Correlation of the levels of DNA-binding inhibitor Id3 and regulatory T cells with SLE disease severity

E proteins, a subset of basic helix-loop-helix (bHLH) proteins, are transcription activators and their functions are inhibited by DNA-binding inhibitor (Id) 1-4. Studies have shown that Treg levels are decreased in Id3 knockout mice. Mice over-expressing Id1 in CD4 T cells possessed a greater number of regulatory T cells (Treg) and exhibited attenuated experimental autoimmune encephalomyelitis (EAE). The significance of Id proteins in human systemic lupus erythematosus (SLE) remains unclear. In this study, we systematically analyzed Id transcription in naïve, memory CD4 cells and regulatory T cells in peripheral blood mononuclear cells (PBMCs) in patients with active or inactive SLE. In parallel, Treg subsets in PBMCs were analyzed using different strategies. Id expression levels were correlated with Treg numbers as well as clinical indicators. We found that Id genes expressed in human peripheral CD4 cells were mainly Id2 and Id3. Id3 levels were significantly elevated in CD4⁺CD25^hi T cells of patients with active SLE. Likewise, Id3 levels were positively correlated with increased CD4⁺FoxP3⁺ and CD4⁺Helios⁺FoxP3⁺ Treg cells in these patients. Id3 levels were found to be positively correlated with erythrocyte sedimentation rate (ESR), lupus anticoagulant (LAC), ribosomal antibody and SLE Disease Activity Index (SLEDAI) in patients with active SLE. Mice overexpressing Id1 in CD4⁺ T cells possessed significantly higher Treg levels in spleen and lower autoantibody concentrations in serum. Our results suggest that during the pathogenesis of SLE, up-regulation of Id3 can promote Treg differentiation to play an inhibitory effect on autoimmune responses.

Ecto-ATPase CD39 Inactivates Isoprenoid-Derived Vγ9Vδ2 T Cell Phosphoantigens

In humans, Vγ9Vδ2 T cells respond to self and pathogen-associated, diphosphate-containing isoprenoids, also known as phosphoantigens (pAgs). However, activation and homeostasis of Vγ9Vδ2 T cells remain incompletely understood. Here, we show that pAgs induced expression of the ecto-ATPase CD39, which, however, not only hydrolyzed ATP but also abrogated the γδ T cell receptor (TCR) agonistic activity of self and microbial pAgs (C5 to C15). Only mevalonate-derived geranylgeranyl diphosphate (GGPP, C20) resisted CD39-mediated hydrolysis and acted as a regulator of CD39 expression and activity. GGPP enhanced macrophage differentiation in response to the tissue stress cytokine interleukin-15. In addition, GGPP-imprinted macrophage-like cells displayed increased capacity to produce IL-1β as well as the chemokine CCL2 and preferentially activated CD161-expressing CD4(+) T cells in an innate-like manner. Our studies reveal a previously unrecognized immunoregulatory function of CD39 and highlight a particular role of GGPP among pAgs.

Usage tests of oak moss absolutes containing high and low levels of atranol and chloroatranol

Atranol and chloroatranol are strong contact allergens in oak moss absolute, a lichen extract used in perfumery. Fifteen subjects with contact allergy to oak moss absolute underwent a repeated open application test (ROAT) using solutions of an untreated oak moss absolute (sample A) and an oak moss absolute with reduced content of atranol and chloroatranol (sample B). All subjects were in addition patch-tested with serial dilutions of samples A and B. Statistically significantly more subjects reacted to sample A than to sample B in the patch tests. No corresponding difference was observed in the ROAT, though there was a significant difference in the time required to elicit a positive reaction. Still, the ROAT indicates that the use of a cosmetic product containing oak moss absolute with reduced levels of atranol and chloroatranol is capable of eliciting an allergic reaction in previously sensitised individuals.

Immunomodulatory effects of the aromatic geranyl derivative filifolinone tested by the induction of cytokine expression

Fish farming crops are constantly exposed to infectious diseases due to intensive production conditions under which microorganisms develop and spread easily, resulting in severe economic losses. The massive use of antibiotics to control these diseases has lead to the accumulation of residues and the development of drug resistance. Consequently, it is urgent to develop new pharmacological tools to stimulate protective immune responses in salmonids to combat infectious diseases. We evaluated the immunostimulant activity of terpenoid derivatives isolated from species of the Heliotropium genus, which had previously shown antiviral activity in salmon. The immunomodulatory effects of the 3 H-spiro [1-benzofuran-2,1'-ciclohexane] derivative called filifolinone, were studied in vitro using the SHK-1 cell line derived from leucocytes of salmon head kidney and in vivo in Atlantic salmon. For the evaluation, we studied the effect of this compound in the expression of various cytokines. The results showed that Filifolinone increases the levels of expression of pro-inflammatory and anti-inflammatory cytokines. This suggests that Filifolinone is a potential alternative immunomodulator for veterinary purposes.

QSAR, docking and in vivo studies for immunomodulatory activity of isolated triterpenoids from Eucalyptus tereticornis and Gentiana kurroo

Two triterpenoids ursolic acid (1) and lupeol (2) isolated and characterized from Eucalyptus tereticornis and Gentiana kurroo were subjected to in silico QSAR modeling and docking studies and later the predicted results were confirmed through in vivo experiments. QSAR modeling results showed that both the triterpenoids possess immunomodulatory and anti-inflammatory activity comparable to boswellic and cichoric acids, but were less active than levamisol. Docking results suggested that both the triterpenoids (1 and 2) showed immune modulatory and anti-inflammatory activity due to high binding affinity to human receptors viz., NF-kappaB p52 (-50.549 kcal/mol), tumor necrosis factor (TNF-alpha) (-47.632 kcal/mol), nuclear factor NF-Kappa-B P50 (-16.798 kcal/mol) and cyclooxygenase-2 (-55.244 kcal/mol). Further both the triterpenoids (1 and 2) were subjected to in vivo immunomodulatory activity in female Swiss albino mice. The experimental mice were divided into nine groups, each comprised of six mice. These received oral treatment for a period of 28 days. The triterpenoids (1 and 2) showed significant increased in humoral immune function, but no significant changes were observed in cell mediated immune response and hematological parameters. The in silico and in vivo experimental data suggested that both the triterpenoids 1 and 2 may be considered as potential immunomodulatory drug-like molecules.

Allergic contact cheilitis due to geraniol in food

Fragrance materials are present in many foods and are referred to as flavours and spices. However, despite their widespread use, there are few reports of allergic contact dermatitis caused by these additives. Here, we report contact allergy to geraniol in a patient who developed cheilitis on exposure to certain foods.

Dissection of the genetic complexity of arthritis using animal models

Rheumatoid arthritis (RA) is a chronic inflammatory disease directed towards peripheral joints. As all common diseases it is associated with several genes and a multitude of environmental factors. In addition, in similarity with most other complex diseases, it is defined only on the basis of clinical signs and symptoms, it is therefore more properly classified as a syndrome rather than a distinct disease entity. This complexity of RA has led to difficulties in finding the underlying genes. In spite of large efforts it is still only the MHC class II region that reaches genome wide significance in confirmed studies. However, this has been known for decades and we are still unable to conclusively identify the underlying gene/s. We hypothesize that an MHC class II gene is involved and although we have detailed knowledge on both structure and function we do not know its possible pathogenic role in RA. In this review I will argue for the usefulness of animal models as a tool to identify genes and pathways associated with disease. The examples to be discussed are genes controlling the oxidative burst pathways and MHC class II genes.

Colophonium and Compositae mix as markers of fragrance allergy: Cross-reactivity between fragrance terpenes, colophonium and Compositae plant extracts

The aim of this study was to assess the strength of any association between sensitization to 'new' fragrance compounds and sensitization to Compositae, fragrance mix, Myroxylon pereirae resin and colophonium, respectively. Consecutive eczema patients were tested with a series of essential oils and selected fragrance compounds and another series of oxidized terpenes in connection with European multicentre fragrance projects. Contact allergy to either series was frequently detected, in 5% of 318 and 4.6% of 262 persons tested, and both had a statistically significant association with Compositae, colophonium and fragrance mix sensitization. The individual results indicated that simultaneously occurring positive reactions to essential oils, colophonium and Compositae were based on cross-reactivity rather than concomitant sensitization. Thus, all patients with positive reaction to the rare fragrance sensitizer beta-caryophyllene had positive colophonium reactions, and cross-reactivity between essential oils and Compositae was related to the Compositae plant extracts of the Compositae mix and not the pure sesquiterpene lactones of the standard series. The implication is that Compositae mix and colophonium may be markers of fragrance allergy, which is important to know when assessing the relevance of positive reactions to Compositae plant extracts and colophonium.

Pristane-induced autoimmunity in germ-free mice

Hypergammaglobulinemia and autoantibodies are reduced in pristane-treated specific pathogen-free mice vs. conventionally housed controls, consistent with the role of microbial stimulation in this model. To determine whether microbial stimulation is required, BALB/c mice housed under germ-free conditions were treated i.p. with sterile PBS or pristane and examined 6 months later. As in conventional mice, pristane-treated germ-free mice developed peritoneal granulomas and hypergammaglobulinemia with increased IgG2a/IgG1 ratios. LPS stimulation induced more IL-6, IL-12, and TNF-alpha, and anti-CD3 induced more IFN-gamma and IL-4 by peritoneal cells from pristane-treated mice vs. control. Anti-nRNP/Sm and -Su autoantibodies were found in 40% and 43%, respectively, of pristane-treated germ-free mice by immunoprecipitation. Thus, bacterial stimulation was not required for lupus autoantibodies, peritoneal granuloma formation, hypergammaglobulinemia, or cytokine overproduction. Although microbial stimulation acts synergistically with pristane, these results clearly indicate that pristane does not act merely by increasing exposure to microbial products such as LPS.

Immune reactivity to connective tissue antigens in pristane induced arthritis

OBJECTIVE

Pristane induced arthritis (PIA) is a seropositive experimental murine model that closely resembles rheumatoid arthritis (RA). Immune reactivity to a broad spectrum of autoantigens has been recognized in this disease model. We investigated the specificity of the autoimmune response in PIA to determine whether reactivity to connective tissue antigens is associated with the development of arthritis.

METHODS

DBA/1 mice were injected with pristane and evaluated for development of joint disease and autoimmunity. Lymph nodes, spleen, sera, and arthritic paws were investigated at 1, 2, 4, 6, 9, and 12 months postinjection. T cell responses to 16 different joint components were evaluated using proliferation assays, and sera were assayed by ELISA for antibodies to these joint antigens. Cytokine concentrations after antigenic stimulation were assessed by ELISA in cultured cell supernatants and by real-time polymerase chain reaction using mRNA from spleens and arthritic paws.

RESULTS

ELISA revealed positive responses to glucose-6-phosphate isomerase, chondroitin sulfate B, collagen I, collagen II, aggrecan, and DNA between 4 and 12 months post-pristane injection. In vitro tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), and interleukin 6 (IL-6) responses were detected during reactions to most antigens tested, while IL-4 responses were absent. Cytokine analysis in arthritic joints revealed consistent expression of IL-1, IL-4, IL-6, TNF-alpha, and IFN-gamma mRNA.

CONCLUSION

These results indicate that PIA animals develop both T cell and antibody responses to a broad spectrum of connective tissue antigens. Biglycan, aggrecan, and decorin may be relevant antigens in the pathogenesis of PIA, but no specific reaction pattern could be associated with the occurrence of disease. The data suggest that the development of pristane arthritis is not dependent upon reactivity against a single connective tissue antigen, but is a polyspecific autoimmune response to joint components elicited in pristane injected mice.

The effects of formulation on the immunostimulatory activity of dihydroheptaprenol

Holstein steer calves received a single injection of Miglyol (Sasol Chemical Industries, Ltd.) subcutaneously as a placebo, dihydroheptaprenol (DHP) (4 mg/kg) emulsified with lecithin subcutaneously, DHP in solution in Miglyol (4 mg/kg) subcutaneously, or DHP in solution in Miglyol (4 mg/kg) intranasally. The DHP emulsified in lecithin emulsion administered subcutaneously caused a substantial increase in body temperature, total leukocyte count, total neutrophil count, neutrophil cytochrome-c reduction, and neutrophil iodination 24 hours after administration and, for some of the parameters, at 48 hours. The DHP formulation in Miglyol did not have any of these effects when administered subcutaneously or intranasally. The carrier and formulation of DHP apparently have major effects on the biologic activity of DHP.

Oxidized citrus oil (R-limonene): a frequent skin sensitizer in Europe

BACKGROUND

Peel oil from citrus fruits consists of R-(+)-limonene, which is one of the most commonly used fragrance materials in technical products and in fine fragrances. This substance forms allergenic oxidation products during handling and storage.

OBJECTIVE

We wanted to study the frequency of allergic reactions to oxidized R-(+)-limonene in patients with dermatitis and find a suitable test preparation.

METHOD

Patch testing with oxidized R-(+)-limonene was performed on 2273 patients at 4 dermatology clinics in Europe.

RESULTS

Of the consecutive patients tested, 3.8% to 3.9% had positive reactions in two of the clinics; 6.5% had positive reactions in the third clinic; and 0.3% had positive reactions in the fourth clinic. A total of 63 patients showed positive reactions. In total, 57% of the patients did not react to fragrance mix or balsam of Peru. We recommend testing with 3% oxidized R-(+)-limonene in patients referred for patch testing.

CONCLUSION

The high frequency of oxidized limonene allergy provides clinical evidence for the European classification of R-(+)-limonene that contains oxidation products as skin sensitizers.

Modulation of multiple experimental arthritis models by collagen-induced arthritis quantitative trait loci isolated in congenic rat lines: different effects of non-major histocompatibility complex quantitative trait loci in males and females

OBJECTIVE

Collagen-induced arthritis (CIA) is a model of inflammatory arthritis with many similarities to rheumatoid arthritis (RA). We previously mapped in F(2) offspring of CIA-susceptible DA and CIA-resistant F344 rats, 5 quantitative trait loci (QTLs) for which F344 alleles were associated with reduced CIA severity. In the present study, we sought to characterize the independent arthritis-modulating effects of these 5 QTLs.

METHODS

CIA-regulatory regions were transferred from the F344 genome to the DA background or vice versa by repeated backcrossing. The arthritis-modulating effects of the transferred alleles were determined by comparing the severity of experimentally induced arthritis in congenic rats with that in DA rats.

RESULTS

Congenic lines with either the F344 major histocompatibility complex (MHC) on the DA background or the DA MHC on the F344 background were resistant to CIA, confirming both MHC and non-MHC contributions to the genetic regulation of CIA. F344 alleles at the Cia3 and Cia5 regions of chromosomes 4 and 10 reduced CIA severity relative to that observed in DA rats. F344 Cia4 and Cia6 regions of chromosomes 7 and 8 failed to significantly alter CIA severity. Arthritis-modifying effects of Cia4 and Cia6 were, however, detected in pristane-induced and/or Freund's incomplete adjuvant oil-induced arthritis. The arthritis-modifying effects of the non-MHC CIA-regulatory loci differed in males and females.

CONCLUSION

These congenic lines confirmed the existence and location of genes that regulate the severity of experimental arthritis in rats. Mechanisms responsible for the sex-specificity of individual arthritis-regulatory loci may explain some of the sex differences observed in RA and other autoimmune diseases in humans.

Distribution and immune responses resulting from oral administration of D-limonene in rats

We investigated the relationship between the absorptive pathway and the immune responses of the lung, particularly the phagocytic function of alveolar macrophages (Mphi) after oral administration of D-limonene in rats. D-Limonene was orally administered in oily solution with a stomach tube in thoracic duct-cannulated rats, and the lymphatic output of D-limonene was measured. D-Limonene levels reached a maximum in thoracic duct lymph and lung 3 h after its oral administration. It also significantly increased in bronchoalveolar lavage fluid (BALF) and alveolar Mphi, in which there was frequently a focal exudation of lipid droplets containing D-limonene into the alveolar cavity through alveolar capillary walls. Second, D-limonene orally given to rats (250, 500, 1,000 mg/kg/d) for 8 consecutive days resulted in a marked increase in both the number and the phagocytic activity of alveolar Mphi compared to the controls. BALF from rats dosed with D-limonene (1,000 mg/kg/d) enhanced the phagocytic activity of alveolar Mphi from control rats because the dose was prolonged. The activity of alveolar Mphi following in vitro incubation with D-limonene also increased in a dose-dependent manner. An oral administration of D-limonene enhanced the Con A-stimulated proliferation of splenocytes. These results suggest that D-limonene taken up from the thoracic duct lymph moves to the lung and directly activates the immune response of alveolar MO there, or indirectly activates it through activated lymphocytes.

Free radicals in antigen formation: reduction of contact allergic response to hydroperoxides by epidermal treatment with antioxidants

BACKGROUND

For patients with allergic contact dermatitis, the main therapy is anti-inflammatory steroids, a non-specific and symptomatic treatment. In contact allergy, the antigen formation is considered to be the binding of a chemical (hapten) to a biological macromolecule, e.g. a protein. Limonene-2-hydroperoxide (Lim-OOH) is a hapten with a known allergenic effect. It is likely to bind to proteins in the skin via a radical mechanism. It might be possible to inhibit the allergic reaction by epidermal application of substances that can trap free radicals, e.g. antioxidants such as ascorbic acid or alpha-tocopherol, prior to the application of the hapten.

OBJECTIVES

To study the influence of antioxidants on the allergenic effect of Lim-OOH in sensitization experiments on guinea pigs.

METHODS

Pretreatment with the antioxidants was performed before induction to study the effect on sensitization as well as before challenge testing to study the effect on elicitation.

RESULTS

A reduction in the response rate was found both at sensitization and at elicitation. The antioxidants had no effect on cobalt allergy or on the allergenic effect of haptens that form antigens via nucleophilic-electrophilic reactions. No reduction of the effect was seen for irritants.

CONCLUSIONS

The protective effect of antioxidants in elicitation could be of practical therapeutic value, as it indicates a possibility for the treatment of patients who have become sensitized to haptens that form full antigens via a radical mechanism.

Extra-articular cartilage affected in collagen-induced, but not pristane-induced, arthritis models

Rheumatoid arthritis (RA) is a chronic inflammatory disease primarily affecting cartilaginous joints but also extra-articular tissues such as the nose and upper respiratory tract. We have investigated extra-articular cartilage involvement in two commonly used animal models for RA, collagen-induced and pristane-induced arthritis, by immunizing rats with different susceptibility to disease (LEW.1 A, LEW.1F and DA rats). We found that nasal and tracheolaryngeal cartilage is affected in LEW.1 A and DA rats to varying degrees in collagen-induced arthritis but not in any strain in the pristane-induced model. Antibodies to matrilin-1, a cartilage-specific protein expressed mainly in tracheolaryngeal and nasal cartilage but not in joints, were positively associated with the presence of inflammation in nasal cartilage. In contrast, no antibody response to matrilin-1 could be detected in pristane-induced arthritis. In addition, nasal vaccination with collagen type II prior to immunization in DA rats significantly decreased the antibody response to matrilin-1 at day 56, but not at earlier time points, indicating a late protective effect on extra-articular cartilage. We conclude that pristane-induced arthritis is a joint-specific model whereas collagen-induced arthritis affect joints as well as extra-articular cartilage. Furthermore, collagen immunization induces an antibody response to matrilin-1.

Amelioration of arthritis in two murine models using antibodies to oncostatin M

OBJECTIVE

Oncostatin M (OSM) is a member of the interleukin-6 cytokine family, with well-documented effects on cell growth and differentiation. OSM also has proinflammatory and cartilage degradative properties. The aim of this study was to investigate the significance of OSM in arthritis pathology using a neutralizing antibody in arthritis models.

METHODS

Collagen-induced arthritis (CIA) was established in male DBA/1 mice. Reverse transcriptase-polymerase chain reaction was used to detect OSM messenger RNA (mRNA) message levels in arthritic joints. Neutralizing anti-OSM antibody or control immunoglobulin was administered on days 1 and 3 after disease onset. Animals were assessed for clinical arthritis for 2 weeks, followed by a histologic analysis of paws. Pristane-induced arthritis (PIA) was produced in male CBA mice dosed with anti-OSM or control immunoglobulin immediately before disease onset. Mice with PIA were assessed for clinical arthritis over a period of 100 days.

RESULTS

Levels of mRNA for OSM, but not GAPDH, were elevated in arthritic joints of mice with CIA compared with those of normal controls. Mice with CIA treated with anti-OSM antibody showed significant amelioration of both the clinical severity (P < 0.01) and the number of affected paws (P < 0.01) compared with control animals. Histologic analysis confirmed these clinical findings, revealing a marked reduction in cellular infiltration of synovium and cartilage damage. In the PIA model, the incidence of arthritis was 65% in the control group compared with 0% in the anti-OSM-treated animals.

CONCLUSION

These results demonstrate a key role for endogenously produced OSM as a potent mediator of joint pathology, and suggest that OSM might be a potentially important, novel therapeutic target for treatment of established rheumatoid arthritis.

Mechanism of the antigen formation of carvone and related alpha, beta-unsaturated ketones

In the present study, the mechanism for the antigen formation of alpha, beta-unsaturated ketones was investigated. A series of analogues of carvone ((5R)-5-isopropenyl-2-methyl-2-cyclohexenone) with altered chemical reactivity and with retained overall structure or with retained reactivity and altered three-dimensional structure were synthesized. These analogues were tested for cross-reactivity in carvone-sensitized animals. Cross-reactivity was observed for analogue 3 ((5R)-5-isopropyl-2-methyl-2-cyclohexen-1-one). No cross-reactions were observed for analogues 1 ((2R,5R)-5-isopropenyl-2-methyl cyclohexanone) and 4 ((5R)-2,3-dimethyl-5-isopropenyl-2-cyclohexene-1-one). Both those compounds also failed to induce sensitization. These findings demonstrate that alpha, beta-unsaturated ketones form antigens after a nucleophilic attack at the beta-carbon with soft nucleophiles such as thiol in cysteine and not with the formation of a Schiff's base after a nucleophilic attack at the carbonyl carbon with nitrogen nucleophiles. Furthermore, no cross-reactivity was observed between R- and S-carvone indicating the importance of the 3-dimensional structure of haptens (and antigens) in T-cell recognition. The analogues were also tested for cross-reactivity on patients allergic to carvone. The results from the animal study were confirmed.

Characterization of T cell responses to fragrances

Fragrances are worldwide a major cause of allergic contact dermatitis (ACD), a delayed-type hypersensitivity reaction mediated by T lymphocytes. We investigated T cell responses to fragrances using peripheral blood mononuclear cells (PBMC) and T cells from skin lesions of fragrance-allergic patients. The components of a fragrance mixture (eugenol, isoeugenol, geraniol, oak moss, alpha-amyl cinnamic aldehyde, cinnamic aldehyde, cinnamic alcohol, and hydroxycitronellal) that is commonly used in the patch test were studied in vitro in the lymphocyte transformation test (LTT). PBMC from fragrance-allergic patients (n = 32) showed significant stimulations to all eight fragrances. The calculated stimulation indices (SI) varied between 2.1 and 21.8. The influence of metabolic enzymes on T cell stimulation was studied for two fragrances. Interestingly, stimulation of eugenol and isoeugenol was increased in the presence of antigen-modified human liver microsomes (CYP450) or recombinant CYP1A1 in five of seven cases. Furthermore, we established 18 T cell clones (TCC) from a skin lesion reacting specifically to eugenol. FACS analysis revealed that the majority (n = 15, 83%) of TCC were CD3(+), CD4(+), and HLA-DR(+). Seventeen percent (n = 3) of the clones were CD8(+). TCC (n = 4) released significant amounts of IL-2 and IFN-gamma but no IL-4 and IL-5. In addition, CD4(+) TCC (n = 3) showed antigen-induced cytotoxic activities against autologous B cells. In summary, we demonstrated for the first time that fragrance-specific CD4(+) and CD8(+) T lymphocytes are present in fragrance-allergic individuals. In addition, our results suggest that CYPs can be involved in the formation of the nominative antigen.

Increased airway responsiveness after skin sensitisation to 3-carene, studied in isolated guinea pig lungs

Inhalation of 3-carene has been shown to induce bronchoconstriction in concentrations not far from the threshold limit value. In this study, one group of guinea-pigs were sensitised by dermal exposure to 3-carene according to the modified Cumulative Contact Enhancement Test protocol and another group of animals was used as controls. Lungs from the skin-sensitised and control guinea-pigs were perfused with diluted autologous blood (13 ml blood/87 ml buffer) and exposed to 3-carene at an air concentration of 3000 mg/m(3). In both groups there was a reduction in compliance and conductance but this reduction was significantly (P<0.05) more pronounced (2.5-3 times) in lungs obtained from sensitised animals than from control animals. In a previous study with similar design, but with plain buffer instead of diluted autologous blood as perfusate, we found no statistically significant difference in lung bronchoconstriction. Thus, it is concluded that skin sensitisation can increase lung reactivity to 3-carene and that important mediators of this effect seem to be present in the blood.

Pristane-induced arthritis in mice selected for maximal or minimal acute inflammatory reaction

The role of inflammatory and specific immune responses in pristane-induced arthritis (PIA) was investigated in mouse lines produced by bi-directional selective breedings for maximal (AIRmax) or minimal (AIRmin) acute inflammatory reaction, comparing the outcome of PIA and the humoral and cellular response to hsp65. Symptoms of arthritis were detected in 50 % AIRmax mice 120 days after pristane injection, reaching a maximal incidence of 65 %, whereas only 7 % of AIRmin mice developed arthritis within an observation period of 200 days. The production of IgG antibody against hsp65 was found to be similar on both lines, although the IgG1 isotype was predominant in AIRmax, and IgG2a in AIRmin line. In vitro T cell proliferation to hsp65 was similar in the two lines, however, ELISPOT assays carried out soon after pristane treatment, demonstrated higher numbers of IL-6-, TNF-alpha- and IL-4-secreting cells in the spleen of AIRmax than in AIRmin mice, while higher numbers of IFN-gamma-producing cells were found in AIRmin mice. These results suggest a major participation of acute inflammatory mechanisms in the susceptibility to PIA. The genetic background which determines high or low AIR favors a Th2-like response in susceptible AIRmax and Th1-like response in resistant AIRmin mice at the initial phase of arthritis induction.

Different therapeutic and bystander effects by intranasal administration of homologous type II and type IX collagens on the collagen-induced arthritis and pristane-induced arthritis in rats

To assess the efficiency of nasally administered cartilage-specific collagens as vaccination against development of arthritis and to ameliorate already established chronic arthritis, experimental models which develop chronic arthritis, pristane-induced arthritis (PIA), and homologous collagen-induced arthritis (CIA) in the rat were selected. Cartilage-specific collagens type IX (CIX) and type II (CII) were used for vaccination intranasally. A single dose of 250 microg CII instilled intranasally in rats with established PIA ameliorated the disease. For the prevention of disease, the same dose given before immunization was found to be most effective. Most importantly, the disease was more severe if this dose was given three times. For treatment of PIA, CIX was found to be more effective than CII, whereas for treatment of CIA only CII was effective. The amelioration of CIA was associated with a marked suppression of delayed type hypersensitivity and the flare reaction to CII and lower levels of IgG2b anti-CII antibodies in serum, i.e., with suppression of the TH1 rather than the TH2 response to CII. These findings, that cartilage proteins, if given intranasally, can both prevent and ameliorate established chronic arthritis in rats, are of significant importance for possible use in rheumatoid arthritis. The identification of two different cartilage-specific proteins (CII and CIX) effective against a disease induced with a well-defined nonimmunogenic adjuvant such as pristane will be of value for enhancing the effectiveness of the treatment.

Polyclonal antibodies against fusaproliferin

Fusaproliferin (FP), a toxic metabolite of the world-wide maize pathogens Fusarium proliferatum and Fusarium subglutinans, was recently found to be a natural contaminant of maize. Its toxic activity on haematopoietic human cell lines and its teratogenic effects on chicken embryos has been recently proved. Therefore a sensitive, rapid, and inexpensive screening test to detect FP in agricultural commodities is necessary to protect human health. FP-hemiglutarate conjugated to modified bovine serum albumin was synthesized, characterized, and used as an antigen for raising polyclonal antibodies by immunizing rabbits. Indirect and competitive ELISA and immunoblotting analyses were performed to determine antibody specificity towards the mycotoxin. The determination of 10 micrograms of free FP/mL was achieved using antibodies purified by means of affinity chromatography on a FP-lysine-Sepharose column. This unsatisfactory detection limit is due to high background values; thus, this method is not competitive with traditional UV-HPLC methods.

Plant immunomodulators for termination of unwanted pregnancy and for contraception and reproductive health

Neem (Azadirachta indica) seed and leaf extracts have spermicidal, anti-microbial, anti-fungal and anti-viral properties. They are also immunomodulators that induce primarily a TH1 type response. These properties are being exploited to develop two different useful methods of fertility control. Neem extracts given orally at early post-implantation stage terminate pregnancy in rodents and primates. Treatment has no residual permanent effect and fertility is regained in subsequent cycles. The mechanism by which the action occurs is not fully clear. A transient increase in CD4 and more significantly in CD8 cells is noticed in mesenteric lymph nodes and spleen. A rise in immunoreactive and bioactive TNF-alpha and IFN-gamma in draining lymph nodes, serum and foetal-placental tissue is observed. A polyherbal cream and pessary have been developed containing three active ingredients of plant origin. These have synergistic spermicidal properties on human sperm as determined by the Sander Cramer test. Their use before mating has high contraceptive efficacy in rabbits and baboons. Another interesting property is their inhibitory action on a wide spectrum of micro-organisms, including Candida albicans, C. tropicalis, Neisseria gonorrhoeae, the multidrug-resistant Staphylococcus aureus and urinary tract Escherichia coli, Herpes simplex-2 and HIV-1. Phase I clinical trials have been completed in India, Egypt and the Dominican Republic, and indicate the safety of the formulation, its acceptability and beneficial action invaginosis due to infections.

In vitro primary sensitization of hapten-specific T cells by cultured human epidermal Langerhans cells--a screening predictive assay for contact sensitizers

BACKGROUND

The need to develop predictive tests which could identify potential allergens has been recognized for many years. There is as yet no accepted in vitro method for the assessment of contact sensitizers.

OBJECTIVE

We have tested the ability of a range of contact allergens to induce in vitro primary sensitization of autologous T cells.

METHOD

T-cell proliferation induced by haptens using 2-day cultured human Langerhans cells as antigen-presenting cell was assessed by 3H thymidine incorporation. Antigen specific stimulation was calculated as stimulation indexes.

RESULTS

Strong allergens induced in vitro a primary T-cell response in all (trinitrophenyl, TNP: 13/13) or in the majority (fluorescein isothiocyanate, FITC: 7/10) of experiments. An irritant, sodium dodecyl sulfate (SDS), failed to generate a significant T-cell proliferation in any of the experiments (0/10). We obtained a significant lymphoproliferative response to weak sensitizers only in a limited number of experiments: (coumarin: 1/12, citronellal: 0/10, hydroxycitronellal: 2/8). p-Phenylenediamine (PPDA), a prohapten and highly sensitizing chemical in vivo, generated primary sensitization in vitro in only one of six experiments, while Bandrowski's base (BB), a metabolization product of PPDA induced a significant T-cell response in all six experiments.

CONCLUSION

The present in vitro model allows discrimination between two groups of substances: strong contact sensitizers (TNP, FITC, BB) on the one hand and weak sensitizers (coumarin, citronellal and hydroxycitronellal) and irritants (SDS) on the other hand. It could be used as a screening in vitro assay to eliminate strong contact allergens before further predictive animal tests have to be performed.

Expression of mammalian 60-kD heat shock protein in the joints of mice with pristane-induced arthritis

Previous work has indicated that autoimmunity to the mammalian 60-kD heat shock protein (hsp60) may be necessary for the development of pristane-induced arthritis (PIA), a murine model of rheumatoid arthritis. To characterize the expression of hsp60 in murine joints, immunoblots of joint extracts and frozen histological sections prepared from normal or arthritic mice were probed with the hsp60-specific MoAb 4B989. Hsp60 could be detected in the joints of mice with PIA by both techniques, and was seen to be localized within the inflamed pannus using immunhistochemistry. Immunoblotting revealed that lower concentrations of hsp60 are also present in normal mouse joints, and that the level of expression increases with age, in parallel with greater susceptibility to PIA. In other studies, it was demonstrated that the titres of serum IgG antibodies reactive with the related mycobacterial hsp65, and the in vitro responsiveness of splenic T cells to hsp65, are both elevated in older mice. It is considered that the results are consistent with the hypothesis that PIA develops following environmental priming with mycobacterial hsp65, and the targeting of cross-reactive T cells to self-hsp60 in the joints.

Pristane induces high titers of anti-Su and anti-nRNP/Sm autoantibodies in BALB/c mice. Quantitation by antigen capture ELISAs based on monospecific human autoimmune sera

Autoantibodies to Su and anti-nRNP/Sm are common in human and murine systemic lupus erythematosus (SLE), and are also produced by BALB/c mice with SLE-like autoimmunity induced by pristane. Antigen capture ELISAs employing monospecific human autoimmune IgG were developed to quantitate the production of anti-Su and anti-nRNP/Sm autoantibodies in 77 sera from BALB/c mice with pristane-induced autoimmunity. The sensitivity and specificity of the anti-Su antigen capture ELISA were 100% compared with immunoprecipitation of 35S-labeled cellular proteins. All 16 immunoprecipitation positive sera were positive in the anti-nRNP/Sm antigen capture ELISA (100% sensitivity), whereas 55/61 immunoprecipitation negative sera were negative by ELISA (90% specificity). The 6/61 immunoprecipitation negative sera that were ELISA positive were probably true positives because subsequent sera obtained from the same mice were positive by both techniques. Thus, the antigen capture ELISA may be somewhat more sensitive than immunoprecipitation. The titers of anti-Su and anti-nRNP/Sm positive antibodies in the sera were as high as 1:25,000-1:250,000 by ELISA, suggesting that autoantibodies may be produced in pristane-primed BALB/c mice at levels comparable to those seen in spontaneous autoimmune disease. We conclude that antigen capture ELISAs based on human autoimmune sera were highly sensitive and specific for detecting murine anti-Su and anti-nRNP/Sm antibodies. This technique will be useful for quantitating antibodies in murine autoimmune disease models, since antigen capture ELISA avoids the use of denatured or recombinant antigens, permitting antibodies recognizing tertiary and quaternary structures to be detected.

Hydroperoxides in oxidized d-limonene identified as potent contact allergens

Hydroperoxides of d-limonene were shown to be potent contact allergens when studied in guinea-pigs. Limonene-2-hydroperoxide (2-hydroperoxy-p-mentha-6,8-diene, a mixture of trans and cis isomers) was synthesized for the first time. The ratio between the trans and cis forms was 3:1. These two hydroperoxides were identified as the major hydroperoxides in autoxidized d-limonene. In photo-oxidized d-limonene, they constituted a minor part of the hydroperoxide fraction. Hydroperoxides may bind to proteins of the skin to make antigens either via a radical mechanism or after reactions to give epoxides. The cross-reactivity between the epoxide limonene-1,2-oxide, a potent contact allergen, and the hydroperoxides was therefore studied. No significant pattern of cross-reactivity was found. Further studies to identify and test the allergenicity of single hydroperoxides are needed to elucidate the mechanism of the allergenicity.

Centella asiatica (Indian pennywort), an effective therapeutic but a weak sensitizer

The sensitizing capacity of Centella asiatica (raw extract) and its triterpenic constituents asiaticoside, asiatic acid and madecassic acid has been studied in guinea pigs. The extract itself as well as the 3 acids were found to be very weak sensitizers. Centella asiatica extract is used effectively in the treatment of keloids, leg ulcers, phlebitis, slow-healing wounds, leprosy, surgical lesions, striae distensae and cellulitis. Although applied frequently to damaged skin, the risk of acquiring contact sensitivity to this plant or its constituents is low.

An arm immersion model of compromised skin (I). Influence on irritation reactions

Patch testing and safety evaluation processes to assess the allergic or irritant potential of substances are usually performed on normal skin. However, the reactivity of compromised skin may be different. Consequently, it is important to have a test procedure which acts as a model for compromised skin and which reproduces on the target sites the cumulative insult which results from repeated exposure, working temperatures, hydration and the action of surfactants. The procedure described uses regular immersion of forearm skin in an aqueous solution of sodium dodecyl sulphate until an identifiable alteration of skin condition is produced. In this first report, the model system has been described in detail and the influence of skin compromise on the response to 3 irritants, citral, sodium dodecyl sulphate and nonanoic acid, has been assessed. The irritation potential of the materials varied, but each irritant produced a greater degree of reaction on skin compromised to be within the normal clinical range one might expect from housework.

Arthritis induced in rats with adjuvant oil is a genetically restricted, alpha beta T-cell dependent autoimmune disease

Adjuvant arthritis in rats is usually induced by injection of mycobacterium tubercle cell walls suspended in various adjuvant oils such as Freund's incomplete adjuvant (FIA) or pristane. We have recently shown that injection of adjuvant oils without inclusion of mycobacterium tubercle cell walls triggers arthritis [oil adjuvant-induced arthritis (OIA)] in the DA rat strain. The OIA is a genetically restricted disease since only DA rats are susceptible while Lewis, DA-fostered Lewis and F1 (Lew x DA) rats are relatively resistant. Activated alpha beta T cells infiltrate the affected joints of adjuvant oil-injected DA rats and treatment with monoclonal antibodies to the alpha beta T-cell receptor abrogates development of arthritis. These findings show that alpha beta T-cell activation is a critical event in the development of OIA.

Prophylactic activity of dihydroheptaprenol, a synthetic polyprenol derivative, against Sendai virus infection in mice

The effect of a chemically synthesized polyprenol derivative, dihydroheptaprenol (DHP), on the non-specific resistance of mice to Sendai virus infection was investigated. The mice that received 200 micrograms of DHP intranasally twice, at 3 days and 1 day before the infection, showed a significant protection against Sendai virus infection. Treatment of mice twice even with as much as 2000 micrograms of DHP through the subcutaneous route, however, had no protective effect against infection. Excess interferon and tumour necrosis factor production in intranasally DHP-treated mice was seen 1 day after the infection when compared with Sendai virus alone controls or with DHP alone controls. Variance analysis of these findings indicates a prophylactic activity of DHP in pulmonary viral infections.

Allergic contact dermatitis resulting from sensitivity to citrus peel, geraniol, and citral

A bartender with hand dermatitis had allergic contact sensitivity to the skin of lemon, lime, and orange but not to their juices. Although most reported cases of citrus peel allergy are due to d-limonene, for our patient, reactions to patch tests for geraniol and citral, two minor components of citrus peel oil, were positive, whereas those for d-limonene were negative. Contact allergy to citrus peel oil should be considered in patients with hand dermatitis who are occupationally exposed to citrus fruits.

Alternatives to pristane priming for ascitic fluid and monoclonal antibody production

A variety of agents were compared to pristane for priming mice prior to ascitic fluid production. Incomplete Freund's adjuvant was found to be as good as or better than pristane for priming before hybridoma cell inoculation. Complete adjuvant was also useful while priming with proteose-peptone; thioglycollate, corn oil or mineral oil elicited only minimum amounts of ascitic fluid after hybridoma injection.

Penicillin immunogenicity in the presence of different pharmaceutical adjuvants

Preliminary results in the variations of the penicillin immunogenicity in the presence of aminosugars, polysaccharides and terpenic substances are presented and the decreasings of the potential antigenicity of the penicillin molecule appeared in the presence of hexosamine molecules are estimated. It might be possible as a consequence of modifications in the early immunogenic interactions between antibiotic and serum proteins of the hipersensitive animals.