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)

The effects of Bordetella bronchiseptica dermonecrotic toxin (DNT) on the in vivo antibody response of mice were investigated. Intravenous injection of DNT at doses of 0.5 and 2.0 ng resulted in a significant suppression of the antibody response both to sheep red blood cells and to Escherichia coli lipopolysaccharide as measured by plaque-forming cell and hemagglutination assays. Spleen weights of mice given the same doses of DNT were significantly reduced, while the weights of thymuses and mesenteric lymph nodes were not. Numbers of Thy-1,2+ T lymphocytes, L3T4+ T lymphocytes, Lyt-2+ T lymphocytes and surface-immunoglobulin-positive lymphocytes decreased in spleens of the DNT-treated mice. Since the ratio of each lymphocyte population to the total number of splenic lymphocytes was not significantly different between the DNT-treated and non-treated mice, it is unlikely that DNT has a cytotoxic activity or a mitogen activity to some specific population of lymphocytes. Thus, we considered that the immunosuppression was attributable to a dysfunction of the spleen atrophied by the DNT.
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PMID:Bordetella bronchiseptica dermonecrotizing toxin suppresses in vivo antibody responses in mice. 155 57

The B220 cell marker is expressed on B cells and on T cell precursors. In order to determine the involvement of the B220 antigen on murine lymphoid differentiation, we treated 5-10-week-old mice periodically with a specific anti-B220 antibody, RA3-6B2, a non-cytolytic IgG2b. After the third injection, a significant reduction (P less than 0.02) in the number of thymocytes and less dramatically in the number of splenocytes was observed. This reduction was predominantly due to a decrease of cells carrying the following markers: Thy-1.2+, Lyt-1+, Lyt-2.3+, L3T4+, and asGM1+. Mitogenic response to concanavalin A, phytohaemagglutinin and lipopolysaccharide, mixed lymphocyte reaction, cytotoxic T cell activity, and plaque-forming cell generation were significantly decreased after the treatment (P less than 0.01). These results show that the in vivo treatment with anti-B220 monoclonal antibody reduced the number of T and B cells and modified their functional activity. This suggests that the B220 antigen is involved in the maturation of both T and B cells.
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PMID:In vivo treatment with anti B-220 monoclonal antibody affects T and B cell differentiation. 169 18

We have recently reported that systemic and chronic administration of recombinant tumour necrosis factor alpha (TNF-alpha), as well as streptococcal preparation (OK-432), inhibits development of insulin-dependent diabetes mellitus (IDDM) in NOD mice and BB rats, models of IDDM. In this study we examined whether serum containing endogenous TNF induced by OK-432 injection could inhibit IDDM in NOD mice. Treatment twice a week from 4 weeks of age with OK-432-injected mouse serum, which contained endogenous TNF (75U), but not IL-1, IL-2 and interferon-gamma (IFN-gamma) activity, reduced the intensity of insulitis and significantly inhibited the cumulative incidence of diabetes by 28 weeks of age in NOD mice, as compared with the incidence in non-treated mice (P less than 0.01) and in mice treated with control serum (P less than 0.02). This inhibitory effect of the serum was diminished, although not significantly, by neutralization of serum TNF activity with anti-mouse TNF antibody. In the mice treated with the serum from OK-432-injected mice, Thy-1.2+ or CD8+ spleen cells decreased (P less than 0.01) and surface-Ig+ (S-Ig+) cells increased (P less than 0.05), whereas the proliferative response of spleen cells to concanavalin A (P less than 0.01) and lipopolysaccharide (P less than 0.05) increased. The results indicate that the inhibition by OK-432 treatment of IDDM in NOD mice was partially mediated by serum factors including endogenous TNF.
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PMID:Inhibition of autoimmune diabetes in NOD mice with serum from streptococcal preparation (OK-432)-injected mice. 174 49

Resting B cells enlarge, enter the cell cycle, and change their surface phenotype when activated via the surface immunoglobulin (Ig) receptor, but subsequent cell growth and antibody production is relatively limited. To identify stimuli that might prime B cells for enhanced function in vitro, we have compared the effects of anti-Ig with helper T (Th) cells on the formation of B lymphoblasts and the subsequent ability of the blasts to grow and secrete Ig. The B blasts first were induced by either anti-Ig, anti-Ig plus T cell-derived lymphokines, or alloreactive T blasts. Each population of B blasts showed enhanced expression of cell surface adhesion molecules, interleukin 2 receptor (IL-2R) p55, and MHC products, as well as decreased expression of IgD. The allo-activated B blasts were distinctive in expressing low levels of Thy-1 and increased reactivity with peanut agglutinin, a marker of germinal center B blasts in situ. The function of the different populations of B blasts was also different. Whereas anti-Ig or anti-Ig plus lymphokines primed for enhanced responses to lipopolysaccharide (LPS), the B blasts induced by Th cells were insensitive to LPS. B lymphoblasts that had been activated in the presence of helper factors or Th cells responded vigorously to recombinant IL-2 with growth and Ig secretion, and this response was enhanced in the presence of anti-Ig. The B blasts activated directly by Th cells, but not by anti-Ig plus lymphokines, were primed to secrete high levels of IgG1 and IgA. Therefore, the phenotype and function of a B lymphoblast depends upon the manner in which it is primed. When primed by Th cells, IL-2 proves to be the predominant mediator of clonal expansion and antibody secretion.
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PMID:T-independent and T-dependent B lymphoblasts: helper T cells prime for interleukin 2-induced growth and secretion of immunoglobulins that utilize downstream heavy chains. 182 5

The results of this study demonstrate that the culture supernatant of lipopolysaccharide (LPS)-stimulated murine spleen cells is able to inhibit the growth of freshly isolated B lymphocytes. The inhibition is specific for B cells because the suppression of the LPS, Fc-fragment of human IgG, dextran sulfate, and anti-mu induced proliferation of B, but not the Concanavalin A response of T lymphocytes could be shown. The cells producing the inhibitor do not adhere to plastic, and are Thy-1 negative but surface Ig positive, i.e. they are B lymphocytes. The regulatory substance is heat resistant, sensitive to trypsin treatment, and has a high molecular weight of approximately 1000 kDa. Moreover, it is specifically adsorbed on, and can be eluted from, anti-mu and anti-Ig immunoaffinity columns. Thus, it seems to be an IgM antibody. Non-specific effects were excluded by the ineffectiveness of poly- and monoclonal IgM proteins. IgM-IgG complexes were also excluded. Thus, these results suggest the existence of a novel IgM antibody mediated control mechanism regulating B cell growth during polyclonal activation.
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PMID:An IgM antibody is a potent immunosuppressive agent that inhibits B cell proliferation. 183 3

This study reports on the earliest stages of mononuclear phagocyte differentiation. A crucial question in this developmental process is whether mature macrophage (M phi) heterogeneity is already appointed at the precursor cell level. For this purpose, we produced clonal populations of mononuclear phagocytes from bone marrow culture by somatic cell hybridization with two hypoxanthine, aminopterin, thymidine-sensitive myeloid cell lines. A panel of 22 stable hybrids was obtained from these fusions. Differentiation stage analysis of the hybrids indicated that all cell lines had immature mononuclear phagocyte characteristics. The hybrids exhibited typical myeloid morphology and mainly nonadherent growth. Mature M phi features, such as expression of the cell surface antigens Mac-1, Mac-2 and F4/80, phagocytosis of latex beads, and expression of nonspecific esterase and acid phosphatase activity, were virtually absent. The immature M phi markers Thy-1, MIV25 and MIV52, on the other hand, were readily expressed, although heterogeneity was observed among different hybrid cell lines. We then analyzed the differentiation potential of seven hybrids by culture of the cells in the presence of post-lipopolysaccharide serum supplemented with interferon-gamma and found that the expression of mature M phi characteristics was induced. However, the various hybrids showed divergent patterns of mature M phi marker induction. R0C2 cells, for instance, showed extensive morphological and phenotypical differentiation without concomitant induction of phagocytosis. In contrast, W1C4 cells showed significant induction of phagocytosis without simultaneous increase of phosphatase and esterase activity. R1C1 cells were unique in the strong induction of Ia antigen expression. Together, our data indicate that (a) early M phi differentiation stages can be rescued by somatic cell hybridization, and that (b) the obtained cell lines are able to mature according to divergent differentiation programs.
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PMID:Murine macrophage precursor characterization. I. Production, phenotype and differentiation of macrophage precursor hybrids. 196 90

Interleukin 4 (IL-4) induces the expression of membrane Thy-1 on the vast majority of lipopolysaccharide (LPS)-stimulated normal murine B cells in vitro. This induction is inhibited by interferon-gamma (IFN-gamma). IL-4 and IFN-gamma are required late in culture to effect maximal induction and inhibition of Thy-1 expression by LPS- or LPS + IL-4-stimulated B cells, respectively. IFN-gamma suppresses IL-4-induced Thy-1 expression by inhibiting the induction of steady-state levels of Thy-1-specific mRNA. Three distinct CD4+ Th2 clones, through their release of IL-4, induce B cells to express high levels of Thy-1, by 24 hr, in striking contrast to the 3 days required to induce Thy-1 expression after stimulation with LPS and IL-4. This induction is abrogated by the addition of IFN-gamma. B cells stimulated with three distinct Th1 clones (IFN-gamma- and IL-2-producing) exhibit a modest, non-IL-4-dependent, expression of Thy-1. In contrast to intrinsic expression of Thy-1 by Th2-stimulated B cells. Thy-1 expressed by Th1-stimulated B cells is acquired, having the allotype specificity of the stimulating T cell.
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PMID:Regulation of murine B cell Thy-1 expression by IL-4, IFN-gamma, and CD4+ T cell subsets. 197 79

15 SM/J mouse hybridoma antibodies that show antithymocyte autoantibody (ATA) activity by immunofluorescence staining were studied. Half of these antibodies react with determinants whose expression is associated with Thy-1, as shown by blocking experiments with anti-Thy-1 and loss of reactivity with Thy-1- mutant cell lines. The Thy-1 dependence of three of these ATA is further confirmed by their reexpression on a Thy-1 gene transfectant. However, the remaining antibodies exhibited binding that showed little or no dependence on Thy-1. Furthermore, we find that most ATA derives from the Ly-1 B subpopulation, as demonstrated by lipopolysaccharide-induced ATA secretion in vitro and by comparison of ATA hybridoma frequencies. VH region gene sequence data of 14 monoclonal ATA from Ly-1 B cell-derived hybridomas reveal the utilization of nine VH genes belonging to four different VH families (J558, 3609, Q52, and Vgam3.8). While we find that two of these hybridomas arose from a clonal expansion, we also find four examples of a 3609 family VH gene utilized in clonally independent lines showing similar specificity. Yet another example of identical VH gene usage by clonally unrelated cells is found in two J558 ATA of a distinct fine specificity. These data suggest that the enrichment of ATA B cells in the Ly-1 B subset is primarily due to repeated independent recruitment of B cells by antigen resulting in the expression of a restricted set of VH genes.
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PMID:Natural autoantibodies to thymocytes: origin, VH genes, fine specificities, and the role of Thy-1 glycoprotein. 197 16

The effects of age and dietary restriction on immune response were investigated using an animal model of accelerated senescence (senescence accelerated mouse, SAM). The experimental groups consisted of control (ad libitum fed) and restricted groups (fed 60% of energy intake of the controls). Spleen weight and total number of splenic cells were significantly lower in the food-restricted group at 8 mo of age. Percentages of T (Thy-1.1+) and B (surface Ig+) cells in the splenic cells were not significantly different between the two groups. The number of direct hemolytic plaque-forming cells per 10(6) spleen cells 4 d following immunization with sheep red blood cells and dinitrophenyl-Ficoll was significantly greater in the 8-mo-old mice in the food-restricted group than in the control group. In the latter group, antibody responses Progressively decreased with age. Mitogen responses to concanavalin A and lipopolysaccharide were maintained in the food-restricted group but were depressed in the control group at 8 mo. In addition, though autoantibody to single-stranded DNA increased in the control group with advancing age, there was a steady decrease in the food-restricted group until 8 mo. Serum immunoglobulin (IgA and IgM) concentrations were significantly lower in the food-restricted group than in controls at 8 mo of age. Therefore, our results suggest that when senescence accelerated mice are subjected to food restriction, there may be a modulatory effect on the immune dysfunction associated with advancing age.
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PMID:Effects of dietary restriction on age-related immune dysfunction in the senescence accelerated mouse (SAM). 223 Oct 28

The population of T-cell subsets, the blastogenic responses of lymphocytes in blood and spleen and splenic NK cell activity were examined in mice transferred from 22 degrees C to 12 degrees C or 32 degrees C environments. The percentage of Thy-1.2 positive cells and Lyt-1.2 positive cells in the spleen decreased after the transfer. However the percentage of Lyt-2.2 positive cells in the spleen was not affected. Thy-1.2 and Lyt-1.2 positive cells in the blood also decreased. The percentage of Lyt-2.2 positive cells in the blood was not affected in mice exposed to 12 degrees C. However, Lyt-2.2 positive cells in the blood decreased on day 1 but increased on day 3 in mice exposed to 32 degrees C. Blastogenic responses of spleen lymphocytes to concanavalin A (Con A) and pokeweed mitogen (PWM) were suppressed in transferred mice, but responses to lipopolysaccharide (LPS) and phytohemagglutinin-P (PHA-P) were not affected in any group. Blastogenic responses of blood lymphocytes to Con A, PHA-P, and PWM tended to be weaker in transferred mice than in mice kept in the 22 degrees C environment. In particular the response to PWM in mice exposed to 12 degrees C was less than 8% of that in the 22 degrees C mice. Splenic NK cell activity decreased in transferred mice, but was not suppressed as much as in mice administered 5mg of cortisone acetate.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of environmental temperature on the population of T-cell subsets, the blastogenic responses of lymphocytes in blood and spleen and splenic NK cell activity in mice. 240 23


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