共查询到20条相似文献，搜索用时 406 毫秒
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细胞因子是一类由造血系统、免疫系统或炎症反应中的活化细胞产生的具有高活性多功能的小分子多肽、蛋白质或糖蛋白。它们主要通过自分泌或旁分泌的方式在机体的免疫应答、炎症反应、物质代谢和神经内分泌以及生长发育等多个方面发挥重要作用。许多重组细胞因子已在一些动物疾病预防、免疫治疗和构建新一代基因工程苗等方面显示出广阔的应用前景。以细胞因子作为免疫佐剂可能是解决目前众多疫苗，特别是寄生虫疫苗效果不良或不稳定问题的有效途径之一。细胞因子在动物疫痛上的防治应用将会为畜牧业生产创造巨大的经济效益。 相似文献
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原虫感染可引起严重的肠道黏膜免疫应答,其侵入机体时,会触发机体的固有免疫应答和适应性免疫系统反应,包括诱导特异性抗体的产生以及效应T淋巴细胞的形成。T淋巴细胞包括CD_4~+和CD_8~+两大类,CD_4~+为辅助性T淋巴细胞,通过膜表面分子及其所分泌的细胞因子辅助并调控B淋巴细胞和巨噬细胞的活化与功能;CD_8~+是杀伤细胞,也是肠道上皮细胞主要表达因子,功能与自然杀伤细胞相似,可以与被感染上皮细胞接触将其杀死。B淋巴细胞主要功能是制备抗原特异性抗体,发挥体液免疫作用。文章将从两方面论述原虫与机体免疫应答之间的相互调节作用。 相似文献
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机体在发生感染或损伤时，瞬即可出现一系列反应，称为急性期应答(APR，acute phase response)。这类反应有局部性和全身性两方面，都可引起一系列生理变化，包括凝固反应、细胞向发热部位游走及激素分泌增加。本文论述对寄生虫侵袭过程的急性期应答的检测，并分析了其对感染转归的影响。 相似文献
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《Domestic animal endocrinology》1998,15(5):389-396
Contained in this report is a review of available data on pituitary cytokines in domestic species of agricultural importance. The concept is advanced that the pituitary gland is essential to appropriate generation of host defense mechanisms and thus should be considered among other tissues contributing to innate immunity. The functions of these intrapituitary cytokines, principally IL-6, are discussed in the context of potential regulation of the pituitary-adrenal axis (ACTH secretion) via intrapituitary PGE2 generation during the acute-phase response to infectious/inflammatory stimuli. Data from other species are cited as appropriate for comparative purposes and elaboration of proposed mechanisms. However, the scope of the review is not intended to comprehensively cover the vast literature on proinflammatory cytokines and prostaglandins generated peripherally and centrally during host responses to inflammatory stimuli. 相似文献
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Schijns VE 《Veterinary immunology and immunopathology》2002,87(3-4):195-198
The immune system evolved to free the host from invading noxious pathogens. Vaccines are inoculated as a prophylactic measure in order to program the immune system for accelerated recognition and elimination of specific pathogens. During vaccination the immune system is exposed to attenuated or inactivated microorganisms, or their fragments. The immune response to these structures, in contrast to virulent pathogens, is often inadequate for the generation of memory cells or immune effector elements such as antibodies, perforines, granzymes or cytokines. Vaccine adjuvants help to overcome these limited responses. They provide instructive signals for the host immune system by mimicking the conditions associated with virulent infection. Hence, they either enhance and prolong expression of antigen components to reactive T cells in lymph nodes (signal 1) or they increase expression of membrane-bound or soluble costimulatory molecules (signal 2). The enhancement of both signals by vaccine adjuvants is not mutually exclusive. Moreover, adjuvants may encode a third signal instructing the type of immune reaction to be generated. Supported by animations this presentation addresses putative immunological concepts of vaccine adjuvant activity, a phenomenon long been known as "the immunologist's dirty little secret". Insight in the mechanisms that underlie adjuvant-induced immunostimulation and generation of memory cells will facilitate rational vaccine design. 相似文献
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Immune responses to gastrointestinal helminth infections have received increasing attention due to similarities to allergen-induced responses. In fact, the whipworm parasite of swine, Trichuris suis, has been used in beginning clinical trials as an antidote to inflammatory bowel disease. This strategy was based on this similarity and the recognition that other worms have been documented to induce anti-inflammatory responses in the host. In an effort to understand the basis for this response, we hypothesized that the proteins and peptides secreted by T. suis stimulate local intestinal epithelial cells to produce anti-inflammatory cytokines. To test this hypothesis in a correlate system of the natural swine host, T. suis excretory secretory products (ESP) were used to treat both differentiated and undifferentiated intestinal pig epithelial cells (IPEC-1) in vitro as a model for the effect on villus tip and crypt epithelial cells in the vicinity of the worms. IPEC-1 were exposed to low-level doses (0.3mg/ml) of T. suis ESP, and IL-4, IL-6 and IL-10 cytokine responses were measured by an enzyme-linked immunosorbant assay (ELISA). IL-6 was the predominant cytokine produced, accompanied by moderate IL-10 secretion from both differentiated and undifferentiated cells. As expected, IL-4 was not produced by IPEC-1. Additionally, IL-6 and IL-10 cytokines were produced within 24h, suggesting that these two cytokines form part of the primary host response to T. suis infections. These data suggest that T. suis ESP could enhance host immune responses and modulation through the induction of enteric IL-6 and IL-10. 相似文献
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皮肤和黏膜上皮细胞既是机体的物理屏障,又是机体防御微生物的第一道防线。上皮细胞与白细胞、树突细胞(DCs)等之间的相互作用,是机体产生适应性免疫反应的重要因素。IL-17细胞因子家族是最近新发现的具有强大的促炎症作用的细胞因子,它们在机体的固有和适应性免疫中发挥着重要作用,IL-17A、IL-17C和IL-17F能够直接作用于组织的上皮细胞,诱导各种免疫反应来对抗病原体,且能够促进组织的修复。IL-17E最基本的作用是作用于白细胞和诱导Ⅱ型免疫,这在其对抗寄生虫的作用中是非常关键的,此外,IL-17E还可以反向调节白细胞对IL-17A和IL-17F的产生;而对于IL-17B和IL-17D的研究则相对较少一些。 相似文献
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W R Waters 《Veterinary Clinics of North America: Food Animal Practice》2001,17(3):517-534
During the past century, research on animal diseases has focused on the characterization of specific etiologies and disease control strategies. Many diseases affecting domestic animals have been successfully controlled using various methods, including vaccination, management, vector control, or antimicrobial agents. A number of microorganisms have proven resistant to these efforts. Control of these organisms requires the development of new strategies. As practitioners and researchers, we need to consider approaches that encompass the entire realm of disease expression from molecular to immune responses and interactions with other functional systems (e.g., endocrine, neurologic, and vascular systems). We need a basic understanding of effective immune responses enabling the tailoring of vaccines to produce the desired response. This tailoring of host responses is augmented by the use of vaccines that use host growth factors, cytokines, or costimulatory molecules to bias the ensuing response. Intestinal microbial flora of food-producing animals can be managed to optimize health and minimize colonization by pathogenic organisms, especially zoonotic agents. New systems for the delivery of cytokines and other factors that favor optimal intestinal health and homeostasis need to be researched and evaluated. With time, it is likely that our clients and the consumers will be less tolerant of antibiotic usage. They will be more aware of the zoonotic potential of many microbes that colonize food animals. Food safety issues will be a continuing concern, as will the protection of our water supply from contamination from feedlots and pasture runoff. We are in the dawn of a new century, and, it is hoped, a new era of discovery of enteric disease pathogenesis and control. 相似文献
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Bovine peripheral blood mononuclear leukocytes (PBML) were stimulated in vitro with the mitogenic lectins concanavalin A (Con A) and phytohemagglutinin. Their cytotoxic capabilities were evaluated in a 51Cr release assay. Lectin-activated bovine effector cells did not mediate antibody dependent cellular cytotoxicity (ADCC) nor direct killing against cultured tumor target cells. Nevertheless, activation of PBML with lectins consistently generated effector cells able to mediate lectin-dependent cellular cytotoxicity. Cultivation of Con A stimulated-PBML for 3 to 4 weeks in the presence of lymphokines-containing IL-2 generated cells with the ability to mediate lysis without using Con A-coated target cells. However, cytotoxic cultures capable of mediating direct lysis of target cells were not able to mediate ADCC. 相似文献
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Infections with gastrointestinal nematodes represent a major problem for human health and animal health and production. The physical size of the parasite, its changing life-cycle stages and the relative inaccessibility to host cells pose unique challenges to the immune system, which has evolved specialized strategies for parasite control. This paper reviews the work performed in the authors' laboratories to identify components that are involved in the natural rejection response against ruminant gastrointestinal nematode parasites, in particular Haemonchus contortus in sheep. The results of these studies indicate that stage-specific antibodies act in concert with effector cells, in particular globular leukocytes (intraepithelial mast cells) and eosinophils, appropriately activated/primed by type 2 (T2) cytokines, to initiate different mechanisms of parasite expulsion and killing. In addition, other molecules, in particular carbohydrate binding galectins, may be involved in strengthening the final effector phase of the rejection response. 相似文献
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Bannerman DD Paape MJ Chockalingam A 《Veterinary immunology and immunopathology》2006,112(3-4):309-315
In contrast to other mastitis pathogens, the host response evoked during Staphylococcus aureus intramammary infection is marked by the absence of the induction of critical cytokines, including IL-8 and TNF-alpha, which have established roles in mediating host innate immunity. The elucidation of changes in the expression of other mediators with the potential to regulate mammary inflammatory responses to S. aureus remains lacking. Transforming growth factor (TGF)-alpha, TGF-beta1, and TGF-beta2 are cytokines that regulate mammary gland development. Because these cytokines also have a demonstrated role in mediating inflammation, the objective of the current study was to determine whether S. aureus intramammary infection influences their expression. Ten cows were challenged with S. aureus and milk samples collected. Increases in milk levels of TGF-alpha were evident within 32h of infection and persisted for 16h. Increases in TGF-beta1 and TGF-beta2 levels were detected within 40h of S. aureus infection and persisted through the end of the study. Thus, in contrast to IL-8 and TNF-alpha, S. aureus elicits host production of TGF-alpha, TGF-beta1, and TGF-beta2. This finding may suggest a role for these cytokines in mediating mammary gland host innate immune responses to S. aureus. 相似文献