Immune reactivity to food coloring.

Artificial food dyes are made from petroleum and have been approved by the US Food and Drug Administration (FDA) for the enhancement of the color of processed foods. They are widely used in the food and pharmaceutical industries to increase the appeal and acceptability of their products. Synthetic food colorants can achieve hues not possible for natural colorants and are cheaper, more easily available, and last longer. However, since the use of artificial food coloring has become widespread, many allergic and other immune reactive disorders have increasingly been reported. During the past 50 y, the amount of synthetic dye used in foods has increased by 500%. Simultaneously, an alarming rise has occurred in behavioral problems in children, such as aggression, attention deficit disorder (ADD), and attention-deficit/hyperactivity disorder (ADHD). The ingestion of food delivers the greatest foreign antigenic load that challenges the immune system. Artificial colors can also be absorbed via the skin through cosmetic and pharmaceutical products. The molecules of synthetic colorants are small, and the immune system finds it difficult to defend the body against them. They can also bond to food or body proteins and, thus, are able to act in stealth mode to circumvent and disrupt the immune system. The consumption of synthetic food colors, and their ability to bind with body proteins, can have significant immunological consequences. This consumption can activate the inflammatory cascade, can result in the induction of intestinal permeability to large antigenic molecules, and could lead to cross-reactivities, autoimmunities, and even neurobehavioral disorders. The Centers for Disease Control (CDC) recently found a 41% increase in diagnoses of ADHD in boys of high-school age during the past decade. More shocking is the legal amount of artificial colorants allowed by the FDA in the foods, drugs, and cosmetics that we consume and use every day. The consuming public is largely unaware of the perilous truth behind the deceptive allure of artificial color.

Molecular analysis of original antigenic sin. I. Clonal selection, somatic mutation, and isotype switching during a memory B cell response.

To determine how the memory B cell population elicited to one epitope might be used in immune responses to other, structurally related epitopes, we explored the phenomenon of original antigenic sin. Strain A/J mice reproducibly respond to immunization with p-azophenylarsonate (Ars) by production of anti-Ars antibodies encoded predominantly by a single VH gene segment (VHIdCR). The structural analogue of Ars p-azophenylsulfonate (Sulf) fails alone to elicit such V regions, but can do so in A/J mice previously immunized with Ars, providing a means to specifically examine B cells capable of responding secondarily to a crossreactive antigen (i.e., memory cells). VHIdCR-expressing hybridomas were derived from the Ars-primed, Sulf-boosted original antigenic sin response of A/J mice at various times after Ars priming, and the properties of the antibodies they express and the structure of the genes encoding these antibodies were characterized. The data obtained support the following conclusions: (a) The Ars-induced memory B cell population capable of being crossreactively stimulated by Sulf is largely formed from a small fraction of all B cells participating in the anti-Ars primary response that express somatically mutated V regions; (b) the antibody repertoire and clonal composition of this population are stable over long periods of time; (c) memory B cells are capable of clonal expansion in the absence of a high rate of V gene somatic mutation; (d) the activation requirements for clonal selection of memory, versus naive B cells appear to differ; and (e) a major fraction of Ars-induced memory B cells express either IgM or IgG3 prior to and during the initial stages of the sin response.

Identification of gene expression changes induced by chemical allergens in dendritic cells: opportunities for skin sensitization testing.

Cellular changes within resident skin dendritic cells (DCs) after allergen uptake and processing are critical events in the acquisition of skin sensitization. Here we describe the development of a set of selection criteria to derive a list of potential target genes from previous microarray analyses of human peripheral blood-derived (peripheral blood mononuclear cells (PBMCs)-DCs) treated with dinitrobenzene sulfonic acid for predicting skin-sensitizing chemicals. Based on those criteria, a probing evaluation of the target genes has been conducted using an extended chemical data set, comprising five skin irritants and 11 contact allergens. PBMCs-DCs were treated for 24 hours with various concentrations of chemicals and in each instance the expression of up to 60 genes was examined by real-time PCR analysis. Consistent allergen-induced changes in the expression of many genes were observed and further prioritization of the targets was conducted by analysis of the same genes in DCs treated with non-sensitizing chemicals to determine their specificity for skin sensitization. Real-time PCR analyses of multiple chemical allergens, irritants, and non-sensitizers have identified 10 genes that demonstrate reproducibly high levels of selectivity, specificity, and dynamic range consistent with providing the basis for robust and sensitive alternative approaches for the identification of skin-sensitizing chemicals.

Production of murine monoclonal antibodies against sulcofuron and flucofuron by in vitro immunisation.

Monoclonal murine anti-pesticide antibodies were produced by in vitro immunisation (IVI) of cultured splenocytes with the pesticides sulcofuron and flucofuron. The majority of both anti-flucofuron and anti-sulcofuron antibodies obtained were of the IgM isotype, rather than IgG. When used in an indirect enzyme-linked immunosorbent assay (ELISA), the antibodies bound to plate coating antigens which incorporated haptens that mimicked moieties present within the immunising pesticide. The antibodies exhibited a high degree of specificity, with the degree of cross-reactivity related to the structural similarity between the hapten present in the plate coating antigen and the moieties present within the immunising pesticide. These results indicated that antibodies specific to both sulcofuron and flucofuron had been produced by IVI. Synthesis of both hapten analogues and immunogens as required for methods based on in vivo immunisation was avoided, whilst antibody production was also comparatively more rapid than traditional methods and minimised animal discomfort.

Cell-surface antigenic modifications with trinitrophenyl sulfonate versus trifluoromethyl-dinitrophenyl sulfonate.

The aim of the work was to justify the use of trifluoromethyl-dinitrobenzene sulfonate (CF3-DNBS) modification rather than trinitrobenzene-sulfonate (TNBS) modification, so as to be able to take advantage of the presence of fluorine atoms in the analogue, which allow the analysis of the hapten-carrier bonds by 19F-NMR nuclear magnetic resonance. Cell-surface antigenic modifications brought about by exposure to TNBS or CF3-DNBS were found to be immunologically cross-reactive, both in cell-mediated lymphocytotoxicity and in indirect immunofluorescence. The extent of haptenic derivatizations was found to be of the same order of magnitude, as appraised both by quantitative-absorption studies or by using radioactive hapten, provided that the less chemically reactive CF3-DNBS was used at the concentration of 10 mM and TNBS at the concentration of 1 mM. However, only TNBS-modified cells were sensitive to destruction by antibody-plus-complement-mediated cytotoxicity.

[Effects of Perilla frutescens extract on anti-DNP IgE antibody production in mice].

Perilla frutescens is a Chinese herbal medicine. In this study, we prepared an extract of Perilla frutescens (PFE) and examined its effects on anti-DNP antibody responses in mice. The mice were immunized with DNP-ovalbumin in Alum adjuvant. To examine the effects of PFE on primary antibody responses, PFE was intraperitoneally injected the day before primary immunization. Anti-DNP IgE antibody production was found to be markedly suppressed by PFE injection. Then, we examined the effects on secondary antibody responses. PFE was injected only the day before secondary immunization. Anti-DNP IgE production was markedly suppressed, but IgG response was not so affected. These results suggest that the immunosuppressive effects of PFE are preferentially on IgE production and that PFE may be useful for the suppression of IgE antibody in certain allergic disorders.

In vitro studies on immunotoxic potential of Orange II in splenocytes.

Orange II, an azo dye, is not permitted in food preparations, but high levels of the dye have been detected in different food commodities. Though there are reports on the toxicity of Orange II but knowledge based on the immunomodulatory properties of Orange II is scanty. The present investigation was undertaken to study the in vitro immunotoxic potential of Orange II in splenocytes. Splenocytes were isolated, cultured and subjected to immunophenotypic analysis, mixed lymphocyte reaction (MLR) assay or stimulated with lipopolysaccharide (LPS) or concanavalin A (Con A) for 72 h. The supernatant was collected for cytokine assays. Orange II showed cytotoxic effects at 100-1000µg/ml concentrations and 50µg/ml was determined as the highest non-cytotoxic dose. Orange II at the non-cytotoxic dose (50µg/ml) significantly altered the relative distribution of T and B-cells, MLR response and the mitogen induced proliferative response of T-cells and B-cells. Consistent with the hypo-responsiveness of the T and B-lymphocytes, Orange II induced a concomitant decline in the secretion of cytokines IL-2, IL-4, IL-6, IFN-γ, TNF-α and IL-17. On the contrary, there was an increase in the production of IL-10, an anti-inflammatory regulatory cytokine, which may be one of the causative factor for immunosuppressive property of Orange II. These results suggest that non-cytotoxic dose of Orange II may have immunomodulatory effects.

Systemic immune tuning in renal cell carcinoma: favorable prognostic impact of TGF-ß1 mRNA expression in peripheral blood mononuclear cells.

Renal cell carcinoma (RCC) can inhibit protective immunity by induction of immunosuppressive cells that produce inhibitory cytokines such as interleukin (IL)-10 and transforming growth factor (TGF)-ß. If this immunosuppression influences response to kinase inhibitors such as sorafenib is not known. Therefore, we asked for the prognostic influence of cells with immunosuppressive properties in peripheral blood (pB) in a cohort of metastatic clear cell renal cell carcinoma (mRCC) patients uniformly receiving sorafenib treatment. IL-10 and TGF-ß mRNA levels, regulatory T-cell (Treg) counts, and frequencies of IL-10/TGF-ß producing mononuclear cell subsets were determined in pB from 46 patients with mRCC before receiving sorafenib treatment. Relationship between established clinical and laboratory prognostic factors and outcome were examined by univariate and multivariate Cox regression analysis. IL-10 and TGF-ß1 mRNA levels, and frequencies of CD4(+)CD25high/CD3(+) and CD4(+)CD25highFoxP3(+)/CD3(+)Treg cells were significantly higher in mRCC patients compared with healthy individuals. Monocytes were suggested as main producers of IL-10 and TGF-ß. In a multivariate analysis low ECOG score and-surprisingly-high TGF-ß1 mRNA levels were independently associated with favorable progression-free survival (P=0.005 and P=0.003, respectively) and overall survival (P=0.001 and P=0.039, respectively). In conclusion, mRCC is associated with an immunosuppressive phenotype in peripheral blood. The positive prognostic influence of high TGF-ß1 mRNA expression levels may reflect immune promoting functions of TGF-ß in combined activity with inflammatory cytokines.

Immunomodulatory effects of sorafenib on peripheral immune effector cells in metastatic renal cell carcinoma.

BACKGROUND: Tyrosine kinase inhibitors (TKI) such as sorafenib have substantially improved the prognosis of metastatic renal cell carcinoma (mRCC) patients, but long-term remissions have only been reached with immunotherapy. Sequencing or combining TKI treatment with immunotherapy may represent an attractive therapeutic concept. However, in vitro data have shown that TKI may not only affect tumour cells, but also inhibit signalling in immune effector cells. Therefore, we asked whether sorafenib had an influence on peripheral immune effector cells in a cohort of 35 mRCC patients receiving sorafenib treatment. METHODS: Peripheral blood (pB) samples were analysed at baseline and after 8 weeks of treatment. IL-10 and TGF-ß mRNA levels were quantified by RT-PCR; regulatory T cell (Treg) counts and intracellular cytokine responses (TNF-α, IFN-γ, IL-10 and TGF-ß) of mononuclear cell subsets were determined by flow cytometry after in vitro stimulation with PMA/ionomycin. RESULTS: Sorafenib did not alter the elevated TGF-ß and IL-10 mRNA levels or elevated frequencies of IL-10 and TGF-ß producing monocytes and had no influence on type 1 cytokine responses in pB. CD4+CD25(high) FOXP3+/CD3+ T cells, likely representing Treg cells, decreased during sorafenib therapy. CONCLUSIONS: In vivo, sorafenib treatment was associated with a decrease in frequency of Treg cells without influencing the function of peripheral immune effector cells. Therefore, although sorafenib did not convert the immunosuppressive phenotype associated with mRCC, it seemed to be a possible candidate for combination with immunotherapy.

Enhancing mda-7/IL-24 therapy in renal carcinoma cells by inhibiting multiple protective signaling pathways using sorafenib and by Ad.5/3 gene delivery.

We have determined whether an adenovirus that comprises the tail and shaft domains of a serotype 5 virus and the knob domain of a serotype 3 virus expressing MDA-7/IL-24, Ad.5/3-mda-7, more effectively infects and kills renal carcinoma cells (RCCs) compared to a serotype 5 virus, Ad.5-mda-7. RCCs are a tumor cell type that generally does not express the receptor for the type 5 adenovirus; the coxsackie and adenovirus receptor (CAR). Ad.5/3-mda-7 infected RCCs to a much greater degree than Ad.5-mda-7. MDA-7/IL-24 protein secreted from Ad.5/3-mda-7-infected RCCs induced MDA-7/IL-24 expression and promoted apoptosis in uninfected "bystander" RCCs. MDA-7/IL-24 killed both infected and bystander RCCs via CD95 activation. Knockdown of intracellular MDA-7/IL-24 in uninfected RCCs blocked the lethal effects of conditioned media. Infection of RCC tumors in one flank, with Ad.5/3-mda-7, suppressed growth of infected tumors and reduced the growth rate of uninfected tumors implanted on the opposite flank. The toxicity of the serotype 5/3 recombinant adenovirus to express MDA-7/IL-24 was enhanced by combined molecular or small molecule inhibition of MEK1/2 and PI3K; inhibition of mTOR, PI3K and MEK1/2; or use of the multi-kinase inhibitor sorafenib. In RCCs, combined inhibition of cytoprotective cell signaling pathways enhanced the MDA-7/IL-24-induction of CD95 activation, with greater mitochondrial dysfunction due to loss of MCL-1 and BCL-XL expression, and tumor cell death. Treatment of RCC tumors in vivo with sorafenib also enhanced Ad.5/3-mda-7 toxicity and prolonged animal survival. Future combinations of these approaches hold promise for developing a more effective therapy for kidney cancer.

[Visualization of different types of hapten-cell membrane interaction by fluorine high-field nuclear magnetic resonance]. / Visualisation, par résonance magnétique nucléaíre du fluor a haut-champ, de différents types d'interaction haptène-membrane cellulaire.

Using a high field spectrometer (5.9 Tesla) 19F-NMR spectrum of soluble material from 4 trifluoromethyl 2,6 dinitrobenzene sulphonate (CF3-DNBS) treated murine lymphocytes was recorded. CF3-DNBS is a fluorinated analog of 2,4,6 trinitrobenzene sulphonate (TNBS), and these compounds have been found to create cross-reacting antigenic modifications of cell surface. At least 4 distinguishable signals have been detected, and we think that 19F-NMR could be used to study, at a molecular level, some immunochemical problems concerning modification with TNBS.

Tartrazine: solid-phase radioimmunoassay studies of an azo dye implicated in allergic reactions (azo dyes and allergy).

A solid-phase radioimmunoassay procedure was adapted for the haptenic study of tartrazine, an azo dye implicated in various forms of allergy. Further, the haptenic relationship of tartrazine and aspirin was investigated, since sensitivity of individuals to the two substances is often clinically associated. The specificity of antibody to tartrazine was directed strongly toward a pyrazolone intermediate of the molecule, 1-(4-sulfophenyl)-3-carboxy-5-hydroxy-pyrazole. Aspirin did not cross-react with anti-tartrazine, suggesting that the clinical association of aspirin and tartrazine sensitivity in patients is a nonimmunological phenomenon.

Unresponsiveness in hapten-specific cytotoxic T lymphocytes. I. Characteristics of tolerance induction in adult mice.

These experiments concern the regulation of cytotoxic T lymphocytes (CTL). Here we describe the induction of unresponsiveness in TNP-specific cytotoxic cells generated in vitro. Previous work has shown that i.v. injection of water-soluble TNP (TNBS) prevents in vivo generation of TNP-specific CTL in C3H/HeN mice. In contrast, this report shows that the in vitro generation of TNP-specific CTL from similarly treated C3H/HeN mice is not inhibited. Nevertheless, unresponsiveness in CTL can be induced with TNBS. This unresponsiveness appears to be H-2 linked, since 3 strains of H-2d mice (BALB/c, DBA/2J, and B10.D2) were rendered unresponsive after a single injection of TNBS, whereas 3 strains of H-2k mice (C58/J, C3H/HeN, and CBA/J) were not. This CTL unresponsiveness is antigen specific in both induction and expression. The unresponsiveness is reversed by pretreatment with cyclophosphamide but not by adult thymectomy. Furthermore, the addition of supernatants from Con A-stimulated spleen cells to cultures containing the unresponsive responder cells enhanced the generation of cytotoxic activity. These results suggest that a) the ability to induce TNP-specific CTL unresponsiveness is linked to H-2 loci, b) a regulatory network is involved in the unresponsiveness, which is sensitive to cyclophosphamide but resistant to adult thymectomy, and c) at least 1 level of regulation involves amplifying T cells.

Differential inhibition of contact sensitivity by suppressor T cells and suppressor factor induced by combined treatment with dinitrobenzenesulphonate and dinitrofluorobenzene.

Suppressor T cells acting on the efferent phase (Ts-eff) of dinitrofluorobenzene-contact sensitivity (DNFB-CS) were induced in BALB/c mice by injection of dinitrobenzenesulphonate (DNBSO3) and subsequent painting (sensitization) with DNFB. Ts-eff cells released a suppressor factor, antigen and strain specific, which was active in vivo in sensitized recipients. Administration of DNBSO3 alone generated suppressor T cells, which acted only on the afferent phase (Ts-aff). Suppressor T cells could not be detected in mice painted with DNFB and desensitized later by injection of DNBSO3.

Cytotoxic T cell responses to haptenated cells. III. Isolation and specificity analysis of continuously growing clones.

Various procedures were used to derive continuously growing cytotoxic T lymphocyte (CTL) clones from a primary culture containing responder cells from immunized mice and 3-(p-sulfophenyldiazo)-4-hydroxylphenyl acetic acid (SP)- or fluorescein isothiocyanate (FL)-coupled stimulator cells. It seems likely that CTL have to undergo some change, possibly genetic, to be able to grow continuously in T cell growth factor conditioned medium in the absence of any stimulator or filler cells. The most convenient and reliable procedure to generate CTL clones with different specificities was to establish from several aliquots of a primary culture cell populations continuously growing in medium conditioned with T cell growth factor(s). Clones with different specificities segregated in the different populations. SP- and FL-specific CTL clones restricted to H-2Kk and H-2Dd and two FL-specific CTL clones with no apparent H-2 restriction are described.

Analysis of IgE turnover in non-sensitized and sensitized rats.

BACKGROUND: Although the levels of immunoglobulin E (IgE) in the circulating blood are often elevated in patients with allergic diseases, such levels cannot always be considered as pathognomonic signs of allergy. The induction of allergic reactions in the tissue was inferred to be related to the amount of IgE passing through the vascular wall. AIMS: We attempted to clarify which compartment, the intravascular or extravascular, plays an important role in the regulation of the turnover of rat IgE. METHODS: The level of DNP-specific rat IgE in the serum was estimated by IgE-capture enzyme-linked immunosorbent assay, and the turnover of IgE was analyzed from its pharmacokinetic parameters. RESULTS: The transfer rate constants from the central to tissue compartment (Kct) were larger than those from the tissue to central compartment (Ktc) irrespective of the sensitized state. The value of the distribution volume of the tissue compartment (Vt) was larger than that of the distribution volume of the central compartment (Vc) irrespective of the sensitized state. CONCLUSIONS: These Findings suggest that the short half-life of rat IgE in the circulation could be attributable to the distribution of IgE from the intravascular to the extravascular compartment.

The cellular mechanism of leukocyte adherence inhibition.

Human blood leukocytes from three subjects who had been contact sensitized to dinitrochlorobenzene were used in direct and indirect leukocyte-adherence-inhibition (LAI) reactions in an attempt to elucidate the cellular mechanism of reactivity. The leukocytes were separated and purified by standard procedures. In direct LAI, only T cells or populations containing T cells gave positive reactions (significantly reduced adherence) with the antigen. Supernatants from suitable leukocyte-antigen mixtures contained a soluble leukocyte-adherence-inhibition-factor (LAIF) that reduced the adherence of normal leukocytes. Only T cells or populations containing T cells were active in LAIF production; B cells, granulocytes, and monocytes were inactive. The cellular requirement for the action of preformed LAIF was not restricted: all major types of blood leukocytes were susceptible to its effect.