| 1. |
- Sandin, Linnea, et al.
(författare)
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Beneficial effects of increased lysozyme levels in Alzheimer’s disease modelled in Drosophila melanogaster
- 2016
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Ingår i: The FEBS Journal. - : John Wiley & Sons. - 1742-464X .- 1742-4658. ; 283:19, s. 3508-3522
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Tidskriftsartikel (refereegranskat)abstract
- Genetic polymorphisms of immune genes that associate with higher risk to develop Alzheimer’s disease (AD) have led to an increased research interest on the involvement of the immune system in AD pathogenesis. A link between amyloid pathology and immune gene expression was suggested in a genome-wide gene expression study of transgenic amyloid mouse models. In this study, the gene expression of lysozyme, a major player in the innate immune system, was found to be increased in a comparable pattern as the amyloid pathology developed in transgenic mouse models of AD. A similar pattern was seen at protein levels of lysozyme in human AD brain and CSF, but this lysozyme pattern was not seen in a tau transgenic mouse model. Lysozyme was demonstrated to be beneficial for different Drosophila melanogaster models of AD. In flies that expressed Aβ1-42 or AβPP together with BACE1 in the eyes, the rough eye phenotype indicative of toxicity was completely rescued by coexpression of lysozyme. In Drosophila flies bearing the Aβ1-42 variant with the Arctic gene mutation, lysozyme increased the fly survival and decreased locomotor dysfunction dose dependently. An interaction between lysozyme and Aβ1-42 in the Drosophila eye was discovered. We propose that the increased levels of lysozyme, seen in mouse models of AD and in human AD cases, were triggered by Aβ1-42 and caused a beneficial effect by binding of lysozyme to toxic species of Aβ1-42, which prevented these from exerting their toxic effects. These results emphasize the possibility of lysozyme as biomarker and therapeutic target for AD.
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| 2. |
- Abelius, Martina, et al.
(författare)
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Pregnancy modulates the allergen-induced cytokine production differently in allergic and non-allergic women
- 2017
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Ingår i: Pediatric Allergy and Immunology. - : WILEY. - 0905-6157 .- 1399-3038. ; 28:8, s. 818-824
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Tidskriftsartikel (refereegranskat)abstract
- Background: The immunological environment during pregnancy may differ between allergic and non-allergic women. This study investigates the effect of maternal allergy on the allergen-induced cytokine and chemokine levels and whether pregnancy modulates these immune responses differently in allergic and non-allergic women. Methods: The birch-, cat-, phytohemagglutinin- and tetanus toxoid-induced interferon-gamma(IFN-gamma), interleukin (IL)-4, IL-5, IL-10, IL-13, the T-helper 1 (Th1)-associated chemokine CXCL10 and the Th2-associated chemokine CCL17 levels were quantified in 20 women with allergic symptoms (sensitized, n=13) and 36 women without allergic symptoms (non-sensitized, n=30) at gestational weeks 10-12, 15-16, 25, 35 and 2 and 12months post-partum. Results: Birch-, but not cat-induced, IL-5, IL-13 and CCL17 levels were increased during pregnancy as compared to post-partum in the sensitized women with allergic symptoms. In contrast, cat-, but not birch-induced, IL-5 and IL-13 levels were increased during pregnancy as compared to post-partum in the non-sensitized women without allergic symptoms. Furthermore, IFN-gamma secretion was increased in the first and decreased in the second and third trimesters in response to birch and decreased in the third trimester in response to cat as compared to post-partum in the non-sensitized women without allergic symptoms. Increased allergen-induced IL-4, IL-5 and IL-13 levels were associated with allergic symptoms and sensitization. Conclusions: Pregnancy had a clear effect on the allergen-induced IL-5, IL-13, CCL17, IFN-gamma and CXCL10 production, with distinct enhanced Th2-responses to birch in the allergic group and to cat in the non-allergic group.
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| 3. |
- Abelius, Martina S, et al.
(författare)
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Gene expression in placenta, peripheral and cord blood mononuclear cells from allergic and non-allergic women
- 2014
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background: The influence of maternal allergy on the development of immune responses and allergy in the offspring is not understood.Objective: To investigate (i) if maternal allergy influences the gene expression locally in placenta, systemically in peripheral blood mononuclear cells (PBMC) and fetally in cord blood mononuclear cells (CBMC), (ii) if the gene expression in the placenta and PBMC influences the gene expression in CBMC and (iii) how the gene expression at birth relates to allergy development during childhood.Methods: A real-time PCR array was used to quantify forty immune regulatory genes in placenta, PBMC (gestational week 39) and in CBMC from 7 allergic and 12 non-allergic women and their offspring. Furthermore, quantitative real-time PCR was used to measure mRNA expression of Tbx21, GATA-3, Foxp3, RORC and CCL22 in CBMC, selected based on present PCR array results and previous protein findings in cord blood, in 13 children who developed and 11 children who did not develop allergy during childhood.Results: The gene expression profile in the placenta revealed a T-helper (Th) 2-/anti-inflammatory environment as compared with gene expression systemically, in PBMC. Maternal allergy was associated with increased expression of p35 in PBMC and CBMC and p40 in placenta. Placental p35 expression correlated with fetal Tbx21 expression (Rho=-0.88, p<0.001) and maternal IL-5 expression in PBMC with fetal Galectin-1 (Rho=0.91, p<0.001) expression. Allergy development in the children was preceded by high mRNA expression of the Th2-associated chemokine CCL22 at birth.Conclusion and clinical relevance: Gene expression locally and systemically during pregnancy influenced the offspring’s gene expression at birth, indicating an interplay between maternal and fetal immunity. Children developing allergy during childhood had an increased expression of the Th2-associated chemokine CCL22 at birth, indicating a Th2 skewing before disease onset. Maternal allergy was not associated with a Th2-dominance in placenta, PBMC or CBMC.
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| 4. |
- Abelius, Martina S, et al.
(författare)
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The Placental Immune Milieu is Characterized by a Th2- and Anti-Inflammatory Transcription Profile, Regardless of Maternal Allergy, and Associates with Neonatal Immunity
- 2015
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Ingår i: American Journal of Reproductive Immunology. - : Wiley-Blackwell. - 1046-7408 .- 1600-0897. ; 73:5, s. 445-459
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Tidskriftsartikel (refereegranskat)abstract
- PROBLEM: How maternal allergy affects the systemic and local immunological environment during pregnancy and the immune development of the offspring is unclear.METHOD OF STUDY: Expression of 40 genes was quantified by PCR arrays in placenta, peripheral blood mononuclear cells (PBMC), and cord blood mononuclear cells (CBMC) from 7 allergic and 12 non-allergic women and their offspring.RESULTS: Placental gene expression was dominated by a Th2-/anti-inflammatory profile, irrespectively of maternal allergy, as compared to gene expression in PBMC. p35 expression in placenta correlated with fetal Tbx21 (ρ = -0.88, P < 0.001) and IL-5 expression in PBMC with fetal galectin1 (ρ = 0.91, P < 0.001). Increased expression of Th2-associated CCL22 in CBMC preceded allergy development.CONCLUSIONS: Gene expression locally and systemically during pregnancy was partly associated with the offspring's gene expression, possibly indicating that the immunological milieu is important for fetal immune development. Maternal allergy was not associated with an enhanced Th2 immunity in placenta or PBMC, while a marked prenatal Th2 skewing, shown as increased CCL22 mRNA expression, might contribute to postnatal allergy development.
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| 5. |
- Armstrong, Andrea, et al.
(författare)
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Lysosomal Network Proteins as Potential Novel CSF Biomarkers for Alzheimers Disease
- 2014
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Ingår i: Neuromolecular medicine. - : Humana Press. - 1535-1084 .- 1559-1174. ; 16:1, s. 150-160
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Tidskriftsartikel (refereegranskat)abstract
- The success of future intervention strategies for Alzheimers disease (AD) will likely rely on the development of treatments starting early in the disease course, before irreversible brain damage occurs. The pre-symptomatic stage of AD occurs at least one decade before the clinical onset, highlighting the need for validated biomarkers that reflect this early period. Reliable biomarkers for AD are also needed in research and clinics for diagnosis, patient stratification, clinical trials, monitoring of disease progression and the development of new treatments. Changes in the lysosomal network, i.e., the endosomal, lysosomal and autophagy systems, are among the first alterations observed in an AD brain. In this study, we performed a targeted search for lysosomal network proteins in human cerebrospinal fluid (CSF). Thirty-four proteins were investigated, and six of them, early endosomal antigen 1 (EEA1), lysosomal-associated membrane proteins 1 and 2 (LAMP-1, LAMP-2), microtubule-associated protein 1 light chain 3 (LC3), Rab3 and Rab7, were significantly increased in the CSF from AD patients compared with neurological controls. These results were confirmed in a validation cohort of CSF samples, and patients with no neurochemical evidence of AD, apart from increased total-tau, were found to have EEA1 levels corresponding to the increased total-tau levels. These findings indicate that increased levels of LAMP-1, LAMP-2, LC3, Rab3 and Rab7 in the CSF might be specific for AD, and increased EEA1 levels may be a sign of general neurodegeneration. These six lysosomal network proteins are potential AD biomarkers and may be used to investigate lysosomal involvement in AD pathogenesis.
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| 6. |
- Boman, Andrea, et al.
(författare)
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The role of LAMP-2 in AβPP processing and Aβ degradation; implications for Alzheimer’s Disease
- 2015
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Dysfunction in the lysosomal network, i.e., the endosomal, lysosomal and autophagy systems, are implicated in the pathways in Alzheimer’s disease brain pathology. This dysfunction is mirrored in the cerebrospinal fluid where a specific subset of lysosomal network proteins are found at elevated levels, lysosomal associated membrane protein-2 (LAMP-2) being one of the identified lysosomal proteins. Here we report that hippocampus and frontal cortex in Alzheimer’s disease cases have increased mRNA and protein expression of LAMP-2, and thus these brain areas are likely involved in the increased LAMP-2 levels seen in cerebrospinal fluid from Alzheimer’s disease patients. The increased LAMP-2 levels correlated with increased levels of β-amyloid1-42 (Aβ1-42). Oligomeric Aβ1-42 caused an upregulation of intracellular LAMP-2 in neuroblastoma cells, but did not trigger the release of LAMP-2 to the extracellular milieu, indicating that other cell types or mechanisms are responsible for the LAMP-2 release seen in cerebrospinal fluid. Overexpression of LAMP-2 in neuroblastoma cells caused a trend of reduction of secreted Aβ1-42 and changed the processing pattern of the Aβ precursor protein. These results indicate that Aβ1-42 mediated increase of LAMP-2 expression can act as a regulator of Aβ generation and secretion. LAMP-2 overexpression did not change the cellular uptake of extracellularly added Aβ1-42, but caused a delayed clearance of Aβ1-42. Whether the prolonged intracellular localization of Aβ1-42 in LAMP-2 overexpressing cells can change the transmission or degradation of Aβ remains to be investigated.
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| 7. |
- Helmfors, Linda, et al.
(författare)
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A protective role of lysozyme in Alzheimer disease
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Alzheimer disease (AD) is a devastating neurodegenerative disorder where extracellular plaques composed of amyloid β (Aβ) peptides and neuroinflammation are some of the main hallmarks of the disease. Activated microglial cells, which are the resident macrophages in the central nervous system, are suggested to trigger the inflammation response in AD. To discover neuroinflammation biomarkers would be important to reveal the pathological mechanisms of AD and develop therapies that target inflammation mediators. Lysozyme is part of the innate immune system and is secreted from macrophages during various inflammation conditions. However, the involvement of lysozyme in AD pathology has not been explored previously. We have discovered that lysozyme is up-regulated in cerebrospinal fluid from AD patients. Cells exposed to Aβ increased the expression of lysozyme indicating that Aβ might be responsible for the upregulation of lysozyme detected in cerebrospinal fluid. In vitro studies revealed that lysozyme binds to monomeric Aβ1-42 and alters the aggregation pathway counteracting formation of toxic Aβ species. In a newly developed Drosophila model, co-expression of lysozyme with Aβ in brain neurons reduced the formation of insoluble Aβ species, prolonged the survival and improved the activity of the double transgenic flies compared to flies only expressing Aβ. Our findings identify lysozyme as a modulator of Aβ aggregation and toxicity and our discoveries has the potential to be used for development of new treatment strategies and to use lysozyme as a biomarker for AD.
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| 8. |
- Helmfors, Linda, et al.
(författare)
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Protective properties of lysozyme on β-amyloid pathology : implications for Alzheimer disease
- 2015
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Ingår i: Neurobiology of Disease. - : Elsevier. - 0969-9961 .- 1095-953X. ; 83, s. 122-133
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Tidskriftsartikel (refereegranskat)abstract
- The hallmarks of Alzheimer disease are amyloid-β plaques and neurofibrillary tangles accompanied by signs of neuroinflammation. Lysozyme is a major player in the innate immune system and has recently been shown to prevent the aggregation of amyloid-β1-40 in vitro. In this study we found that patients with Alzheimer disease have increased lysozyme levels in the cerebrospinal fluid and lysozyme co-localized with amyloid-β in plaques. In Drosophila neuronal co-expression of lysozyme and amyloid-β1-42 reduced the formation of soluble and insoluble amyloid-β species, prolonged survival and improved the activity of amyloid-β1-42 transgenic flies. This suggests that lysozyme levels rise in Alzheimer disease as a compensatory response to amyloid-β increases and aggregation. In support of this, in vitro aggregation assays revealed that lysozyme associates with amyloid-β1-42 and alters its aggregation pathway to counteract the formation of toxic amyloid-β species. Overall, these studies establish a protective role for lysozyme against amyloid-β associated toxicities and identify increased lysozyme in patients with Alzheimer disease. Therefore, lysozyme has potential as a new biomarker as well as a therapeutic target for Alzheimer disease.
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| 9. |
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| 10. |
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| 11. |
- Janefjord, Camilla, et al.
(författare)
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PHA-induced IL-12Rb2 mRNA expression in atopic and non-atopic children
- 2001
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Ingår i: Clinical and Experimental Allergy. - : Wiley. - 0954-7894. ; 31:10, s. 1493-1500
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Tidskriftsartikel (refereegranskat)abstract
- Background IL-12 is a strong inducer of Th1 responses. Stimulation via the CD2 receptor increases IFN-γ production and enhances the responsiveness of activated T-cells to IL-12, possibly due to an up-regulation of the signal transducing β2 chain of the IL-12 receptor (IL-12Rβ2). Atopic children have a reduced Th1-like immunity and a reduced CD2 expression. Our hypothesis is that atopic individuals have a reduced function of the CD2 pathway, causing reduced responsiveness to IL-12 and decreased IFN-γ production. Objective The aim was to study the mRNA expression of the IL-12Rβ2 chain, after stimulation via the CD2 pathway in peripheral blood mononuclear cells (PBMC), of atopic and non-atopic children, and to investigate correlations to the production of Th1 and Th2 cytokines. Materials and methods The study included 23 skin prick test positive, and 9 non-sensitized, 12-year-old children. PBMC were stimulated for 24 h with phytohemagglutinin (PHA) (2 µg/mL), which stimulates T cells through the CD2 pathway. Expression of IL-12Rβ2 mRNA was analysed by quantitative real time PCR and the cytokine production was detected with ELISA. Results Atopic and non-atopic children had similar baseline expression of IL-12Rβ2 mRNA, whereas PHA-induced IL-12Rβ2 mRNA expression was lower in atopic than in non-atopic children. The PHA-induced IL-12Rβ2 mRNA expression correlated well with the PHA-induced IFN-γ production and with the IFN-γ/IL-4 ratio. Conclusion PBMC from atopic children expressed less IL-12Rβ2 mRNA than non-atopic children after stimulation via the CD2 pathway (PHA). This may indicate a reduced capacity to respond to Th1-inducing stimuli in atopic children.
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| 12. |
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| 13. |
- Janefjord, Camilla, 1976-
(författare)
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Th1, Th2 and Treg associated factors in relation to allergy
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Immune responses are often divided into T helper 1 (Th1), Th2 and Treg like immunity. Allergy is associated with Th2 like responses to allergens and possibly to reduced regulatory functions. Activation via the CD2 receptor increases the production of the Th1 associated cytokine IFN-g and enhances the responses of activated T cells to IL-12. This may be due to an up-regulation of the signal-transducing β2-chain of the IL-12 receptor. CD2 function may be impaired in allergic children. As IL-12 is a strong promoter of Th1 like responses, this may be one contributing factor to the Th2-skewed immune responses found in allergic children. IL-27 and its receptor component WSX-1 may also play a role in Th1 like responses. The transcription factors T-bet, GATA-3 and Foxp3 are associated with Th1, Th2 and Treg type of immune responses, respectively.Aim: To investigate possible mechanisms behind the reduced Th1 and/or Treg associated immunity in relation to allergy by studying the CD2 induced regulation of IL-12Rβ2, WSX-1, T-bet, GATA-3 and Foxp3, as well as the production of different cytokines in children and adults. The aim was also to study the development of these factors during the first two years of life in relation to development of allergy in children from a country with high (Sweden) and low (Estonia) prevalence of allergy.Material and methods: Four different study groups were included; 32 12-year-old children, 38 7-year-old children, 61 children followed from birth to two years of age and 20 adults. Peripheral blood mononuclear cells were cultured with PHA (which partly signals via CD2), IL-2 and IL-12 alone and in combination or with anti-CD2 alone or combined with anti-CD28 antibodies. mRNA expression of cytokine receptors and transcription factors was analysed with real-time PCR and production of Th1, Th2 and Treg associated cytokines with ELISA.Results: We found lower PHA-induced IL-12Rβ2 and IFN-γ production in 12-year-old children with positive skin prick tests (SPT), compared with SPT negative children. We also found lower IL-2 induced IL-12Rβ2 in children with allergic airway symptoms and high IgE levels compared to children without a history of allergy and low IgE levels. This was accompanied with lower IL-2 and IL-12 induced IFN-γ. The spontaneous mRNA expression of IL-12Rβ2, WSX-1, T-bet, GATA-3 and Foxp3 was similar at birth and at 24 months. PHA induced up-regulation of all markers at all ages except for GATA-3, which was up-regulated in allergic children only at 6 and 12 months. PHA-induced T-bet and WSX-1 increased from birth to 24 months in non-allergic children. At a specific age, similar levels of all markers were found in allergic and non-allergic children, except for higher spontaneous IL-12Rβ2 at 24 months and higher PHA-induced WSX-1 at birth in allergic children. All cytokines increased with age. No clear differences were found between Swedish and Estonian children. CD2 stimulation induced Foxp3 and IL-10, while CD2 together with CD28 stimulation induced both Th1 and Th2 related transcription factors and cytokines. The combination also hampered the CD2 induced expression of Foxp3.Conclusions: The CD2 pathway and the response to IL-2 may be impaired in allergic children as lower IL-12Rβ2 and IFN-g were found in allergic, compared to non-allergic children. This difference was not found in adults. CD2 may be involved in induction of regulatory T cell responses as stimulation via CD2 in the absence of other co-stimulatory molecules induced Foxp3 and IL-10. Different developmental patterns of Th1 and Th2 associated factors may influence the development of allergic diseases in childhood.
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| 14. |
- Jarefors, Sara, et al.
(författare)
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Decreased up-regulation of the interleukin-12Rbeta2-chain and interferon-gamma secretion and increased number of forkhead box P3-expressing cells in patients with a history of chronic Lyme borreliosis compared with asymptomatic Borrelia-exposed individuals
- 2007
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Ingår i: Clinical and Experimental Immunology. - : Oxford University Press (OUP). - 0009-9104 .- 1365-2249. ; 147:1, s. 18-27
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Tidskriftsartikel (refereegranskat)abstract
- Lyme borreliosis (LB) can, despite adequate antibiotic treatment, develop into a chronic condition with persisting symptoms such as musculoskeletal pain, subjective alteration of cognition and fatigue. The mechanism behind this is unclear, but it has been postulated that an aberrant immunological response might be the cause. In this study we investigated the expression of the T helper 1 (Th1) marker interleukin (IL)-12Rβ2, the marker for T regulatory cells, forkhead box P3 (FoxP3) and the cytokine profile in patients with a history of chronic LB, subacute LB, previously Borrelia-exposed asymptomatic individuals and healthy controls. Fifty-four individuals (12 chronic LB, 14 subacute LB, 14 asymptomatic individuals and 14 healthy controls) were included in the study and provided a blood sample. Mononuclear cells were separated from the blood and stimulated with antigens. The IL-12Rβ2 and FoxP3 mRNA expression was analysed with real-time reverse transcription–polymerase chain reaction (RT–PCR). The protein expression of IL-12Rβ2 on CD3+, CD4+, CD8+ and CD56+ cells was assessed by flow cytometry. Furthermore, the secretion of interferon (IFN)-γ, IL-4, IL-5, IL-10, IL-12p70 and IL-13 was analysed by enzyme-linked immunospot (ELISPOT) and/or enzyme-linked immunosorbent assay (ELISA). Chronic LB patients displayed a lower expression of Borrelia-specific IL-12Rβ2 on CD8+ cells and also a lower number of Borrelia-specific IFN-γ-secreting cells compared to asymptomatic individuals. Furthermore, chronic LB patients had higher amounts of Borrelia-specific FoxP3 mRNA than healthy controls. We speculate that this may indicate that a strong Th1 response is of importance for a positive outcome of a Borrelia infection. In addition, regulatory T cells might also play a role, by immunosuppression, in the development of chronic LB.
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| 15. |
- Sandin, Linnea, 1984-
(författare)
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The influence of lysozyme and oligothiophenes on amyloid-β toxicity in models of Alzheimer’s disease
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Alzheimer’s disease (AD) is a neurodegenerative disease and the most common cause of dementia worldwide. Apart from dominantly inherited mutations, age is the major risk factor and as life expectancy increases the prevalence for AD escalates dramatically. AD causes substantial problems for the affected persons and their families, and the society suffers economically. To date the available treatments only temporarily relieve the symptoms, wherefore the development of a cure is of utmost importance. The etiology of AD is still inconclusive but many believe that small aggregates (oligomers) of the protein amyloid-β (Aβ) are central for the onset of AD.The aims of this thesis were to investigate how different molecules affect the aggregation and toxicity of Aβ. In paper I and II, two oligothiophenes were studied; p-FTAA and h-FTAA and in paper III and IV the inflammatory protein lysozyme was explored. Differentiated neuroblastoma cells and Drosophila melanogaster were used as models of AD to address the issue.The results show that p-FTAA rescues neuroblastoma cells from Aβ toxicity when Aβ is coaggregated with lysozyme. Various biophysical studies show that the co-aggregation increases the formation of fibrillar Aβ structures rich in β-sheets. Noteworthy, these Aβ fibrils were more resistant to both degradation and denaturation, and less prone to propagate seeding from Aβ monomers. Furthermore, h-FTAA, but not p-FTAA, was able to protect neuroblastoma cell toxicity when exposed to Aβ with the Arctic mutation (AβArc), which probably reflects the weaker binding of AβArc to p-FTAA, compared to h-FTAA.Lysozyme levels were increased in CSF from patients that were both biochemically and clinically diagnosed with AD. In mice models of AD it was revealed that the mRNA increase in lysozyme correlates to increased Aβ pathology, but not to tau pathology, indicating that Aβ could drive the expression of lysozyme. To evaluate the effect for increased expression of lysozyme, co-expression of lysozyme was achieved in flies that expressed Aβ in the retina of the eyes, or in flies that expressed AβArc in the central nervous system. In all AD fly models, co-expression of lysozyme protected the cells from the Aβ induced toxicity. Of note, flies that expressed the toxic AβArc in the CNS of the flies showed an improvement in both lifespan and activity. Finally, we demonstrate that Aβ aggregating in the presence of lysozyme inhibits the cellular uptake of Aβ and also the cytotoxic effect of Aβ.The work included in this thesis demonstrates that the oligothiophenes p-FTAA and h-FTAA, and also lysozyme have the potential to be used as treatment strategies for sporadic AD, but remarkable, also in familial AD with the highly toxic Arctic mutation. The protective mechanism of p-FTAA seems to be attributed to the ability to generate stable Aβ fibrils with reduced seeding capacity, and that lysozyme inhibits the neuronal uptake of Aβ, which could prevent both the intracellular toxicity and cell-to-cell transmission of Aβ.
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| 16. |
- Zdolsek, Helena, et al.
(författare)
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Reduced IL-2-induced IL-12 responsiveness in atopic children
- 2003
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Ingår i: Pediatric Allergy and Immunology. - : Wiley. - 0905-6157 .- 1399-3038. ; 14:5, s. 351-357
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Tidskriftsartikel (refereegranskat)abstract
- Atopy may be associated with a reduced T-cell function particularly regarding maturation of T helper 1 (Th1) responses. We hypothesized that atopic children may have a reduced capacity to up-regulate the β2 subunit of the interleukin-12 (IL-12) receptor (IL-12Rβ2, the signal-transducing component). The study included 38 children followed from birth to the age of 7 years. Twenty one had a cumulative history of atopic disease, whereas 17 had none. Sixteen out of 21 children also had atopic symptoms within the past year (current), out of whom 10 children had atopic airway symptoms. The expression of IL-12Rβ2 mRNA was analyzed by quantitative real-time PCR and the secretion of interferon-γ (IFN-γ), IL-5 and IL-10 was assessed by enzyme-linked immunosorbent assay (ELISA). Children with current atopic airway symptoms and high levels of total IgE up-regulated IL-12Rβ2 mRNA expression less than non-atopic children with low IgE levels after IL-2 stimulation. This was accompanied by a low IL-2- and IL-12-induced IFN-γ production, possibly reflecting the reduced capacity of atopic children to up-regulate the IL-12 receptor. As IL-2 is needed to initiate and sustain immune responses and IL-12 promotes Th1 responses, this may contribute to the Th2-skewed pattern in atopic children.
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