ABSTRACT
BACKGROUND The B subunit of Escherichia coli heat-labile enterotoxin (LTB) is a potent mucosal immune adjuvant. However, there is little information about LTB's potential as a parenteral adjuvant. OBJECTIVES We aimed at evaluating and better understanding rLTB's potential as a parenteral adjuvant using the fused R1 repeat of Mycoplasma hyopneumoniae P97 adhesin as an antigen to characterise the humoral immune response induced by this construct and comparing it to that generated when aluminium hydroxide is used as adjuvant instead. METHODS BALB/c mice were immunised intraperitoneally with either rLTBR1 or recombinant R1 adsorbed onto aluminium hydroxide. The levels of systemic anti-rR1 antibodies (total Ig, IgG1, IgG2a, and IgA) were assessed by enzyme-linked immunosorbent assay (ELISA). The ratio of IgG1 and IgG2a was used to characterise a Th1, Th2, or mixed Th1/Th2 immune response. FINDINGS Western blot confirmed rR1, either alone or fused to LTB, remained antigenic; anti-cholera toxin ELISA confirmed that LTB retained its activity when expressed in a heterologous system. Mice immunised with the rLTBR1 fusion protein produced approximately twice as much anti-rR1 immunoglobulins as mice vaccinated with rR1 adsorbed onto aluminium hydroxide. Animals vaccinated with either rLTBR1 or rR1 adsorbed onto aluminium hydroxide presented a mixed Th1/Th2 immune response. We speculate this might be a result of rR1 immune modulation rather than adjuvant modulation. Mice immunised with rLTBR1 produced approximately 1.5-fold more serum IgA than animals immunised with rR1 and aluminium hydroxide. MAIN CONCLUSIONS The results suggest that rLTB is a more powerful parenteral adjuvant than aluminium hydroxide when administered intraperitoneally as it induced higher antibody titres. Therefore, we recommend that rLTB be considered an alternative adjuvant, even if different administration routes are employed.
Subject(s)
Animals , Female , Mice , Bacterial Toxins/toxicity , Adjuvants, Immunologic/administration & dosage , Adhesins, Bacterial/immunology , Escherichia coli Proteins/administration & dosage , Escherichia coli Proteins/immunology , Pneumonia of Swine, Mycoplasmal/immunology , Pneumonia of Swine, Mycoplasmal/prevention & control , Enterotoxins/administration & dosage , Swine , Enzyme-Linked Immunosorbent Assay , Mycoplasma hyopneumoniae , Aluminum HydroxideABSTRACT
Objective To investigate the effect of different adjuvants and challengemethods on asthma mice′s lung inflammation . Methods BALB/c mice were sensitized with ovalbumin in aluminium hydroxide or alum adjuvant .After 7 days challenges ,choose the proper adjuvant with intranasal or atomized to prepare mice asthma model .Count and classify the white blood cells (WBC) in bronchoalveolar lavage fluid(BALF) ,observe the peribronchial and perivascular inflammation .Results Compare the WBC and eos-nophils in BALF ,the alum group are higher than aluminum hydroxide group(P0 .05) .10 days after the last challenge ,the inflammation fade sharply ,and the corresponding result occured in the lung inflammation .Conclusion In establishing asthma model ,alum is better than aluminum hydroxide ,atomization is better than intranasal .Inflammation will fade after stop atomization a period of time .
ABSTRACT
Solubility, structure and position of charges in a peptide antigen sequence can be mentioned as being amongst the basic features of adsorption. In order to study their effect on adsorption, seven analogue series were synthesized from a MSP-1 peptide sequence by systematically replacing each one of the positions in the peptide sequence by aspartic acid, glutamic acid, serine, alanine, asparagine, glutamine or lysine. Such modifications in analogue peptide sequences showed a non-regular tendency regarding solubility and adsorption data. Aspartic acid and Glutamic acid analogue series showed great improvements in adsorption, especially in peptides where Lysine in position 6 and Arginine in position 13 were replaced. Solubility of position 5 analogue was greater than the position 6 analogue in Aspartic acid series; however, the position 6 analogue showed best adsorption results whilst the Aspartic acid in position 5 analogue showed no adsorption in the same conditions. Nuclear Magnetic Resonance structural analysis revealed differences in the -helical structure extension between these analogues. The Aspartic acid in position 6, located in the polar side of the helix, may allow this analogue to fit better onto the adsorption regions suggesting that the local electrostatic charge is responsible for this behavior.
La solubilidad, la estructura y la posición de las cargas en una secuencia de un péptido antígeno, se encuentran entre las características básicas de la adsorción. Con el fin de estudiar su efecto sobre la adsorción, fueron sintetizadas siete series de análogos de la secuencia de un péptido de la proteína MSP-1, reemplazando sistemáticamente cada una de las posiciones en la secuencia del péptido por ácido aspártico, ácido glutámico, serina, alanina, asparagina, glutamina o lisina. Las modificaciones en las secuencias de los péptidos análogos no mostraron tendencias regulares respecto a los datos de solubilidad y adsorción. Las series de análogos de ácido aspártico y ácido glutámico presentaron grandes incrementos en la adsorción, en especial cuando fueron reemplazadas la lisina de la posición 6 y la arginina de la posición 13. La solubilidad del análogo en posición 5 fue mayor que la del análogo en posición 6 en la serie del ácido aspártico; sin embargo, los mejores resultados en adsorción se obtuvieron al sustituir con ácido aspártico la posición 6, mientras que el análogo con el ácido aspártico en la posición 5 no presentó adsorción a las mismas condiciones. El análisis estructural por resonancia magnética nuclear mostró diferencias en la extensión de la estructura helicoidal entre estos análogos. El ácido aspártico en la posición 6, localizado en la cara polar de la hélice, podría permitir a este análogo ajustarse mejor sobre los sitios de adsorción, sugiriendo que la carga electrostática local es la responsable de este comportamiento.
ABSTRACT
BACKGROUND: It has been reported that Korean Red Ginseng saponins are effective in increasing the synthesis of serum proteins, in cellular proliferation, in producing antibody against sheep red blood cells, and in various cancer. However, there have been no reports yet on the immunomodulating activity of this allergic disease. OBJECTIVE: This study was conducted to find the immunomodulating activity of a single highly purified ginsenoside, Rb1, by using ovalbumin(OVA) as the antigen. METHOD: BALB/c mice were immunized subcutaneously with OVA containing the alum or ginsenoside, Rb1, twice per 2wk interval. Antigen-specific antibodies and IgG subclasses were determined from serum recovered by cardiac puncture 2 wk after the second immunization by using ELISA method. Antigen-specific cellular proliferation and cytokines were quantified from splenotes obtained from spleens immunized. Cytokine level in cell culture supernatants were determined by ELISA method. NK cell cytotoxicity was generated by co-culture of splenic mononuclear cells against YAC-1 cells as target cells. Hemolytic activity of Rb1 was determined by an in vitro assay using sheep red blood cells. RESULTS: BALB/c mice immunized with OVA plus Rb1 produced significantly higher titers of antibodies than mice immunized with alum-adsorbed antigen. Rb1 remarkably increased titers in IgG2a and IgG2b subclasses. Antigen-specific proliferative response was more significantly increased with the use of Rb1 than with alum-adsorbed antigen. Rb1 reduced IL-4 production, increased IL-10 production more than alum-adsorbed OVA, but did not affect the IFN-gamma production. High concentration of Rb1 increased the splenic mononuclear cells that were capable of killing YAC-1 cells. Rb1 did not stimulate the production of reaginic antibody (IgE) but alum was able to induce it. Rb1 did not show any hemolytic activity up to 500microgram/ml. CONCLUSION: The data suggest that the highly purified ginsenoside extracted from Korean Red Ginseng Radix, Rb1, can actively influence the switch of Igs produced by OVA. The data also suggest that Rb1 may be an immunosurveillant in NK cytotoxic activity.