Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In vitro studies have previously shown that the myelomonocytic differentiation antigen CD14 is a receptor for a complex consisting of lipopolysaccharide (LPS) and LPS-binding protein. To investigate the role of CD14 in vivo and its relationship to induction of LPS-induced endotoxin shock, transgenic mice expressing human CD14 were produced. These mice express human CD14 strongly on the surface of their monocytes, neutrophils, and Thy-1(+) lymphocytes and are hypersensitive to LPS, as evidenced by their increased susceptibility to endotoxin shock. These results document the importance of CD14 in vivo as a primary mediator of this lethal syndrome. Furthermore, these mice provide an important model for testing the therapeutic effects of agents directed specifically against the human, as opposed to the murine, CD14 protein in preventing LPS-induced endotoxin shock.
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PMID:Transgenic mice expressing human CD14 are hypersensitive to lipopolysaccharide. 768 94

The activity of sea squirt antigen, one of the allergy-inducing substances for humans, on murine and human lymphocytes was studied in vitro. Sea squirt antigen stimulated normal mouse spleen cells to proliferate, as detected by [3H]-TdR incorporation, in a dose-dependent manner. The responder cells are B cells because the response was reduced by the treatment of spleen cells with anti-immunoglobulin antibody and complement and passing through a nylon wool column, but not with anti-Thy-1 antibody and complement. Spleen cells of C3H/HeJ mice, which are lipopolysaccharide low responders, were also stimulated as well as spleen cells of C3H/HeN mice, suggesting that this response is not due to lipopolysaccharide in the antigen fraction. Sea squirt antigen stimulated not only proliferative response of B cells, but also polyclonal immunoglobulin production. Furthermore, sea squirt antigen also stimulated human lymphocytes to proliferate and to produce immunoglobulin. All these results suggest that sea squirt antigen has mitogenic activity on B cells, and this ability is concerned with the induction of allergic reaction.
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PMID:B cell mitogenic activity of sea squirt antigen. 803 38

We established a thyroglobulin (Tg)-specific, thyroiditis-inducing T-cell clone, B12G, from B6C3F1 mice by the immunization of mouse Tg with lipopolysaccharide (LPS) from Klebsiella strain LEN (O3:K1). B12G was Thy-1.2+, CD3+, CD4+, CD18+, and CD8-, and could transfer thyroiditis to recipient mice after in vitro stimulation with mouse or bovine Tg. Histological examination showed severe thyroiditis with predominant infiltrations of polymorphonuclear cells; few mononuclear cells were observed. B12G proliferated in response to bovine, mouse, porcine, and rat Tg in the presence of irradiated spleen cells, but did not respond to chicken or human Tg. H-2b, a low-responder haplotype of experimental autoimmune thyroiditis, governed the response of the clone to Tg. B12G produced interleukin-4 (IL-4) and IL-6, but not IL-2 or interferon-gamma (IFN-gamma), on stimulation with mouse Tg. These findings were different from characteristics of previously reported Tg-specific T-cell clones from high-responder mice in terms of epitope specificity and cytokine production pattern, raising the possibility that the specificities and functions of T cells involved in the development of autoimmune thyroiditis in low-responder mice differ from those in high responders.
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PMID:Characterization of a thyroiditis-inducing thyroglobulin-specific T-cell clone restricted by the H-2 molecule of a low responder mouse strain. 828 21

Previous studies have reported an association of gamma/delta T cells with microbial infection in both human lesions and murine infectious disease models. In this study we provide a comprehensive analysis of the conditions under which the induction of gamma/delta T cells occurs at a site of infection. We found a site-specific induction of gamma/delta T cells after the injection of Listeria monocytogenes in the peritoneal cavity of C3H mice. No changes were seen in the splenic or lymph node populations after these injections. Both the proportion and the absolute number of gamma/delta T cells increased in the peritoneal cavity. Additionally, when peritoneal T cells from Listeria-immune mice were restimulated in vitro, the induced gamma/delta T cells exhibited a greater expansion potential than the alpha/beta T cells. Neither the induced gamma/delta T cells nor those from normal mice expressed CD4 or CD8 on the cell surface. Thy-1 was expressed on only 29% of normal peritoneal gamma/delta T cells, but after intraperitoneal Listeria injection 65% of induced gamma/delta T cells expressed. Thy-1, Pgp-1 and CD45R expression on both normal and induced gamma/delta T cells was consistent with an activation phenotype. Significant increases in peritoneal gamma/delta T cells were not seen until 5-7 d after Listeria injection. The proportion of the CD3+ population expressing the gamma/delta T cell receptor remained elevated for 6-7 wk, while the absolute numbers of peritoneal gamma/delta T cells declined gradually over this time period, reflecting a decrease in both the number of lymphocytes and the percentage of these that were CD3+. Peak numbers of gamma/delta T cells were seen at day 10 with live microbes such as Listeria. A variety of microbes, toxins, mitogens, antigens, cytokines, and nonspecific inflammatory agents were evaluated for their ability to induce gamma/delta T cells in the peritoneal cavity. Both Gram-positive and Gram-negative bacteria as well as Mycobacteria were able to induce gamma/delta T cells that showed increased in vitro expansion potential. An exotoxin from a Gram-positive organism, listeriolysin-o, and the lipopolysaccharide (LPS) endotoxin from a Gram-negative organism were also effective. gamma/delta T cell responses to LPS were under lps gene control. Peak numbers of gamma/delta T cells were observed at day 3 after injection with exotoxins and endotoxins. Modifications that abrogated the virulence of a bacterial strain also eliminated the inductive effect for gamma/delta T cells.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Induction of murine peritoneal gamma/delta T cells and their role in resistance to bacterial infection. 835 63

A single dose of inactivated streptococci (OK-432) was injected into the popliteal lymph nodes of male CDF1 mice and its effects on popliteal, inguinal, and para-aortic lymph node cells and spleen cells were investigated and compared with the effects of subcutaneous injections of the same dosage of OK-432. Regional lymph node cells and spleen cells obtained from intralymphnodally injected mice lysed not only natural killer (NK)-sensitive YAC-1 cells, but also NK-resistant P-815 and meth-A cells. Lysis of target cells was inhibited when effector cells were treated with anti-Thy-1.2 or anti-Lyt-2.2 monoclonal antibody and complement, but no inhibition was apparent after treatment with anti-asialo-GM1 or anti-Lyt-1.2 antibody and complement. These results suggest that the effector cells are lymphocyte-activated killer (LAK) cells. An enhanced capacity of lymph node cells to produce cytokines, tumor necrosis factor and interleukin 1 upon restimulation with lipopolysaccharide was found only in intralymphnodally injected mice. Thus, the induction of LAK-like cells and cytokine production in regional lymph nodes and spleen cells by the intralymphnodal administration of OK-432 should be effective for the inhibition or treatment of lymph node metastases.
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PMID:Enhancement of LAK-like activity and cytokine induction in regional lymph nodes and spleen cells of mice after intralymphnodal injection of OK-432, a killed streptococcal preparation. 835 67

Immunoregulatory states in acute cold-stressed or cold-acclimatized mice were investigated. When male C57BL/6 mice were exposed to environmental temperature of 5 degrees for 24 hr (acute cold stress), the spleen cells showed depressed proliferative responses to stimulation with concanavalin A (Con A) or lipopolysaccharide (LPS) compared with control mice (reared at 25 degrees). The proportion of Thy-1.2+ cells increased significantly in spleens from these acute cold-stressed mice. The Con A responses of T-enriched cells from acute cold-stressed mice were restored to the normal level by adding plastic-adherent cells from control mice. Further, adherent cells from acute cold-stressed mice markedly suppressed the Con A responses of control spleen cells. Thus, the plastic-adherent cells appeared to be responsible for the suppressed Con A responses. On the other hand, proliferative responses to Con A or LPS were elevated in spleen cells from mice exposed to 5 degrees for 3 weeks (cold acclimatization). A significant decrease of Thy-1.2+ cells was detected in these spleens. It was shown that the enhanced proliferative responses were attributable to functional alterations of the plastic adherent cell population but not to those of lymphoid cell population. These findings indicate that the low or high responsiveness of spleen cells to Con A observed in cold-stressed or cold-acclimatized mice, respectively, may be due to a mechanism including the contrary modulations of functions of cells of mononuclear phagocyte lineage.
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PMID:Immunomodulation by cells of mononuclear phagocyte lineage in acute cold-stressed or cold-acclimatized mice. 855 85

In this study, the modulation of inflammatory cytokine production by lipopolysaccharide (LPS) in two T cell lines, RL-male-1 and L5178Y-ML was examined. Both cell lines produced interleukin 1 (IL-1) activity in response to LPS, which was largely independent of the presence of serum. The IL-1 activity induced was neutralized by an anti-IL-1beta antibody, but not by an anti-IL-1alpha antibody. Induction of IL-1alpha and beta was also confirmed by polymerase chain reaction of reverse-transcribed mRNA (RT-PCR), although in RL-male-1 cells, IL-1alpha mRNA was constitutively expressed and somewhat enhanced by LPS. RT-PCR analysis revealed that these cell lines also upregulated tumour necrosis factor alpha (TNF-alpha) and IL-1 receptor antagonist mRNAs in response to LPS, although RL-male-1 cells expressed TNF-alpha mRNA constitutively. Flow cytometric analysis showed that, although these cells expressed Thy-1 antigen, they hardly expressed CD14 and gammadelta T cell receptor. In conclusion, LPS modulated inflammatory cytokine production in these T cell lines.
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PMID:Modulation by lipopolysaccharide of inflammatory cytokine production by two T cell lines. 934 3

To clarify the involvement of growth and differentiation of liver macrophages mediated by macrophage colony-stimulating factor (M-CSF) in the liver injury induced by Propionibacterium acnes (P. acnes) and lipopolysaccharide (LPS), we used M-CSF-deficient osteopetrotic (op/op) mice. Seven days after injection of P. acnes, granulomas as well as the numbers of Thy-1.2-, Mac-1-, and ERMP-20-positive cells and F4/80-positive areas in the liver were significantly reduced in the op/op mice compared to the normal littermates. After injection of LPS, serum levels of alanine aminotransferase as well as concentrations of IL-1beta and TNF-alpha in the serum and liver were significantly lower in the op/op mice than in the normal littermates, whereas the concentrations of IL-1beta and TNF-alpha in the spleen were similar in op/op mice and normal littermates. These results suggest that M-CSF plays a partial but highly significant role in the development of liver injury induced by P. acnes and LPS via an intrahepatic increase of primed macrophages including those in granulomas, in response to P. acnes, which produce proinflammatory cytokines such as IL-1beta and TNF-alpha.
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PMID:Experimental liver injury induced by Propionibacterium acnes and lipopolysaccharide in macrophage colony stimulating factor-deficient osteopetrotic (op/op) mice. 1054 45

Endothelins exert pathological effects in the eye and much interest centres on their role in causing retinal neuronal death in ischemic diseases like glaucoma. In the present study the influence of the non-selective endothelin antagonist, sulfisoxazole on raised intraocular pressure-induced ischemia to the rat retina was investigated. Moreover, in vitro studies on primary rat retinal cultures were undertaken to see whether sulfisoxazole is able to blunt the toxic effect of lipopolysaccharide (LPS) to retinal neurones. In order to determine whether sulfisoxazole provides protection to the retina the a- and b-wave amplitudes of the electroretinogram (ERG), the localisation of retinal choline acetyltransferase (ChAT), nitric oxide synthase (nNOS) and Thy-1 and the retinal mRNA levels of Thy-1 and FGF-2 were deduced in retinas subjected to ischemia in the absence or presence of sulfisoxazole. The results showed that the ischemia-induced changes to the a- and b-wave amplitudes of the ERG and changes associated with the localisation of ChAT, nNOS and Thy-1 to be significantly blunted by sulfisoxazole. However, while the ischemia-induced changes to Thy-1 and FGF-2 mRNAs were reduced by sulfisoxazole, the reduction was non-significant. The in vitro studies provided support for the protective effect of sulfisoxazole. Here, it was clearly shown that sulfisoxazole attenuated the elevation of nitric oxide (deduced by measuring nitrite) and the reduction in numbers of GABA-containing neurones caused by LPS. The present study provides evidence for the first time that endothelin antagonist can protect the retina from ischemic-like insults as occurs in glaucoma.
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PMID:Sulfisoxazole, an endothelin receptor antagonist, protects retinal neurones from insults of ischemia/reperfusion or lipopolysaccharide. 1646 16

Neuroinflammation is a critical component in the progression of several neurological and neurodegenerative diseases and cyclooxygenases (COX)-1 and -2 are key regulators of innate immune responses. We recently demonstrated that COX-1 deletion attenuates, whereas COX-2 deletion enhances, the neuroinflammatory response, blood-brain barrier permeability and leukocyte recruitment during lipopolysaccharide (LPS)-induced innate immune activation. Here, we used transgenic mice, which overexpressed human COX-2 via neuron-specific Thy-1 promoter (TgCOX-2), causing elevated prostaglandins (PGs) levels. We tested whether neuronal COX-2 overexpression affects the glial response to a single intracerebroventricular injection of LPS, which produces a robust neuroinflammatory reaction. Relative to non-transgenic controls (NTg), 7 month-old TgCOX-2 did not show any basal neuroinflammation, as assessed by gene expression of markers of inflammation and oxidative stress, neuronal damage, as assessed by Fluoro-JadeB staining, or systemic inflammation, as assessed by plasma levels of IL-1beta and corticosterone. Twenty-four hours after LPS injection, all mice showed increased microglial activation, as indicated by Iba1 immunostaining, neuronal damage, mRNA expression of cytokines (TNF-alpha, IL-6), reactive oxygen expressing enzymes (iNOS and NADPH oxidase subunits), endogenous COX-2, cPLA(2) and mPGES-1, and hippocampal and cortical IL-1beta levels. However, the increases were similar in TgCOX-2 and NTg. In NTg, LPS increased brain PGE(2) to the levels observed in TgCOX-2. These results suggest that PGs derived from neuronal COX-2 do not play a role in the neuroinflammatory response to acute activation of brain innate immunity. This is likely due to the direct effect of LPS on glial rather than neuronal cells.
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PMID:Neuronal overexpression of cyclooxygenase-2 does not alter the neuroinflammatory response during brain innate immune activation. 2045 80


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