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1.
The respiratory epithelium is a primary site for the deposition of microorganisms that are acquired during inspiration. The innate immune system of the respiratory tract eliminates many of these potentially harmful agents preventing their colonization. Collectins and cationic antimicrobial peptides are antimicrobial components of the pulmonary innate immune system produced by respiratory epithelia, which have integral roles in host defense and inflammation in the lung. Synthesis and secretion of these molecules are regulated by the developmental stage, hormones, as well as many growth and immunoregulatory factors. The purpose of this review is to discuss antimicrobial innate immune elements within the respiratory tract of healthy and pneumonic lung with emphasis on hydrophilic surfactant proteins and beta-defensins. 相似文献
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Over the past 20 years, there have been significant inroads into understanding the roles of antimicrobial peptides in homeostatic functions and their involvement in disease pathogenesis. In addition to direct antimicrobial activity, these peptides participate in many cellular functions, including chemotaxis, wound healing and even determination of canine coat colour. Various biological and genetic approaches have helped to elucidate the role of antimicrobial peptides with respect to innate immunity and host defense. Associations of antimicrobial peptides with various skin diseases, including psoriasis, rosacea and atopic dermatitis, have been documented in humans. In the longer term, therapeutic modulation of antimicrobial peptide expression may provide effective new treatments for disease. This review highlights current knowledge about antimicrobial peptides of the skin and circulating leukocytes, with particular focus on relevance to physiology and disease in companion animals. 相似文献
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Georgios Michailidis 《Veterinary research communications》2010,34(5):459-471
In recent years host antimicrobial peptides and proteins have been recognised as key mediators of the innate immune response
in many vertebrate species, providing the first line of defense against potential pathogens. In chickens a number of cationic
antimicrobial peptides have been recently identified. However, although these peptides have been studied extensively in the
avian gastrointestinal tract, little is known about their function in the chicken reproductive organs and embryos. Chicken
Liver Expressed Antimicrobial Peptide-2 (cLEAP-2) has been previously reported to function in protecting birds against microbial
attack. The aim of this study was to investigate the expression of cLEAP-2 gene in the chicken reproductive organs, as well
as in chicken embryos during embryonic development, and to determine whether cLEAP-2 expression in the chicken reproductive
organs was constitutive or induced as a response to Salmonella enteritidis infection. RNA was extracted from ovary, oviduct, testis and epididymis of sexually mature healthy and Salmonella infected birds, as well as from chicken embryos until day ten of embryonic development. Expression analysis data revealed
that cLEAP-2 was expressed in the chicken ovary, testis and epididymis as well as in embryos during early embryonic development.
Quantitative real-time PCR analysis revealed that cLEAP-2 expression was constitutive in the chicken epididymis, but was significantly
up regulated in the chicken gonads, following Salmonella infection. In addition, expression of cLEAP-2 during chicken embryogenesis appeared to be developmentally regulated. These
data provide evidence to suggest a key role of cLEAP-2 in the protection of the chicken reproductive organs and the developing
embryos from Salmonella colonization. 相似文献
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Srikumaran S Kelling CL Ambagala A 《Animal health research reviews / Conference of Research Workers in Animal Diseases》2007,8(2):215-229
Bovine respiratory tract disease is a multi-factorial disease complex involving several viruses and bacteria. Viruses that play prominent roles in causing the bovine respiratory disease complex include bovine herpesvirus-1, bovine respiratory syncytial virus, bovine viral diarrhea virus and parinfluenza-3 virus. Bacteria that play prominent roles in this disease complex are Mannheimia haemolytica and Mycoplasma bovis. Other bacteria that infect the bovine respiratory tract of cattle are Histophilus (Haemophilus) somni and Pasteurella multocida. Frequently, severe respiratory tract disease in cattle is associated with concurrent infections of these pathogens. Like other pathogens, the viral and bacterial pathogens of this disease complex have co-evolved with their hosts over millions of years. As much as the hosts have diversified and fine-tuned the components of their immune system, the pathogens have also evolved diverse and sophisticated strategies to evade the host immune responses. These pathogens have developed intricate mechanisms to thwart both the innate and adaptive arms of the immune responses of their hosts. This review presents an overview of the strategies by which the pathogens suppress host immune responses, as well as the strategies by which the pathogens modify themselves or their locations in the host to evade host immune responses. These immune evasion strategies likely contribute to the failure of currently-available vaccines to provide complete protection to cattle against these pathogens. 相似文献
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Quintana AM Landolt GA Annis KM Hussey GS 《Veterinary immunology and immunopathology》2011,140(3-4):226-236
Our understanding of innate immunity within the equine respiratory tract is limited despite growing evidence for its key role in both the immediate defense and the shaping of downstream adaptive immune responses to respiratory disease. As the first interface to undergo pathogen invasion, the respiratory epithelium is a key player in these early events and our goal was to examine the innate immune characteristics of equine respiratory epithelia and compare them to an in vitro equine respiratory epithelial cell model cultured at the air-fluid interface (AFI). Respiratory epithelial tissues, isolated epithelial cells, and four-week old cultured differentiated airway epithelial cells collected from five locations of the equine respiratory tract were examined for the expression of toll-like receptors (TLRs) and host defense peptides (HDPs) using conventional polymerase chain reaction (PCR). Cultured, differentiated, respiratory epithelial cells and freshly isolated respiratory epithelial cells were also examined for the expression of TLR3, TLR9 and major histocompatibility complex (MHC) class I and class II using fluorescence-activated cell sorting (FACS) analysis. In addition, cytokine and chemokine profiles from respiratory epithelial tissues, freshly isolated respiratory epithelial cells, and cultured, differentiated, epithelial cells from the upper respiratory tract were examined using real-time PCR. We found that respiratory epithelial tissues and isolated epithelial cells expressed TLRs 1-4 and 6-10 as well as HDPs, MxA, 2'5' OAS, β-defensin-1, and lactoferrin. In contrast, epithelial cells cultured at the AFI expressed TLRs 1-4 and 6 and 7 as well as MxA, 2'5' OAS, β-defensin-1, but had lost expression of TLRs 8-10 and lactoferrin. In addition, MHC-I and MHC-II surface expression decreased in epithelial cells cultured at the AFI compared to isolated epithelial cells whereas TLR3 and TLR9 were expressed at similar levels. Lastly, we found that equine respiratory epithelial cells express an array of pro-inflammatory, antiviral and regulatory cytokines and that after four weeks of in vitro growth conditions, equine respiratory epithelial cells cultured at the AFI retained expression of GM-CSF, IL-10, IL-8, TGF-β, TNF-α, and IL-6. In summary, we describe the development of an in vitro equine respiratory epithelial cell culture model that is morphologically similar to the equine airway epithelium and retains several key immunological properties. In the future this model will be a used to study equine respiratory viral pathogenesis and cell-to-cell interactions. 相似文献
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Davis EG Sang Y Rush B Zhang G Blecha F 《Veterinary immunology and immunopathology》2005,105(1-2):163-169
NK-lysin is an antimicrobial peptide of cytotoxic and NK lymphocytes that has powerful antibacterial properties as well as antitumoral activity. Here we report the full-length cDNA and deduced amino acid sequence for equine NK-lysin. Equine NK-lysin is 67% identical to porcine NK-lysin, 53% identical to bovine NK-lysin and 41% identical to granulysin in amino acid sequence. Complete conservation of cysteine residues between equine, bovine and porcine NK-lysin suggests similar disulfide bonding patterns among these peptides. Equine NK-lysin has the most positive surface charge when compared with other homologues. Similar to expression profiles in other species, equine NK-lysin is constitutively transcribed in various lymphocytes that include CD4+ and CD8+ staining cells. These findings suggest that equine NK-lysin, similar in cDNA sequence to the porcine, bovine and human homologues may play a role in antimicrobial defense. 相似文献
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防御素是广泛分布于动植物界的一类富含半胱氨酸的内源性阳离子抗菌肽,它在先天性免疫系统宿主防御机制中起着重要的作用。笔者从哺乳动物β-防御素的组成分布入手,对β-防御素的分子结构与染色体定位、基因表达调控、生物学作用及应用前景等最新研究作一全面综述。 相似文献
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Berge AC Sischo WM Craigmill AL 《Journal of the American Veterinary Medical Association》2006,229(8):1279-1281
OBJECTIVE: To determine the antimicrobial susceptibility of common respiratory tract pathogens from sheep and goats. DESIGN: Cross-sectional study. SAMPLE POPULATION: 41 respiratory tract isolates from sheep and 36 isolates from goats. PROCEDURES: Disk diffusion assay was used to determine antimicrobial susceptibility of isolates to amoxicillin-clavulanic acid, ceftiofur, ciprofloxacin, florfenicol, and tetracycline. Minimum inhibitory concentrations of florfenicol for these isolates were determined by use of the microbroth dilution technique. RESULTS: The most common isolates were Pasteurella multocida (n = 28) and Mannheimia haemolytica (39). All isolates were susceptible to amoxicillin-clavulanic acid, ceftiofur, ciprofloxacin, and florfenicol. Five percent (4/77) of isolates were resistant to tetracycline. CONCLUSIONS AND CLINICAL RELEVANCE: Susceptibility of respiratory tract pathogens isolated from sheep and goats to commonly used antimicrobial drugs in this study was high. Treatment of these species for bacterial respiratory tract disease is likely not complicated by antimicrobial resistance. 相似文献
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Evans EW Harmon BG 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》1995,24(4):109-116
Cationic antimicrobial peptides are present throughout the plant and animal kingdoms and bear striking structural and functional similarities across species lines. They provide primitive, nonspecific means of combating a variety of bacteria, fungi, enveloped viruses, and protozoa. Some are also cytotoxic against host cells, including neoplastic cells. Cationic antimicrobial peptides may play various roles in inflammation and tissue repair. Antimicrobial peptides are found in epithelial tissues regularly exposed to microbial attack as well as in cells whose primary function is defense against potential pathogens. They constitute an important part of the nonoxidative antimicrobial arsenal of leukocytes. They are preformed and/or readily synthesized when the cells are stimulated by exposure to pathogens. They exert their effects directly by inserting into membranes of target cells and forming ion channels which increase membrane permeability; however, antimicrobial peptides can also act as opsonins to facilitate phagocytosis. Resistance to defensins is a virulence factor for organisms such as Salmonella sp. The study of cationic antimicrobial peptides is increasing our understanding of innate immunity, inflammation, and the pathogenesis of genetic diseases such as specific granule disease in humans. Therapeutic applications of antimicrobial peptides are currently under investigation. 相似文献
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U. Christmann V.A. Buechner-Maxwell S.G. Witonsky R.D. Hite 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2009,23(2):227-242
Lung surfactant is produced by type II alveolar cells as a mixture of phospholipids, surfactant proteins, and neutral lipids. Surfactant lowers alveolar surface tension and is crucial for the prevention of alveolar collapse. In addition, surfactant contributes to smaller airway patency and improves mucociliary clearance. Surfactant-specific proteins are part of the innate immune defense mechanisms of the lung. Lung surfactant alterations have been described in a number of respiratory diseases. Surfactant deficiency (quantitative deficit of surfactant) in premature animals causes neonatal respiratory distress syndrome. Surfactant dysfunction (qualitative changes in surfactant) has been implicated in the pathophysiology of acute respiratory distress syndrome and asthma. Analysis of surfactant from amniotic fluid allows assessment of fetal lung maturity (FLM) in the human fetus and exogenous surfactant replacement therapy is part of the standard care in premature human infants. In contrast to human medicine, use and success of FLM testing or surfactant replacement therapy remain limited in veterinary medicine. Lung surfactant has been studied in large animal models of human disease. However, only a few reports exist on lung surfactant alterations in naturally occurring respiratory disease in large animals. This article gives a general review on the role of lung surfactant in respiratory disease followed by an overview of our current knowledge on surfactant in large animal veterinary medicine. 相似文献
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家蚕防御素(defensin)是家蚕抗菌肽家族的主要成员之一,为家蚕先天性免疫的重要效应因子。采用生物信息学方法分析家蚕防御素基因BmdefA、BmdefB的序列中各有2个外显子,2个基因分别定位于家蚕第4号和第13号染色体上;等电点预测BmdefA带有负电荷,属于罕见的阴离子型抗菌肽,而BmdefB带有正电荷,属于常见的阳离子型抗菌肽;预测2个基因编码的成熟肽分子质量均在4 kD左右。用RT-PCR方法检测BmdefA在家蚕整个发育过程中有表达,且在检测的幼虫和成虫各组织中均有表达;BmdefB从幼虫5龄第3天到成虫期表达,雄性表达量高于雌性,且在5龄第3天幼虫的生殖腺、脂肪体和血细胞中高水平表达。家蚕防御素BmdefA、BmdefB具有不同的分子特性和表达特征,暗示它们在家蚕先天免疫过程中可能行使不同的功能,甚至可能具有不同的抗菌机理。构建融合GST标签的家蚕防御素基因原核表达载体,通过在大肠杆菌细胞内诱导表达,获得可溶性的目的蛋白,使用GST亲和层析柱初步纯化表达的融合蛋白并进行Western blotting鉴定,为进一步研究BmdefA、BmdefB的体外活性和抑菌机制奠定基础。 相似文献
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宿主防御肽是动物体产生的一种多功能肽,不仅具有广谱的抗菌功能,还可作为先天性免疫调节因子,有效增强动物机体免疫力,阻止病原微生物的侵扰,对保证动物健康具有重要意义。宿主防御肽在动物体内的表达受到日粮中各种营养物质的调控,有研究者认为,以营养调控的方式促进宿主内源防御肽的表达有益于动物健康和生产性能的提高,是未来实现无抗、健康养殖的可能策略之一。本文综合论述了动物饲粮中多种营养物质对宿主内源防御肽表达的调控作用,为评价营养物质调节宿主免疫和对动物健康及生产的影响提供新的理论参考。 相似文献
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Avian defensins 总被引：4，自引：0，他引：4
Modulation of defensin expression may be one way to improve animal health and to reduce zoonotic diseases. Defensins are small, cationic, and amphipathic cysteine-rich antibiotic peptides found in plants, insects, mammals and birds. Whereas alpha- and theta-defensins appear to be absent in birds, several beta-defensins have been isolated from avian heterophils. In addition, beta-defensins were found to be constitutively or inducibly expressed at mucosal surfaces of the respiratory, intestinal and urogenital tracts. In this review the current knowledge of the defensin repertoire of birds, their tissue-specific expression, regulation and corresponding biological functions are described. 相似文献
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J D Olsen 《Veterinary Clinics of North America: Small Animal Practice》2000,30(6):1337-1355
Therapy of respiratory tract infections presents some unique challenges to the veterinary practitioner. These infections often involve underlying disease processes that have predisposed the patient to secondary bacterial infection and may complicate the response to therapy. Because of the diversity of microbial organisms that may colonize and invade the respiratory tract, treatment targeted at the infecting pathogens is best accomplished with bacterial culture and susceptibility testing. When these data are unavailable, rational antibiotic treatment should be based on familiarity with historical data and clinical experience. Optimal drug selection is based on predicted microbial susceptibility, drug distribution in the respiratory tract, and safety of the patient. Instituting the appropriate dosage regimen and duration of therapy maximizes the opportunity for a successful resolution of bacterial infections. 相似文献
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昆虫的先天免疫系统包括细胞免疫与体液免疫,它们共同作用于入侵的微生物,保护机体免受各种病原物的侵染。在漫长的进化中,病原微生物也发展了一系列策略应对昆虫的细胞与体液免疫。已有研究表明,病原物主要采取杀死血细胞,抑制细胞吞噬及结节形成,分泌毒力因子或利用体表的脂类成分等策略逃避昆虫细胞免疫;通过分泌蛋白酶降解抗菌肽,利用病原物细胞表面缺乏免疫诱导因子或抑制宿主抗菌肽的表达等策略应对昆虫体液免疫。本文结合相关研究成果,综述病原物抵抗昆虫免疫反应的一系列策略,阐释宿主昆虫同病原物之间免疫与抗免疫的动态互作过程。 相似文献
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CMAP27, a novel chicken cathelicidin-like antimicrobial protein 总被引：6，自引：0，他引：6
van Dijk A Veldhuizen EJ van Asten AJ Haagsman HP 《Veterinary immunology and immunopathology》2005,106(3-4):321-327
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beta-Defensins are cysteine-rich endogenously produced antimicrobial peptides that play an important role in innate immune defense. Although, previous investigations have identified beta-defensins in several mammalian species, no reports have identified equine beta-defensins. Using a strategy of database searching for expressed sequence tags (EST) we identified putative expression of equine beta-defensins in hepatic tissue. Based on this information, sequence specific primers were designed for the equine gene enabling the identification of the full-length cDNA sequence of equine beta-defensin-1. Comparative analyses showed that equine beta-defensin-1 has 46-52% amino-acid identity with other beta-defensins, sharing the greatest identity with porcine beta-defensin-1. Complete conservation of cysteine residues was maintained between the species evaluated, and RT-PCR analysis revealed diverse mRNA tissue expression for equine beta-defensin-1. These data extend the repertoire of equine antimicrobial peptides and expand our understanding of equine innate immunity. 相似文献
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Mycoplasma spp were isolated in pure culture from bronchoalveolar lavage specimens from three cats with clinical, cytological and radiographic signs of bron-chopneumonia or suppurative bronchitis. Predisposing factors were not identified in the first case, the second cat had oesophageal hypomotility, while the third cat had been exposed to cigarette smoke and had advanced periodontal disease. Respiratory signs resolved promptly and completely in all cases following antimicrobial therapy directed against mycoplasmas. Mycoplasma spp are possible causes of lower respiratory tract disease in cats and this should be considered when selecting empirical therapy for feline airway disease and pneumonia. In some situations mycoplasmas may behave as primary lower respiratory tract pathogens in cats. 相似文献