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)

Effect of water soluble extracts and purified derivatives from the root of the plant Bupletum falcatum L. upon the immune response of BALB/c mice was investigated using heterologous erythrocytes and bacterial lipopolysaccharide. This Chinese Medicine is famous for its reputed anti-inflammatory, anti-tumor and other biological activities, and has been widely used alone or in a complexed form since ancient times in Oriental Countries. The effect on immune responsiveness of this drug was judged by the measurement of antibody secreting cells causing localized hemolysis in agar gel. The purified derivatives, Saikosaponin (SS) a and d, suppressed anti-SRBC plaque-forming cells (PFC), but the other derivatives, b1 and b2 and c, did not. Moreover, derivatives a and d also enhanced anti-LPS PFC. From experiments establishing minimum effective doses for anti-SRBC PFC in mice, one mg/kg was optimum for BALB/c mice. The effect of the drug on antibody formation against heterologous erythrocytes was nonspecific because treated mice had greatly depressed PFC responses against both sheep and rabbit erythrocytes. The phenotypic effect of this drug as judged by PFC against T-dependent or T-independent antigen was not identified. However, it was suggested that the purified derivatives SSa and d stimulated both T- and B-cells. The possible mechanism of effect against immunocompotent cells is discussed.
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PMID:Effect of saikosaponin derivatives upon the immune response against T-dependent and T-independent antigens in mice. 390 44

Purified protein derivative (PPD) tuberculin induced immunoglobulin production in cultures of nonimmune mouse spleen cells, as measured by plaque-forming cells (PFC) against sheep erythrocytes (SRBC), horse erythrocytes, and 4-hydroxy-3,5-dinitrophenacetyl-SRBC. The increase started between 15 and 20 h of culture and reached a peak at 48-72 h. Higher PPD concentrations resulted in earlier peak responses than low concentrations. The Ig produced was mainly 19S and of very low avidity. The response elicited by PPD was of the same type as that caused by lipopolysaccharide of bacterial origin. Mitomycin treatment of cells before culture did not change the numbers of PFC/10(6) recovered cells but the cell recovery was considerably lower. Also injection of PPD in vivo resulted in increased numbers of PFC. On the basis of these results it is suggested that PPD nonspecifically activates a majority of the B cell population to proliferation and immunoglobulin synthesis.
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PMID:Purified protein derivative of tuberculin induces immunoglobulin production in normal mouse spleen cells. 412 93

The ability to clone hapten-specific B cells in agar and to subsequently trigger their clonal progeny to antibody synthesis was investigated. Fluorescein (FL) specific B cells were purified on FL-gelatin dishes and cultured in semisolid agar for 6 to 7 days; individual colonies were then picked for restimulation in microculture. FL-specific B cells could be cloned as efficiently as unpurified splenic B cells. The number of colonies formed depended on the presence of sheep erythrocytes (SRBC) or E. coli lipopolysaccharide (LPS) in the cultures. An additive number of colonies were observed with SRBC + LPS compared to that of SRBC or LPS alone. The colonies obtained from SRBC-containing cultures were stimulatable at high frequency by various FL-conjugated antigens to yield anti-FL PFC. However, colonies grown with LPS as the only additive were not stimulatable by any of the antigens tested. On the other hand, addition of M phi or SRBC as additional "mitogens" along with LPS in the agar resulted in progeny colonies that could respond in vitro. Although M phi did not increase the number of colonies, their presence enhanced the size and in some cases the frequency of stimulatable colonies. These data complement earlier observations in suggesting that different B cell subpopulations may grow under different cloning conditions. Moreover, the ability to stimulate the clonal progeny of single B cells to antibody synthesis should permit further definition of triggering and tolerance events at the single-cell level.
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PMID:Hapten-specific murine colony-forming B cells: in vitro response of colonies to fluoresceinated thymus independent antigens. 616 21

In order to investigate the mechanism of action of disulfide compounds in the augmentation of the antibody response in vitro, we attempted to identify the target cells of the action of disulfides using oxidized dithiothreitol (DTTox; an intramolecular disulfide). DTTox markedly augmented the antibody responses not only to sheep erythrocytes, a T cell-dependent antigen, but also to T cell-independent antigens like dinitrophenyl-Ficoll and trinitrophenyl-lipopolysaccharide. The augmenting effect of DTTox in the response to SRBC was markedly abrogated when murine spleen lymphocytes were depleted of T cells and cultured in the presence of concanavalin A-conditioned medium containing the activity of T cell-replacing factor. The augmentation was restored by adding back purified T cells. On the other hand, the augmentation by 2-mercaptoethanol was not affected by these treatments. The antibody responses to dinitrophenyl-Ficoll and trinitrophenyl-lipopolysaccharide, and the polyclonal antibody response induced by lipopolysaccharide were no longer enhanced by DTTox when T cells were depleted. These results suggested that the augmenting effect of DTTox was not due to the direct activation of B cells, as with 2-mercaptoethanol, but was mediated by the stimulation of T cells. This assumption was further supported by the observation that DTTox stimulated the in vitro induction of helper T cell activity in the presence of antigens.
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PMID:Augmentation of in vitro antibody response by disulfide compounds. II. T cell-mediated augmentation by oxidized dithiothreitol, an intramolecular disulfide. 623 68

The effect of dibutyryl cyclic guanosine monophosphate (dbc-GMP) on butylated hydroxyanisole (BHA)-induced suppression of the primary in vitro thymus-dependent antibody response of BDF1 mouse spleen cultures was studied. When added at 0 hr relative to antigen addition, 1 mg of dbc-GMP (8 mM) restored by greater than 70% the BHA-inhibited primary immunoglobulin (Ig)M plaque-forming cell (PFC) response to sheep erythrocytes (SRBC). The suppression was not reversed by the addition of 50 microgram of dibutryl cyclic adenosine monophosphate (dbc-AMP), which is known to reverse suppressor T-cell activity. The addition of 10 mM extracellular calcium (Ca2+) at the same time as antigen to BHA-inhibited cultures resulted in more than 80% restoration of the anti-SRBC PFC response. Quantitation of c-GMP by radioimmunoassay demonstrated that BHA lowered by 58% the c-GMP content of splenic lymphocytes and abrogated the ability of lipopolysaccharide of E. coli (LPS) to elevate c-GMP levels in splenic lymphocytes. The data suggest that BHA exerts its immunosuppressive effect on the primary in vitro antibody response by inhibiting guanylate cyclase activity and effectively lowering c-GMP levels; exogenous dbc-GMP and Ca2+ can freely reverse the immunosuppressive effect of BHA.
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PMID:Restoration by cyclic guanosine monophosphate and extracellular calcium of butylated hydroxyanisole-suppressed primary murine thymus-dependent antibody response. 627 34

Immunological cell functions were evaluated during 24, 48 and 96 h O2 exposure in C57Bl/6 mice. A normobaric O2 exposure resulted in depression of delayed type hypersensitivity (DTH) to oxazolone and Staphylococcus aureus antigens. This effect was proportional to the duration of O2 exposure. The antibody response of splenic cells was more rapidly (24 h O2 exposure) and markedly depressed using a T-dependent antigen (sheep red blood cell, SRBC) than with a T-independent antigen (trinitrophenylated lipopolysaccharide, TNP-LPS). While mitogen-induced proliferative responses of spleen cells to Con A and PHA were inhibited after 72 h of O2 exposure, proliferative responses to LPS were inhibited after 96 h. A dissociated antigen and mitogen responses was observed after a short time of O2 exposure (48 h): the antigen specific responses were impaired with a more pronounced effect on T lymphocytes, whereas the DNA synthesis in response to mitogen remained normal.
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PMID:Characterization of immunological depression in mice exposed to normobaric oxygen. 636 Apr 40

Because our past studies have shown that oral administration of thymic-dependent antigens induces higher IgA responses in lipopolysaccharide (LPS) nonresponsive C3H/HeJ mice than in syngeneic, LPS-responsive C3H/HeN animals, it was of interest to compare anti-LPS responses in these mouse strains after oral administration of particulate antigens containing LPS. C3H/HeJ and C3H/HeN mice were given smooth Salmonella typhimurium LT-2 or rough S. minnesota Rb (R345) or Re (R595) organisms by gastric intubation for 3 consecutive days/wk for 2 wk and were boosted by the i.v. route with either the same bacterial immunogen or with purified homologous LPS. Four days later, splenic anti-LPS plaque-forming cell (PFC) responses were assessed with a panel of indicator sheep erythrocytes (SRBC) coated with LPS derived from either smooth (S-LPS-SRBC) or rough (Rb-LPS-SRBC or Re-LPS-SRBC) Salmonella. In separate studies, both serum and salivary antibodies of the IgM, IgG, and IgA isotypes were determined by ELISA, with whole Salmonella cells used as the coating antigen. Oral immunization with LT-2 resulted in good IgM, IgG1 and IgA splenic anti-LPS PFC responses in C3H/HeJ mice, with the major isotype being IgA. Mice boosted i.v. with purified LPS gave five- to sixfold higher anti-S-LPS PFC responses than did mice given whole bacteria by the i.v. route. Low anti-Rb-LPS and anti-Re-LPS PFC responses were seen in both mouse strains. Enhanced immune responses in orally primed C3H/HeJ mice was not due to LPS-induced polyclonal responses, because splenic cultures from these mice gave poor mitogenic responses to LPS. A similar pattern of response was obtained when C3H/HeJ or C3H/HeN mice were given RB (R345) or Re (R595) bacteria orally and boosted i.v. with purified homologous LPS or whole cells. C3H/HeJ mice again showed higher immune responses in all isotypes than did C3H/HeN animals. Mice given Rb (R345) immunogen gave maximum responses to Rb-LPS, lower responses to Re-LPS, and no responses to S-LPS, whereas C3H/HeJ mice immunized with Re (R595) immunogen gave maximum PFC responses to Re-LPS and lower responses to Rb-LPS. Serum and salivary antibody titers closely paralleled the splenic PFC responses, and IgA antibodies were the predominant isotype observed, with higher IgA responses occurring in orally immunized C3H/HeJ mice than in C3H/HeN animals. These results clearly indicate that C3H/HeJ mice given whole Salmonella by gastric intubation elicit higher PFC and antibody responses to the three major LPS regions than do identically treated LPS-responsive C3H/HeN mice.
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PMID:Murine immune responses to Salmonella lipopolysaccharide: oral administration of whole bacteria to C3H/HeJ mice induces secondary anti-LPS responses, especially of the IgA isotype. 636 51

B cell hyperactivity, a feature common to all lupus-prone murine strains, may be caused by hyperresponsiveness to, overproduction of, or bypassing of certain signals required for B cell activation, proliferation, and differentiation. In this study, we have compared the responses of B cells from three lupus-prone strains of mice (BXSB males, MRL and NZB/W females) and normal strains in a number of assays for which two or more signals are required to obtain a response. In medium to low density cultures of B cells from BXSB and NZB/W but not MRL/l lupus mice, the cells' proliferation induced by bacterial lipopolysaccharide (LPS) or anti-mu antibody was much higher than that of B cells from normal controls. At low B cell density, polyclonal activation by these substances and subsequent Ig secretion were dependent on accessory signals present in supernatants of concanavalin A-treated normal lymphocytes (CAS) or on the MRL/l proliferating T cell-derived B cell differentiation factor (L-BCDF) in both lupus-prone and immunologically normal mice. However, the responses of B cells from BXSB and NZB/W, but not MRL/l, mice to these accessory signals were higher than those of normal mice. Ig synthesis by fresh B cells of BXSB and NZB/W mice cultured in the absence of mitogens but in the presence of CAS or L-BCDF was higher than by similar cells from other strains, suggesting an increased frequency of B cells activated in vivo in these two autoimmune strains of mice. The patterns of IgG subclass secretion in response to LPS (without added CAS or L-BCDF) were abnormal in all lupus strains, with a predominance of IgG2b and/or IgG2a and low levels of IgG3, contrary to normal B cells for which IgG3 synthesis predominated. However, IgG1 synthesis in vitro by autoimmune and normal B cells alike was highly dependent on T cell-derived soluble mediators. Antigen-specific responses to SRBC in vitro of B cells from all lupus strains, like those of B cells from normal strains, required a minimum of three signals (antigen, LPS, T cell-derived antigen nonspecific helper factors). Yet, once triggered, B cells of BXSB and NZB/W mice gave higher responses than those of the other strains. We conclude that B cells of lupus mice have signal requirements similar to those of normal mice. Nevertheless, B cells of BXSB and NZB/W, but not MRL/l, lupus mice hyperrespond or process some accessory signals abnormally.
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PMID:B cell dependence on and response to accessory signals in murine lupus strains. 640 39

Variants of four hybridoma lines secreting antibodies specific for either trinitrophenyl (TNP) or sheep erythrocytes (SRBC) were isolated which have lost either the specific heavy (H) chain or the specific light (L) chain. They were fused to lipopolysaccharide-stimulated mouse spleen cells and the resulting secondary hybridomas were screened for the restoration of the original antibody specificity. Antibody activity was 37 times more frequently restored with fusion lines donating H chain than with those donating L chain. We obtained a variety of different (spleen cell derived) L chains in association with one H chain and one specificity. We found that those L chains originally associated with a given H chain were rescued most often. Their frequencies were 1:74 and 1:490 for an anti-SRBC- and an anti-TNP-restoring kappa L chain, respectively. Two most commonly observed V-J kappa combinations in one anti-SRBC complementation group were detected with a 5- and 30-fold reduced frequency in two anti-TNP groups, indicating somatic diversification of kappa chains. It is shown that the Sp7/HK line resumes anti-TNP activity with a mutated, non-germline lambda 1 chain, which was found in 30% of lambda 1-expressing hybridomas.
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PMID:Frequency of expressed immunoglobulin light chain genes in lipopolysaccharide-stimulated BALB/c spleen cells. 643 91

Controversy concerning the immunologic role of antigen-binding cells (ABC) has prompted us to attempt to quantitate the proportion of stimulable ABC, in immunized animals, which are precursors for cells producing antibody specific for the antigen bound. Using a lipopolysaccharide (LPS)-driven limiting dilution analysis system, the precursor frequency (PF) of cells secreting IgM and IgG and sheep erythrocyte (SRBC)-specific IgM and IgG was established for highly purified SRBC antigen-binding cell (SRBC-ABC) and unfractionated populations taken from CBA/J mouse spleens on days 5, 12 and 180 of the in vivo primary immune response to SRBC. At all these times, almost all SRBC-ABC spontaneously secreting immunoglobulin (Ig) secreted SRBC-specific Ig, and almost all precursors of Ig-secreting cells in the ABC populations were precursors of cells secreting specific anti-SRBC antibody. In SRBC-ABC populations, the PF for total and SRBC-specific Ig secretion was seen to decrease on days 5 and 12 after immunization and to increase to 3.5 to 7 times nonimmune levels 180 days after immunization. The absolute number of precursors, within the SRBC-ABC population, for the secretion of SRBC-specific Ig decreased on day 12 after immunization. In the unfractionated population, the PF for SRBC-specific Ig secretion temporarily increased after immunization, reaching peak levels 5 days (IgM) and 12 days (IgG) after immunization. These two changes may be related, representing the progress of stimulated cells out of the ABC pool as they lose receptors en route to full maturation. The small clone sizes on days 5 and 12 indicate that ABC divide less in response to LPS when already engaged in a response to antigen. In contrast, the PF for total IgM and IgG secretion in the unfractionated population was not greatly affected by immunization.
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PMID:Antibody-secreting cell precursor frequencies among the sheep-erythrocyte-binding cells after immunization. 668 42


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