sapogenins and quillaic-acid

Vaccines require optimal adjuvants including immunopotentiator and delivery systems to offer long term protection from infectious diseases in animals and man. Initially it was believed that adjuvants are responsible for promoting strong and sustainable antibody responses. Now it has been shown that adjuvants influence the isotype and avidity of antibody and also affect the properties of cell-mediated immunity. Mostly oil emulsions, lipopolysaccharides, polymers, saponins, liposomes, cytokines, ISCOMs (immunostimulating complexes), Freund's complete adjuvant, Freund's incomplete adjuvant, alums, bacterial toxins etc., are common adjuvants under investigation. Saponin based adjuvants have the ability to stimulate the cell mediated immune system as well as to enhance antibody production and have the advantage that only a low dose is needed for adjuvant activity. In the present study the importance of adjuvants, their role and the effect of saponin in immune system is reviewed.

Topics: Adjuvants, Immunologic; Animals; Astragalus Plant; Immune System; ISCOMs; Oleanolic Acid; Panax; Sapogenins; Saponins

The iscom is a supramolecular spherical structure, about 40nm in diameter, built up by structure-forming and immunomodulating quillaja triterpenoids, lipids and antigens. Iscoms with a defined quillaja triterpenoid formulation named QH 703 are in human trials. The advantages of using the particulate iscom form of quillaja components are (i) that local reactions at the site of injection can be avoided; a manifold higher dose of quillaja components in iscoms than in free form can be injected without causing side effects; (ii) considerably lower doses of both quillaja components and antigens are required to obtain a certain level of immune response. The iscom particle targets the antigen and adjuvant components to both the endosomal and cytosolic pathways for antigen presentation, resulting in both MHC class I and class II restricted immune responses. Further, iscoms induce APC to produce IL-1, IL-6 and IL-12 and a TH1 type of response with enhanced IL-2 and IFN-gamma production. Iscoms are now constructed to target the mucosal lymphatic systems. Iscoms administered intranasally induce secretory IgA responses in lungs and distant mucosal membranes e.g. in the genital tract.

Topics: Drug Delivery Systems; Humans; Immunity, Cellular; Immunity, Mucosal; ISCOMs; Oleanolic Acid; Sapogenins; Vaccination

Topics: Adjuvants, Immunologic; Animals; Oleanolic Acid; Quillaja Saponins; Sapogenins; Saponins

QS-21 is one of the most promising new adjuvants for immune response potentiation and dose-sparing in vaccine therapy given its exceedingly high level of potency and its favorable toxicity profile. Melanoma, breast cancer, small cell lung cancer, prostate cancer, HIV-1, and malaria are among the numerous maladies targeted in more than 80 recent and ongoing vaccine therapy clinical trials involving QS-21 as a critical adjuvant component for immune response augmentation. QS-21 is a natural product immunostimulatory adjuvant, eliciting both T-cell- and antibody-mediated immune responses with microgram doses. Herein is reported the synthesis of QS-21A(api) in a highly modular strategy, applying novel glycosylation methodologies to a convergent construction of the potent saponin immunostimulant. The chemical synthesis of QS-21 offers unique opportunities to probe its mode of biological action through the preparation of otherwise unattainable nonnatural saponin analogues.

Topics: Adjuvants, Immunologic; Carbohydrate Sequence; Molecular Sequence Data; Oleanolic Acid; Quillaja; Sapogenins; Saponins; Trisaccharides

Ninety-six pigs (initially 8.9 kg and 24 d of age) were used in a 28-d experiment to determine the effects of Quillaja saponaria extract (QS) on weanling pig growth performance and immune function in response to enteric disease challenge with Salmonella typhimurium (ST). Experimental treatments were arranged in a 2 x 4 factorial with main effects of disease challenge (control vs ST-challenge) and dietary addition of QS (0, 125, 250, or 500 mg/kg). Pigs were fed QS diets for 14 d and then challenged orally with ST or sterile media. There were no differences in ADG or ADFI among dietary treatments, but gain/feed ratio (G/ F) was depressed (P < 0.06) in pigs fed 250 mg/kg QS. ST-challenge reduced ADG (P < 0.05), ADFI (P < 0.05), and G/F (P < 0.05) 1 wk after challenge. Daily estimates revealed reductions in feed intake in ST-infected pigs on d 2 to 5 following infection (P < 0.05), and rectal temperature was increased maximally 2 d following infection (P < 0.05). There was a marked decline in serum IGF-I during the 6 d after ST-infection (P < 0.05). ST-challenge produced a rise (P < 0.05) in serum haptoglobin on d 7 after challenge, and serum alpha1-acid glycoprotein (AGP) in ST-challenged pigs also was elevated (P < 0.05) above controls on d 7 and 14 after challenge. Serum immunoglobulin (Ig) M increased (P < 0.05) over time in both groups, and serum IgM of ST-challenged pigs was greater than controls on d 7 after challenge (P < 0.05). Serum IgG was not affected by enteric disease challenge; however, on d 7 and 14 after disease challenge, serum IgG for both groups was greater (P < 0.05) than on d 0. Dietary QS had no significant influence on any of the end points used to characterize the acute phase response to ST-challenge. Phagocytic cell function was depressed in pigs fed 250 (P < 0.05) and 500 (P < 0.05) mg/kg as compared to pigs fed 125 mg/kg QS. Yet, there was no difference in phagocytic function among pigs fed 0, 250, or 500 mg/kg QS. We conclude that this model of enteric disease invokes an acute phase response accompanied by decreases in feed intake and serum IGF-I. Furthermore, dietary QS, at the levels fed in this study, appears to offer little benefit to growth performance or immune function in the presence or absence of ST-challenge.

Topics: Acute-Phase Proteins; Animals; Dietary Supplements; Immunoglobulin G; Immunoglobulin M; Oleanolic Acid; Phagocytosis; Plant Extracts; Salmonella Infections, Animal; Salmonella typhimurium; Sapogenins; Saponaria; Swine; Swine Diseases; Time Factors; Weaning

Quillaja saponins are readily hydrolyzed under physiological conditions, yielding deacylated forms that are significantly less toxic than their precursors. Yet, deacylated saponins are unable to stimulate a strong primary immune response. Although deacylated saponins elicit a strong total IgG response, their capacity to stimulate a Thl type IgG isotype profile (i.e. high levels of IgG2a and IgG2b) has been significantly diminished. Instead, an IgG profile closer to that of a Th2 immune response is stimulated (i.e. high IgG1 levels). Deacylated saponins have also lost their capacity to elicit an effective T cell immunity, as shown by their stimulation of a marginal lymphoproliferative response and their inability to elicit the production of cytotoxic lymphocytes (CTL). Modification of the immune-modulating properties brought by the degradation of quillaja saponins during vaccine storage may change the intended immune response from a Th1 to a Th2 type. This alteration would have negligible effects on vaccines depending on Th2 immunity mediated by neutralizing antibodies. However, the performance of vaccines directed against intracellular pathogens as well as therapeutic cancer vaccines may be seriously affected by the loss of their capacity to stimulate both a Th1 immune response and the production of CTL.

Topics: Adjuvants, Immunologic; Animals; Female; Immunoglobulin G; Mice; Mice, Inbred C57BL; Oleanolic Acid; Ovalbumin; Sapogenins; T-Lymphocytes, Cytotoxic; Th1 Cells; Vaccines

The effects of supplementation of a Quillaja saponin (QS) mixture in the diets of tilapia have been studied using a respirometer system that allowed feeding and continuous measurement of oxygen consumption of individual fish. Five fish each were given control diet (C group) and control diet supplemented with 150 mg kg(-1) (S150 group) or 300 mg kg(-1) (S300 group) QS. At the end of 14 weeks the weight gain of the S300 group was significantly higher than control (P<0.05) whereas that of the S150 group had an intermediate value. The S150 group had a higher growth rate (P=0.05) after the first 3 weeks of feeding with the experimental diets, compared to the other two groups. At the end of the experiment the S300 group had significantly higher (P<0.05) average values for energy retention, apparent lipid conversion, carcass fat, energy and significantly lower (P<0.05) average values for apparently unutilised energy and carcass ash content compared to the C group. The corresponding values of the S150 group were intermediate between the C and S300 groups. One out of two female fish in the S150 group and both female fish in the S300 group never produced eggs during the entire 14-week experimental period. Contrarily, all three female fish in the control group and one out of the two female fish in the S150 group regularly produced eggs, at a rate of approximately once in every 14 days. The muscle cholesterol level in the S300 group was significantly higher than that of the C group. Possible mechanisms of action of the dietary saponins are discussed.

Topics: Animals; Body Weight; Cholesterol; Dietary Supplements; Electron Spin Resonance Spectroscopy; Female; Lipid Metabolism; Muscle, Skeletal; Oleanolic Acid; Oocytes; Oxygen Consumption; Proteins; Reproduction; Respiratory Transport; Sapogenins; Tilapia; Weight Gain

A fraction of saponins from Quillaja saponaria Molina, QH-B, was fractionated by consecutive separations on three different reverse-phase HPLC systems. Eight compounds were isolated and the structures of these were elucidated mainly by sugar analysis and NMR spectroscopy. The structures consisted of a quillaic acid substituted with two different trisaccharides at C-3, beta-D-Galp-(1-->2)-[alpha-L-Rhap-(1-->3)]-beta-D-GlcpA and beta-D-Galp-(1-->2)-[beta-D-Xylp-(1-->3)]-beta-D-GlcpA, and a tetra- or pentasaccharide at C-28, beta-D-Xylp-(1-->4)-[beta-D-Glcp-(1-->3)]-alpha-L-Rhap-(1--> 2)-beta-D-Fucp and beta-D-Apif-(1-->3)-beta-D-Xylp-(1-->4)-[beta-D-Glcp-(1-->3) ]-alpha-L- Rhap-(1-->2)-beta-D-Fucp. These compounds were further substituted with an acyl group either at O-3 or O-4 of the fucose residue, which is the sugar linked to C-28 of the quillaic acid.

Topics: Carbohydrate Sequence; Chromatography, Gas; Chromatography, High Pressure Liquid; Magnetic Resonance Spectroscopy; Mass Spectrometry; Molecular Sequence Data; Oleanolic Acid; Rosales; Sapogenins; Saponins; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Time Factors

Sixteen saponins were identified from a bark extract of Quillaja saponaria Molina. The compounds were characterized, using NMR spectroscopy, mass spectrometry and monosaccharide analysis, as quillaic acid substituted at C-3 with oligosaccharides consisting of a disaccharide, beta-D-Galp-(1-->2)-beta-D-GlcpA substituted with either D-xylose or L-rhamnose and at C-28 with complex oligosaccharide structures consisting of a disaccharide, alpha-L-Rhap-(1-->2)-4-O-acetyl-beta-D-Fucp, substituted with various amount of D-xylose. D-glucose, D-apiose, and L-rhamnose.

Topics: Acetylation; Chromatography, Affinity; Magnetic Resonance Spectroscopy; Methylation; Monosaccharides; Oleanolic Acid; Oligosaccharides; Sapogenins; Saponins; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Trees

We have previously shown that oral immunization with non-replicating antigens hardly induced serum IgG antibody response in chickens and addition of sodium fluoride (NaF) to the immunogen markedly improved their immunological states. In the present study, taurine, lithium and Quillaja saponin (Q-SAP) were compared with NaF with respect to their enhancement of serum IgG antibody response in chickens after oral immunization. The antibody titer of chickens which received Q-SAP as the mucosal adjuvant tended to be higher than that of chickens which received antigen plus NaF. Simultaneous administration of antigen with lithium or taurine elicited a higher antibody titer in chickens compared to those of chickens orally immunized with antigen alone, but the effect of these two adjuvants was less efficient compared with that of NaF. These results suggested that Q-SAP as well as NaF is useful as an oral adjuvant for chickens.

Topics: Adjuvants, Immunologic; Administration, Oral; Animals; Chickens; Immunity, Mucosal; Immunoglobulin G; Lithium; Oleanolic Acid; Sapogenins; Sodium Fluoride; Specific Pathogen-Free Organisms; Taurine; Vaccination

A recombinant form of the EBV envelope glycoprotein and vaccine candidate gp340, lacking its hydrophobic transmembrane region, was incorporated into Iscoms after coupling to phosphatidyl ethanolamine via carbohydrate residues. Coupling by partial oxidation of gp340 carbohydrate with sodium periodate partly denatured the incorporated gp340 as indicated by its reduced reactivity with monoclonal antibodies that recognise the major neutralising epitope. Immunisation of cottontop tamarins with these Iscoms elicited antibody responses to gp340, but these antibodies only poorly recognised the major neutralising epitope in a competition ELISA and were unable to neutralise EBV in vitro. Despite the lack of neutralising antibody, immunisation with these Iscoms primed significant in vitro proliferative responses to soluble gp340 in lymphocytes from the draining lymph nodes and spleen. T-cell lines were raised from both immunised and control animals by in vitro stimulation of peripheral blood lymphocytes or spleen cells with autologous EBV-transformed lymphoblastoid cell lines. The T-cell lines from control animals had higher numbers of CD4+ T-cells than CD8+ T-cells and were not cytotoxic for autologous lymphoblastoid cell lines (LCL). In contrast the lines from immunised animals contained more CD8+ T-cells than CD4+ T-cells and had marked cytotoxicity for autologous LCL.

Topics: Animals; Antibodies, Viral; Antigens, Viral; CD4-CD8 Ratio; Cell Division; Enzyme-Linked Immunosorbent Assay; Herpesvirus 4, Human; ISCOMs; Mice; Oleanolic Acid; Protein Denaturation; Recombinant Proteins; Saguinus; Sapogenins; T-Lymphocytes, Cytotoxic; Vaccination; Viral Matrix Proteins

The immune responses to immunostimulating complexes (iscoms) containing recombinant Epstein-Barr virus (EBV) gp340 envelope protein was evaluated in BALB/c (H-2(d)) and CBA (H-2(k)) mice. Gp340-iscoms were used either with a low content of Quillaja triterpenoid adjuvant (L-iscoms) or supplemented with additional Quillaja adjuvant in the form of iscomatrix (S-iscoms). Class and subclass distribution of anti-gp340 antibodies, EBV-neutralizing antibodies, antigen-specific T cell proliferation and cytokine production were determined and these results compared to those obtained by immunization with non-adjuvated gp340. The H-2(d) and H-2(k) mice were characterized as low or high responders in respect to the level of specific anti-gp340 antibodies, secretion of IgG2a isotype, antigen-specific lymphoproliferative capacity, interferon-gamma (IFN-gamma) and interleukin-10 (IL-10) production in the basic immunizations with gp340. While presentation of the antigen in iscom formulations with low levels of Quillaja triterpenoids induces a moderate enhancement of the immune responses in the low responder H-2(d) mice, supplementation with high levels of iscomatrix immunomodulator was required to enhance the immune responses in the high responder H-2(k) mice. In both mouse strains subcutaneous immunization with S-iscoms resulted in a significant increase of IgG1- and IgG2a-specific antibodies, as well as in strong antigen-specific proliferative response confirmed by the simultaneous cytokine production. The enhanced antigen-specific secretion of IL-2 and IFN-gamma together with the abrogation of IL-10 and the absence of IL-4 indicates that the responses were driven towards a Th1-type rather than Th2-type immune response. The S-iscom formulations minimized the differences in immune responses between the two mouse strains, but the capacity of immune sera to neutralize EBV transformation in vitro remained completely strain-dependent. These data indicate that immune responses generated by iscoms can be manipulated by altering the triterpenoid composition of the iscoms and that the levels of triterpenoids can determine whether or not a Th1-type response is made.

Topics: Adjuvants, Immunologic; Animals; Antibodies, Viral; Binding, Competitive; Cytokines; Epitopes; Female; Herpesvirus 4, Human; ISCOMs; Mice; Mice, Inbred BALB C; Mice, Inbred CBA; Neutralization Tests; Oleanolic Acid; Sapogenins; Triterpenes; Viral Matrix Proteins