Protection Against Gram-Negative Infections with Antiserum to Lipid A from Salmonella minnesota R595

Peroral immunization with a live strain of Escherichia coli 06K13H1 against experimental ascending pyelonephritis caused by the same strain was studied in rats, and the effect of immunization on antibody titers against the 0 and K antigens and lipid A was determined. Peroral immunization with live bacteria protected significantly against pyelonephritis. Sera collected 1 week after infection from the immunized group were increased in immunoglobulin G (IgG) anti-06 and IgM anti-K13 in comparison with the nonimmunized group. The peroral immunization did not correspondingly affect the response to lipid A. In urine, there was an IgG antibody response to the 06 antigen. In bronchopulmonary secretion, IgM, IgG, and IgA antibodies to 06 were detected. Perorally immunized animals had significantly higher levels of IgG and IgA anti-06 compared with the nonimmunized group 1 week after infection. Passive transfer of anti-lipid A did not increase resistance against pyelonephritis.

Section: Resultssupporting

confidence: 91%

Experimental Escherichia coli ascending pyelonephritis in rats: active peroral immunization with live Escherichia coli

Mattsby‐Baltzer¹,

Hanson²,

Olling³

et al. 1982

“…The unusually large amount of fatty acids with one unsaturated bond in the lipid portion suggests that the complex under study also included so-called lipid B (although this complex is not soluble in chloroform), which may consist of this type of fatty acids. The chemical composition of pure lipid A, as compared with lipid A-protein complex in S. dysenteriae type 1, is subject to further study oriented especially toward protection experiments in vivo (17,21,23). An objection that the lipid A-protein complex used might be contaminated by a relatively large amount of free protein-aceous substance would not seem plausible considering the results of spectrophotometry.…”

mentioning

confidence: 99%

Characteristics of lipid A-protein complex from endotoxin of Shigella dysenteriae type 1 (S and R strains)

Sourek¹,

Trnka²,

Levin³

et al. 1979

Mild acetic acid hydrolysis of endotoxin (lipopolysaccharide-protein complex) of Shigella dysenteriae type 1 (S and R forms) yielded a lipid A-protein complex that consisted of amino acids, fatty acids, and sugar and, in terms of chemical composition, displayed no marked differences between the S and R forms. Its protein portion (53 to 56%) consisted of at least 16 amino acids. In the fatty acid portion (14 to 18%), myristic, 3-hydroxymyristic, palmitic, and stearic acids accounted for 50%. The sugar portion (10 to 12%) consisted solely of glucosamine. The remainder was unidentified substances, most of which contained phosphorus. Lipid A-protein complexes derived from both S and R forms were not toxic for mice in doses up to 1,000 jig/mouse, but their Limulus test activity had increased considerably as compared with the starting lipopolysaccharide-protein complex material: from 10-6 to 10-l1010-l2 mg/ml. The lipid A-protein complexes were readily soluble in a water solution of triethylamine, in dimethyl sulfoxide, and in pyridine.Dubois et al. (7).Assay for fatty acids of lipids. The assays for 465 on July 16, 2020 by guest http://iai.asm.org/ Downloaded from

“…Slow neutralization was enhanced after immunization with rough mutants and was directed against all LPSs examined. It was not observed with lipid A antiserum (data not shown), which generally has been found to be nonprotective in experimental models (16). The LPS of S. minnesota was less potent than other LPSs in producing limulus lysate gelation and was especially susceptible to slow neutralization by both pre-and postimmune sera.…”

Section: Discussionmentioning

confidence: 87%

Endotoxin neutralization with rabbit antisera to Escherichia coli J5 and other gram-negative bacteria

Warren¹,

Novitsky²,

Bucklin³

et al. 1987

To study the mechanisms of protection against endotoxin challenge offered by antisera to smooth and rough gram-negative organisms, we have developed an assay to quantitate endotoxin neutralization based on inhibition of the Limulus amoebocyte lysate test. Dilutions of different bacterial lipopolysaccharides (LPSs) were incubated with hyperimmune rabbit sera against Escherichia coli 0113, E. coli 018, and rough mutants E. coli J5 and Salmonella minnesota Re595 and were then combined with limulus lysate. The gelation reaction induced by LPS in the lysate was monitored spectrophotometrically, and the concentration of LPS resulting in a 50% lysate response was determined and correlated with antibody titers measured by enzyme-linked immunosorbent assay. Antisera to smooth organisms neutralized homologous LPS markedly and heterologous LPSs only minimally relative to neutralization by preimmune serum. Neutralization of homologous LPS occurred immediately without preincubation of serum and LPS. Antisera to rough mutants neutralized more heterologous LPS than did antisera to smooth organisms. However, this heterologous neutralization required preincubation of serum and LPS and did not appear to be correlated with antibody concentrations. We conclude that antisera to LPS rapidly neutralize the biological activity of the homologous LPS, as detected by limulus lysate, and that neutralization is at least in part antibody mediated. Antisera to rough-mutant organisms slowly neutralized the activity of heterologous LPSs, but this effect appeared not to be correlated with concentrations of antibody to the LPS of the rough mutant, as measured by enzyme-linked immunosorbent assay.