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

We evaluated the in vitro opsonophagocytic killing activity of monoclonal human immunoglobulin G (IgG), IgM, and IgA specific for Pseudomonas aeruginosa lipopolysaccharide and the in vivo protective capacity in neutropenic mice of both monoclonal and purified polyclonal IgG, IgM, and IgA. Monoclonal IgM was efficacious in mediating opsonophagocytic killing only in conjunction with complement, whereas monoclonal IgG opsonic killing was potentiated by complement, and monoclonal IgA opsonic killing was independent of complement. These findings are similar to those previously reported for purified polyclonal IgM, IgG, and IgA. The monoclonal and polyclonal immunoglobulins had comparable 50% protective doses in neutropenic mice (range, 0.28 to 0.46 microgram per mouse). The protective activity of IgM in neutropenic mice was abolished by cobra venom factor treatment, whereas IgG and IgA maintained efficacy in cobra venom factor-treated mice. These data indicate that all three major human serum immunoglobulin isotypes have opsonophagocytic and protective activities against P. aeruginosa, with a critical role for complement in the function of IgM.
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PMID:In vitro and in vivo activity of polyclonal and monoclonal human immunoglobulins G, M, and A against Pseudomonas aeruginosa lipopolysaccharide. 249 35

Analysis of fatal sensitivity to 0.2 microgram of S. enteritidis lipopolysaccharide in cycloheximide-treated mice identified two independent lethal elements. First, an absolute requirement for steroid supplementation to ensure survival suggests a crucial role for cycloheximide-mediated inhibition of steroidogenesis. The second factor is the development of virtually total bilateral renal cortical necrosis, itself a consequence of glomerular capillary occlusion with fibrin-like material. The survival of cycloheximide and endotoxin-challenged mice requires both hydrocortisone treatment and defibrination with ancrod. Cycloheximide and a smaller dose of endotoxin (0.1 microgram per mouse) is also fatal, but here steroid deficiency is not a crucial factor, protection being conferred by ancrod defibrination alone.
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PMID:Factors involved in the fatal susceptibility to submicrogram doses of endotoxin in cycloheximide-treated mice. 264 18

Antitumor activity of three derivatives of chemically synthesized diacyloxyacylglucosamine-4-phosphate (acyl-GlcN-4P) linked 3-deoxy-D-manno-2-octulosonic acid (KDO) and 12 derivatives of acyl-GlcN-4P or acyloxyacylglucosamine-6-phosphate (acyl-GlcN-6P) with chiral acyloxyacyl groups at the C-2 and C-3 positions was examined. Ehrlich carcinoma cells (1 x 10(4] were inoculated i.p. into ddY mice on day 0, and these compounds (100 micrograms/d/mouse) were administered i.p. on days -5, -2, +1, +3, and +5. Although the antitumor activity of the acyl-GlcN-4P linked KDO was weaker than that of the natural lipopolysaccharide, groups of mice administered A-301 with di-3-hexadecanoyloxytetradecanoyl [(R)C14-O-C16] at C-2, -3, and A-303 with di-3-tetradecanoyloxytetradecanoyl [(R)C14-O-C14] showed longer mean survival times than the control group. However, KDO-attachment appeared not to enhance the antitumor activity of acyl-GlcN-4P. The group of mice administered acyl-GlcN-4P (A-145) or acyl-GlcN-6P (A-144 and A-146), which have an acyloxyacyl group at C-2, -3, showed prolonged survival times when compared to the control group, but the differences were not significant. On the other hand, when compound A-107 with [(S)C14-O-C14] at the C-2 position and 6-phosphate was administered to 5 mice, 3 mice survived for 25 d. Furthermore, mitogenicity for splenocytes of C57BL/6 mice and lethal toxicity in C57BL/6 mice sensitized with D-galactosamine were observed with the acyl-GlcN-4P or -6P derivatives with (R) or (S) isomers of fatty acid.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Antitumor activity, mitogenicity, and lethal toxicity of chemically synthesized monosaccharide analogs of lipid A. 318 27

A high degree of non-specific resistance to a lethal systemic Escherichia coli infection was induced in mice by pretreatment with a small dose (less than 5 micrograms/mouse) of the homologous lipopolysaccharide (LPS) or with heterologous rough-type LPS from E. coli K-12. The route of LPS administration, intraperitoneally or subcutaneously, did not influence the development of resistance, suggesting that a systemic cell activation was responsible for the effect. The enhanced elimination of bacteria was similar to that in mice recovering from a sublethal E. coli infection. In the LPS-treated mice, elimination of the challenge bacteria from the peritoneal cavity and the blood started 3-4 h after challenge whereas, in controls, the bacterial numbers continued to increase until the mice died. The detoxified LPS derivative, monophosphoryl lipid A (MPL), also increased the survival of mice infected with E. coli O18:K1. However, the dose of MPL required for optimal infection resistance was 100-fold greater than that of native, E. coli K-12 LPS, corresponding to the 100-fold reduced toxicity of MPL for mice and rabbits in lethality and pyrogenicity assays.
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PMID:Lipopolysaccharide-induced non-specific resistance to systemic Escherichia coli infection in mice. 327 15

The biological activities of lipopolysaccharide-like substance (LLS) extracted from Leptospira interrogans serovar canicola strain Moulton by the hot phenol-water method were studied in mice. The addition of 12.5 micrograms/ml or more of LLS fraction increased the incorporation of [3H]thymidine into in vitro cultured spleen cells of C57BL/6 mice, while the activity of the LLS fraction was about 20 times weaker than that of Salmonella typhimurium lipopolysaccharide (LPS). Pretreatment of murine spleen cells with rabbit anti-mouse thymocyte antiserum did not diminish the mitogenic activity of leptospiral LLS, and the LLS could not increase the incorporation of [3H]thymidine into thymocytes, suggesting that LLS acts on a B-lymphocyte population of lymphocytes. When sheep erythrocytes and LLS fraction were injected intraperitoneally into BALB/c mice, LLS exhibited an enhancing effect on antibody response in vivo. However, lethal toxicity of the LLS fraction was about 500 times lower than that of LPS in C57BL/6 mice loaded with galactosamine. No antitumor activity of leptospiral LLS (250-1,000 micrograms/mouse) against the ascites form of Ehrlich carcinoma in ddY mice was observed. The biological activities of the LLS fraction from the organism were weaker than those of gram-negative bacterial LPS, suggesting that Leptospira possesses no typical LPS.
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PMID:Biological activities of lipopolysaccharide-like substance (LLS) extracted from Leptospira interrogans serovar canicola strain Moulton. 350 Mar 90

C57BL/6 mice were injected intraperitoneally (i.p.) with Corynebacterium parvum and subsequently, after an interval of 7-10 days, i.p. with lipopolysaccharide (LPS). The peritoneal wash-fluid was recovered at various times after injection of LPS. Marked interferon (IFN) titers were observed between 2 and 10 h after injection of LPS, whereas no IFN was detected in mice injected with either C. parvum or LPS alone. Very low doses of LPS (0.1 microgram/mouse) were sufficient to cause IFN production in the double-stimulation protocol. The IFN produced was neutralized by an antibody against IFN-alpha/beta. In additional experiments, mice were treated by C. parvum alone; the peritoneal exudate cells (PEC) were recovered and stimulated in vitro by LPS. Again substantial titers of IFN were induced by small concentrations of LPS, whereas untreated PEC did not produce IFN. The cell producing IFN in these cultures was not a T lymphocyte, as experiments with a monoclonal anti-thy 1.2 antibody showed.
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PMID:Local interferon induction by bacterial lipopolysaccharide in mice after pretreatment with Corynebacterium parvum. 380 84

The aims of this report are: to investigate the kinetics of the E. coli lipopolysaccharide polyclonal response as a function of the background response, to test the capacity of lipopolysaccharide to activate presumably resting memory cells for IgM. Because mice do not produce a plaque-forming cell background against rat erythrocytes, the mouse-rat erythrocyte system was chosen. Random bred Swiss albino mice, aged 2-3 months, were inoculated with rat erythrocytes (5 X 10(5)/mouse) and the course of the plaque response was followed up; no response was detected on day 0, it rose sharply up to day 4, dropped abruptly between days 4 and 7 and trailed off afterwards to disappear by day 29. As to the lipopolysaccharide-triggered anti-rat erythrocyte response, lipopolysaccharide (100 micrograms/mouse) was inoculated on days--3, 1, 4, 7, 18 and 29. post-rat erythrocytes and the responses were measured 3 days after lipopolysaccharide inoculation. The curve paralleled that of the antigenic response, although at a higher level; thus, both the specific and the polyclonal responses followed the same kinetics. At one month post-rat erythrocyte priming, the animals displayed a background comparable to that of naive mice, although their IgM response to a booster (2 X 10(7) erythrocytes, iv) was faster and greater (p less than 0.01) than the primary response to the same dose; i.e., there was IgM memory. Nevertheless, lipopolysaccharide stimulation (100 micrograms/mouse, ip) of primed animals gave a response comparable (p greater than 0.10) to that of naive mice; i.e., lipopolysaccharide alone was unable to elicit a secondary-like response.
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PMID:The lipopolysaccharide polyclonal response is a function of the background response. 389 May

Previous experimental and clinical studies have demonstrated the ability of polyclonal antibody directed against the core lipopolysaccharide (LPS)-lipid A component of endotoxin to reduce mortality. We sought to characterize the ability of a single murine monoclonal IgG1 antibody (8A1 MAb) to react to a variety of gram-negative microorganisms, to promote phagocytosis, and to provide protection during experimental murine sepsis. The 8A1 MAb reacted to various gram-negative bacterial whole cell and LPS antigens examined by enzyme-linked immunosorbent assay. Reactivity was highest to Salmonella minnesota Re LPS and lipid A. Phagocytosis was promoted by this monoclonal antibody to several gram-negative bacteria, except Pseudomonas aeruginosa. The 8A1 MAb (2 mg per mouse) enhanced survival during bacteremia due to either Escherichia coli 0111:B4 or Klebsiella pneumoniae, and during endotoxemia due to all types of LPS examined except P aeruginosa. We concluded that a single MAb with anti-lipid A specificity was cross reactive in vitro and cross protective in vivo. A clinical trial comparing polyclonal and monoclonal antibody in high-risk septic patients seems warranted.
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PMID:Immunotherapy of gram-negative bacterial sepsis. A single murine monoclonal antibody provides cross-genera protection. 394

Background responses have been assessed by fusing lipopolysaccharide- (LPS) stimulated spleen cells from unimmunized mice with MOPC 315.43 myeloma cells and screening the hybrids for the production of antibody against chicken red blood cells (CRBC). Clones specific for CRBC represented about 1% of total hybrid clones (1000 to 5000 clones were obtained per mouse). The majority of the anti-CRBC clones (greater than 95%) secreted antibody against polymorphic CRBC determinants (present on CRBC from some but not all chickens) rather than species-specific determinants present on all CRBC. Some of the polymorphic determinants were linked to the B locus (the MHC of the chicken) and some were non-B antigens. The relative amount of these 2 categories varied slightly according to the mouse strain. These results agree well with the specificities of natural mouse antibody and rosette-forming spleen cells. The response of immunized mice against CRBC and human RBC was also selective for polymorphic determinants. These results have considerable importance for the use of xenogeneic RBC as "standard" antigens, and are interpreted in terms of a model for the advantages of genetic polymorphism as a protection against antigen mimicry by parasites.
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PMID:The high background immune reactivity of mice to polymorphic determinants on xenogeneic erythrocytes: theoretical and practical implications. 617 71

The induction of immune responses to orally administered trinitrophenyl (TNP)-haptenated Streptococcus mutans and its enhancement with muramyldipeptide (MDP), peptidoglycan (PG), and concanavalin A (Con A) were investigated in lipopolysaccharide (LPS)-non-responsive C3H/HeJ mice and the syngeneic, LPS-responsive C3H/HeN strain. Both mouse strains manifested similar immune responses, primarily of the IgM isotype, after a single gastric intubation (GI) with TNP-S. mutans. However, when groups of animals were first carrier-primed by GI with S. mutans for 2 consecutive days, followed by a single GI with TNP-S. mutans 1 week later, C3H/HeJ mice gave a significantly higher (P less than or equal to 0.01) splenic IgA anti-TNP plaque-forming cell (PFC) response than identically treated C3H/HeN mice. Furthermore, saliva, urine and serum from these C3H/HeJ mice possessed high levels of IgA anti-TNP antibodies as determined by the enzyme-linked immunosorbent assay, whereas C3H/HeN mice exhibited low antibody levels. Oral administration of Con A (either 250 micrograms or 500 micrograms/mouse) or purified PG (1 mg/mouse) at the time of TNP-S. mutans immunization resulted in significantly (P less than or equal to 0.01) enhanced splenic IgA anti-TNP PFC responses, especially in C3H/HeJ mice. On the other hand, MDP promoted IgA anti-TNP PFC responses in LPS-responsive C3H/HeN mice but did not augment responses in C3H/HeJ animals. A similar immune response pattern was seen when antibody levels were measured in serum, saliva, and urine of both mouse strains. These results demonstrate that haptenated S. mutans is a good antigen for the induction of high IgA responses in orally immunized C3H/HeJ mice and that this high response can be enhanced with the adjuvants Con A and PG. However, MDP is ineffective in C3H/HeJ mice but enhances IgA responses in normal LPS-responsive C3H/HeN animals.
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PMID:Enhancement of murine immune responses to orally administered haptenated Streptococcus mutans. 618 12


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