 factorial design. Significant upregulation in lung, lymph, or both of infected pigs relative to controls occurred for all but one gene. Expression differences were greater in HD than I pigs. Significant downregulation for certain immune genes in low pigs, relative to littermate controls, was detected in lung and BLN, particularly in line I. Serum levels of the immune cytokines affirmed the gene expression differences. High preinfection serum levels of IL 8 were significantly associated with PRRS virus-resistant, low pigs. After infection, low expression of interferon gamma in cDNA and in serum was also correlated with PRRS virus resistance. Important genetic associations were revealed for fine mapping of candidate genes for PRRS virus resistance and determining the causative alleles.  相似文献   

7.
A variety of biotinylated lectins was applied to formalin-fixed intestinal sections from isolator-reared pigs ranging in age from newborn through 12 weeks. Lectin binding to brush borders of villus enterocytes, crypt enterocytes, and dome epithelium, and lectin reactivity within goblet cells and Brunner's glands was semiquantified by microscopy and was used to estimate temporal changes in complex carbohydrates of enteric epithelium. Although variability in binding scores often was observed among pigs of the same age, several general patterns of lectin binding were detected. Dolichos biflorus and Ulex europaeus lectins had increasing binding to brush border membranes as pigs aged. The Dolichos biflorus, however, had decreased binding at the 12-week time point. Neuraminidase-treated Arachis hypogaea and Triticum vulgaris were associated with high mean binding scores at all time points. Canavalia ensiformis bound, with high mean score at all time points, to villus but not to crypt enterocytes. Arachis hypogaea was associated with variable but often high binding scores, regardless of pig age. Succinylated wheat germ agglutinin bound more to crypt than to villus enterocytes. Goblet cells were generally less reactive than were corresponding villi and crypts. Dome epithelium reactivity varied with the lectin used, whereas Brunner's glands reacted with all lectins tested. We conclude that age and regional variations in lectin binding may reflect differences in intestinal function and differentiation. Because complex carbohydrates may act as cell surface receptors for a variety of enteric pathogens, our results indicate that these differences may be partially responsible for age and anatomic differences in susceptibility or resistance to enteric disease.  相似文献   

8.
9.
Viral and bacterial diseases remain a threat to the poultry industry and countermeasures to prevent and control them are needed due to production losses. With the continued threat of exotic and emerging diseases and concern over the use of antibiotics in animal production, there is a serious and urgent need to find safe and practical alternatives to prevent or control pathogens. Identification of new tools for the design of new immunological interventions or therapeutic antimicrobials to reduce microbial pathogens in poultry is now required more than ever. Immunological interventions to reduce microbial pathogens in poultry would be of great value to the poultry industry and to the consumer. We have been advocating boosting immunity and encouraging the host to utilize its innate immune system to control and clear infections. Our research has addressed the use of innate immune mechanisms and components to develop new immune modulators (prophylactic and therapeutic) and the characterization and production of antimicrobial peptides as potential immune modulators in poultry. Dietary bioactive food components that interact with the immune response have considerable potential to reduce susceptibility to infectious diseases. With this premise, this paper asks and answers a series of pertinent questions on the utilization of avian immunity for increasing resistance to a variety of potential pathogens problematic in today's commercial poultry industry. Using experimental data to provide answers to these questions, we hope to stimulate a dialog between avian immunologists and nutritionists that results in coordinating and integrating their expertise into specific practical solutions that will benefit the industry and improve the well-being of commercial poultry.  相似文献   

10.
不同中外猪种对疾病的抵抗能力有一定差异,原因之一是不同猪种猪白细胞抗原(swine leukocyte antigen,SLA)分子的多样性不同。本研究旨在探究中外猪种的SLA基因差异,为阐明地方猪的抗病机理提供重要参考。本研究首先对健康的8头民猪以及4头大白猪进行基因组重测序,并对所获得的SNP进一步质控用于后续分析。使用VCFtools、GEVALT软件分析SLAⅠ类基因的SNP以及单倍型,并将SNP利用ENSEMBL中的VEP工具进行注释,在全局层面阐述两个猪种的SLAⅠ类基因多样性。通过Mega软件比对两猪种的经典SLAⅠ类基因外显子2和3的核苷酸及编码氨基酸序列,利用Expasy服务器上的ProtParam工具和Protscale程序分析蛋白质特性,并利用DnaSP软件计算核苷酸多样性,分析两个猪种经典SLAⅠ类基因抗原递呈能力的差异。结果表明,民猪的SLAⅠ类基因具有更多的SNPs和长度较短的单倍型块,并且错义突变的碱基数量较多。在经典SLAⅠ类基因的外显子2和3可分别鉴定出2个等位基因,民猪在等位基因上的核苷酸多样性要明显高于大白猪,并且民猪具有更多的碱基突变以及位于抗原结合位点上的氨基酸突变。两个猪种的经典SLAⅠ类基因氨基酸表现为亲水性,民猪的亲水性要强于大白猪。综上所述,SLAⅠ类基因在民猪上有更强的多态性。民猪经典SLAⅠ类基因的碱基突变数量和抗原结合位点上氨基酸突变的数量都要多于大白猪。本研究所检测到的民猪在经典SLAⅠ类基因ARSs上的变异可为猪抗病育种标记的筛选提供参考。  相似文献   

11.
ABSTRACT

1. Chicken salmonellosis is a common zoonotic infectious disease transmitted both vertically and horizontally. Avian beta-defensins (gallinacins) play an important role in the innate defence of the host and provide broad-spectrum immunity against multiple pathogens.

2. To detect the relationship between immune genes and salmonella carrier status and susceptibility to salmonellosis in chickens, polymorphisms with carrier-state susceptibility to salmonella and, hence, developing salmonellosis, were investigated in three avian beta-defensin genes (AvBD4, AvBD5, and AvBD14) in a Chinese local chicken breed, based on a case-control study.

3. Fifteen, twenty and nineteen SNPs were found in AvBD4, AvBD5 and AvBD14, respectively. Among the 54 total SNPs, four resulted in non-synonymous substitution of amino acid changes. Five SNPs in AvBD5 and four SNPs in AvBD14 were significantly associated with salmonellosis susceptibility (P < 0.05). Using the PHASE program, thirteen, ten and twelve major haplotypes were constructed in AvBD4, AvBD5 and AvBD14. Logistic regression analysis revealed that five haplotypes in AvBD5 and six haplotypes in AvBD14 were significantly associated with salmonellosis susceptibility, but no significant haplotype in AvBD4 was detected. A total of six strongly susceptible haplotypes with odds ratio (OR) values greater than 2.0 and four strongly resistant haplotypes with OR value less than 0.5 were revealed in the three genes examined.

4. These results suggested that the AvBD5 and AvBD14 genes may play an important role in the susceptibility to salmonellosis in chickens.  相似文献   

12.
ABSTRACT: Bovine mastitis remains the most common and costly disease of dairy cattle worldwide. A complementary control measure to herd hygiene and vaccine development would be to selectively breed cattle with greater resistance to mammary infection. Toll-like receptor 1 (TLR1) has an integral role for the initiation and regulation of the immune response to microbial pathogens, and has been linked to numerous inflammatory diseases. The objective of this study was to investigate whether single nucleotide polymorphisms (SNPs) within the bovine TLR1 gene (boTLR1) are associated with clinical mastitis (CM).Selected boTLR1 SNPs were analysed within a Holstein Friesian herd. Significant associations were found for the tagging SNP -79 T > G and the 3'UTR SNP +2463 C > T. We observed favourable linkage of reduced CM with increased milk fat and protein, indicating selection for these markers would not be detrimental to milk quality. Furthermore, we present evidence that some of these boTLR1 SNPs underpin functional variation in bovine TLR1. Animals with the GG genotype (from the tag SNP -79 T > G) had significantly lower boTLR1 expression in milk somatic cells when compared with TT or TG animals. In addition, stimulation of leucocytes from GG animals with the TLR1-ligand Pam3csk4 resulted in significantly lower levels of CXCL8 mRNA and protein.SNPs in boTLR1 were significantly associated with CM. In addition we have identified a bovine population with impaired boTLR1 expression and function. This may have additional implications for animal health and warrants further investigation to determine the suitability of identified SNPs as markers for disease susceptibility.  相似文献   

13.
Salmonella enterica serovar Enteritidis is a gram-negative bacterium that negatively affects human and animal health. Many eukaryotes use antimicrobial peptides (alpha-defensins, beta-defensins, gamma-defensins, and cathelicidins) in innate immune responses to fight bacterial infections. Poultry gallinacins are the functional equivalents of mammalian beta-defensins. Two related advanced intercross lines of chickens were analyzed for association of gallinacin genotypic variation with Salmonella Enteritidis burden levels in the cecum and spleen after infection. Thirteen genes of the chicken beta-defensin cluster (GAL1-13) were sequenced from individuals of each advanced intercross line, plus the founder broiler sire and representatives of the highly inbred Leghorn and Fayoumi founder dam lines. The mean was 17 single-nucleotide polymorphisms (SNPs) per kilobase. One single-nucleotide polymorphism per gene was genotyped with SNaPshot to test for statistical associations with Salmonella Enteritidis colonization after challenge. Among the 13 gallinacin genes evaluated, the single-nucleotide polymorphisms in all genes in a cluster of three adjacent genes (GAL11, GAL12, and GAL13) were associated with bacterial load in the cecal content in the broiler x Leghorn advanced intercross line (three-gene SNP genotype effect, P < 0.008). The results strongly suggest a role of the gallinacins in defense of poultry against enteric pathogens. The use of gallinacin single-nucleotide polymorphisms as molecular markers for genetic selection for Salmonella Enteritidis resistance might result in reduced bacterial burden via development of an enhanced innate immune response.  相似文献   

14.
European sea bass (Dicentrarchus labrax L.) is a marine species of great economic importance, particularly in Mediterranean aquaculture. However, numerous pathogenic viruses, bacteria, fungi and parasites affect the species, causing various infectious diseases and thereby leading to the most heavy losses in aquaculture production of sea bass. In this respect, knowledge on molecular and genetic mechanisms of resistance to pathogens and specific features of immune response against various infectious agents should greatly benefit the development of effective vaccines and proper vaccination strategies in marker-assisted selection of fish resistant to a range of infections. To date, genetic knowledge on sea bass immune regulatory genes responsible for resistance to pathogens is relatively poor but tends to accumulate rapidly. In this review, we summarize and update current knowledge on the immune system and immune regulatory genes of the sea bass.  相似文献   

15.
宋宇琨  何俊 《中国畜牧兽医》2020,47(6):1709-1718
脾脏作为猪最大的次级淋巴器官,含有多种免疫活性细胞和免疫因子,是先天性免疫和适应性免疫重要的应答场所,具有广泛的免疫调控功能;同时可清除衰老、损伤红细胞及过滤病原体,并在造血和储藏血细胞方面具有重要作用。这些功能与脾脏的结构密切相关,其中红髓主要作为血液滤过器,执行造血、储血和清除异物的功能;白髓是免疫的主要区域,含有多种免疫细胞,可执行特异性免疫应答调控功能;而边缘区是连接两个区室的重要桥梁,使所有细胞和抗原都能通过其进入脾脏不同部位。不同的发育和免疫关键基因是实现脾脏功能的根本,发育基因的表达保证了其结构的完整,为脾脏执行各种功能提供空间。免疫关键基因的表达确保了免疫反应进行,其中不同模式识别受体基因的表达保证了先天性免疫的吞噬和识别应答,而各种免疫细胞分泌的多种细胞因子和免疫活性物质是获得性免疫反应的基础,实现机体清除和监控抗原的生理过程。随着脾脏研究的深入,对其各种免疫细胞和免疫功能有了新的认识。作者首先阐述了脾脏组织不同区域的生物学功能;然后结合机体免疫应答机制,论述脾脏先天性和特异性免疫功能以及所需免疫细胞和免疫因子的作用与关联;最后简单介绍了脾脏胚胎期和出生后期的组织发育和免疫相关基因,总结了猪脾脏先天性免疫中重要的模式识别受体及其基因家族,为研究猪脾脏先天性免疫功能提供参考。  相似文献   

16.
为寻找与巴马香猪产活仔数相关的分子标记,试验利用全基因组关联分析(GWAS)定位并筛选了影响产活仔数性状的候选基因,采集297头具有多胎产仔记录的巴马香猪耳组织样品,提取DNA并利用猪50K SNP芯片进行基因分型,分型结果经质控与基因型填充后,使用Tassel软件对巴马香猪产活仔数性状进行全基因组关联分析。结果显示,巴马香猪平均窝产活仔数在1~9胎内随着胎次增加逐渐升高;经质控过滤后共获得32 816个SNPs位点,利用全基因组关联分析共筛选到8个与巴马香猪产活仔数相关的SNPs位点,分别在基因组或染色体水平达到显著;对关联显著SNP位点上下游500 kb内的编码基因进行富集分析,并依据猪繁殖性状相关QTL区域及基因功能,最终筛选到4个基因(CAPZB、MSH3、CITED2和HSD17B7)作为影响巴马香猪产活仔数的候选基因。  相似文献   

17.
Seasonal changes in the histochemical properties of the vomeronasal and olfactory epithelia of the Japanese striped snake were examined in four seasons, viz. the reproductive, pre-hibernating, hibernating and post-hibernating seasons. In the vomeronasal and olfactory supporting cells, secretory granules were much more abundant in the hibernating season than in the other seasons. In the vomeronasal and olfactory receptor cells, the lipofuscin granules were much fewer in the post-hibernating season than in the other seasons. In histochemical studies with 21 lectins, several lectins stained the vomeronasal and olfactory epithelia (receptor cells, supporting cells and free border) more weakly in the hibernating season than in the reproductive season. However, all lectins stained both epithelia in the hibernating season after sialic acid removal in a similar manner as in the reproductive season after sialic acid removal. These lectin histochemical studies indicate that sialic acid residues in the vomeronasal and olfactory epithelia are more numerous in the hibernating season than in the reproductive season. The results suggest that during hibernation, the vomeronasal and olfactory receptor cells possibly undergo rapid cell turnover, and that during this time, the vomeronasal and olfactory epithelia are securely protected from pathogens by an innate immune defence system.  相似文献   

18.
The inducible nitric oxide synthase (iNOS) enzyme has long been recognized as a key mediator of innate immune responses to infectious diseases across the phyla. Its role in killing or inactivating bacterial, parasitic, and viral pathogens has been documented in numerous host systems. iNOS, and its innate immune mediator NO has also been described to have negative consequence on host tissues as well; therefore understanding the pathogenesis of any infectious agent which induces iNOS expression requires a better understanding of the role iNOS and NO play in that disease. Previous studies in our laboratory and others have demonstrated evidence for increased levels of iNOS and activity of its innate immune mediator NO in the intestine of turkeys infected with astrovirus. To begin to characterize the role iNOS plays in the innate immune response to astrovirus infection, we identified, characterized, developed tkiNOS specific reagents, and demonstrated that the intestinal epithelial cells induce expression of iNOS following astrovirus infection. These data are the first to our knowledge to describe the tkiNOS gene, and demonstrate that astrovirus infection induces intestinal epithelial cells to express iNOS, suggesting these cells play a key role in the antiviral response to enteric infections.  相似文献   

19.
Immunological basis of differences in disease resistance in the chicken   总被引:9,自引:0,他引:9  
Genetic resistance to diseases is a multigenic trait governed mainly by the immune system and its interactions with many physiologic and environmental factors. In the adaptive immunity, T cell and B cell responses, the specific recognition of antigens and interactions between antigen presenting cells, T cells and B cells are crucial. It occurs through a network of mediator proteins such as the molecules of the major histocompatibility complex (MHC), T cell receptors, immunoglobulins and secreted proteins such as the cytokines and antibodies. The diversity of these proteins that mainly is due to an intrinsic polymorphism of the genes causes phenotypic variation in disease resistance. The well-known linkage of MHC polymorphism and Marek's disease resistance difference represents a classic model revealing immunological factors in resistance differences and diversity of mediator molecules. The molecular bases in any resistance variation to infectious pathogens are vaguely understood. This paper presents a review of the major immune mediators involved in resistance and susceptibility to infectious diseases and their functional mechanisms in the chicken. The genetic interaction of disease resistance with production traits and the environment is mentioned.  相似文献   

20.
In order to identify the molecular markers related to alive litter size of Bama Xiang pigs,the genome-wide association study (GWAS) was used to map and screen the candidate genes affecting the alive litter size trait.Ear tissue samples of 297 Bama Xiang pigs with multiple parity records were collected,and DNA was extracted and genotyped by porcine 50K SNP beadchip.After quality control and genotype imputation,the alive litter size of Bama Xiang pigs were GWAS by Tassel.The results showed that the average number born alive per litter of Bama Xiang pigs increased gradually with the increasing of parity in the range of 1-9 parities.A total of 32 816 SNPs were obtained after quality control and filtration.8 SNPs related to alive litter size of Bama Xiang pigs were screened by genome-wide association analysis,which were significant at genome or chromosome level.Based on the enrichment analysis of the coding genes in the region between 500 kb upstream and downstream of the associated significant SNP loci,and the QTL regions and gene functions related to porcine reproductive traits,4 genes (CAPZB,MSH3,CITED2 and HSD17B7) were finally identified to be candidate genes related to alive litter size of Bama Xiang pigs.  相似文献   

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