Oral immunization with a shiga toxin B subunit::rotavirus NSP490 fusion protein protects mice against gastroenteritis

A fusion protein containing the shiga toxin-1 B subunit (STB) linked to a 90 amino acid peptide (aa residues 86--175) from simian rotavirus (SA--11) nonstructural protein NSP4 was synthesized in Escherichia coli. Mice orally inoculated with 60 microg of STB::NSP4(90) fusion protein per dose generated higher humoral and intestinal antibody titers than mice inoculated with 30 microg of NSP4 alone. Serum anti-NSP4 IgG2a isotype titers were substantially greater than IgG1 titers, suggesting a dominant Th1 immune response. ELISA measurement of cytokines secreted from splenocytes isolated from immunized mice confirmed the STB::NSP4(90) fusion protein stimulation of a strong Th1 cell mediated immune response. Diarrhea in SA-11 rotavirus challenged neonates suckling from STB::NSP4 immunized dams was significantly reduced in severity and duration in comparison with virus challenged neonates from unimmunized mice. Together, our experiments demonstrate for the first time that the shiga toxin B subunit provides ligand mediated delivery of virus antigens to the gut-associated lymphoid tissues for enhanced stimulation of humoral and cellular responses against rotavirus gastroenteritis.

Mucosal immunization with a ricin toxin B subunit-rotavirus NSP4 fusion protein stimulates a Th1 lymphocyte response

The castor-oil plant Ricinus communis A-B dimeric toxin B subunit (RTB) was genetically linked at its N-terminus with a 90 amino acid peptide from simian rotavirus SA-11 non-structural protein NSP4(90) and produced in Escherichia coli BL21 cells. Biologically active recombinant NSP4(90)-RTB fusion protein was shown to bind glycoprotein asialofetuin receptor molecules in an in vitro enzyme-linked immunosorbent assay (ELISA). Oral inoculation of the purified NSP4(90)-RTB ligand-antigen fusion protein delivered the chimeric protein to intestinal epidermal cells for mucosal immunization against rotavirus infection. Mice fed the NSP4(90)-RTB fusion protein generated higher humoral and intestinal antibody titers than mice inoculated with NSP4(90) alone. Titers of serum IgG2a antibodies were significantly higher than IgG1 titers suggesting a dominant Th1 lymphocyte immune response. ELISA measurement of cytokines secreted from splenocyte isolated from immunized mice confirmed NSP4(90)-RTB fusion protein stimulates a strong Th1 cell-mediated immune response. The experimental results demonstrate that the ricin toxin B subunit N-terminus can be used as a site for delivery of virus antigens to the gut associated lymphoid tissues for RTB-mediated immune stimulation of antiviral mucosal immune responses.

Antibody microarrays for native toxin detection

We have developed antibody-based microarray techniques for the multiplexed detection of cholera toxin beta-subunit, diphtheria toxin, anthrax lethal factor and protective antigen, Staphylococcus aureus enterotoxin B, and tetanus toxin C fragment in spiked samples. Two detection schemes were investigated: (i) a direct assay in which fluorescently labeled toxins were captured directly by the antibody array and (ii) a competition assay that employed unlabeled toxins as reporters for the quantification of native toxin in solution. In the direct assay, fluorescence measured at each array element is correlated with labeled toxin concentration to yield baseline binding information (Langmuir isotherms and affinity constants). Extending from the direct assay, the competition assay yields information on the presence, identity, and concentration of toxins. A significant advantage of the competition assay over reported profiling assays is the minimal sample preparation required prior to analysis because the competition assay obviates the need to fluorescently label native proteins in the sample of interest. Sigmoidal calibration curves and detection limits were established for both assay formats. Although the sensitivity of the direct assay is superior to that of the competition assay, detection limits for unmodified toxins in the competition assay are comparable to values reported previously for sandwich-format immunoassays of antibodies arrayed on planar substrates. As a demonstration of the potential of the competition assay for unlabeled toxin detection, we conclude with a straightforward multiplexed assay for the differentiation and identification of both native S. aureus enterotoxin B and tetanus toxin C fragment in spiked dilute serum samples.

Production of vaccines against leading biowarfare toxins can utilize DNA scientific technology

There are a significant number of different natural toxins that are potential biological warfare agents against which a vaccine is needed. DNA science has been a key to the development of potential vaccines against the top threat toxin and should contribute such effects for other toxin's vaccines. Several different DNA technological scientific techniques have been used to accomplish the general goals of (1) cloning of the toxin or large toxin fragments, (2) altering the specific gene sequence to obtain high level expression of vaccine candidate production in alternate species (3) placement of the vaccine gene in very different presentation types of species.

Cloning and expression of mistletoe lectin III B-subunit

Aqueous extracts of mistletoe (Viscum album L.) contain toxic proteins (lectins) MLI (viscumin), MLII, and MLIII. We previously cloned the gene encoding MLIII precursor. In the present study, a gene fragment encoding the carbohydrate-binding subunit of mistletoe toxic lectin MLIII was cloned and expressed in Escherichia coli cells. The structure and immunochemical properties of recombinant MLIII B-subunit were investigated using a panel of monoclonal antibodies against ML-toxins. Sugar-binding activity of recombinant MLIII B-subunit was determined by ELISA. Amino acid sequence analysis of the cloned MLIII compared with known mistletoe toxins and other ribosome-inactivating type II proteins (ricin, abrin a, and nigrin b B-subunits) revealed essential features of the recombinant MLIIIB primary structure that could determine sugar specificity of the lectin as well as immunomodulating and anti-tumor properties of mistletoe extracts.

Structure-based preliminary analysis of immunity and virulence of SARS coronavirus

The research on SARS-associated coronavirus (SARS-CoV) has not stopped since its discovery, but the pathogenesis of SARS is still unclear. To explore the possible molecular mechanisms of the invasion and virulence of SARS-CoV, we investigated the structural basis of the viral proteins using computational biology. Forty-five motifs relating to superantigens, toxins and other bioactive molecules were detected in the proteins of SARS-CoV. The results showed that the distribution of the motifs varied in different proteins. Enzyme-like motifs were located in the R protein, while ICAM- 1-like and toxin-like molecules were located in the spike, envelop, nucleocapsid, PUP1, PUP 2 and PUP 4 proteins. Comparison of SARS-CoV with other viruses (OC43, PEDV, HRSV, HHerpV and HAdenoV) showed that each group of motifs was different for each type of virus. Data suggest that the proteins of SARS-CoV with toxic motifs might play crucial roles in targeting host cells and interfering with the immune system. This study provides new information for drug and vaccine design, as well as therapeutic strategies against SARS.

From toxin to adjuvant: basic mechanisms for the control of mucosal IgA immunity and tolerance

We provide compelling evidence that delivery of Ag in the absence of ADP-ribosylation can promote tolerance, whereas ADP-ribosyltransferase activity induces IgA immunity and prevents tolerance. By linking Ag to the ADP-ribosylating enzyme, cholera toxin subunit A1 (CTA1), we could show that the combination of targeting to antigen-presenting cells (APC) and enzymatic activity is a highly effective means of controlling the induction of tolerance or immunity. Firstly, we demonstrated that cholera toxin (CT), although potentially binding to all nucleated cells, in fact, bound preferentially to dendritic cells (DC) in vivo. Following injection of CT-conjugated Ag, we found that DC in the marginal zone (MZ) of the spleen accumulated Ag, a process that was GM1-ganglioside receptor dependent. Contrary to CTB, which also delivered Ag to the MZ DC, CT matured and activated co-stimulatory functions in the targeted DC and greatly augmented immune responses to Ag. Secondly, when Ag was incorporated into the CTA1-DD fusion protein, which equals the CT in adjuvant function but lacks GM1-ganglioside-binding ability, we greatly augmented specific responses to Ag. The DD-bound Ag was distinctly targeted to B cells and probably also to follicular dendritic cells (FDC) in vivo. Thus, in both constructs Ag was targeted to APC and associated with an ADP-ribosylating enzyme, which resulted in greatly enhanced immunogenicity. When the enzymatic activity was absent, as in CT B-subunit (CTB) or in the inactive CTA1R7K-DD mutant, Ag largely failed to stimulate an active immune response. Rather, this type of Ag exposure resulted in Ag-specific tolerance, especially when mucosal delivery of Ag was attempted. Therefore, targeting to APC in the absence or presence of the CTA1-enzyme appears to be an effective means to control tolerance and active protective IgA immunity.

Humoral immune response to rotavirus NSP4 enterotoxin in Spanish children

The rotavirus non-structural protein 4 (NSP4) has been shown to play a crucial role in rotavirus-induced diarrhea, acting as a viral enterotoxin. It has also been demonstrated that antibody to NSP4 can reduce the severity of rotavirus-induced diarrhea in newborn mice. Two recombinant baculoviruses, expressing the NSP4 protein from the SA11 and Wa rotavirus strains, genotypes A and B, respectively, were used to produce and purify these glycoproteins, which were applied as antigen in an enzyme-linked immunosorbent assay (ELISA) to test the specific antibody response to NSP4 in human sera. Serum samples from 30 children convalescing from a rotavirus infection, from 54 healthy children under 5-years-old, and from 49 adults were tested to determine the presence of antibodies to the viral enterotoxin and to rotavirus structural proteins. Seventy percent of the sera from rotavirus-infected children showed an IgG antibody response to either one or both NSP4 proteins used in this study, although the response was weak. However, IgG antibodies towards either one or both NSP4 proteins were only detected in 26% of the non-convalescent healthy children and in only 18% of the adults. No serum IgA antibodies towards NSP4 were found in this study. IgG antibody recognition of the NSP4 protein from the SA11 and Wa rotavirus strains was not always heterotypic.

Tumor-associated CD75s gangliosides and CD75s-bearing glycoproteins with Neu5Acalpha2-6Galbeta1-4GlcNAc-residues are receptors for the anticancer drug rViscumin

The anticancer drug rViscumin, currently under clinical development, has been shown in previous studies to be a sialic acid specific ribosome inactivating protein (RIP). Comparative binding assays with the CD75s-specific monoclonal antibodies HB6 and J3-89 revealed rViscumin to be a CD75s-specific RIP due to identical binding characteristics toward CD75s gangliosides. The receptor gangliosides are IV6nLc4Cer, VI6nLc6Cer, and the newly characterized ganglioside VIII6nLc8Cer, all three carrying the Neu5Acalpha2-6Galbeta1-4GlcNAc motif. To elucidate the clinical potential of the rViscumin targets, CD75s gangliosides were determined in several randomly collected gastrointestinal tumors. The majority of the tumors showed an enhanced expression of CD75s gangliosides compared with the unaffected tissues. The rViscumin binding specificity was further investigated with reference glycoproteins carrying sialylated and desialylated type II N-glycans. Comparative Western blots of rViscumin and ricin, an rViscumin homologous but galactoside-specific RIP, revealed specific recognition of type II N-glycans with CD75s determinants by rViscumin, whereas ricin failed to react with terminally sialylated oligosaccharides such as CD75s motifs and others. This strict binding specificity of rViscumin and the increased expression of CD75s gangliosides in various tumors suggest this anticancer drug as a promising candidate for an individualised adjuvant therapy of human tumors.

[Detection of immune complexes using atomic force microscopy]

Complex formation between immunoglobulins and ligands immobilized on mica was studied by atomic force microscopy in two different systems. In the first system, 60-kDa ligands possessing only one site for antibody recognition were used. In the other system, a more complex interaction of human immunoglobulin with immobilized polyclonal antibodies was studied. In both systems, specific complexes with proper ligand appeared, and unspecific interaction was not detected. The method of revealing immunocomplexes by image atomic force microscopy can be used in the development of modern diagnostic systems.

Mistletoe lectin I is a sialic acid-specific lectin with strict preference to gangliosides and glycoproteins with terminal Neu5Ac alpha 2-6Gal beta 1-4GlcNAc residues

Mistletoe lectin I (ML-I) is a type II ribosome-inactivating protein, which inhibits the protein biosynthesis at the ribosomal level. ML-I is composed of a catalytically active A-chain with rRNA N-glycosidase activity and a B-chain with carbohydrate binding specificities. Using comparative solid-phase binding assays along with electrospray ionization tandem mass spectrometry, ML-I was shown to preferentially bind to terminally alpha2-6-sialylated neolacto series gangliosides from human granulocytes. IV(6)Neu5Ac-nLc4Cer, VI(6)Neu5Ac-nLc6Cer, and VIII(6)Neu5Ac-nLc8Cer were identified as ML-I receptors, whereas the isomeric alpha2-3-sialylated neolacto series gangliosides were not recognized. Only marginal binding of ML-I to terminal galactose residues of neutral glycosphingolipids with a Galbeta1-4Glc or Galbeta1-4GlcNAc sequence was determined, whereas a distal Galalpha1-4Gal, GalNAcbeta1-3Gal, or GalNAcbeta1-4Gal disaccharide did not bind at all. Among the glycoproteins investigated in Western blot and microwell adsorption assays, only those carrying Neu5Acalpha2-6Galbeta1-4GlcNAc residues, exclusively, predominantly, or even as less abundant constituents in an assembly with Neu5Acalpha2-3Galbeta1-4GlcNAc-terminated glycans, displayed high ML-I binding capacity. From our data we conclude that (i) ML-I has to be considered as a sialic acid- and not a galactose-specific lectin and (ii) neolacto series gangliosides and sialoglycoproteins with type II glycans, which share the Neu5Acalpha2-6Galbeta1-4GlcNAc terminus, are true ML-I receptors. This strict preference might help to explain the immunostimulatory potential of ML-I toward certain leukocyte subpopulations and its therapeutic success as a cytotoxic anticancer drug.

Innate immunity and biodefence vaccines

Host defence in vertebrates is achieved by the integration of two distinct arms of the immune system: the innate and adaptive responses. The innate response acts early after infection (within minutes), detecting and responding to broad cues from invading pathogens. The adaptive response takes time (days to weeks) to become effective, but provides the fine antigenic specificity required for complete elimination of the pathogen and the generation of immunologic memory. Antigen-independent recognition of pathogens by the innate immune system leads to the rapid mobilization of immune effector and regulatory mechanisms that provide the host with three critical advantages: (i) initiating the immune response (both innate and adaptive) and providing the inflammatory and co-stimulatory context for antigen recognition; (ii) mounting a first line of defence, thereby holding the pathogen in check during the maturation of the adaptive response; and (iii) steering the adaptive immune system towards the cellular or humoral responses most effective against the particular infectious agent. The quest for safer and more effective vaccines and immune-based therapies has taken on a sudden urgency with the increased threat of bioterrorism. Only a handful of vaccines covering a small proportion of potential biowarfare agents are available for human use (e.g. anthrax and small pox) and these suffer from poor safety profiles. Therefore, next generation biodefence-related vaccines and therapies with improved safety and the capacity to induce more rapid, more potent and broader protection are needed. To this end, strategies to target both the innate and adaptive immune systems will be required.

Production of antibodies and antibody fragments in Escherichia coli and a comparison of their functions, uses and modification

Antibody-based drugs are now used in the clinic, and their importance as therapeutics is expected to increase in the coming decade, both in terms of diseases treated and market value. However, the proportion of patients that can be treated is to some extent affected by the availability and cost of the therapeutic. Therefore, the means of production and purification of the therapeutic entity, as well as the type of therapeutic entity, are of great concern. Escherichia coli represents a good production host in terms of scale and speed of production, but it also has technical and biological limitations. The aim of this review is to describe and discuss the relative benefits and limitations of E coli as a host for the production of antibodies and engineered antibody fragments.

A new antigenic epitope appears in the catalytic subunit of viscumin during intracellular transport

The plant toxin viscumin (60 kD) consists of B- ("binding") and A- ("active") subunits joined by a disulfide bond. The B-subunit is a lectin interacting with galactose-containing glycolipids and glycoproteins of the cell surface. The A-subunit possesses N-glycosidase activity which modifies 28S ribosomal RNA. This results in irreversible inhibition of protein synthesis. After binding and receptor-mediated endocytosis viscumin-containing vesicles are transported to endoplasmic reticulum where the A- (catalytic) subunit is subsequently translocated to cytosol. It is possible that translocation of A-subunit requires its unfolding. For identification of epitopes which might appear during such unfolding, we developed hybridomas producing monoclonal antibodies against denatured viscumin A-chain. Resistance of hybridoma cells to cytotoxic action of viscumin suggests antibody-toxin interaction inside these cells. TA7 hybridoma cells against an epitope which appears only in denatured viscumin are insensitive to the toxin. This suggests that antibody-toxin interaction occurs before transmembrane translocation of the catalytic A-chain into the cytoplasm. Consequently, toxin resistance of TA7 hybridoma cells implies the appearance of a new epitope in viscumin during its intracellular transportation inside of vesicles. Sixty five octapeptides have been synthesized and epitopes have been identified for monoclonal TA7 antibody and immune mouse serum by means of ELISA. Based on the epitopic mapping the peptide A96-ETHLFTGT-T105 was chemically synthesized and binding of this peptide to the monoclonal antibody TA7 and conformation of antigenic determinant (L100-FTGT-T105) was investigated by means of (1)H-NMR spectroscopy.

"Venom" of the slow loris: sequence similarity of prosimian skin gland protein and Fel d 1 cat allergen

Bites inflicted on humans by the slow loris (Nycticebus coucang), a prosimian from Indonesia, are painful and elicit anaphylaxis. Toxins from N. coucang are thought to originate in the brachial organ, a naked, gland-laden area of skin situated on the flexor surface of the arm that is licked during grooming. We isolated a major component of the brachial organ secretions from N. coucang, an approximately 18 kDa protein composed of two 70-90 amino-acid chains linked by one or more disulfide bonds. The N-termini of these peptide chains exhibit nearly 70% sequence similarity (37% identity, chain 1; 54% identity, chain 2) with the two chains of Fel d 1, the major allergen from the domestic cat (Felis catus). The extensive sequence similarity between the brachial organ component of N. coucang and the cat allergen suggests that they exhibit immunogenic cross-reactivity. This work clarifies the chemical nature of the brachial organ exudate and suggests a possible mode of action underlying the noxious effects of slow loris bites.

Detection of rViscumin in plasma samples by immuno-PCR

To allow for pharmacokinetic studies in adjunction with the current clinical developments of the potent cytostatic anti-cancer drug rViscumin, a sandwich immuno-PCR (IPCR) assay was developed for the detection of rViscumin in blood plasma. The IPCR was carried out with a commercially available reagent kit, consisting of pre-assembled rViscumin-specific antibody-DNA conjugates as well as a specific competitor DNA fragment to be amplified by PCR. Various combinations of capture- and detection-antibodies were compared for performance in IPCR. Using the optimized assay, as few as 50 zeptomol (approx. 100 fg/ml) rViscumin (MW 57 kDa) was detectable in standardized human serum samples. The IPCR assay was very selective for rViscumin and in spiking experiments in proband plasma samples, signal recovery rates between 70% and 120% were obtained. The linear sensitivity range of the assay covered more than five orders of magnitude. Repeated measurements of rViscumin resulted in a mean standard deviation value of 14.2%.

Effects of a lectin- and a viscotoxin-rich mistletoe preparation on clinical and hematologic parameters: a placebo-controlled evaluation in healthy subjects

BACKGROUND AND OBJECTIVES

Mistletoe preparations, which are widely used among patients with cancer in Germany, have immunomodulating properties in vitro and in vivo. The aim of this evaluation was to determine and compare the effects of a lectin-rich (Iscador Qu [IQ] special, Weleda Company, Schwäbisch, Gmünd, Germany.) and a lectin-poor but viscotoxin-rich (Iscador Pini [IP] Weleda Company) mistletoe preparation on clinical and hematologic parameters in healthy subjects.

DESIGN

In a double-blinded study, 48 volunteers were randomized to one of three groups: 16 received IQ or IP in increasing doses or placebo twice per week subcutaneously for 12 weeks. The differential blood count and the acute phase markers haptoglobin and C-reactive protein were examined weekly and the symptoms were scored using standardized questionnaires.

RESULTS

IQ resulted in significant eosinophilia (315 +/- 109) beginning at week 5 (until week 12) compared to IP (183 +/- 120) or placebo (200 +/- 179). Furthermore, the acute phase marker haptoglobin was significantly increased in the IQ group during week 4. Dose-dependent local reactions (LRs) at the injection site occurred in all subjects who received mistletoe preparations but were stronger in the IQ-treated subjects than in the IP-treated group. The LRs observed in the IQ-treated group were characterized by stronger itching and longer latency than LRs in the IP-treated group (p < 0.05). Severe side-effects did not occur in any of the probands.

CONCLUSIONS

IQ but not IP can induce eosinophilia in healthy individuals, and this may be related to its content of mistletoe lectins. In contrast, exposure to the viscotoxin-enriched extract IP did not result in specific changes of hematologic parameters. Furthermore, intensity and time course of local reactions seemed to depend on the concentration of mistletoe lectins in those extracts.

1st class ticket to class I: protein toxins as pathfinders for antigen presentation

A number of bacterial toxins have evolved diverse strategies for crossing membrane barriers in order to reach their substrates in the mammalian cytosol. Recent studies show that this property can be exploited for the delivery of fused antigens into the major histocompatibility complex class I-restricted presentation pathway, with the goal of eliciting a specific immune response. Here we discuss the peculiarities of the trafficking pathways of a variety of toxins, and how these may allow the toxins to be used as delivery vehicles for therapeutic and diagnostic purposes.

Mistletoe lectins enhance immune responses to intranasally co-administered herpes simplex virus glycoprotein D2

The mucosal adjuvant properties of the three type 2 ribosome-inactivating proteins (RIPs) from the European mistletoe, Viscum album L., were investigated. Mistletoe lectins were compared with cholera toxin (CT) as adjuvants when delivered nasotracheally together with herpes simplex virus glycoprotein D2 (gD2). All three mistletoe lectins (MLI, MLII, MLIII) were potent mucosal adjuvants. Co-administration of MLI, MLII or MLIII with gD2 led to significantly higher levels of gD2-specific mucosal immunoglobulin A (IgA) and systemic immunoglobulin G (IgG) antibody than when the antigen was delivered alone. The levels of antibodies induced were similar to those generated in mice immunized with gD2 and the potent mucosal adjuvant CT. Administration of ML1 with gD2 enhanced the antigen-specific splenic T-cell proliferative response. Interleukin-5 (IL-5), but not interferon-gamma (IFN-gamma), was detected in supernatants from splenocytes stimulated in vitro with gD2. This indicates that MLI enhanced type 2 T-helper cell (Th2) responses to the bystander antigen, gD2. Analysis of the gD2- and lectin-specific IgG subclass titres in mice immunized with gD2 and MLI, MLII or MLIII revealed a high ratio of IgG1 : IgG2a, which is compatible with the selective induction of Th2-type immune responses.

Induction of antibodies to viscotoxins A1, A2, A3, and B in tumour patients during therapy with an aqueous mistletoe extract

Mistletoe extracts exert immunomodulatory properties on immunocompetent cells of the innate as well as the specific immune system. These effects have been mainly ascribed to mistletoe lectin 1 (ML-1) present in most of the extracts. However, it became evident that also other components of these extracts may induce immunological reactions, and especially viscotoxins (VT) may be of relevance. Aim of the study was, therefore, to evaluate whether VT like ML-1 could activate B-cells and lead to the production of VT-specific antibodies. Sera from 26 patients with different tumours who were treated with the mistletoe extract ABNOBAviscum Mali (AM) 4 for at least 18 weeks were analysed before therapy and after 3, 6, 9, 12, and 18 weeks. Sera were tested by ELISA against the four viscotoxins A1, A2, A3, B, as well as against ML-1. Within the observation period twenty-four (92%) of the 26 patients developed antibodies to at least one of the four VT and 25 (96%) to ML-1. In most instances, anti-VT antibodies appeared after 6-9 weeks of treatment. The antibodies were predominantly of the IgG type belonging preferentially to the IgG1 and IgG3 subclass. IgE antibodies were found only to VT-B and to ML-1. There was no relation between the development of antibodies to VT and ML-1, and also cross-reactivity could be excluded with high probability. These data indicate that not only ML-1 but also VT induce immunological responses in patients treated with mistletoe extracts. Whether there is any relationship to the postulated anti-tumour effect of mistletoe extracts has, however, still to be evaluated.

[Role of the interchain interaction domain of chain a in viscumin cytotoxicity]

The sequence coding for the viscumin (mistletoe lectin I, MLI) A-chain (MLA) was cloned from Viscum album genomic DNA with the use of synthetic primers. This yielded three recombinant (r) MLA variants differing in number of amino acid substitutions. The rMLA structure and properties were probed using monoclonal antibodies against native MLA. Native MLI B-chain (MLB) was shown to facilitate the rMLA folding. Native MLI and chimeric proteins consisting of rMLA and native MLB did not differ in cytotoxic effect on 3T3 fibroblastoid cells. Residues were identified that are located in the MLB-contacting region and have a considerable effect on the immunochemical and cytotoxic properties of rMLA.

[Blood and tissue eosinophilia, mistletoe lectin antibodies and quality of life in a breast cancer patient undergoing intratumoral and subcutaneous mistletoe therapy]

BACKGROUND

Mistletoe therapy (MT) is a method of complementary medicine whose efficacy is controversially discussed. Until now there is a lack of data of high-dose intratumoral application.

PATIENT AND METHODS

We are presenting a 3-year follow-up of an 80-year-old woman with metastasized breast cancer (c(2)T3/N1/M1) receiving combined intra- and peritumoral and subcutaneous MT with ABNOBAviscum(r) and concomitant pamitron acid. At time of admission the patient had bone metastases (thoracic vertebra 11 fracture), a lymphangiosis carcinomatosa, bilateral pleural effusions, and a reduced quality of life (QoL).

RESULTS

Under MT we induced an eosinophilia and an elevation of eosinophil cationic protein (ECP). Simultaneously, we ascertained a reduction of 50% of Ca 15-3 and a sustained partial tumor remission. After 5 months the mistletoe-lectin-1 antibodies IgG-1 and -3 were maximally increased and we perceived a second Ca 15-3 reduction. After 3 months we observed a benefit in QoL. During the following 5 months the patient gained about 10 kg in weight. In the second year slow tumor progress was observed. After 19 months the patient had pneumonia which caused an MT pause. Subsequently, a combined intratumoral mistletoe and letrozol therapy brought a partial remission. The patient lived without chemo and radiation therapy more than 3 years with good QoL and died after 41 months, after a sepsis and a following stroke without signs of tumor progress.

CONCLUSION

In metastasized breast cancer a palliative high-dose local MT can make a contribution to a tumor reduction and a benefit in QoL.

In vivo-induction of antibodies to mistletoe lectin-1 and viscotoxin by exposure to aqueous mistletoe extracts: a randomised double-blinded placebo controlled phase I study in healthy individuals

BACKGROUND

Several studies have been performed in tumour patients to analyse the immunological response to mistletoe extracts. Considering the fact that these extracts are given subcutaneously in most instances, the kind of application resembles a typical immunization schedule. We therefore wanted to see how those extracts act on immunocompetent cells of healthy individuals hoping that this kind of provocation test may give new informations about a more specific application of these extracts in certain diseases.

SUBJECTS/METHODS

47 healthy individuals were exposed for twelve weeks either to Iscador Quercus special (IQ) known to be rich in mistletoe lectin (ML)-1 (n = 16), to Iscador Pini (IP) being poor in ML-1 but enriched in viscotoxins (n = 15), or to placebo (physiological saline) (n = 16) in a randomised, double-blinded placebo-controlled study. Humoral immunoreactivity was analysed by measuring antibodies towards the two compounds ML-1 and viscotoxin VA2 (VA2). Sera were collected in intervals of four weeks up to week 12 and again three months after last exposure.

RESULTS

None of the subjects had antibodies to ML-1 or VA2 before exposure. In week 12, anti-ML-1 antibodies of the IgG-type were found in all 16 IQ-treated individuals but only 6 of the 15 probands exposed to IP. In contrast, anti-VA2 IgG-antibodies could be detected in all individuals of both groups. The antibodies were preferentially of the IgG1 and IgG3 type while antibodies of the IgA and IgM type were produced only in a few probands. Antibodies of the IgE-type occurred only in the IQ-exposed individuals and were directed against ML-1 but not VA2. None of the probands receiving placebo developed antibodies to ML-1 or VA2. Severe side effects were not observed in any of the probands.

CONCLUSIONS

These data obtained in healthy individuals clearly indicate that IQ and IP-extracts can induce antigen-specific humoral responses. They may, therefore, provide, a solid basic for the evaluation of the humoral immune response in disease states.