RESUMEN
A bacterial extract (IBEC, OM-89, Uro-Vaxom), consisting of immunostimulating components derived from 18 Escherichia coli (E. coli) bacterial strains, is used for the treatment of recurrent infections of the urinary tract. Previously it was demonstrated that IBEC constitutes an active immunogen after parenteral administration to mice. Here, the immunogenic properties of IBEC after oral administration to mice are demonstrated. It was shown that, after repeated oral administrations of the extract, an IBEC-specific serum immunoglobulin (Ig), IgA and IgG response was obtained. A weak increase of IBEC-specific faecal IgA was also observed. The sera also bound to the bacterial strains used for the preparation of the extract. Moreover they recognized the bacterial cell wall components muramyl dipeptide (MDP) protein I (porin) and lipopeptide (P3C). In addition to the increase of bacteria-specific Ig, a rise in total serum IgA was demonstrated. Also in supernatants of splenocyte cultures of IBEC-immunized mice an increased level of IgA could be determined. These findings on the immunostimulating properties of IBEC after oral administration, which is also the application route in human patients, might partially explain the therapeutic effect of the extract shown in clinical studies.
Asunto(s)
Adyuvantes Inmunológicos/farmacología , Antígenos Bacterianos/farmacología , Escherichia coli/inmunología , Animales , Ensayo de Inmunoadsorción Enzimática , Heces/química , Inmunoensayo de Polarización Fluorescente , Inmunoglobulina A/análisis , Inmunoglobulina A/biosíntesis , Inmunoglobulina G/análisis , Inmunoglobulina G/biosíntesis , Linfocitos/efectos de los fármacos , Linfocitos/inmunología , Ratones , Ratones Endogámicos BALB C , Ganglios Linfáticos Agregados/citología , Ganglios Linfáticos Agregados/efectos de los fármacos , Ganglios Linfáticos Agregados/inmunología , Bazo/citología , Bazo/efectos de los fármacos , Bazo/inmunologíaRESUMEN
To generate conventional or monoclonal antibodies for the serological detection of drugs, antibiotics, toxins and other low molecular mass substances, a suitable and effective adjuvant is needed. Lipopeptides derived from a major component of the bacterial cell wall constitute potent nontoxic and nonpyrogenic immunoadjuvants when mixed with conventional antigens. Here we demonstrate that the synthetic lipopeptide N-palmitoyl-S-[2,3-bis(palmitoyloxy)-(2R,S)-propyl]-(R)-cysteinyl- serine (P3CS) coupled to a Th-cell epitope (P3CS-Th) can efficiently enhance the specific immune response against low molecular weight compounds in different species. In the presence of the synthetic lipopeptide P3CS-Th, the peptides which are per se non-immunogenic stimulated a specific humoral immune response in mice after intraperitoneal application. Mixtures containing adjuvants without the Th sequence showed no significant antibody induction. A marked enhancement of the humoral immune response was obtained with the low molecular mass antigens Iturin AL, Herbicolin A and Microcystin (MLR) coupled to poly-l-lysin (MLR-PLL), in rabbits and in chickens. Lipopeptide-Th cell epitope conjugates also constituted adjuvants for the in vitro immunization of either human mononuclear cells or mouse B-cells with MLR-PLL; after fusion of the immunized cultures with the heteromyeloma cell lines CB-F7 or the mouse myeloma cell line SP 2/0, respectively, we observed a significantly increased yield of antibody secreting hybridomas.
Asunto(s)
Adyuvantes Inmunológicos/fisiología , Epítopos de Linfocito T/metabolismo , Lipoproteínas/metabolismo , Péptidos/inmunología , Animales , Formación de Anticuerpos , Especificidad de Anticuerpos , Reacciones Antígeno-Anticuerpo , Pollos , Dipéptidos/inmunología , Inhibidores Enzimáticos/inmunología , Epítopos de Linfocito T/inmunología , Humanos , Inmunización , Leucocitos Mononucleares/inmunología , Lipoproteínas/inmunología , Prueba de Cultivo Mixto de Linfocitos , Ratones , Microcistinas , Péptidos Cíclicos/inmunología , Fosfoproteínas Fosfatasas/antagonistas & inhibidores , ConejosRESUMEN
The bioavailability of the major fraction of a 14C-labeled Escherichia coli extract (OM-89) of high molecular mass > 30 kD (HEC) was investigated in rats after a single oral administration of a dose of 100 mg/kg b.w. The determination of radioactivity in blood and plasma showed that HEC was absorbed by the digestive tract, either in its original form or partly degraded. In plasma, the radioactivity reached a Cmax value after 4 h, equivalent to an extract concentration of 31.7 micrograms/g of plasma with an elimination half live of 33 h. High molecular weight molecules of HEC (> 30 kD) were found by radiochromatography in rat serum 4 h after administration. Immunoprecipitation in the serum showed that HEC retains intact determinants throughout the digestive and absorptive processes. It is therefore absorbed either in its original form or partly degraded. A high incorporation of radiolabel was found in liver, secretory glands (adrenals, thyroid gland, pancreas), and in lymphoid organs (spleen, mesenteric lymph nodes).
Asunto(s)
Adyuvantes Inmunológicos/farmacocinética , Antígenos Bacterianos , Escherichia coli/metabolismo , Animales , Disponibilidad Biológica , Cromatografía Líquida de Alta Presión , Femenino , Semivida , Absorción Intestinal , Masculino , Pruebas de Precipitina , Ratas , Ratas WistarRESUMEN
The bacterial extract OM-89 is used for the treatment of recurrent infections of the urinary tract. It consists of immunostimulating components derived from 18 Escherichia coli bacterial strains and constitutes a non-specific leukocyte activator. We here could demonstrate for the first time that, in a long-term immunization protocol, OM-89 acts as an effective immunogen in mice. After multiple parenteral applications of the extract, OM-89-specific antisera were obtained; the maximum serum antibody content was found after 6-9 immunizations. The antibodies induced were mainly of the IgG isotype, and a weak increase of IgM was observed. The sera also bound to the bacterial strains used for the preparation of the extract. Moreover, we could show that defined bacterial cell-wall components like protein I (porin), lipopeptide and murein were recognized. Our findings on the immunogenicity of OM-89 might partially explain the therapeutic effect of the extract as shown in clinical studies.
Asunto(s)
Adyuvantes Inmunológicos/farmacología , Anticuerpos Antibacterianos/biosíntesis , Antígenos Bacterianos , Escherichia coli/inmunología , Activación de Linfocitos/efectos de los fármacos , Adyuvantes Inmunológicos/administración & dosificación , Adyuvantes Inmunológicos/uso terapéutico , Animales , Pared Celular/inmunología , Ensayo de Inmunoadsorción Enzimática , Escherichia coli/ultraestructura , Sueros Inmunes/inmunología , Inmunización , Inmunización Secundaria , Inmunoglobulinas/biosíntesis , Lipoproteínas/metabolismo , Ratones , Ratones Endogámicos BALB C , Peptidoglicano/metabolismo , Porinas/metabolismo , Infecciones Urinarias/tratamiento farmacológicoRESUMEN
An immunostimulating bacterial extract (IBE, Broncho-Vaxom) used for the prevention and treatment of recurrent respiratory tract infections consists of lyophilized fractions derived from 21 bacterial strains occurring in these infections. The immunogenic properties of IBE were determined in vivo in a murine model. It could be demonstrated that the extract constitutes an active immunogen in Balb/c mice. As shown by ELISA, IBE-specific antisera could be obtained after repeated i.p. immunizations; the antibodies were mainly of the IgG and IgM isotypes. The antibodies also bound - to a variable degree - to the bacterial strains used for the preparation of the extract. Additionally the antisera were shown to recognize the bacterial cell wall components porin, lipoprotein/lipopeptide and murein. Thus, IBE constitutes an active immunogen in vivo inducing antibodies directed against bacterial cell wall components; this could be of importance for understanding the therapeutic effect of the extract.
Asunto(s)
Adyuvantes Inmunológicos/farmacología , Bacterias/inmunología , Extractos Celulares , Pared Celular/inmunología , Adyuvantes Inmunológicos/química , Animales , Bacterias/química , Bacterias/ultraestructura , Pared Celular/química , Ensayo de Inmunoadsorción Enzimática , Inmunoglobulina G/inmunología , Inmunoglobulina M/inmunología , Ratones , Ratones Endogámicos BALB CRESUMEN
The immunogenic and immunomodulatory properties of a lysed fraction from selected E. coli strains (OM-89, Uro-Vaxom) were determined in vivo and in vitro. It could be demonstrated that OM-89 constitutes an active immunogen in mice. Maximum OM-89-specific antibody titers were obtained after 4-5 i.p. immunizations; the titers could be further enhanced by the simultaneous injection of lipopeptide adjuvants. It was shown by ELISA that the antibodies obtained bound to the bacterial strains used for the preparation of the OM-89 extract. Immunogenicity was observed both after intraperitoneal and oral application of the extract. Besides being active as an immunogen. OM-89 was able to act in vitro as a polyclonal lymphocyte activator, as determined in splenocyte cultures of different inbred murine strains, and in cultures of human peripheral blood lymphocytes. Our results show that the B lymphocyte stimulating activity of the bacterial extract OM-89 was comparable to that of lipopeptide adjuvants. In conclusion, the bacterial extract both an active immunogen in vivo, and a polyclonal B cell activator in vitro. These findings may be of importance for the understanding of the therapeutic effect of OM-89.