Effect Of Bacterial Lipopolysaccharide Research Articles

Protection Against Experimental Allergic Encephalomyelitis in Guinea Pigs by Bacterial Lipopolysaccharide

Protection against experimental allergic encephalomyelitis (EAE) was studied in guinea pigs. Antibody titers to bovine myelin basic protein (BP), measured by means of passive hemagglutination on day 12 or 13 after sensitization with bovine spinal cord (BSC) in complete Freund’s adjuvant (CFA), were higher in animals which recovered later from mild EAE than in those which showed severe EAE. The effect of bacterial lipopolysaccharide (LPS), a B lymphocyte stimulator, on the suppression of EAE was examined. Pretreatment of guinea pigs with LPS 3 days prior to the sensitization with BSC-CFA at the same sites resulted in marked attenuation of both clinical and histologic EAE. The protective effect of LPS against EAE, however, depended upon the times and sites of its use; LPS suppressed EAE only when it was given 3 days prior to the sensitization with BSC-CFA at the same sites. Intraperitoneal injection of LPS, even if given 3 days prior to sensitization, failed to suppress EAE. In the group of guinea pigs protected against EAE by pretreatment with LPS, delayed hypersensitivity skin reactions to BP were depressed and humoral antibody titers to BP were increased several days earlier than in the control group although their peak titers were not significantly different. The ratio of T to B lymphocytes, as assessed by rosette formation, was diminished in the draining lymph nodes of guinea pigs protected against EAE, indicating an increased proliferation of B lymphocytes. These results suggested that the stimulation and proliferation of B lymphocytes themselves or their products, antibodies to BP, could inhibit T lymphocytes and suppress EAE.

Effects of Bacterial Lipopolysaccharide on the Induction and Expression of Cell-Mediated Immunity

Abstract The delayed-type hypersensitivity (DTH) produced by subcutaneous or intravenous immunization of mice with sheep red blood cells (SRBC) is mediated by T cells in cooperation with accessory cells (monocytes). Different effects of bacterial lipopolysaccharide (LPS) on this T cell activity were found at different stages of the immune response. a) T cell activity was enhanced by LPS given 1 to 3 days after sensitization. Enhancement, which was most marked when treatment was given on the 2nd day of the immune response, did not occur unless LPS was introduced into a site that drains to the responding lymph node. This stimulatory effect was dose dependent. b) A similar effect on the response to intravenous immunization caused DTH to appear transiently in mice given a T cell-blocking dose (109) of SRBC. c) DTH was suppressed by LPS given at the height of the T cell response (day 4). This effect, which was short lived and reversible, was due to the action of LPS on the accessor cells needed for the expression of DTH. Treatment of recipients with LPS completely blocked the adoptive transfer of DTH to both normal and spenectomized mice. The ability to react was regained slowly, but it returned promptly to splenectomized recipients. LPS has clearly more than one effect on the expression of cell-mediated immunity because it affects specific and non-specific mediator cells in different ways.

Effects of Bacterial Lipopolysaccharide on the Induction and Expression of Cell-Mediated Immunity

Abstract Bacterial lipopolysaccharide (LPS), being a B cell mitogen, enhances antibody production. When given prior to an injection of sheep red blood cells (SRBC) it caused a premature but not significantly increased production of antibody forming cells in regionally stimulated lymph nodes. There was a corresponding depression of T cell activity, as measured by the relative levels of delayed-type hypersensitivity (DTH) in normal and LPS-treated mice. Although LPS also induced hyperplasia of the reticuloendothelial system, and a consequent reduction in the effective antigenic dose of SRBC, this was not the reason for the reduced level of T cell activity. The opposing effects of LPS on T and B cell responses was due to premature inhibition of the T cell response by an accelerated production of antibody. This caused an earlier onset of the inhibitory mechanism which regulates the T cell response and is specific for the inducing antigen.

Effect of bacterial lipopolysaccharide, lipid A, and concanavalin a on lethality of 5-fluorouracil for mice

The administration of a nonlethal dose (100 mg/kg) of the antimetabolite 5-fluorouracil (5-FU) to male BALB c mice 3–24 hr after 2 mg of Escherichia coli 026:B6 B lipopolysaccharide/kg resulted in a significant potentiation of lethality. The time course of potentiated lethality closely resembled that due to high doses of 5-FU alone. When 5-FU was administered prior to or simultaneously with bacterial lipopolysaccharide (LPS), there was no potentiation of lethality. The jack bean mitogen concanavalin A was able to substitute for bacterial LPS in the synergy. Likewise, a complex of bovine serum albumin and lipid A from Salmonella minnesota R595 was able to substitute for the entire LPS molecule. Mice treated with bacterial LPS and 5-FU exhibited a severe leukopenia 7 days after administration of 5-FU, and granulocytes were nearly absent in the circulation and marrow. Oral administration of tetracycline 72 hr prior to and continuing for 14 days after challenge provided significant ( p < 0.05) protection for mice against 200 mg of 5-FU/kg, and against synergistic combinations of LPS and 5-FU. Mice given 1 spleen equiv/recipient from donors previously treated with LPS were protected against the synergistic lethality of LPS and 5-FU. However, spleen cells did not provide protection against high doses of 5-FU alone.

Macrophage Cytophilic Antibody in Mice: Effect of Bacterial Lipopolysaccharide on the Uptake of Immunoglobulins by Mouse Peritoneal Cells

Injection of lipopolysaccharide from Escherichia coli intravenously into mice affected the ability of their peritoneal macrophages to adsorb antisheep erythrocyte cytophilic antibodies in vitro. After a single intravenous injection of lipopolysaccharide, the alteration in antibody uptake took the form of a triphasic response. An early evanescent increase in adsorptive capacity took place, which reached a maximum 5 min after injection and was followed immediately by a phase of depressed uptake of antibody. Enhancement of antibody uptake then increased to reach a maximum about 24 hr after injection, before declining slowly. The second enhancement phase was inhibited by prior immunization with E. coli or after multiple injections of lipopolysaccharide. Exposure of macrophages to lipopolysaccharide in vitro did not alter their capacity to take up cytophilic antibody. Changes in the capacity of macrophages and polymorphonuclear neutrophil leukocytes to adsorb opsonized erythrocytes were induced by injection of lipopolysaccharide and were similar to those induced with respect to the uptake of cytophilic antibodies by macrophages.

Platelet volume: effect of temperature and agents affecting platelet aggregation.

ARTICLESPlatelet volume: effect of temperature and agents affecting platelet aggregationEW Salzman, TP Ashford, DA Chambers, LL Neri, and AP DempsterEW Salzman, TP Ashford, DA Chambers, LL Neri, and AP DempsterPublished Online:01 Nov 1969https://doi.org/10.1152/ajplegacy.1969.217.5.1330MoreSectionsPDF (3 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited BySpecific Combination of Salvianolic Acids As Core Active Ingredients of Danhong Injection for Treatment of Arterial Thrombosis and Its Derived Dry Gangrene13 June 2017 | Frontiers in Pharmacology, Vol. 8Hypothermia-induced Haemostatic and Biochemical Phenomena. An Experimental Model7 July 2009 | Platelets, Vol. 4, No. 1Adenosine and ATP: mutually exclusive modifiers of the kinetics of ADP-induced aggregation of calf-plateletsJournal of Biosciences, Vol. 15, No. 4Differences between the effects of EDTA and citrate anticoagulants on platelet count and mean platelet volume28 June 2008 | Clinical & Laboratory Haematology, Vol. 12, No. 3Evidence for in vivo Platelet Activation Following the Injection of Conventional Unfractionated Heparin7 July 2009 | Platelets, Vol. 1, No. 4An investigation into the effects of bacterial lipopolysaccharide on human platelets24 April 2009 | European Journal of Haematology, Vol. 43, No. 2Volume-regulating behavior of human plateletsJournal of Cellular Physiology, Vol. 131, No. 3Current aspects on human platelet activation and responses24 April 2009 | European Journal of Haematology, Vol. 38, No. 5Particle volume changes associated with light transmittance changes in the platelet aggregometer: Dependence upon aggregating agent and effectiveness of stimulusThrombosis Research, Vol. 41, No. 5Measurement of ionized calcium in blood platelets with the photoprotein aequorin. Comparison with Quin 2.Journal of Biological Chemistry, Vol. 260, No. 4Estimation of platelet size by measurement of intracellular water space using an oil techniqueThrombosis Research, Vol. 31, No. 2Effects of prolonged cold injury on the subcutaneous microcirculation of the hamsterResearch in Experimental Medicine, Vol. 181, No. 1Platelet kinetics during deep hypothermiaJournal of Surgical Research, Vol. 28, No. 1Adenosine analogs and human platelets—IIBiochemical Pharmacology, Vol. 28, No. 4Application of a new surface labeling reagent, EDTA derivative, on erythrocytes and plateletsBiochimica et Biophysica Acta (BBA) - Biomembranes, Vol. 512, No. 1Regulation of Polymorphonuclear Leukocyte, Macrophage, and Platelet FunctionEnergy Metabolism in Washed Human Platelets Responsive to ADP: Comparison with Platelets in PlasmaBritish Journal of Haematology, Vol. 25, No. 5In Vitro Studies of Immunologically Induced Secretion of Mediators from Cells and Related PhenomenaAn apparatus for producing and monitoring platelet aggregation in whole bloodIrish Journal of Medical Science, Vol. 141, No. 1PLATELET-FUNCTION STUDIES IN THE BERNARD-SOULIER SYNDROME*16 December 2006 | Annals of the New York Academy of Sciences, Vol. 201, No. 1Platelets and thrombogenesis—Current conceptsAmerican Heart Journal, Vol. 83, No. 4Methods for the Preparation of Washed Platelet Suspensions28 February 2012ORIGIN, PRODUCTION, AND LIFE-SPAN OF BLOOD PLATELETS**Supported in part by grant AM-08263 and Research Career Development Award 1-K3 AM-8634 from the National Institute of Arthritis and Metabolic Diseases, by a Research Grant from the American Cancer Society (Massachusetts Division), Inc., and Grant No. T-505 from the American Cancer Society, Inc.Platelet Response to Hypotonic Stress after Storage at 4 C or 22 CTransfusion, Vol. 10, No. 6Platelet swelling and prostaglandinsMicrovascular Research, Vol. 2, No. 3 More from this issue > Volume 217Issue 5November 1969Pages 1330-1338 Copyright & PermissionsCopyright © 1969 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1969.217.5.1330PubMed5346297History Published online 1 November 1969 Published in print 1 November 1969 Metrics