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)

Intraperitoneal treatment of mice with adjuvants affects the in vitro response of their lymphocytes toward class-specific mitogen. Spleen cells from animals injected with Corynebacterium parvum organisms showed in some cases an increase in their response to all mitogens, while in other experiments, a moderate decrease in the reaction to T-specific mitogens (concanavalin A and phytohemagglutinin) was found. Injection of lipopolysaccharide (LPS) and in particular Bordetella pertussis bacteria, brought about a marked reduction in the response of spleen cells to B mitogens (LPS and PPD) but had little or no effect on the reaction to the T mitogens. Intraperitoneal administration of B. pertussis caused a marked depletion of lymph nodes and a high level of lymphocytosis. Blood cells of the treated mice showed an increased response to T mitogens, whereas mesenterial lymph node cultures reacted higher than the controls to LPS and without stimulation. No change was noted in the responses of cells from the axillary lymph nodes of these pertussis-treated mice.
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PMID:Effects of in vivo administered B. pertussis and other adjuvants on the mitotic responses of lymphocytes in vitro. 19 Jan 70

The nature of infected stimulator cells in the in vitro secondary cytotoxic T cell response to ectromelia infection was investigated. It was found that macrophages were better stimulator cells than spleen cells. B cells (Ig-positive cells) were superior to T cells (Ig-negative cells) both on a relative proportion and on a cell-to-cell basis. Concanavalin A and lipopolysaccharide-stimulated lymphocytes were also effective stimulator cells but appeared to be slightly inferior to spleen cells. Spleen cells depleted of Ia-positive cells were markedly inferior to normal spleen cells as stimulators. It was also found that primary and secondary cytotoxic T cells were largely Ia-negative. These findings are discussed in relation to the likely events during T cell responses to infection in vivo.
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PMID:Requirements for stimulation of T cell responses against virus-infected cells: nature of ectromelia virus-infected cells capable of stimulating cytotoxic T cells in a secondary response in vitro. 20 60

Spleen cells from F1 mice undergoing chronic graft-vs-host (GVH) reaction, induced by injection of parental cells, were shown to be immunosuppressed since their in vitro responses to the mitogens concanavalin A (Con A) and bacterial lipopolysaccharide (LPS) were substantially lower than control animals. Serum, from mice undergoing GVH, when cultured in vitro with normal spleen cells was immunosuppressive. The proliferation response to Con A and allogeneic cells of normal syngeneic, allogeneic, and parental spleen cells was 90% suppressed when serum from mice undergoing chronic GVH was added in comparison to the addition of serum from untreated F1 mice. Similarly, the in vitro antibody response to a T-dependent antigen was impaired; however, the antibody response to a T-independent antigen was not impaired. These results indicate that T cell functions are more sensitive than are B cell functions to immunosuppressive factors in the serum of mice undergoing GVH.
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PMID:Immunosuppression of normal lymphoid cells by serum from mice undergoing chronic graft-vs-host disease. 24 Aug 91

The early events in lipopolysaccharide (LPS)-induced B-cell activation were investigated by studying the binding of 14C-labeled LPS to murine lymphocytes in vitro. In these studies we utilized intrinsically labeled 14C-labeled LPS from Salmonella minnesota or the 14C-labeled glycolipid derived from the Re mutant of S. minnesota (R595). Bone marrow-derived (B) lymphocytes bound more LPS than did thymus-derived (T) lymphocytes. Binding of LPS to murine spleen lymphocytes from strain C3H/HeN was compared with the binding to spleen lymphocytes from strain C3H/HeJ, a strain resistant to certain biological activities of LPS including mitogenesis. Spleen cells from both strains bound LPS equally well, suggesting that unresponsiveness of C3H/HeJ mice to LPS is due to factors other than a defect in binding of LPS. LPS binding to cells appeared to be due to a nonspecific interaction between the lipid moiety of LPS and the lipid components of the cell membrane. Thus, the highly lipophilic, polysaccharide-deficient glycolipid from R595 bound at least 20 times better than did LPS. Furthermore, partial removal of cell surface proteins with trypsin or sialic acids with neuraminidase enhanced glycolipid binding, suggesting that binding is not through a protein- or sialic acid-containing receptor. The binding of glycolipid to lymphocytes was only partially specific since unlabeled glycolipid R595, lipid A, and LPS did not completely inhibit the uptake of 14C-labeled glycolipid R595. In addition, binding could be inhibited by a nonmitogenic phospholipid (phosphatidyl ethanolamine), which also is consistent with a nonspecific lipid-lipid interaction. Experiments were performed to determine the relationship of LPS binding to lymphocyte activation in the lymphocytes. The process of activation of lymphocytes by LPS was a slow one, since LPS was required to be present in culture for at least 24 h in order to obtain significant lymphocyte activation, suggesting that the amounts of LPS bound earlier are either quantitatively or qualitatively insufficient to irreversibly activate the cell.
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PMID:Binding of bacterial endotoxin to murine spleen lymphocytes. 29 51

Lipid A, prepared from lipopolysaccharide, was labeled with 125 I. Such iodinated lipid A possesses the full mitogenic activity of untreated lipid A. Comparison of the 125 I-lipid A-binding activity of splenocytes and thymocytes from the same rabbit revealed that the extent of labeling of splenocytes was 10 to 20 times greater than that observed with an equivalent number of thymocytes. A similar preferential binding was detected in comparing cells in mouse and rat. Spleen populations depleted of adherent cells were essentially unaltered with regard to binding when compared to the original population. In addition, spleen cell populations enriched for thymus-derived cells (T cells) exhibited a marked loss of specific binding activity. On the other hand, spleen cell populations enriched for bone marrow-derived cells (B cells) exhibited the expected binding. The difference in binding behavior of B and T cell-enriched populations was confirmed by using three independent techniques to separate B and T cells. These findings are consistent with the mitogenic specificity of lipid A toward B cells rather than T cells and suggest that the observed cellular specificity resides in an early event in mitogenesis, i.e., binding of the mitogen.
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PMID:Differentiation of lymphoid cells: the preferential binding of the lipid A moiety of lipopolysaccharide to B lymphocyte populations. 30 67

The effect of age on the mitogenic and antigenic responsiveness of B cells is examined in spleen cell cultures of CBA/N and (CBA/N X DBA/2) F1 mice. Spleen cells from young male F1 mice (4- to 6-wk old) show lower mitogenic responses to lipopolysaccharide, a lower frequency of sheep erythrocytes (SRBC)-reactive B-cell precursors, and a lower percentage of Ig-bearing cells than age-matched female F1 mice. The expression of all three functions were found to increase with the age of the F1 male mice. Whereas male F1 mice at 60 wk of age showed an equivalent percentage of Ig-bearing spleen cells and a similar mitogenic responsiveness to LPS when compared to adult female F1 mice, the frequency of SRBC-reactive B-cell precursors remained threefold lower. These findings reveal that there is a slower maturation of B cells in mice expressing the X-linked defect and suggests that the defect has differential effects on the mechanisms of antigen and mitogen activation of B cells.
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PMID:B-cell differentiation in the CBA/N mouse. I. Slower maturation of mitogen and antigen-responsive B cells in mice expressing an X-linked defect. 31 94

The generation of humoral immunity in vitro by normal and antigen-primed mouse spleen cells was suppressed by in vitro treatment with hydrocortisone. Functions of normal and antigen-activated helper T lymphocytes and of accessory cells were inhibited by the corticosteroids. Spleen cells cultured overnight in medium containing fetal bovine serum became highly resistant to the effects of hydrocortisone. Similar resistance was found to occur when spleen cells were cultured with accessory cells that previously had been activated with bacterial lipopolysaccharide. These studies show that immunologically nonspecific processes significantly alter the effects of the steroids on specific immune responses and suggest that accessory cell products modulate T cells in ways which differ from antigen induction.
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PMID:The role of activated accessory cells in preventing immunosuppression by hydrocortisone. 32 53

Spleen cells from mice injected with 2 to 50 microgram bacterial lipopolysaccharide (LPS) have a reduced capacity to make an antibody response in vitro to trinitrophenylated sheep erythrocytes (TNP-SRBC) when tested 1 to 7 days later. Recovery is gradual, and these cells are full functional 2 weeks after in vivo LPS treatment. Unresponsiveness resides in the nonadherent splenic cell populations, and can be shown to have a suppressive cell component, which is irradiation sensitive and has somme characteristics of a thymus-derived lymphocyte (T cell). In addition, neither bone marrow-derived lymphocytes (B cells) nor T cells in the spleens of LPS-treated mice are functionally normal in their abilities to cooperate during an antibody response in vitro. LPS-B cells cooperated poorly with nylon wool-enriched T cells from normal mice but cooperated well with irradiated carrier-primed T cells or nylon wool-purified splenic T cells from carrier-primed mice. LPS-T cells have a reduced capacity to interact with normal B cells and appear to contain a suppressor cell component. These results indicate that the effects of exposure of immunocompetent cells to LPS are multifocal and can include suppression as well as stimulation of antibody formation.
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PMID:Modulation of immune response by bacterial lipopolysaccharide (LPS): multifocal effects of LPS-induced suppression of the primary antibody response to a T-dependent antigen. 36 44

Spleen cells of C57B1/6J mice immunized with complete Freund's adjuvant produced macrophage migration inhibitory factor (MIF) when incubated in vitro with tuberculin purified protein derivative (PPD). For optimal MIF production spleen cells were cultured for 48 h in a serum-free medium, at a concentration of 2 x 10(7) cells/ml. MIF was assayed in a xenogenic system, using oil-induced guinea pig peritoneal exudate cells as targets. MIF synthesis could also be induced by pulsing spleen cells for 2 h with concanavalin A, phytohemagglutinin, pokeweed mitogen or lipopolysaccharide, followed by culture in plain medium. No MIF secretion was induced by incubation of spleen cells with anti-theta or rabbit anti-mouse IgG sera. Cells producing MIF in response to PPD were characterized as B cells by virtue of being insensitive to anti-theta serum and complement, by being retained on nylon wool, glass bead and anti-Ig colums and by the presence of Fc receptors. PPD-stimulated T cells did not produce MIF. PPD-induced mouse spleen cell MIF demonstrated a moderate loss of activity by heating at 56 and 80 degrees C and was completely inactivated after digestion with chymotrypsin. By fractionation on Sephadex G-200, migration inhibitory activity was recovered in a molecular range of 100,000-12,400 daltons.
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PMID:Antigen and mitogen induced production of macrophage migration inhibitory factor in the mouse. 37 63

A spontaneous BALB/c B lymphocyte leukemia could be stimulated in vitro by the polyclonal B cell activator lipopolysaccharide (LPS) and the conditions for activation were studied. Spleen cells or peripheral blood lymphocytes from tumor-bearing animals responded by increased DNA synthesis and the peak of activation occurred earlier than with normal mouse spleen cells. Tumor cells harvested from the spleen, but not from the peripheral blood, could be induced by LPS to secrete IgM. Direct demonstration that the response was due to tumor cell activation and not that of contaminating normal B lymphocytes was provided by karyotype analysis and by immunoprecipitation, which showed the restriction of light chains on secreted IgM molecules to the lambda isotype.
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PMID:Characterization of a spontaneous murine B cell leukemia (BCL1). II. Tumor cell proliferation and IgM secretion after stimulation by LPS. 38 13


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