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1.
Natural adjuvants: endogenous activators of dendritic cells. 总被引:29,自引:0,他引:29
Dendritic cells, the most potent antigen-presenting cells, need to be activated before they can function to initiate an immune response. We report here that, in the absence of any foreign substances, dendritic cells can be activated by endogenous signals received from cells that are stressed, virally infected or killed necrotically, but not by healthy cells or those dying apoptotically. Injected in vivo with an antigen, the endogenous activating substances can function as natural adjuvants to stimulate a primary immune response, and they may represent the natural initiators of transplant rejection, spontaneous tumor rejection, and some forms of autoimmunity. 相似文献
2.
M R Tripp 《Journal of invertebrate pathology》1992,59(3):228-234
Lectins in the serum of the clam Mercenaria mercenaria agglutinate some red blood cells, bacteria, and yeast. The interaction of these substances with particles is affected by sugars, ions, temperature, and alteration of particle surfaces. Lectins are not needed for phagocytosis of foreign particles in vitro. In M. mercenaria these recognition molecules do not enhance defense mechanisms. 相似文献
3.
The ovoid cells of the branchial heart complex of Sepia officinalis L. were investigated with respect to their role in detoxification processes. The electron microscopical localization of in situ injected ferritin in the endocytotic-lysosomal system, and the fluorescence microscopical localization of protein-bound Evans blue in the ovoid cells of in vivo incubated animals, indicate that foreign materials are eliminated from the hemolymph by the branchial heart tissue. In addition to the non-circulating ovoid cells of the branchial heart, hemocytes in the circulating blood and in the wall of the branchial heart are also involved in the incorporation of allogeneic substances and bacteria, or their debris. Based on these observations, we propose that the ovoid cells, together with circulating and adhesive hemocytes in the branchial hearts, are an important component of a more comprehensive defence and detoxification system in dibranchiate cephalopods that prevents contamination of the whole organism by endocytotic removal of noxious substances from the hemolymph. 相似文献
4.
A NOVEL TYPE OF HEMOCYTES LOCALIZING MELANIZATION WITH HIGH‐SPREADING BEHAVIOR IN MYTHIMNA SEPARATA
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Yoshiaki Kato Tatsuhiro Yoshida Ken Miura Toshiharu Tanaka Yutaka Nakamatsu Masanori Ochiai 《Archives of insect biochemistry and physiology》2014,86(4):220-239
Lepidopteran larvae show a cellular response to invading foreign substances that are larger than hemocytes, for example, parasitoid eggs or larvae. This response is called hemocyte encapsulation and is often accompanied by phenoloxidase (PO)‐catalyzed melanization. In the present study, we artificially transplanted endoparasitoid larvae and small glass fragments into the hemocoel of the common armyworm, Mythimna separata. We observed that the host larva showed a cellular response and that, 2–4 h after transplantation, melanin formation was spatially confined to the surface of the encapsulated substances. We further noted that specific morphological hemocytes surrounded by melanin formation became attached to the surface of the foreign substances. We designated these hemocytes hyperspread cells (HSCs) on the basis of their specific characteristics and circumferential spread. We confirmed the occurrence of prophenoloxidase (PPO)/phenoloxidase (PO) on the periphery of the HSCs and in the substance secreted around the HSCs by using anti‐PPO antibody. We were unable to detect PPO‐mRNA in HSCs by using in situ hybridization, although we showed that oenocytoids contained PPO‐mRNA and PPO protein. We used light microscopy and scanning electron microscopy to discriminate five main types of circulating M. separata hemocytes. We observed that HSCs differed from plasmatocytes, but spread out well. Further, during the encapsulation process, HSCs appeared to provide a localized melanization spot on the surface of foreign invaders. 相似文献
5.
LITTLE is known about the mechanism by which antibodies are produced against foreign substances but not against components of the body. Mishell and Dutton1 developed a cell culture system for formation of antibody against sheep red blood cells (RBC) as antigen1. Mosier demonstrated that both macrophages and lymphocytes in mouse spleen are responsible for antibody formation2. 相似文献
6.
Endocytotic-active cells in the branchial heart complex of Sepia officinalis were studied by in situ injection of different types of xenobiotics and by in vitro perfusion of the organ complex with a bacterial suspension. The rhogocytes (ovoid cells) ingest particles of all tested sizes by endocytosis and phagocytosis. The hemocytes of the circulating blood and the adhesive hemocytes in the wall of the branchial heart incorporate all tested kinds of foreign materials, including bacterial cells due to phagocytosis achieved by the triangular mesenchymatic cells. The ultrastructural findings also give strong evidence that the triangular mesenchymatic cells are fixed hemocytes that have migrated into the branchial heart tissue. The ingestion and digestion of allogeneic substances and bacteria or their debris by rhogocytes and/or all (forms of) hemocytes suggests the involvement of these either fixed or mobile endocytotic-active cells in the defense and detoxification system of cephalopods. 相似文献
7.
Utilization of general morphological, histochemical, morphometric and electron microscopic methods revealed marked structural changes of the liver in experimental chronic hepatitis and its subsequent correction with benzonal. The drug administration results in reversibility of the process due to significant action of cellular, and especially intracellular regenerative processes. The latter is supported by the presence of 2 types of cells, the 1st of which are characterized by predominant mitochondrial hypertrophy and hyperplasia suggesting increase in hepatocyte energy activity and the 2nd ones by hypertrophy of the elements of the smooth reticulum responsible for metabolism of foreign body substances being typical for the action of inductors of hepatic microsomal enzymes. 相似文献
8.
Endocytotic-active cells in the branchial heart complex of Sepia officinalis were studied by in situ injection of different types of xenobiotics and by in vitro perfusion of the organ complex with a bacterial suspension. The rhogocytes (ovoid cells) ingest particles of all tested sizes by endocytosis and phagocytosis. The hemocytes of the circulating blood and the adhesive hemocytes in the wall of the branchial heart incorporate all tested kinds of foreign materials, including bacterial cells due to phagocytosis achieved by the triangular mesenchymatic cells. The ultrastructural findings also give strong evidence that the triangular mesenchymatic cells are fixed hemocytes that have migrated into the branchial heart tissue. The ingestion and digestion of allogeneic substances and bacteria or their debris by rhogocytes and/or all (forms of) hemocytes suggests the involvement of these either fixed or mobile endocytotic-active cells in the defense and detoxification system of cephalopods. 相似文献
9.
E. B. Rukavtsova V. V. Alekseeva Ya. I. Buryanov 《Russian Journal of Bioorganic Chemistry》2010,36(2):146-156
The metabolic engineering of plants is aimed at the realization of new biochemical reactions by transgenic cells. These reactions
are determined by enzymes encoded by foreign or self-modified genes. Plants are considered to be the most interesting objects
for metabolic engineering. Although they are characterized by the same pathways for the synthesis of basic biological compounds,
plants differ by the astonishing diversity of their products: sugars, aromatic compounds, fatty acids, steroid compounds,
and other biologically active substances. RNA interference aimed at modifying metabolic pathways is a powerful tool that allows
for the obtainment of plants with new valuable properties. The present review discusses the main tendencies for research development
directed toward the obtainment of transgenic plants with altered metabolism. 相似文献
10.
痘苗病毒载体研究进展 总被引:1,自引:0,他引:1
制备高活性的真核蛋白,必须使用哺乳动物细胞,痘苗病毒为这一工作提供了简便、实用的工具.痘菌病毒宿主范围广,无致癌性,插入长达20多kb的外源基因后仍有感染性,能够高效表达外源蛋白,有效地加工表达产物.而且,痘菌病毒的表达产物可刺激机体免疫系统产生良好的体液免疫和细胞免疫.利用这些特点构建成的哺乳动物细胞高效表达系统将是基因工程药物和基因工程疫苗的有效工具. 相似文献
11.
12.
We have reported that foreign protein injected into the abdominal cavity of Sarcophaga peregrina (flesh fly) larvae is degraded in the hemolymph by a proteinase secreted by hemocytes [Suzuki, T. and Natori, S. (1985) Comp. Biochem. Physiol. 81A, 191-193]. Here we report the purification and characterization of a proteinase from larval hemocytes. This enzyme is a cysteine proteinase consisting of 26-kDa and 29-kDa subunits with similar substrate specificity to mammalian cathepsin B. This enzyme was shown to be released from hemocytes into the hemolymph of larvae following injection of sheep red blood cells into the larvae, suggesting that it participates, at least in part, in elimination of foreign substances introduced into the body cavity. 相似文献
13.
N. A. Odintsova 《Cell and Tissue Biology》2009,3(5):403-408
The review surveys own and the literature data on the plasticity of marine invertebrate stem cells. Stem and embryonic cell cultures of marine invertebrates are a novel model system characterized by a high level of physiological and synthetic processes. The production of biologically active substances in vitro may be an alternative to chemical synthesis and aquaculture. The factors involved in determination and maintenance of the pluripotency of marine invertebrate stem cells have been analyzed. The technology of the directed differentiation of marine invertebrate stem cells into certain functionally active cells in vitro embraces the use of different growth factors, various natural and artificial substrates, and unique bioactive compounds from marine invertebrate tissues. To increase the expression levels of regulatory genes, we applied genetically engineered constructions with foreign genes. The regulation of growth and differentiation of marine invertebrate stem cells opens new prospective uses for their application in marine biotechnology and is helpful for research in developmental biology. 相似文献
14.
The non-immune mechanisms of recognition of self and non-self substances by macrophages has not yet been clarified. In this work, we report the ability of mouse peritoneal macrophages to attach to and phagocytize in vitro autologous and homologous erythrocytes in proportions as high as those for certain heterologous red blood cells. This ability was abrogated by autologous or homologous serum but not by heterologous serum or a serum-free supplement. This effect of serum was dose dependent and did not affect the phagocytosis of homologous "old" red cells. Procedures for the identification of this serum factor indicated that it was dialyzable (10 kD cut off) and was excluded by filtration in Sephadex G-25. We conclude that this finding supports the possibility that macrophages do not selectively phagocytize foreign particles or senescent cells but, rather, that they do phagocytize all particles or cells indiscriminately and this serum factor may prevent phagocytosis of normal self cells. 相似文献
15.
Baranov AE Rozhdestvenskiĭ LM 《Radiatsionnaia biologiia, radioecologiia / Rossi?skaia akademiia nauk》2008,48(3):287-302
The analysis of the original sources showed that there are some differences in approaches to radiation injuries treatment used mainly by Russian and foreign researches in their experiments. In Russian radiobiology the main way was the single usage of high molecular substances of different chemical structure and of natural origin soon after radiation exposure. These substances were designated then as cytokine inductors. Foreign researchers investigated in the beginning analogous substances too, but then--recombinant cytokines exclusively. In native radiobiology the urgent (in limits of 2 h) and early (in limits of 6-24 h) pathogenic therapy develops already for a long time. There are preparations, betaleukine (recombinant human interleukine 1 beta) and dezoksinat (degraded DNA), as results of developing the directions. Both have licenses on the administration at radiation accidents. But the issues of various medicaments optimal combinations in a common scheme of early (in first 24 h) medical help remain undefined accurately. The consensus protocol of radiation injuries treatment in clinic consists of the supportive therapy (aseptic conditions, wide antimicrobic antibiotics, thrombocytes and erythrocytes transfusions) and the myelostimulation therapy by cytokine combinations. The hemopoietic stem cells transplantation in cases of severe radiation damages treatment remains under question in the reason of immunological conflict between a host and a graft. 相似文献
16.
Saegusa S Totsuka M Kaminogawa S Hosoi T 《FEMS immunology and medical microbiology》2004,41(3):227-235
Intestinal epithelial cells (IEC) are important in initiation and regulation of immune responses against numerous foreign substances including food, microorganisms and their metabolites in the intestine. Since the responses of IEC against yeasts have not yet been well understood, we investigated the effects of Candida albicans, Saccharomyces cerevisiae, and their cell wall components on interleukin-8 (IL-8) secretion by the IEC-like Caco-2 cells. Live cells of both yeast species stimulated Caco-2 cells to produce IL-8 only in the presence of butyric acid, which is a metabolite produced by intestinal bacteria. S. cerevisiae zymosan and glucan also enhanced IL-8 secretion. Treatment of Caco-2 cells with butyric acid increased the expression of mRNAs coding for Toll-like receptor 1 (TLR1), TLR6 and dectin-1, which recognize zymosan. C. albicans induced more IL-8 secretion and also decreased transepithelial electrical resistance more rapidly than S. cerevisiae. These results suggest that both yeasts in the intestine stimulate the host's mucosal immune systems by interacting with IEC. 相似文献
17.
A G Bulychev 《Tsitologiia》1986,28(4):387-402
Current literature on the cell segregation function is reviewed. The modern data on the role of coated pits, coated vesicles and endosomes in receptor-mediated and fluid endocytosis are regarded. Mechanisms of segregation both of inorganic and organic substances in lysosomes are considered. A special attention is paid to the selective accumulation in lysosomes of substances penetrating through plasma membrane. Some modern considerations concerning the role of the ATP-dependent proton pump in maintaining low intralysosomal pH and accumulation of weak bases in lysosomes by means of protonation are given. A great attention is paid to the effect of accumulated foreign substances in lysosomes on lysosomal apparatus functions and some metabolic disorders as consequences of it. The importance of the cell segregation functions and of lysosomotropic compounds for cytopharmacology and cytopathology is emphasized. 相似文献
18.
I Parker C B Gundersen R Miledi 《Proceedings of the Royal Society of London. Series B, Containing papers of a Biological character. Royal Society (Great Britain)》1985,226(1244):263-269
Xenopus oocytes can be made to incorporate into their membrane foreign neurotransmitter receptors and voltage-activated sodium channels. In their original location the receptors are normally activated by the extracellular action of transmitter substances. Tests were made to see if some of the newly synthesized foreign receptors were inserted in the oocyte membrane with their active site facing inwards. Since intracellular injections of acetylcholine, gamma-aminobutyric acid, serotonin and kainic acid and tetrodotoxin into the oocyte failed to elicit a response, we conclude that very few, or none, of the receptor molecules expressed in the oocyte by the exogenous mRNA are inserted with the wrong orientation in the membrane. 相似文献
19.
Pattern recognition receptors (PRRs) have been found on all cells of the body—cells of the innate and adaptive immune systems, epithelial and endothelial cells, keratinocytes, etc. PRRs can recognize specific molecular structures of microorganisms as well as allergens and other substances. The interaction with ligands of foreign microorganisms activates PRRs, after which host cells start to produce cytokines both to specifically activate innate immunity and to control adaptive immune reactions. On the othe hand, no immune response develops against microorganisms of the normal microflora. Practically, the development of all immune responses is controlled by PRRs. These responses start in epithelial cells, skin cells, and vascular epithelial cells, which meet alien first. The immune system uses these cells to control the composition of normal microflora. Accordingly, the definition of immune system functions should be complemented by the regulation of body’s microflora in addition to the protection from alien and altered self. 相似文献
20.
V R Pennisi 《Plastic and reconstructive surgery》1984,74(4):535-538
Two patients are presented whose breasts were injected directly or indirectly with paraffin and silicone, respectively. Both patients had breast cancer that was obscured by the overwhelming granulomatous resection produced by both these foreign substances. It is suggested that paraffin could have been a causative agent in the development of cancer. The role of injected silicone in breast cancer is questionable. 相似文献