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

Using lymph node T cells from poly-L(Tyr,Glu)-poly-D,L-Ala--poly-L-Lys[(TG)-A--L]-primed animals and B cells from animals primed with trinitrophenylated (TNP) protein or lipopolysaccharide, we have obtained anti-TNP-(TG)-A--L direct plaque-forming responses in vitro. Response to this antigen was shown to be controlled by the H-2 haplotype of the animal studied. The strain distribution of in vitro response was very similar to that previously reported by others for in vivo secondary IgG responses to (TG)-A--L. We investigated the cell types expressing the Ir gene(s) for (TG)-A--L in our cultures. F1, high responder x low responder mice were primed with (TG)-A--L. Their T cells were active in stimulating anti-TNP-(TG)-A--L responses of high responder but not low responder B cells and macrophages (MPHI), even though both preparations of B cells and Mphi were obtained from mice congenic at H-2 with one of the parents of the F1. For three low responder strains tested, of the H-2h2, H-2k, and H-2f haplotypes, the anti-TNP-(TG)-A--L response of low responder B cells and Mphis in the presence of high responder, F1 T cells could not be improved by the addition of high responder, antigen-bearing Mphis to the cultures. In one strain of the H-2a haplotype, it was shown that neither the B cells nor Mphis could be functional in anti-TNP-(TG)-A--L responses. Our results therefore suggested the Ir genes for anti-TNP-(TG)-A--L responses were expressed at least in B cells in all the low responder strains we studied, and, in mice of the H-2a haplotype, in Mphis too.
 ...
PMID:The role of H-2-linked genes in helper T-cell function. III. Expression of immune response genes for trinitrophenyl conjugates of poly-L(Tyr, Glu)-poly-D,L-Ala--poly-L-Lys in B cells and macrophages. 9 10

1. Protein extracts obtained from Salmonella minnesota Re mutant cells by treatment with EDTA/NaC1 solution contain a protein which exhibits high affinity to bacterial lipopolysaccharides. The isolation and partial characterization of this lipopolysaccharide-binding protein is described. 2. The protein was purified from EDTA extracts by a two-step procedure consisting of ion-exchange chromatography on CM-Sephadex and preparative polyacrylamide gel electrophoresis at pH 9.5. The yield of the total purification procedure was around 16%. 3. The resulting protein preparation was homogeneous on the basis of disc gel electrophoresis, dodecylsulfate gel electrophoresis, isoelectric focusing in polyacrylamide gel and immunoelectrophoresis. 4. The isoelectric point of the protein was found to be 10.3 at 4 degrees C. Its molecular weight determined by dodecylsulfate gel electrophoresis is 15000. Its amino acid composition is characterized by the absence of histidine and proline, a low content in tyrosine and high amounts of alanine, lysine, aspartic and glutamic acid residues, or their respective amides. 5. The lipopolysaccharide-protein association was shown to be mainly due to ionic interactions of the basic protein with negatively charged groups (probably phosphate and pyrophosphate groups) of the lipid A moiety. 6. Purified lipopolysaccharide-binding protein is immunogenic in rabbits, thus enabling the preparation of specific antiserum. 7. The protein is located at the surface of Salmonella minnesota Re mutant cells as revealed by antiserum absorption with total bacteria. Ferritin-labelling studies further demonstrated that it is evenly spread over the entire cell surface. 8. Comparative antiserum absorption studies using smooth and rough strains of Salmonella minnesota, Salmonella typhimurium, Escherichia coli, Klebsiella and Shigella revealed the presence of lipopolysaccharide-binding protein (or a serologically cross-reacting antigen) in most of the strains tested. From these results the protein can be considered as a common antigen of Enterobacteriaceae.
 ...
PMID:A lipopolysaccharide-binding cell-surface protein from Salmonella minnesota. Isolation, partial characterization and occurrence in different Enterobacteriaceae. 11 33

The experiments presented in this paper demonstrate that the induction of tolerance on the one hand and the induction of delayed sensitivity on the other hand can be accomplished by administration of similar doses of azobenzene-arsonate conjugated to N-chloracetyl tyrosine (ABA-T) to guinea pigs with the determining factor being the absence or presence, respectively, of activating bacterial products in the adjuvant mixture used. Thus, complete, persistent ABA-T-specific T-cell tolerance can be induced in adult guinea pigs with 20 mug of ABA-T given intradermally in incomplete Freund's adjuvant (IFA) whereas this same dose of ABA-T induces ABA-specific immunity when administered in complete Freund's adjuvant. This tolerance was not reversible by administration of ABA-T and IFA in the presence of bacterial lipopolysaccharide, was generated before the formation of primed T cells, and persisted for at least 3 mo after initiation. Moreover, cell transfer studies performed herein demonstrate that the unresponsiveness resulting from administration of ABA-T in IFA reflects the activity of suppressor cells to induce and maintain a state of unresponsiveness could only be demonstrated in unprimed animals may indicate a severe limitation on the potential clinical usefulness of such an approach to regulation of the immune system.
 ...
PMID:Induction of T-lymphocyte responses to a small molecular weight antigen. II. specific tolerance induced in azebenzenearsonate (ABA)-specific T cells in Guniea pigs by administration of low doses of an ABA conjugate of chloroacetyl tyrosine in incomplete Freund's adjuvant. 80 48

We have investigated the relationship between tyrosine phosphorylation and respiratory-burst activity in mouse bone-marrow-derived macrophages (BMM). We demonstrate that zymosan, an agent known to trigger the macrophage respiratory burst, also triggers the activation of tyrosine kinase activity, resulting in rapid tyrosine phosphorylation on numerous proteins, and provide evidence for the role of tyrosine phosphorylation in the triggering of the BMM respiratory burst. Agents, such as tumour necrosis factor alpha (TNF alpha), interferon-gamma (IFN-gamma) or lipopolysaccharide (LPS), which prime the macrophage for an enhanced zymosan-triggered respiratory burst, increase tyrosine phosphorylation triggered by zymosan. The zymosan-triggered tyrosine phosphorylation and respiratory-burst activity were partially suppressed by the tyrosine kinase inhibitors alpha-cyano-3-ethoxy-4-hydroxy-5-phenylmethylcinnamide (ST638) and herbimycin A. In addition, pre-exposure of BMM to vanadate, a phosphotyrosine phosphatase inhibitor, greatly enhanced the ability of zymosan to induce tyrosine phosphorylation and trigger the respiratory burst. These data highlight the importance of the balance between tyrosine kinase and phosphotyrosine phosphatase activity in determining the ultimate level of tyrosine phosphorylation in BMM and suggest that zymosan-triggered tyrosine phosphorylation is an important biochemical signal for triggering of the respiratory burst.
 ...
PMID:Zymosan-triggered tyrosine phosphorylation in mouse bone-marrow-derived macrophages is enhanced by respiratory-burst priming agents. 128 5

Bacterial lipopolysaccharide (LPS) is a potent activator of antibacterial responses by macrophages. Following LPS stimulation, the tyrosine phosphorylation of several proteins is rapidly increased in macrophages, and this event appears to mediate some responses to LPS. We now report that two of these tyrosine phosphoproteins of 41 and 44 kDa are isoforms of mitogen-activated protein (MAP) kinase. Each of these proteins was reactive with anti-MAP kinase antibodies and comigrated with MAP kinase activity in fractions eluted from a MonoQ anion-exchange column. Following LPS stimulation, column fractions containing the tyrosine phosphorylated forms of p41 and p44 exhibited increased MAP kinase activity. Inhibition of LPS-induced tyrosine phosphorylation of these proteins was accompanied by inhibition of MAP kinase activity. Additionally, induction of p41/p44 tyrosine phosphorylation and MAP kinase activity by LPS appeared to be independent of activation of protein kinase C, even though phorbol esters also induced these responses. These results demonstrate that LPS induces the tyrosine phosphorylation and activation of at least two MAP kinase isozymes. Since MAP kinases appear to modulate cellular processes in response to extracellular signals, these kinases may be important targets for LPS action in macrophages.
 ...
PMID:Bacterial lipopolysaccharide induces tyrosine phosphorylation and activation of mitogen-activated protein kinases in macrophages. 132 21

The role of endogenous catecholamines in the regulation of brain prostaglandin (PG) synthesis was studied in the rat. Male rats were injected in the brain lateral ventricle or in the ventral noradrenergic bundle with either the catecholaminergic neurotoxin 6-hydroxydopamine or vehicle. Other groups of rats were injected intraperitoneally with the tyrosine hydroxylase inhibitor, alpha-methyl-p-tyrosine, or with the inhibitor of dopamine-beta-hydroxylase, FLA-63. All these drugs produced a significant depletion of norepinephrine (NE) content in the cortex and hypothalamus. The rats that had lower levels of NE exhibited reduced capacity to synthesize PGE2 but not thromboxane B2 and 6-keto-PGE1 alpha in the cortex and hypothalamus. However, induced production of PG, stimulated by the bacterial endotoxin lipopolysaccharide (LPS), remained unchanged, namely, a similar (2- to 2.5-fold) increase of PG synthesis was noted in control and in NE-depleted rats. We suggest that the regulation of PG synthesis under basal condition requires intact adrenergic input, whereas LPS-induced production of PG is independent of the adrenergic innervation.
 ...
PMID:Role of the central adrenergic system in the regulation of prostaglandin biosynthesis in rat brain. 134 41

We have examined the role of tyrosine phosphorylation during the course of macrophage activation. Initial experiments indicated that vanadate, a known phosphotyrosine phosphatase inhibitor, enhanced the phorbol 12-myristate 13-acetate (PMA)-triggered respiratory burst and potentiated the priming effects of bacterial lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma), suggesting that tyrosine phosphorylation may be important in these end cell functions. As src-related kinases have been implicated in the activation of cells of other haemopoietic lineages, we examined the relationship between the activity of two such kinases, hck and lyn, and priming of the respiratory burst. We found that the level of hck and lyn is increased following exposure of bone marrow-derived macrophages (BMM) to LPS or IFN-gamma. The induction of both of these kinases follows similar kinetics with maximal activity occurring at 24-48 h. Interestingly, the kinetics of induction of hck and lyn kinase activity in BMM demonstrated a close temporal relationship with the priming effects of LPS and IFN-gamma on the macrophage respiratory burst. Collectively, these observations raise the possibility that modulation of expression of hck and lyn is involved in the regulation of the respiratory burst.
 ...
PMID:Lipopolysaccharide- and interferon-gamma-induced expression of hck and lyn tyrosine kinases in murine bone marrow-derived macrophages. 137 83

Because subunit vaccines may create artificial epitopes, the goal of this study was to concentrate the immune response toward protective epitopes contained in a peptide, [(NAGG)5]Y. This peptide consisted of five repeat sequences of the immunodominant epitope of the circumsporozoite protein of the simian malaria parasite Plasmodium cynomolgi and a terminal tyrosine. It was conjugated to bovine serum albumin and mixed with various adjuvant formulations, including block copolymers L121, L141, L180.5 and a lipopolysaccharide (LPS). Outbred mice were vaccinated with seven vaccine formulations. Postvaccination sera from each group of mice were then pooled, and antibody responses against peptide [(NAGG)5]Y or (NAGG)5 were tested in an enzyme-linked immunosorbent assay and against sporozoites of P. cynomolgi in an indirect fluorescent antibody assay. Although all groups elicited a high antibody response to the peptide [(NAGG)5Y], the presence of the tyrosine induced a different antibody response to the peptide (NAGG)5, and formulations containing LPS alone did not induce an antibody response to either (NAGG)5 or P. cynomolgi sporozoites. The formulation including both LPS and the copolymer L121 was the only one to inhibit the development of P. cynomolgi sporozoites in rhesus monkey hepatocytes by 50%. These results suggest that vaccine formulations influence B-cell epitope selection.
 ...
PMID:Effect of adjuvant formulations on the selection of B-cell epitopes expressed by a malaria peptide vaccine. 137 51

The mode of action of tachyplesin I, an antimicrobial cationic heptadecapeptide amide isolated from the hemocyte debris of a horseshoe crab, Tachypleus tridentatus, toward lipid matrices was studied with synthetic tachyplesin I, its analogs with Phe in place of Trp or Tyr, a linear analog with no disulfide bonds, and two linear short fragments. Circular dichroism spectra showed that tachyplesin I took an antiparallel beta-structure in buffer solution and a certain less ordered structure in acidic liposomes composed of egg phosphatidylcholine and egg phosphatidylglycerol (3:1). Spectrophotometric titration of the peptides with laurylphosphorylcholine revealed that both Trp and Tyr residues orient toward the inside of lipid matrices, suggesting that they are on the same side of the peptide backbone. The carboxyfluorescein leakage experiment and fluorescence data indicated that tachyplesin I interacted strongly with neutral and acidic lipid bilayers and an aromaticity-rich hydrophobic part of the peptide was embedded in lipid membranes. All the peptides except for the short fragments were almost equally active in lipopolysaccharide binding. The energy-transfer experiment showed that a conformational change occurred such that the Tyr and Trp residues are positioned more closely to each other in acidic liposomes than in buffer solution. The present study strongly suggested that amphipathic lipid bilayers induced a conformational change of tachyplesin I from an energetically stable beta-structure to a less ordered, probably more amphipathic structure.
 ...
PMID:Conformation of tachyplesin I from Tachypleus tridentatus when interacting with lipid matrices. 145 21

Tyrosine phosphorylation and dephosphorylating events have been shown to be central to the process of growth regulation and signal transduction. We report here, the identification of a new gene with a tyrosine phosphatase domain (EC 3.1.3.48) which is expressed exclusively in thymus and spleen. A cDNA of 2760 bp encodes a 339-amino acid, intracellular, single-domain tyrosine phosphatase. When expressed as a glutathionine-S-transferase fusion protein, efficient lysis of p-nitrophenyl phosphate is noted, indicating in vitro enzymatic activity of the cloned gene product. Normal mouse lymphocytes increase mRNA expression 10-15-fold upon stimulation with phytohemagglutinin, concanavalin A, lipopolysaccharide or anti-CD3 monoclonal antibody. This new hematopoietic tyrosine phosphatase, (HePTP), may play a role in the regulation of T and B lymphocyte development and signal transduction.
 ...
PMID:Cloning and expression of an inducible lymphoid-specific, protein tyrosine phosphatase (HePTPase). 153 Sep 18


1 2 3 4 5 6 7 8 9 10 Next >>