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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Spleen lymphocytes from C4-deficient (C4D) and Albany strains of guinea-pigs, 1-7 days, 3-6 and 12-16 months old, genetically related to inbred strains 13 and 2 respectively, were analysed in terms of their expression of cell surface markers, allogenic and T- and B-cell mitogenic responses, and interleukin-1 (IL-1) and IL-2 production. There were strain- and age-associated differences in phenotypic expression and immune responsiveness levels. In both strains a significant shift in immunocompetence apparently occurs postnatally before 3-6 months of age, with no further significant changes noticed in animals 12-16 months old. Phenotypic changes in cell surface markers did not always correlate with functional capability of lymphoid cells. H159+ (pan T) and H155+ (CD4) lymphocyte number and levels of T-cell responsiveness (mitogenic and allogenic responses, and IL-2 production) were higher in C4D neonates compared with age-matched Albany guinea-pigs or with young animals of the same strain. On the other hand, 31D2+ (B) lymphocytes in a significantly higher proportion in Albany neonates compared with similarly aged C4D, did not correlate at this age or at any other time with their proliferative response to lipopolysaccharide (LPS) or dextran sulphate (DS), two B-cell-specific mitogens.
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PMID:Strain- and age-associated differences in lymphocyte phenotypes and immune responsiveness in C4-deficient and Albany strains of guinea-pigs. 142 70

Germ-free (GF) animals exhibit an abnormally diminished, cell-mediated immune response which can be rapidly normalized by bacterial colonization of the intestine. This conventionalization suggests that the development and/or regulation of the immune system is dependent upon intestinal bacteria or their products. Here we consider the ontogeny of gut-associated lymphoid tissue (GALT) immunocytes by isolating and characterizing the intestinal lamina propria cells (LPC) of GF rats responding to bacterial colonization or an irrelevant protein antigen, and compared to LPC of specific pathogen-free (SPF) rats which were conventionalized (CV) from birth. Isolation of cells was accomplished by successive EDTA washings of small intestine to remove the epithelium, and enzymatic digestion of the tissue generating single-cell suspensions. Resulting cell suspensions were characterized by monoclonal antibodies directed against leukocyte epitopes using flow cytometry. Functional characterization was measured by the tritiated thymidine proliferation assay with concanavalin A (Con A) and lipopolysaccharide (LPS) as co-stimulators. Germ-free and SPF rats had fewer total LPC than CV rats. Antibody staining revealed that GF rats had fewer total leukocytes than CV and SPF rats, and that CV rats had a greater percentage of T-cells and cells positive for the C3 receptor than GF rats. Co-stimulation of LPC with mitogens only increased proliferation of cells from CV rats compared to GF and SPF rats. In addition, spleen cells from CV rats demonstrated significantly enhanced proliferative responses compared to spleen cells from GF rat and were more analogous to spleen cells from SPF rats in their ability to proliferate in vitro, with and without mitogens. We conclude that T-cells and CD35-positive (C3BR+) cells are recruited and/or proliferate in response to intestinal bacteria and/or their products, and that this results in the induction of immune competency.
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PMID:Identification and characterization of rat intestinal lamina propria cells: consequences of microbial colonization. 144 Dec 22

We used lipopolysaccharide (LPS) to provoke immune responses and observed the changes in the localization of iron and iron-related proteins, such as transferrin receptor, ferritin and hemosiderin in the rat spleen. After intravenous injection of 250 micrograms LPS (salmonella minnesota R595), spleen weight and serum IgM levels increased, cells incorporating 5-bromo-2'-deoxyuridine (BrdU), and transferrin receptor positive cells increased in the peripheral portion of the periarterial lymphoid sheath (PALS), the marginal zone (MZ) and the follicles. Ferritin positive cells increased markedly in the white pulp and stainable iron increased in the marginal metallophils (MM) and in the macrophages in the MZ and the outer PALS. Even in iron deficient rats, a similar change was observed for the localization of iron and iron-related proteins after injection of LPS. After injection of 0.4 mg keyhole limpet hemocyanin (KLH), changes similar to but less pronounced than that in the LPS injected rats were observed for serum IgM levels and for the localization of iron and iron-related proteins. These results showed that the iron in the MM and the macrophages in the white pulp have a dynamic response to immunological challenges and suggested that they play some role in immune responses.
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PMID:Mobilization of iron and iron-related proteins in rat spleen after intravenous injection of lipopolysaccharides (LPS). 144 84

Forty-eight cattle were used in 4 experiments; 6-week-old calves in experiments 1-3 (n = 24) and 10-month-old heifers in experiment 4 (n = 24). In experiments 1-3, 7 groups of 3 calves each were inoculated SC with 5 strains of Brucella abortus: virulent strain 2308 (2 groups), vaccine strain 19 (2 groups), and mutant strains RB51. 19 delta 31K, and 19 delta SOD. Sera and lymph node tissues were examined at 2-week intervals for evidence of infection. At postinoculation (PI) week 12, 2 calves in each group were given dexamethasone for 5 days. Calves were then euthanatized and lymphoid tissue, spleen, liver, and bone marrow were examined for evidence of B abortus. Calves given strain 2308 had large numbers of bacteria in their lymph nodes, marked granulomatous lymphadenitis in the deep cortex, and loss of lymphoid cells in superficial cortical areas. In addition, they had high serum antibody titers at PI week 16. Calves given strain 19, or genetic mutants derived from strain 19, cleared bacteria from lymph nodes more rapidly, had less lymphoid destruction, and developed antibody titers that did not persist for 16 weeks. The RB51 strain (rough) was cleared most rapidly from lymphoid tissues and induced serum antibody responses only to the core of the lipopolysaccharide molecule. Treatment of calves with dexamethasone did not cause B abortus to reappear in tissues of any calves, nor did serum antibody titers increase.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Bacterial survival, lymph node changes, and immunologic responses of cattle vaccinated with standard and mutant strains of Brucella abortus. 145 36

We have previously reported that subcutaneous injection of casein, a potent inducer of the immunomodulatory acute phases reactant, serum amyloid A (SAA) protein, produces a marked suppression of humoral responses that require macrophage accessory cell cooperativity in the B6C3F1 mouse. The objective of these studies was to further characterize the immunological changes produced by casein treatment. It was observed that the inhibition of the sRBC IgM AFC response which accompanies casein treatment is dose related to the amount of casein introduced subcutaneously to the mouse. These studies, as well as those previously reported by several laboratories including our own have demonstrated that spleen cells isolated from casein-treated mice also exhibit markedly suppressed humoral responses in vitro. However, casein added directly to naive spleen cell cultures at concentrations significantly higher than those which would be found in the lymphoid tissues of the intact animal have no direct inhibitory effect on the sRBC IgM AFC response, suggesting that casein alone does not exert a direct immunosuppressive effect. Kinetics of recovery studies indicate that the casein-induced immunosuppression is readily reversible. Humoral responses are fully recovered within 3 days, once subcutaneous injections of casein are terminated. In vitro measurements of IL-1 secretion following stimulation of splenic macrophages, isolated from casein treated mice, with lipopolysaccharide indicate no significant effect on the capacity of these cells to produce this cytokine. Direct addition of recombinant IL-1 or interferon-gamma to spleen cell cultures isolated from casein-treated mice also was found to be incapable of reversing the inhibited IgM AFC response. Taken together, these studies strongly suggest that the accessory cell dysfunction associated with macrophages from casein-treated mice is not due to the inability of these cells to secrete IL-1 and indicate that the dysfunction cannot be reversed by IL-1 or interferon-gamma. Casein treatment was also found to markedly inhibit DTH, a cell-mediated immune response requiring macrophage accessory cell function. interestingly, the DTH responses were only affected by casein when it was administered post-sensitization with antigen (sRBC) but prior to antigen challenge. When casein was administered prior to sensitization with antigen, which is analogous to the treatment schedule that was found to suppress the sRBC antibody response, no effect was observed on DTH.
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PMID:A functional characterization of macrophage alterations in casein-treated B6C3F1 mice. 147 55

Although IL-2 receptor beta chain (IL-2R beta) expressed in various lymphoid cell lines binds IL-2 with an intermediate affinity, IL-2R beta expressed in fibroblasts is unable to bind IL-2, suggesting that IL-2R beta is on its own not sufficient for generating the intermediate-affinity receptor and that lymphoid-specific regulatory control may be operated to allow IL-2R beta to bind IL-2. In the present study, we observed that human IL-2R beta expressed in a mouse myeloma X63-Ag8.653 (X63) by cDNA transfection did not bind IL-2, while the same IL-2R beta expressed in an IL-6-dependent mouse B cell hybridoma F12-28, which was obtained by cell fusion between X63 and lipopolysaccharide (LPS)-induced lymphoblasts, bound IL-2 with the intermediate affinity. Interestingly, when the human IL-2R beta cDNA-transfected X63 clone, which by itself manifests no IL-2 binding, was fused with LPS-induced lymphoblasts, the resultant hybridomas manifested intermediate-affinity IL-2 binding. The IL-2 binding was specifically inhibited by addition of antihuman IL-2R beta mAb (Mik-beta 1) but not by mAb against mouse IL-2R subunits, indicating that human IL-2R beta was responsible for the IL-2 binding, i.e. non-functional human IL-2R beta in X63 was converted to competent IL-2R beta by complementation with a mouse spleen cell-derived factor(s) through the cell fusion. Cross-linking experiments with [125I]IL-2 revealed the presence of a 61 kDa protein other than IL-2R beta in cells expressing the intermediate-affinity IL-2R.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Reconstitution of the intermediate-affinity interleukin-2 receptor by cell fusion. 148 30

A phosphorothioate oligonucleotide that has been employed to inhibit HIV-1 viral expression in chronically infected H9 cells was examined for its ability to associate with murine lymphoid cells. The relationship between cellular oligonucleotide concentration and the lymphoid target tissues is important to the selection of an animal model, evaluation of potential side effects, and understanding the actions of a therapeutically useful antisense oligonucleotide. Lymphoid cells were harvested from murine peripheral blood, bone marrow, thymus, lymph node, and spleen. Cell subpopulations that bind the oligonucleotide were distinguished by two-color flow cytometry employing a fluorescein-labeled anti-rev oligonucleotide and phycoerythrin-labeled antibodies to selected cell surface molecules associated with unique subpopulations of cells. Very little oligonucleotide binding was observed in peripheral blood mononuclear cells or thymic T cells, but substantial numbers of cells, primarily B cells from bone marrow and spleen, accumulated the oligonucleotide. The cell-associated oligonucleotide was increased significantly in lymphoid populations when the cells were mitogen pretreated with either concanavalin-A (ConA), a T cell mitogen, or lipopolysaccharide (LPS), a B cell mitogen. These data clearly demonstrate the ability of fluorescein-conjugated oligonucleotides to bind to unique cell populations in suspension, allowing simultaneous two-color phenotypic analysis, suggesting that fluorescein-conjugated oligonucleotides may be a useful bridge between in vitro molecular biology techniques and in vivo cell biology. In addition, these data provide optimism concerning the in vivo treatment of chronically infected HIV patients using antisense oligonucleotides.
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PMID:Binding of antisense phosphorothioate oligonucleotides to murine lymphocytes is lineage specific and inducible. 149 73

Specifically targeted expression of a toxin gene potentially represents a novel approach to cancer therapy. With a view to the ablation of B-cell malignancies, we have constructed a plasmid, designated pTHA71, which expresses the A-chain of diphtheria toxin (DT-A) with high efficiency and specificity in transfected, mature B-lymphoid cells. The construction incorporated immunoglobulin (Ig) kappa light chain gene regulatory sequences, including a kappa promoter, small intron, partial constant region exon, and 3'-flanking sequence (but lacking a known enhancer). These sequences conferred substantially more efficient expression of DT-A in mature B-cells than was seen from constructs that included only Ig promoters and enhancers. When transfected into the 70Z/3 murine pre-B-cell line, pTHA71 was only expressed efficiently if the cells were induced to express their endogenous, rearranged Ig kappa gene by prior exposure to lipopolysaccharide. The insertion of the enhancer from the Ig kappa large intron into pTHA71, generating pTHA81, did not markedly influence the level of DT-A expression in 70Z/3 cells. The observed absence of expression in pre-B-cells suggests that DT-A constructs similar to pTHA71 might be used for the therapeutic ablation of malignant B-cells of mature stages, while sparing normal progenitor cells.
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PMID:Expression of diphtheria toxin A-chain in mature B-cells: a potential approach to therapy of B-lymphoid malignancy. 149 46

Sprague Dawley (SD) rats were immunized by subcutaneous injections with heat-killed E. coli 0:14 and lipopolysaccharide (LPS) extracted from E. coli for 15, 29 and 39 weeks which induced arthritis in the ankle. Localization of interleukin-1 (IL-1) and LPS in the ankle joints were investigated immunohistochemically. Serum IgM rheumatoid factor-like substance (RFLS) and anti-LPS IgM were detected by enzyme-linked immunosorbent assay (ELISA). Rats immunized with LPS for 39 weeks developed synovial lining cell hyperplasia in 25 of 40 ankles and lymphoid cell infiltration in 25 and pannus formation in 23, the rates of which were significantly higher than those of control and rats immunized with LPS for 15 and 29 weeks. The induction rate of arthritis in rats immunized with LPS was the same as that in rats immunized with E. coli. LPS and IL-1 were located in synovial cells and pannus in arthritic joints. Changes of RFLS level in rats immunized with LPS were elevated more gradually than those in rats immunized with E. coli. These findings suggest that LPS could stimulate IL-1 and RFLS production and may induce arthritis in rats resembling rheumatoid arthritis.
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PMID:[Immunohistochemical localization of interleukin-1 and lipopolysaccharide (LPS) of experimental arthritis in the ankles of rats immunized with LPS extracted from Escherichia coli]. 150 48

The implantation of splenic tissue at different implantation sites (intraomental and subcutaneous) into one animal (Lewis rats) results in the development of splenic nodules at both sites. In a quantitative immunohistological analysis of splenic compartments such as red pulp (RP), periarteriolar lymphoid sheaths (PALS), marginal zone (MZ) and follicles (F) the T-cell reduction was related to the T(helper) cells in the MZ and T(supp/cyt) cells in the PALS. In contrast, the cell density of B cells and ED-1+ macrophages in the PALS and T(supp/cyt) cells in the MZ was increased. Significant differences between the implantation sites were restricted to CD5+ cells (thymocytes and T cells) in the MZ and OX-33+ cells (B cells with LCAB antigen) in the PALS. The reorganisation of the compartments of subcutaneous implants showed a delay of one week as compared with omental ones. Functional assays like haemolytic plaque assay, mitogen stimulation and mixed lymphocyte assay elicited an analogous delay of the functional maturation of IgM-positive B cells, a reduced proliferation of both transplant groups after pokeweed mitogen (PWM) stimulation, a decreased response after lipopolysaccharide (LPS) stimulation in solely subcutaneous replants and no differences concerning the mitogens concanavalin A (ConA) and phytohaemagglutinin (PHA). Both transplant groups showed a significantly reduced allogeneic response. The results of the functional analysis and the abnormal mRNA expression of Il-5, Il-6 (Interleukin 5 and 6), GMCSF (Granulocyte-Macrophage-Colony-Stimulation-Factor) and IFN-gamma (Interferon gamma) in subcutaneous replants indicate subtle molecular alterations (independent of a spleen-like immunoarchitecture) at this site.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Autotransplantation of the spleen in rats: development, function and cytokine expression in intra-omental and subcutaneous regeneration]. 151 93


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