| 1. |
- Andresen Bergström, Moa, 1978, et al.
(författare)
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A skin-like cytochrome P450 cocktail activates prohaptens to contact allergenic metabolites.
- 2007
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Ingår i: The Journal of investigative dermatology. - : Elsevier BV. - 1523-1747 .- 0022-202X. ; 127:5, s. 1145-53
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Tidskriftsartikel (refereegranskat)abstract
- Allergic contact dermatitis is a complex syndrome representing immunological responses to cutaneous exposure to protein-reactive chemicals. Although many contact sensitizers directly can elicit this disorder, others (prohaptens) require activation. Knowledge regarding the activating mechanisms remains limited, but one possibility is metabolic activation by cytochrome P450 (CYP) enzymes in the skin. We have, after quantitative reverse transcriptase-PCR studies of the CYP content in 18 human skin samples, developed an enriched skin-like recombinant human (rh) CYP cocktail using CYP1A1, 1B1, 2B6, 2E1, and 3A5. To validate the rhCYP cocktail, a prohaptenic conjugated diene ((5R)-5-isopropenyl-2-methyl-1-methylene-2-cyclohexene) was investigated using: the skin-like rhCYP cocktail, a liver-like rhCYP cocktail, single rhCYP enzymes, liver microsomes, keratinocytes, and a dendritic cell (DC) assay. The diene was activated to sensitizing epoxides in all non-cell-based incubations including the skin-like rhCYP cocktail. An exocyclic epoxide metabolite ((7R)-7-isopropenyl-4-methyl-1-oxaspiro[2.5]oct-4-ene) was found to be mainly responsible for the allergenic activity of the diene. This epoxide also induced pronounced DC activation indicated by upregulation of IL-8. The skin-like rhCYP cocktail provides a simplified alternative to using skin tissue preparations in mechanistic studies of CYP-mediated skin metabolism of prohaptens and offers the future possibility of designing in vitro predictive assays for assessment of allergenic activity of prohaptens.
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| 2. |
- Bauer, Brigitte, 1978, et al.
(författare)
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Modification and expulsion of keratins by human epidermal keratinocytes upon hapten exposure in vitro.
- 2011
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Ingår i: Chemical research in toxicology. - : American Chemical Society (ACS). - 1520-5010 .- 0893-228X. ; 24:5, s. 737-43
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Tidskriftsartikel (refereegranskat)abstract
- Allergic contact dermatitis is the most prevalent form of human immunotoxicity. It is caused by reactive low molecular weight chemicals, that is, haptens, coming in contact with the skin where hapten-peptide complexes are formed, activating the immune system. By using sensitizing fluorescent thiol-reactive haptens, that is, bromobimanes, we show how keratinocytes respond to hapten exposure in vitro and reveal, for the first time in a living system, an exact site of haptenation. Rapid internalization and reaction of haptens with keratin filaments were visualized. Subsequently, keratinocytes respond in vitro to hapten exposure by release of membrane blebs, which contain haptenated keratins 5 and 14. Particularly, cysteine 54 of K5 was found to be a specific target. A mechanism is proposed where neoepitopes, otherwise hidden from the immune system, are released after hapten exposure via keratinocyte blebbing. The observed expulsion of modified keratins by keratinocytes in vitro might play a role during hapten sensitization in vivo and should be subject to further investigations.
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| 3. |
- Bråred Christensson, Johanna, 1965, et al.
(författare)
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Limonene hydroperoxide analogues differ in allergenic activity
- 2008
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Ingår i: Contact Dermatitis. - : Wiley. - 0105-1873 .- 1600-0536. ; 59:6, s. 344-352
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Tidskriftsartikel (refereegranskat)abstract
- Background: The fragrance terpene R-limonene is a very weak sensitizer but forms allergenic oxidation products upon contact with air. Oxidized (ox.) limonene is a frequent cause of contact allergy in clinical testing. Objectives: This study investigates the sensitizing potencies of ox. and non-ox. limonene and of structurally closely related limonene hydroperoxides. The clinical importance of the difference in sensitizing potency of two hydroperoxides in autoxidized limonene was studied. Patients/Methods: Ox. and non-ox. limonene were investigated in the murine local lymph node assay (LLNA). Limonene hydroperoxides were investigated using a modified LLNA involving non-pooled lymph nodes and statistical calculations; patch testing of patients with known contact allergy to ox. limonene was performed. Results: A marked increase in the sensitizing potency of ox. limonene compared with that of pure limonene was observed in the LLNA. One analogue, limonene-1-hydroperoxide, was a significantly more potent sensitizer than the other hydroperoxides and gave more positive test reactions in the allergic patients. Conclusions: The results support that hydroperoxides have a specific reactivity indicating that oxygen-centred radicals are important in hapten–protein complex formation of hydroperoxides. The primary oxidation products of ox. limonene, the hydroperoxides, have an important impact on the sensitizing capacity of the oxidation mixture.
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| 4. |
- Carlsten, Hans, 1954, et al.
(författare)
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The impact of a new immunomodulator oxo-quinoline-3-carboxamide on the progression of experimental lupus
- 2004
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Ingår i: Int Immunopharmacol. - : Elsevier BV. - 1567-5769. ; 4:12, s. 1515-23
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Tidskriftsartikel (refereegranskat)abstract
- Autoimmune, lupus-prone MRL lpr/lpr mice were treated orally with oxo-quinoline-3-carboxamide (ABR-25757), a newly developed immunomodulator. Treatment was initiated in one set of experiment at the age of 10 weeks, before the onset of clinically apparent disease, and in another set at 15 weeks, after the development of established lupus disease. Beneficial therapeutic effects were obtained even when ABR-25757 was administered at the lowest dose tested (7.5 microg/mouse/week) to 15 weeks old mice with established lupus disease. The effects of ABR-25757 on longevity, as well as on development of glomerulonephritis were pronounced and comparable with those of LS-2616, a potent immunomodulator. Administration of ABR-25757 did not significantly alter T cell responses in vivo nor in vitro. In addition, it only marginally suppressed B cell responses measured as frequencies of immunoglobulin secreting cells. By the same token this compound did not affect overall leukocyte content in primary (bone marrow) or secondary (spleen) lymphoid tissues. In contrast, treatment with ABR-25757 up regulated expression of pro-inflammatory transcription factors NF-kappaB and AP-1. These results suggest (a) a potential therapeutic role of ABR-25757 in the treatment of experimental lupus and (b) that the effect of the treatment is mediated by immunodeviation rather than by immunosuppression.
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| 5. |
- Evenbratt, Hanne, 1980, et al.
(författare)
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In vivo study of an instantly formed lipid-water cubic phase formulation for efficient topical delivery of aminolevulinic acid and methyl-aminolevulinate
- 2013
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Ingår i: International Journal of Pharmaceutics. - : Elsevier BV. - 0378-5173 .- 1873-3476. ; 452:1-2, s. 270-275
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate a rapidly formed cubic liquid crystalline phase, i.e. typically 1 g cubic phase in less than 1 min confirmed by X-ray diffraction, consisting of an ether lipid, 1-glyceryl monooleyl ether (GME), an aprotic solvent (propylene glycol or pentane-1,5-diol) and water. The efficacy of the cubic formulation was tested in vivo by administrating formulations containing 3% (w/w) of the HCl salts of delta-aminolevulinic acid (ALA) or methylaminolevulinate (MAL) to hairless mice. The endogenous formation of protoporphyrin IX (PpIX) was monitored spectrophotometrically as a marker for cellular uptake of active compound. As reference, a commercial product containing 16% (w/w) MAL in an oil-in-water emulsion (Metvix (R)), and a cubic phase based on an ester lipid (glyceryl monooleate, GMO), previously shown to facilitate topical delivery of both ALA and MAL, were applied. It was found that in general the cubic phases gave rise to higher fluorescence levels than the mice exposed to the commercial product. The instantly formed cubic formulations based on GME demonstrated the same efficiency as the GMO based formulations. The results imply that instantly formed cubic formulations opens up new opportunities, particularly for transdermal drug delivery of substances subject to stability problems in, e. g. aqueous environments.
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| 6. |
- Gatto, Mariele, et al.
(författare)
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Early increase of circulating transitional B cells and autoantibodies to joint-related proteins in patients with metastatic melanoma developing checkpoint inhibitor-induced inflammatory arthritis.
- 2023
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Ingår i: Arthritis & rheumatology (Hoboken, N.J.). - : Wiley. - 2326-5205 .- 2326-5191. ; 75:5, s. 856-863
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Tidskriftsartikel (refereegranskat)abstract
- To investigate potential associations between B cell-related immunological changes and development of inflammatory arthritis (IA) after treatment with immune checkpoint inhibitors (ICI).Patients who developed IA (ICI-IA) and patients who did not develop immune-related adverse events (non-irAE) after receiving ICI due to metastatic melanoma were consecutively recruited. Blood samples were collected at the time of ICI-IA occurrence and at different timepoints during treatment. Peripheral blood B cell subsets during ICI treatment were analyzed by flow cytometry. Rheumatoid factor, autoantibodies against citrullinated peptides and against joint-related proteins were measured.Proportions of CD19+ B cells were higher in patients with ICI-IA (n=7) vs. non-irAE (n=15; median (interquartile range, IQR), %: 11.7 (9.7-16.2) vs. 8.1 (5.7-11.0), p=0.03). The proportion and absolute numbers of transitional CD19+ CD10+ CD24hi CD38hi B cells were increased in patients with ICI-IA vs. non-irAE (median (IQR); %: 8.1 (4.9-12.1) vs. 3.6 (1.9-4.9); cells/μl: 10.7 (8.9-19.6) vs. 4.4 (2.3-6.6), p<0.01 for both), and higher levels of transitional B cells were associated with development of ICI-IA (OR 95% CI: 2.25 (1.03-4.9), p=0.04). Transitional B cells increased before the onset of overt ICI-IA and decreased from active to quiescent ICI-IA (p=0.02). Autoantibodies to collagen II epitopes were detected in up to 43% of ICI-IA patients compared to none of the non-irAE patients (p=0.02).Development of ICI-IA is accompanied by an increase in transitional B cells and by production of autoantibodies to joint-related proteins. Monitoring of B cell-driven abnormalities upon ICI treatment may help earlier recognition of ICI-IA. This article is protected by copyright. All rights reserved.
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| 7. |
- Gjertsson, Inger, 1962, et al.
(författare)
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A close-up on the expanding landscape of CD21-/low B cells in humans
- 2022
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Ingår i: Clinical and Experimental Immunology. - : Oxford University Press. - 0009-9104 .- 1365-2249. ; 210:3, s. 217-229
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Forskningsöversikt (refereegranskat)abstract
- Memory B cells (MBCs) are an essential part of our immunological memory. They respond fast upon re-encountering pathogens and can differentiate into plasma cells that secrete protective antibodies. The focus of this review is on MBCs that lack, or express low levels of, CD21, hereafter referred to as CD21-/low. These cells are expanded in peripheral blood with age and during chronic inflammatory conditions such as viral infections, malaria, common variable immunodeficiency, and autoimmune diseases. CD21-/low MBCs have gained significant attention; they produce disease-specific antibodies/autoantibodies and associate with key disease manifestations in some conditions. These cells can be divided into subsets based on classical B-cell and other markers, e.g. CD11c, FcRL4, and Tbet which, over the years, have become hallmarks to identify these cells. This has resulted in different names including age-associated, autoimmune-associated, atypical, tissue-like, tissue-resident, tissue-restricted, exhausted, or simply CD21-/low B cells. It is however unclear whether the expanded 'CD21-/low' cells in one condition are equivalent to those in another, whether they express an identical gene signature and whether they have a similar function. Here, we will discuss these issues with the goal to understand whether the CD21-/low B cells are comparable in different conditions.
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| 8. |
- Jonsson, Charlotte A, 1971, et al.
(författare)
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Mycophenolate mofetil ameliorates perivascular T lymphocyte inflammation and reduces the double-negative T cell population in SLE-prone MRLlpr/lpr mice.
- 1999
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Ingår i: Cellular immunology. - : Elsevier BV. - 0008-8749. ; 197:2, s. 136-44
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Tidskriftsartikel (refereegranskat)abstract
- Effects on T lymphocyte mediated pathology, phenotypes, and functions in MRLlpr/lpr mice given mycophenolate mofetil (MMF) (100 mg/kg/day) via drinking water or controls given ip cyclophosphamide (CYC) injections (1.8 mg/mouse/week) or water were described. Both MMF and CYC treatment diminished kidney and large salivary gland perivascular cell infiltrates, reduced profoundly double-negative (DN) T cell frequencies, decreased total lymphocyte number in spleen, and increased in vitro proliferative response to Con A. IFN-gamma and IL-10 in supernatants from Con A stimulated spleen cells were augmented after MMF but not CYC treatment. MMF treatment increased whereas CYC reduced IL-12 in serum. Kidney expressions of IFN-gamma, IL-10, and IL-12 mRNA were unaffected by MMF but decreased by CYC. Our results demonstrate that MMF and CYC suppress perivascular T lymphocyte inflammation by reducing the DN T cell population and by amelioration of T cell function. The varying cytokine patterns suggest different mechanisms of the two drugs.
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| 9. |
- Jonsson, Charlotte A, 1971
(författare)
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Purine synthesis inhibition in experimental lupus
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Systemic lupus erythematosus (SLE) is an autoimmune disease that mainly affects women. The effect of the immune modulating drug mycophenolate mofetil (MMF) on experimental SLE was investigated. Mycophenolic acid (MPA), the active metabolite of MMF, inhibits inosine 5 -monophosphate dehydrogenase (IMPDH), an important enzyme in the de novo synthesis of the purine guanine. The clinical and histopathological outcome of MMF administration to SLE-prone MRLlpr/lpr mice in vivo was assessed. In addition, the immunomodulating properties of MPA in vitro on splenocytes from MRLlpr/lpr mice as well as on the macrophage cell line IC-21 were studied.Treatment of MRLlpr/lpr mice with MMF prolonged survival and diminished kidney damage as demonstrated by reduced albuminuria, hematuria and immune complex depositions in glomeruli. Perivascular cell infiltrates in kidneys and salivary glands were also reduced following MMF treatment. MMF reduced lymphoproliferation, the production of IgG anti-dsDNA antibodies and the populations of double-negative T cells as well as immunoglobulin-producing B cells. All the clinical effects of MMF were comparable with those achieved with cyclophosphamide treatment. In vitro, mitogen-stimulated splenocytes from MMF-treated mice displayed increased proliferative responses and augmented IFN-g and IL-10 production. In vitro treatment of MRLlpr/lpr spleen cells with MPA resulted in decreased mitogen-induced proliferative responses and the decreased production of IFN-g, IL-10, immunoglobulins and anti-DNA antibodies. Furthermore, exposure of the macrophage cell line IC-21 to MPA decreased mitogen-induced proliferation and the production of NO2-, IL-1b, and TNF-a. Addition of guanosine in vitro totally abrogated the action of the drug, proving that guanine-nucleotide depletion is the mechanism whereby MPA exerts its immunomodulating effects. It is concluded that the immunomodulating effects of MMF are to a large extent mediated by purine synthesis inhibition in lymphocytes and in macrophages. In addition, the results indicate that MMF can be considered as a potentially efficacious treatment for SLE patients with glomerulonephritis.
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| 10. |
- Karlsson, Isabella, et al.
(författare)
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The Fate of a Hapten - From the Skin to Modification of Macrophage Migration Inhibitory Factor (MIF) in Lymph Nodes
- 2018
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Skin (contact) allergy, the most prevalent form of immunotoxicity in humans, is caused by low molecular weight chemicals (haptens) that penetrate stratum corneum and modify endogenous proteins. The fate of haptens after cutaneous absorption, especially what protein(s) they react with, is largely unknown. In this study the fluorescent hapten tetramethylrhodamine isothiocyanate (TRITC) was used to identify hapten-protein conjugates in the local lymph nodes after topical application, as they play a key role in activation of the adaptive immune system. TRITC interacted with dendritic cells but also with T and B cells in the lymph nodes as shown by flow cytometry. Identification of the most abundant TRITC-modified protein in lymph nodes by tandem mass spectrometry revealed TRITC-modification of the N-terminal proline of macrophage migration inhibitory factor (MIF) - an evolutionary well-conserved protein involved in cell-mediated immunity and inflammation. This is the first time a hapten-modified protein has been identified in lymph nodes after topical administration of the hapten. Most haptens are electrophiles and can therefore modify the N-terminal proline of MIF, which has an unusually reactive amino group under physiological conditions; thus, modification of MIF by haptens may have an immunomodulating role in contact allergy as well as in other immunotoxicity reactions.
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