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Chicken type I interferons (type I IFNs) are key antiviral players of the chicken immune system and mediate the first line of defense against viral pathogens infecting the avian species. Recognition of viral pathogens by specific pattern recognition receptors (PRRs) induce chicken type I IFNs expression followed by their subsequent interaction to IFN receptors and induction of a variety of IFN stimulated antiviral proteins. These antiviral effectors establish the antiviral state in neighboring cells and thus protect the host from infection. Three subtypes of chicken type I IFNs; chIFN-α, chIFN-β, and a recently discovered chIFN-κ have been identified and characterized in chicken. Chicken type I IFNs are activated by various host cell pathways and constitute a major antiviral innate defense in chicken. This review will help to understand the chicken type 1 IFNs, host cellular pathways that are involved in activation of chicken type I IFNs and IFN stimulated antiviral effectors along with the gaps in knowledge which will be important for future investigation. These findings will help us to comprehend the role of chicken type I IFNs and to develop different strategies for controlling viral infection in poultry. 相似文献
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Wells GA 《Veterinary research communications》2003,27(Z1):25-28
Before the emergence of bovine spongiform encephalopathy (BSE) and recognition of its zoonotic potential, the major example of the transmissible spongiform encephalopathies (TSEs) of animals was scrapie of sheep. But there is no evidence that scrapie transmits naturally to any species other than sheep and goats. The pathogenesis of scrapie has been studied most in experimental laboratory rodent species. In most experimental models of scrapie, after peripheral non-neural routes of infection, replication of the agent can first be detected in lymphoreticular system (LRS) tissue. When the route of introduction of agent into the body is localized, initial involvement will be in LRS tissue draining the infection site. Thereafter, there is a striking amplification of the agent in the LRS and spread by lymphatic/haematogenous routes, giving widespread dissemination in the LRS. This precedes replication in the CNS, but is not the means by which infection reaches the CNS. There is now substantial evidence from experimental models of scrapie that involvement of the CNS is by peripheral nervous system (PNS) pathways. In some models employing oral exposure the earliest localized LRS replication is in the gut-associated lymphoid tissue (GALT) and autonomic PNS routing to the CNS has been implicated. However, the relative importance of different routes of spread of TSEs within the body is determined by a number of host- and agent-dependent factors and, therefore, generalizations from an experimental model to a natural disease across a species barrier may not be appropriate. With the occurrence of BSE and recognition of its food-borne route of transmission via meat and bone meal, has come greater awareness of the probable importance of the oral route of infection in ruminant species affected by TSEs. In consequence, studies have increasingly focused on the natural host species to examine pathogenetic events. 相似文献
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Before the emergence of bovine spongiform encephalopathy (BSE) and recognition of its zoonotic potential, the major example of the transmissible spongiform encephalopathies (TSEs) of animals was scrapie of sheep. But there is no evidence that scrapie transmits naturally to any species other than sheep and goats. The pathogenesis of scrapie has been studied most in experimental laboratory rodent species. In most experimental models of scrapie, after peripheral non-neural routes of infection, replication of the agent can first be detected in lymphoreticular system (LRS) tissue. When the route of introduction of agent into the body is localized, initial involvement will be in LRS tissue draining the infection site. Thereafter, there is a striking amplification of the agent in the LRS and spread by lymphatic/haematogenous routes, giving widespread dissemination in the LRS. This precedes replication in the CNS, but is not the means by which infection reaches the CNS. There is now substantial evidence from experimental models of scrapie that involvement of the CNS is by peripheral nervous system (PNS) pathways. In some models employing oral exposure the earliest localized LRS replication is in the gut-associated lymphoid tissue (GALT) and autonomic PNS routing to the CNS has been implicated. However, the relative importance of different routes of spread of TSEs within the body is determined by a number of host- and agent-dependent factors and, therefore, generalizations from an experimental model to a natural disease across a species barrier may not be appropriate. With the occurrence of BSE and recognition of its food-borne route of transmission via meat and bone meal, has come greater awareness of the probable importance of the oral route of infection in ruminant species affected by TSEs. In consequence, studies have increasingly focused on the natural host species to examine pathogenetic events. 相似文献
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Oliveira SC de Almeida LA Carvalho NB Oliveira FS Lacerda TL 《Veterinary immunology and immunopathology》2012,148(1-2):129-135
The innate immune system constitutes an efficient defense mechanism against invading microbial pathogens. Recent studies have revealed the intracellular signaling cascades involved in the TLR-initiated immune response to Brucella spp. infection. However, there is a piece of the puzzle missing that is the role of non-TLR receptors in innate immunity. The involvement of TLR receptors in brucellosis has been investigated by different research groups. It was demonstrated that TLR2 clearly does not play any role in controlling Brucella abortus infection in vivo, whereas TLR9 has been shown to be required for clearance of this bacterium in infected mice. The participation of adaptor molecules, such as MyD88 and TRIF has also been discussed. Recently, we and others have reported the critical role of MyD88- and not TRIF-mediated signaling in dendritic cell maturation and in vivo resistance during B. abortus infection. However, the relationship between specific Brucella molecules and non-TLR receptors and signal transduction pathways needs to be better understood. It is now clear that the interaction between TLRs and recently identified cytosolic innate immune sensors is crucial for mounting effective immune responses. Finally, this review discusses the mechanisms used by Brucella to escape detection by the host innate immune system. 相似文献
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Brisbin JT Gong J Sharif S 《Animal health research reviews / Conference of Research Workers in Animal Diseases》2008,9(1):101-110
The chicken gut-associated lymphoid tissue is made up of a number of tissues and cells that are responsible for generating mucosal immune responses and maintaining intestinal homeostasis. The normal chicken microbiota also contributes to this via the ability to activate both innate defense mechanisms and adaptive immune responses. If left uncontrolled, immune activation in response to the normal microbiota would pose a risk of excessive inflammation and intestinal damage. Therefore, it is important that immune responses to the normal microbiota be under strict regulatory control. Through studies of mammals, it has been established that the mucosal immune system has specialized regulatory and anti-inflammatory mechanisms for eliminating or tolerating the normal microbiota. The mechanisms that exist in the chicken to control host responses to the normal microbiota, although assumed to be similar to that of mammals, have not yet been fully described. This review summarizes what is currently known about the host response to the intestinal microbiota, particularly in the chicken. 相似文献
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Coussens PM 《Animal health research reviews / Conference of Research Workers in Animal Diseases》2001,2(2):141-161
Mycobacterium avium subspecies paratuberculosis (M. paratuberculosis) is the causative agent of Johne's disease, a deadly intestinal ailment of ruminants. Johne's disease is of tremendous economic importance to the worldwide dairy industry, causing major losses due to reduced production and early culling of animals. A highly controversial but developing link between exposure to M. paratuberculosis and human Crohn's disease in some individuals has led to the suggestion that M. paratuberculosis is also a potential food safety concern. As with many other mycobacteria, M. paratuberculosis is exquisitely adapted to survival in the host, despite aggressive immune reactions to these organisms. One hallmark of mycobacteria, including M. paratuberculosis, is their propensity to infect macrophages. Inside the macrophage, M. paratuberculosis interferes with the maturation of the phagosome by an unknown mechanism, thereby evading the host's normal first line of defense against bacterial pathogens. The host immune system begins a series of attacks against M. paratuberculosis-infected macrophages, including the rapid deployment of activated gammadelta T cells, CD4+ T cells and cytolytic CD8+ T cells. These cells interact with the persistently infected macrophage and with each other through a complex network of cytokines and receptors. Despite these aggressive efforts to clear the infection, M. paratuberculosis persists and the constant struggle of the immune system leads to pronounced damage to the intestinal epithelial cells. Enhancing our ability to control this important and tenacious pathogen will require a deeper understanding of how M. paratuberculosis interferes with macrophage action, the cell types involved in the immune response, the cytokines these cells use to communicate, and the host genetic factors that control the response to infection. 相似文献
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Segundo FD Sevilla N Gutiérrez JP Brun A 《Veterinary immunology and immunopathology》2008,122(3-4):204-215
Transmissible spongiform encephalopathies (TSEs) or prion diseases develop as central nervous system (CNS) disorders characterized by extremely long incubation periods. Although TSEs do not go along with inflammatory infiltrates and/or antibody production against the prion protein (PrP(Sc)), the immune system plays an important role in pathogenesis as long as different lymphoid organs (Peyer's patches, lymph nodes and spleen) may facilitate the accumulation and further spread of prions after peripheral exposure. In this work we investigated the changes in lymphoid and dendritic cell (DC) populations as well as the implications of different cytokines during disease progression after experimental oral inoculation of prions in a transgenic mouse model. At different days post-inoculation (dpi), T and B lymphocytes and DC populations from lymphoid organs, blood and brain were analyzed by flow cytometry and immunohistochemistry. Besides time related variations in lymphoid cell numbers due to the aging of the animals significant changes related with the infection were found in mesenteric lymph nodes, peripheral blood leukocytes (PBLs) as well as in spleen, affecting the CD4/CD8 ratio. In contrast, little or no variation was detected in Peyer's Patches or in thymus either associated with aging or the infection status. At individual time points significant differences between infected and control mice were seen in the CD8, CD4 and DC populations, with less evidence of differences in the B cell compartment. Finally, a pro-inflammatory phenotype occurred at early times in the spleen, where the levels of lymphotoxin-beta mRNA were found augmented with respect to controls. Altogether, these results suggest that normal regulation of lymphocyte populations becomes altered along the progression of a prion infection. 相似文献
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V. K. Affolter 《Veterinary dermatology》2004,15(Z1):70-70
Similar to intestine and pulmonary tissue, skin is in contact with the environment and hence, requires efficient immune surveillance. The concept of skin‐associated lymphoid tissue (SALT) was first introduced in 1978. The skin immune system (SIS) with its cellular and humoral components and the associated draining lymph nodes fulfills the three major functions of the innate and adaptive immune system: (1) induction of the primary immune response; (2) expression of immunity to previously encountered antigens (memory); and (3) avoidance of deleterious immune responses to nonthreatening antigens (tolerance). The cellular components of the SIS include dendritic antigen‐presenting cells (Langerhans cells and dermal dendritic cells), skin‐homing αβ‐T lymphocytes and γδ‐T lymphocytes, keratinocytes and their environment, the microvascular unit (endothelial cells of the dermal postcapillary venules), neural cells and dendritic neural processes, and the draining lymph node with its high endothelial venules. Humoral components of the SIS are defensins, complement components, immunoglobulins, cytokines, chemokines, fibrinolysin, eicosanoids and neuropeptides. Important characteristics and functions of these components and their interactions with each other will be discussed with regard to normal skin versus recruitment phase, retention phase and resolution phase associated with inflammatory conditions. The discussion will primarily focus on cutaneous dendritic antigen‐presenting cells, cutaneous lymphocytes and their homing into the skin, and keratinocytes. Moreover, the importance of the microvascular unit in relation to leukocyte recruitment and migration will be discussed. 相似文献
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Kobayashi S Sato R Aoki T Omoe K Inanami O Hankanga C Yamada Y Tomizawa N Yasuda J Sasaki J 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(5):429-435
Feline immunodeficiency virus (FIV) infection is characterized by chronic overactivation of immune and inflammatory system, resulting in anergic state and dysfunction of immune cells. Lactoferrin (LF), a glycoprotein present in exocrine secretions and neutrophils, plays an important role in host defense system. Our previous study showed that oral administration of bovine LF (bLF) suppressed oral inflammation, improved the clinical symptoms and decreased serum gamma-globulin as a marker of inflammation in FIV-infected cats with intractable stomatitis. The anti-inflammatory effect was partly involved in regulation of neutrophil function by bLF. In this study, to clarify the relationship between anti-inflammatory effects of bLF and peripheral blood mononuclear cells (PBMC), we examined the effect of bLF on proliferation, cell cycle progression and cytokine expression in mitogen-activated PBMC. MTT [3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyl tetrazolium bromide] assay showed that bLF inhibited the concanavalin A (ConA)-induced cell proliferation in FIV-infected cats with the asymptomatic carrier and AIDS-related complex (ARC) phase. Bovine LF restored ConA-induced cell cycle progression and resulted in suppression of the induced apoptosis in feline PBMC. Real-time RT-PCR showed that bLF suppressed ConA-induced expression of interferon-gamma and interleukin-2 in cells of the ARC group regardless of the time of its addition to the medium. These results suggest the hypothesis that therapy with bLF may have the potential to improve and protect functions of overactivated lymphocytes by modulating the cell proliferation, cell cycle and cytokines expression in cats in terminal stage of FIV infection. 相似文献
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Similar to intestine and pulmonary tissue, skin is in contact with the environment and hence, requires efficient immune surveillance. The concept of skin-associated lymphoid tissue (SALT) was first introduced in 1978. The skin immune system (SIS) with its cellular and humoral components and the associated draining lymph nodes fulfills the three major functions of the innate and adaptive immune system: (1) induction of the primary immune response; (2) expression of immunity to previously encountered antigens (memory); and (3) avoidance of deleterious immune responses to nonthreatening antigens (tolerance). The cellular components of the SIS include dendritic antigen-presenting cells (Langerhans cells and dermal dendritic cells), skin-homing αβ-T lymphocytes and γδ-T lymphocytes, keratinocytes and their environment, the microvascular unit (endothelial cells of the dermal postcapillary venules), neural cells and dendritic neural processes, and the draining lymph node with its high endothelial venules. Humoral components of the SIS are defensins, complement components, immunoglobulins, cytokines, chemokines, fibrinolysin, eicosanoids and neuropeptides. Important characteristics and functions of these components and their interactions with each other will be discussed with regard to normal skin versus recruitment phase, retention phase and resolution phase associated with inflammatory conditions. The discussion will primarily focus on cutaneous dendritic antigen-presenting cells, cutaneous lymphocytes and their homing into the skin, and keratinocytes. Moreover, the importance of the microvascular unit in relation to leukocyte recruitment and migration will be discussed. 相似文献
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Streptococcus uberis and Serratia marcescens are Gram-positive and Gram-negative bacteria, respectively, that induce clinical mastitis. Once initial host barrier systems have been breached by these pathogens, the innate immune system provides the next level of defense against these infectious agents. The innate immune response is characterized by the induction of pro-inflammatory cytokines, as well as increases in other accessory proteins that facilitate host recognition and elimination of the pathogens. The objective of the current study was to characterize the innate immune response during clinical mastitis elicited by these two important, yet less well-studied, Gram-positive and Gram-negative organisms. The pro-inflammatory cytokine response and changes in the levels of the innate immune accessory recognition proteins, soluble CD14 (sCD14) and lipopolysaccharide (LPS)-binding protein (LBP), were studied. Decreased milk output, induction of a febrile response, and increased acute phase synthesis of LBP were all characteristic of the systemic response to intramammary infection with either organism. Infection with either bacteria similarly resulted in increased milk levels of IL-1 beta, IL-8, IL-10, IL-12, IFN-gamma, TNF-alpha, sCD14, LBP, and the complement component, C5a. However, the duration of and/or maximal changes in the increased levels of these inflammatory markers were significantly different for several of the inflammatory parameters assayed. In particular, S. uberis infection was characterized by the sustained elevation of higher milk levels of IL-1 beta, IL-10, IL-12, IFN-gamma, and C5a, relative to S. marcescens infection. Together, these data demonstrate the variability of the innate immune response to two distinct mastitis pathogens. 相似文献
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为探究病原菌感染杂交鲟肠道转录组变化情况,本试验以常见病原菌类志贺邻单胞菌接种约360 d杂交鲟,于接种24 h后,采集杂交鲟肠道组织样本,提取组织总RNA,采用Illumina HiSeqTM 2000进行转录组测序,筛选杂交鲟肠道差异表达免疫应答基因并进行GO功能分类和KEGG信号通路分析,结果显示：与正常对照组比较,试验感染组杂交鲟肠道差异表达基因为13 542个,其中上调基因为9 774个,下调基因为3 768个;GO分析发现,杂交鲟肠道差异表达基因显著性富集到生物学过程的主要有免疫系统过程、免疫效应过程、刺激反应等;显著性富集到分子功能的主要有DNA结合、信号受体活性、核酸转录因子活性等;显著性富集到细胞组分的主要是胞外区、胞外区组成部分、细胞膜等。KEGG分析发现,杂交鲟肠道差异表达基因参与的免疫信号通路有RIG-Ⅰ样受体信号通路、Toll样受体信号通路和细胞溶质DNA传感途径。这些研究结果为深入探究杂交鲟对肠道病原微生物感染的防御分子机制奠定了良好的基础。 相似文献
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哺乳动物防御素研究进展 总被引：2，自引：1，他引：2
防御素是动植物先天免疫系统的主要成分。哺乳动物体内的防御素在宿主的嗜中性粒细胞、粘膜表面、皮肤和其他上皮细胞免疫中起重要作用。作者综述了哺乳动物防御素的来源与分布、分子结构特征、生物活性、作用机理及应用前景。 相似文献
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Howard CJ Charleston B Stephens SA Sopp P Hope JC 《Animal health research reviews / Conference of Research Workers in Animal Diseases》2004,5(2):191-195
Dendritic cells are central to the initiation of primary immune responses. They are the only antigen-presenting cell capable of stimulating naive T cells, and hence they are pivotal in the generation of adaptive immunity. Dendritic cells also interact with and influence the response of cells of the innate immune system. The manner in which dendritic cells influence the responses in cells of both the innate and adaptive immune systems has consequences for the bias of the adaptive response that mediates immunity to infection after vaccination or infection. It also provides an opportunity to intervene and to influence the response, allowing ways of developing appropriate vaccination strategies. Mouse and human studies have identified myeloid, lymphoid and plasmacytoid dendritic cells. Studies in domesticated animals with agents of specific infectious diseases have confirmed the applicability of certain of the generic models developed from mice or from in vitro studies on human cells. In vivo and ex vivo studies in cattle have demonstrated the existence of a number of subpopulations of myeloid dendritic cells. These cells differ in their ability to stimulate T cells and in the cytokines that they produce, observations clearly having important implications for the bias of the T-cell response. Dendritic cells also interact with the innate immune system, inducing responses that potentially bias the subsequent adaptive response. 相似文献