Allergen-induced Th1 and Th2 cytokine secretion in relation to specific allergen sensitization and atopic symptoms in children

COVID-19 knowledge deconstruction and retrieval: an intelligent bibliometric solution

COVID-19 has been an unprecedented challenge that disruptively reshaped societies and brought a massive amount of novel knowledge to the scientific community. However, as this knowledge flood continues surging, researchers have been disadvantaged by not having access to a platform that can quickly synthesize emerging information and link the new knowledge to the latent knowledge foundation. Aiming to fill this gap, we propose a research framework and develop a dashboard that can assist scientists in identifying, retrieving, and understanding COVID-19 knowledge from the ocean of scholarly articles. Incorporating principal component decomposition (PCD), a knowledge mode-based search approach, and hierarchical topic tree (HTT) analysis, the proposed framework profiles the COVID-19 research landscape, retrieves topic-specific latent knowledge foundation, and visualizes knowledge structures. The regularly updated dashboard presents our research results. Addressing 127,971 COVID-19 research papers from PubMed, the PCD topic analysis identifies 35 research hotspots, along with their inner correlations and fluctuating trends. The HTT result segments the global knowledge landscape of COVID-19 into clinical and public health branches and reveals the deeper exploration of those studies. To supplement this analysis, we additionally built a knowledge model from research papers on the topic of vaccination and fetched 92,286 pre-Covid publications as the latent knowledge foundation for reference. The HTT analysis results on the retrieved papers show multiple relevant biomedical disciplines and four future research topics: monoclonal antibody treatments, vaccinations in diabetic patients, vaccine immunity effectiveness and durability, and vaccination-related allergic sensitization.

Allergic sensitization trajectories to age 8 years in the Singapore GUSTO cohort

Background

Allergic sensitization is linked to allergy development, with early sensitization often associated with worse outcomes. We aimed to identify if distinct allergic sensitization trajectories existed within a diverse and multi-ethnic Asian cohort.

Methods

We administered modified ISAAC questionnaires in the first 8 years and conducted skin prick testing at ages 18 months, 3, 5 and 8 years in the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort. We used latent class analysis to derive allergic sensitization trajectories, and adjusted odds ratios (AOR) to evaluate predictive risk factors and associations with allergic comorbidities.

Results

Among 997 children, three trajectories were identified: early food and mite sensitization (16.2%), late mite sensitization (24.2%) and no/low sensitization (59.6%). Early food and mite sensitization was associated with early eczema by 6 months [AOR (95%CI) 4.67 (1.78-12.28)], increased risk of wheeze by 3-8 years (ARR 1.72-1.99) and eczema in the first 8 years of life (ARR 1.87-2.41). Late mite sensitization was associated with female sex [AOR 0.58 (0.35-0.96)], cesarean section [AOR 0.54 (0.30-0.98)], early eczema by 6 months [AOR 3.40 (1.38-8.42)], and increased risk of eczema by 18 months [ARR 1.47 (1.03-2.08)] and 8 years [ARR 1.35 (1.05-1.73)].

Conclusion

Early onset of eczema and early allergic sensitization were strongly associated. Early sensitization, especially to house dust mites, was associated with increased risks of developing wheeze and eczema, pointing to the importance of developing preventive perinatal interventions and effective therapeutics for sensitized toddlers.

Lactiplantibacillus plantarum 22A-3 isolated from pickle suppresses ovalbumin-induced food allergy in BALB/c mice and 2,4-dinitrochlorobenzene-induced atopic dermatitis in NC/Nga mice

In the previous study, pickle-derived Lactiplantibacillus plantarum 22A-3 (LP22A3) suppressed ear edema in passive cutaneous anaphylaxis by its oral administration. Moreover, LP22A3 treatment directly to RBL-2H3 cells shows no effect on β-hexosaminidase release from RBL-2H3 but inhibited its release using the Caco-2/RBL-2H3 cells co-culture system stimulated with LP22A3 from the apical side. In this study, oral administration of LP22A3 decreased total IgE and ovalbumin (OVA) specific IgE contents in blood of BALB/c mice induced food allergy by OVA. Moreover, its oral administration suppressed the development of dermatitis induced by 2,4-dinitrochlorobenzene (DNCB) which was used to develop atopic dermatitis-like lesions in NC/Nga mice. This alleviation was further correlated with a reduction of elevated serum total IgE, transepidermal water loss and elevated acanthosis in the LP22A3-treated group compared with vehicle-treated positive group. In co-culture system composed of Caco-2 and RBL-2H3 cells, LP22A3 treatment on apical side before or after the sensitization with anti-dinitrophenyl (DNP) IgE antibody indicated the different effect on β-hexosaminidase release from RBL-2H3. Its treatment before the sensitization decreased β-hexosaminidase release, but not after sensitization, indicating that LP22A3 affected mast cells sensitized with allergen through intestinal epithelial cells. These results suggest that LP22A3 may have a potential therapeutic property for Type 1 hypersensitivity and atopic dermatitis.

Pregnancy modulates the allergen-induced cytokine production differently in allergic and non-allergic women

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-γ (IFN-γ), 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 12 months 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-γ 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-γ and CXCL10 production, with distinct enhanced Th2-responses to birch in the allergic group and to cat in the non-allergic group.

The mother-offspring dyad: microbial transmission, immune interactions and allergy development

The increasing prevalence of allergy in affluent countries may be caused by reduced intensity and diversity of microbial stimulation, resulting in abnormal postnatal immune maturation. Most studies investigating the underlying immunomodulatory mechanisms have focused on postnatal microbial exposure, for example demonstrating that the gut microbiota differs in composition and diversity during the first months of life in children who later do or do not develop allergic disease. However, it is also becoming increasingly evident that the maternal microbial environment during pregnancy is important in childhood immune programming, and the first microbial encounters may occur already in utero. During pregnancy, there is a close immunological interaction between the mother and her offspring, which provides important opportunities for the maternal microbial environment to influence the immune development of the child. In support of this theory, combined pre- and postnatal supplementations seem to be crucial for the preventive effect of probiotics on infant eczema. Here, the influence of microbial and immune interactions within the mother-offspring dyad on childhood allergy development will be discussed. In addition, how perinatal transmission of microbes and immunomodulatory factors from mother to offspring may shape appropriate immune maturation during infancy and beyond, potentially via epigenetic mechanisms, will be examined. Deeper understanding of these interactions between the maternal and offspring microbiome and immunity is needed to identify efficacious preventive measures to combat the allergy epidemic.

Mould-sensitized adults have lower Th2 cytokines and a higher prevalence of asthma than those sensitized to other aeroallergens

BACKGROUND

Evidence suggests that specific allergen sensitizations are associated with different allergic diseases which may reflect different underlying immune profiles. We aimed to examine the cytokine profiles of individuals sensitized to eight common aeroallergens.

METHODS

We used data from the Tasmanian Longitudinal Health Study a population-based cohort study of 45-year-olds. Serum cytokines (IL-4, IL-5, IL-6, IL-8, IL-10, TNF-α) were measured in 1157 subjects using the LINCOplex assays. Participants underwent skin prick testing for house dust mite, cat, grasses and moulds. Multivariable linear regression was used to compare serum cytokine levels between sensitized and nonatopic subjects.

RESULTS

The prevalence of allergic sensitization to any aeroallergen was 51% (95% CI 47-54). Being sensitized to any aeroallergen was strongly associated with current asthma (OR = 3.7, 95% CI 2.6-5.3), and being sensitized to any moulds was associated with a very high risk of current asthma (OR = 6.40, 95% CI 4.06-10.1). The geometric mean (GM) levels of Th2 cytokines (IL-4, IL-5 and IL-6) for adults sensitized to Cladosporium were significantly lower than the levels for nonatopic individuals (IL-4 ratio of GMs = 0.25, 95% CI 0.10-0.62, P = 0.003; IL-5 GM = 0.55, 95% CI 0.30-0.99, P = 0.05; and IL-6 GM = 0.50, 95% CI 0.24-1.07, P = 0.07). Individuals sensitized to other aeroallergens all showed elevated Th2 cytokine levels.

CONCLUSION

Our study is the first large population-based study to demonstrate reduced Th2 cytokines levels in people sensitized to mould. Underlying biological mechanisms driving allergic inflammatory responses in adults sensitized to moulds may differ from those sensitized to other aeroallergens. These findings suggest that it may be necessary to tailor treatments in individuals sensitized to moulds compared with other aeroallergens in order to optimize outcomes.

Probiotic Dahi containing Lactobacillus acidophilus and Bifidobacterium bifidum modulates immunoglobulin levels and cytokines expression in whey proteins sensitised mice

BACKGROUND

Cow milk allergy is the most common food allergy in children. So far, no effective treatment is available to prevent or cure food allergy. This study investigated whether orally administrated probiotics could suppress sensitisation in whey proteins (WP)-induced allergy mouse model. Two types of probiotic Dahi were prepared by co-culturing Dahi bacteria (Lactococcus lactis ssp. cremoris NCDC-86 and Lactococcus lactis ssp. lactis biovar diacetylactis NCDC-60) along with selected strain of Lactobacillus acidophilus LaVK2 and Bifidobacterium bifidum BbVK3. Mice were fed with probiotic Dahi (La-Dahi and LaBb-Dahi) from 7 days before sensitisation with WP, respectively, in addition to milk protein-free basal diet, and control group received no supplements.

RESULTS

Feeding of probiotic Dahi suppressed the elevation of whey proteins-specific IgE and IgG response of WP-sensitised mice. In addition, sIgA levels were significantly (P < 0.001) increased in intestinal fluid collected from mice fed with La-Dahi. Production of T helper (Th)-1 cell-specific cytokines, i.e. interferon-γ (IFN-γ), interleukin (IL)-12, and IL-10 increased, while Th2-specific cytokines, i.e. IL-4 decreased in the supernatant of cultured splenocytes collected from mice fed with probiotic Dahi as compared to the other groups. Moreover, the splenic mRNA levels of IFN-γ, interleukin-10 were found to be significantly increased, while that of IL-4 decreased significantly in La-Dahi groups, as compared to control groups.

CONCLUSION

Results of the present study indicate that probiotic Dahi skewed Th2-specific immune response towards Th1-specific response and suppressed IgE in serum. Collectively, this study shows the potential use of probiotics intervention in reducing the allergic response to whey proteins in mice. © 2015 Society of Chemical Industry.

Picornavirus-Induced Airway Mucosa Immune Profile in Asymptomatic Neonates

BACKGROUND

Bacterial airway colonization is known to alter the airway mucosa immune response in neonates whereas the impact of viruses is unknown. The objective was therefore to examine the effect of respiratory viruses on the immune signature in the airways of asymptomatic neonates.

METHODS

Nasal aspirates from 571 asymptomatic 1-month-old neonates from the Copenhagen Prospective Studies on Asthma in Childhood 2010 birth cohort were investigated for respiratory viruses. Simultaneously, unstimulated airway mucosal lining fluid was obtained and quantified for levels of 20 immune mediators related to type 1, type 2, type 17, and regulatory immune paths. The association between immune mediator levels and viruses was tested by conventional statistics and partial least square discriminant analysis.

RESULTS

Picornaviruses were detected in 58 neonates (10.2%) and other viruses in 10 (1.8%). A general up-regulation of immune mediators was found in the neonates with picornavirus (P < .0001; partial least square discriminant analysis). The association was pronounced for type 1- and type 2-related markers and was unaffected by comprehensive confounder adjustment. Detection of picornavirus and bacteria was associated with an additive general up-regulating effect.

CONCLUSIONS

Asymptomatic presence of picornavirus in the neonatal airway is a potent activator of the topical immune response. This is relevant to understanding the immune potentiating effect of early life exposure to viruses.

Immune responses to inhalant allergens

This overview describes the nature of the immune responses induced by the inhalation of allergens. There is a dichotomy in that B cells have multiple mechanisms that limit the amount of immunoglobulin E (IgE) antibody production, whereas T-cell responses are large even in nonallergic subjects. With the possible exception of responses to cat allergen, however, T cells from nonallergic subjects have limited effector function of helping IgG antibody, and in house-dust mite allergy, this declines with age. Regulation by interleukin 10 (IL-10)-producing cells and CD25⁺ T-regulatory cells has been proposed, but critically, there is limited evidence for this, and many studies show the highest IL-10 production by cells from allergic subjects. Recent studies have shown the importance of nonlymphoid chemokines thymic stromal lymphopoietin and IL-27, so studying responses in situ is critical. Most sources of allergens have 1 or 2 dominant allergens, and for house-dust mite, it has been shown that people have a predictable responsiveness to high-, mid-and poor-IgE-binding proteins regardless of the total size of their response. This allergen hierarchy can be used to design improved allergen preparations and to investigate how antiallergen responses are regulated.

Longitudinal interferon-β effects in multiple sclerosis: differential regulation of IL-10 and IL-17A, while no sustained effects on IFN-γ, IL-4 or IL-13

BACKGROUND

Recent studies in experimental models and in vitro indicate lowering of IL-17/Th17 as an important mechanism of interferon-beta (IFN-β) treatment in multiple sclerosis (MS).

MATERIAL AND METHODS

In this longitudinal study of MS patients (n=25), spontaneous and myelin antigen-induced secretion of IL-4, IFN-γ and IL-10 (ELISPOT), mitogen stimulated secretion of IL-13 and IL-17A (ELISA) and circulating cytokine levels (Luminex) were recorded at inclusion and after 1.5, 3, 6 and 12months of IFN-β treatment.

RESULTS

Early changes were noted for IL-4, while after one year of treatment the only recorded significant effects were a decrease in secreted IL-17A levels and an increase in IL-10 secreting cells. While IL-17A levels tended to be higher in non-responders (n=8), the decrease in IL-17A levels seemed to be more pronounced in responders (n=17) showing significantly lower IL-17A levels after one year as compared with non-responders.

CONCLUSION

IFN-β treatment seems to mainly affect IL-17/IL-10-associated pathways rather than the IFN-γ/IL-4 axis.

Oral administration of allergen extracts from mugwort pollen desensitizes specific allergen-induced allergy in mice

Clinically, sublingual immunotherapy (SLIT) using allergen extracts effectively alleviates the symptoms of allergic rhinitis and asthma. We hypothesized that oral administration of a high-dose of allergen extracts imitates SLIT, which may prevent IgE-related responses in allergic diseases. In the present study, we investigated the effects of oral administration of allergen extracts from mugwort pollen (MP) on allergen-induced inflammation and airway hyperresponsiveness (AHR) in an allergic mouse model. After administration of MPdrop containing Art v 1 and Art v 4 extracts derived from MP specifically in MP-sensitized mice, the effects of MPdrop on AHR, inflammatory cell accumulation, cytokine production in the bronchoalveolar lavage fluid and lung tissue, and serum IgE and IgG levels were investigated. The results indicated that MPdrop not only prevented the AHR in response to methacholine in a dose-dependent manner but also significantly reduced the total serum and allergen-specific IgE levels. All of the maximal effects were achieved at a dose of 100μg/(kgd) and were comparable to the effects of dexamethasone at a dose of 0.5mg/(kgd). Furthermore, oral administration of MPdrop dose-dependently elevated allergen-specific serum IgG2a levels, reduced total and allergen-specific IgE levels and normalized the imbalance between the Th1 cytokine IL-12 and Th2 cytokines IL-4 and IL-5. Finally, oral administration of MPdrop significantly reduced goblet cell hyperplasia and eosinophilia in the MP-sensitized allergic mouse model. These data suggest that MPdrop effectively improves specific allergen-induced inflammation and AHR in MP-sensitized and -challenged mice and provides the rationale for clinical use of MPdrop in the specific allergen-induced asthma.

Interleukin-13 receptor A1 gene polymorphism and IL-13 serum level in atopic and non-atopic Egyptian children

OBJECTIVES

To assess serum interleukin (IL) 13 levels in atopic diseases and to determine the role of IL-13R A(1) gene polymorphism (+1398 A/G) in pathogenesis of these diseases.

METHODS

Serum total immunoglobulin (Ig) E and IL-13 levels were measured by ELISA and the IL-13R A(1) gene (+1398 A/G) was screened by PCR-restriction fragment length polymorphism (RFLP) in 240 asthmatic children (120 atopic and 120 nonatopic) and 120 allergic rhinitis patients compared with 120 age-matched controls.

RESULTS

No significant association was observed between genotype frequencies of the IL-13R A(1) +1398 A/G polymorphism in patients groups compared to in controls. There was a significant increase in serum levels of total IgE & IL-13 towards heterozygous AG and homozygous GG than homozygous AA in atopic asthma, non-atopic asthma and allergic rhinitis groups (P < 0.001 for each). A highly significant increase of serum IL-13 in atopic asthma as compared with controls (P < 0.001) and with nonatopic asthmatics (P < 0.001) was shown.

CONCLUSION

The IL-13R A(1) +1398 A/G polymorphism does not contribute to asthma or allergic rhinitis susceptibility, yet serum IL-13 can be used as a marker in atopic diseases and to differentiate between atopic and non-atopic asthma.

Dynamics in cytokine responses during the development of occupational sensitization to rats

BACKGROUND

Occupational allergy forms an attractive model to study the development of allergic responses, as in some occupations it has a high incidence and develops quickly. In a cohort of starting laboratory animal workers, we previously found 20% sensitization to animal allergens within 2 years.

METHODS

We compared cellular responses of incident laboratory animal workers who developed rat-specific sensitization (cases, n = 18) during 2 years of follow-up to control animal workers matched for atopic status but without sensitization after follow-up (controls, n = 18). Practically, this is a case-control study, nested within the cohort. Rat-specific IgE antibodies were measured in sera, and allergen-specific and nonspecific cytokine responses were measured in whole blood and in isolated peripheral blood mononuclear cells.

RESULTS

Self-reported allergic symptoms were related to the presence of rat-specific IgE (P ≤ 0.01). Cases developed a rat allergen-specific interleukin (IL)-4 response during sensitization, while controls did not show an increased IL-4 response (at visit D: 33 vs 5 IL-4 producing cells/10(6) cells, P < 0.001). The IL-4 response was related to the levels of rat-specific IgE in cases (visit D: rho = 0.706, P < 0.001). By contrast, allergen-specific IL-10 and interferon γ (IFNγ) responses as well as nonspecific cytokine responses were comparable between cases and controls.

CONCLUSION

This study is the first to show the development of an allergen-specific IL-4 response in adult human subjects during allergen-specific sensitization. This IL-4 response was quantitatively associated with the development of the specific IgE antibodies. Allergen-specific or nonspecific IL-10 and IFNγ responses showed no protective effect on the development of allergic sensitization.

Dysregulated Th1 and Th2 responses in food-allergic children--does elimination diet contribute to the dysregulation?

Infants with eczema and sensitization to foods are recommended skin care and, if food allergy is proven, an elimination diet. Although most of these children tolerate foods before 3 yr of age, some children experience prolonged food allergy. To our knowledge, no prospective study has investigated the cytokine profile in food-sensitized eczematous children with prolonged food intolerance. The aim of the study was to prospectively investigate the development of cytokine production induced by food allergen in food-sensitized eczematous children who, at 4(1/2) yr of age, were allergic or tolerant to egg or milk. Twenty-one eczematous infants, [age 5 (3-10) months; median and range], sensitized to egg and/or milk were included, put on elimination diet and followed prospectively. At 4(1/2) yr of age, the children were defined as tolerant or allergic to egg and/or milk based on open or double-blind placebo-controlled food challenges. Peripheral blood mononuclear cells (PBMC) were isolated from the children on inclusion, after 6 wk of elimination diet, and at 3 and 4(1/2) yr of age. Ovalbumin, beta-lactoglobulin and tetanus toxoid-induced IL-4, -5, -10, -13 and IFN-gamma production from PBMC were analyzed with enzyme-linked immunosorbent assay. The IFN-gamma and IL-5 secretion induced by food allergen at 4(1/2) yr was higher in cell cultures from children who were allergic to egg or milk than in tolerant children. In food-allergic children, the levels of IFN-gamma and IL-5 were higher at 4(1/2) yr compared with inclusion levels, but this increase was generally not observed in the tolerant children who consumed milk and egg. In conclusion, immune cells from food-allergic children on an elimination diet respond with up-regulated T helper 1 and T helper 2 cytokine secretion induced by food allergen. We hypothesize that allergen elimination may influence the regulatory mechanisms maintaining balanced immune responses to innocuous food antigens.

Effect of HLA genotype or CTLA-4 polymorphism on cytokine response in healthy children

Type 1 diabetes (T1D) is considered to be a T-cell-mediated autoimmune disease in which genetic predisposition is affected by HLA class II alleles and polymorphisms in cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) gene. We tested the hypothesis whether these T1D-related gene polymorphisms modulate cytokine response and thus contribute to the development of autoimmunity. The study includes 67 non-diabetic children, typed for HLA class II alleles and CTLA-4 polymorphisms (+49A/G, CT60A/G, CTBC217_1C/T). We measured cytokine secretion of peripheral blood mononuclear cells after stimulation with tetanus toxoid (TT), polio virus, coxsackie virus B4, pertussis toxin (PT) and phytohemagglutinin (PHA). We saw higher IL-13 response to TT in individuals with DR3-DQ2 haplotype (P = 0.002). HLA class II protective haplotype, DR2-DQ6, showed association with increased production of IFN-gamma (P < 0.001) and IL-2 (P = 0.005) in response to polio virus. In children with the autoimmunity-related homozygous genotypes CTLA-4 +49G/G, CT60G/G and CTBC217_1T/T, we found enhanced PT- and PHA-induced IFN-gamma production (P < 0.05). The cytokine responses to studied antigens were weakly modified by HLA class II risk haplotypes, and children with T1D-associated HLA risk haplotypes are not specifically inclined to develop an immune response in general. Higher IFN-gamma and IL-2 response to enterovirus in children with HLA class II protective haplotype DR2-DQ6 could be of importance in the protection from T1D-associated enterovirus infections. All autoimmunity related CTLA-4 polymorphisms were associated with enhanced IFN-gamma. This suggests impaired downregulation of cellular immunity by these CTLA-4 polymorphisms.

Perturbations of natural killer cell regulatory functions in respiratory allergic diseases

BACKGROUND

Allergic diseases are characterized by abnormal responses to allergens favored by an inappropriate regulation of the T(H)1-T(H)2 polarization. Natural killer (NK) cells give rise to a complex NK/dendritic cell (DC) cross-talk that would help T(H)1 responses.

OBJECTIVE

By analyzing peripheral blood NK cells from 12 patients with either allergic rhinitis or rhinitis and intermittent asthma, we evaluated whether these cells were impaired in their ability to interact with DCs.

METHODS

Different circulating NK cell subsets were analyzed by flow cytofluorimetry. Mixed NK/DC cultures were performed to assess the reciprocal functional interactions. NK cells were analyzed for their ability to induce DC maturation and cytokine production, and to kill immature DCs. In addition, DCs were assessed for their ability to induce cytokine production by NK cells.

RESULTS

We first analyzed the CD56++CD16+/- cells, a subset of circulating NK cells that is able to respond to DCs by proliferating and producing IFN-gamma. Our analysis revealed that this NK cell subpopulation was significantly reduced in most patients. This was reflected by reduced NK cell-mediated IFN-gamma production in response to DCs. Also, the capability of promoting DC maturation and/or killing immature DCs, a function sustained by CD56+CD16+ NK cells, was reduced in most patients.

CONCLUSIONS

We suggest that allergic diseases are accompanied by a partial impairment of the NK cell capability of promoting and maintaining appropriate T(H)1 responses.

Effects of etanercept are distinct from infliximab in modulating proinflammatory genes in activated human leukocytes

Proinflammatory diseases like rheumatoid arthritis, Crohn's disease, and psoriasis have been treated by the tumor necrosis factor (TNF) antagonists infliximab and etanercept with different degrees of success. Although these agents are widely used in humans, little is known about their mechanisms of action or why etanercept and infliximab have differences in clinical activity. In this study, we define leukocyte genes that are suppressed by etanercept within 24 hours of exposure. Compared to previous work with infliximab, fewer immune-related genes are suppressed by etanercept. Importantly, the range of genes suppressed by these alternative TNF inhibitors is only partially overlapping, suggesting each has unique immune modulating effects. In sharp contrast to etanercept, infliximab strongly suppresses genes associated with "Type 1" immune responses (IFN-gamma and the IL-12-receptor beta 2 subunit), providing a clear mechanism for clinically relevant immune suppression.

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

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)-12Rbeta2, 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-12Rbeta2 and FoxP3 mRNA expression was analysed with real-time reverse transcription-polymerase chain reaction (RT-PCR). The protein expression of IL-12Rbeta2 on CD3(+), CD4(+), CD8(+) and CD56(+) cells was assessed by flow cytometry. Furthermore, the secretion of interferon (IFN)-gamma, 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-12Rbeta2 on CD8(+) cells and also a lower number of Borrelia-specific IFN-gamma-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.

IL-9 promotes anti-Mycobacterium leprae cytotoxicity: involvement of IFNgamma

Interleukin 9 (IL-9) is a T-cell derived factor preferentially expressed by CD4+ Th2 cells and it has been characterized both in human and murine systems. It is a pleiotropic cytokine with multiple functions on cells of the lymphoid, myeloid and mast cell lineages, as well as on lung epithelial cells. Other activities described for IL-9 support its contribution to asthma and its important role in helminthic infections, where a Th2 response can be protective and IL-9 enhances resistance or is responsible for elimination of the nematode. Nevertheless, until recently there were no studies on its role in bacterial infections in man. We have demonstrated that cytokines can modulate the specific cytotoxicity generation in peripheral blood mononuclear cells from leprosy patients and normal controls. In the present report we studied the effect of IL-9 in this experimental model. Our results indicate that IL-9 can counteract the negative effect mediated by IL-4 on the generation of M. leprae-induced cytotoxic T lymphocytes. Moreover, it can increase this lytic activity in controls and enhance the stimulatory effect of IL-2 or IL-6 in cells from leprosy patients and controls. IL-9 is also able to revert the inhibitory effect of IL-10 and IL-13 on the M. leprae-induced cytotoxic activity. Although the exact mechanism of action of IL-9 remains to be determined, interferon gamma seems to be required for the effect of IL-9 in this experimental model. These data suggest that IL-9 may have an atypical Th2 behaviour and play a role in the modulation of the immune response to mycobacterial infections.

Allergen-induced interleukin-9 production in vitro: correlation with atopy in human adults and comparison with interleukin-5 and interleukin-13

BACKGROUND

The contribution of IL-9 to human atopy is supported by genetic studies. However, IL-9 production in response to allergen in vitro has been reported only in children.

OBJECTIVE

Study IL-9 induction by allergen in adults, compare it with IL-5 and IL-13 and evaluate its association with atopy.

METHODS

Peripheral blood mononuclear cell (PBMC) from control adults and from atopic patients were cultured with various allergens or phytohaemagglutinin (PHA) and secreted IL-5, IL-9 and IL-13 were measured by ELISA.

RESULTS

IL-9 was produced in response to Dermatophagoides pteronyssinus (Der p) by PBMC from Der p-hypersensitive adults at levels equivalent to those induced by PHA but with slower kinetics. The induction of IL-9 was allergen specific, reflecting donor RAST profile. In Der p-triggered reactions of non-atopic and atopic subjects, IL-9 showed the highest selectivity for atopics, IL-5 and IL-13 being produced more frequently in non-atopic donors. Significant correlations with specific IgE titres were found for IL-9 with all allergens tested (Der p and two peptides of Bet v 1 birch allergen). For IL-5 and IL-13, they were in the same range for Der p but more variable for birch allergens. Patterns of cytokine production by individual patients in response to allergen reflected these differences: for Der p, IL-5, IL-9 and IL-13 productions were strongly correlated but for birch IL-5 differed from the latter two. The in vitro production of IL-9 reflected clinical hypersensitivity profiles and was higher in individuals with asthma than in those with disease limited to rhinitis and/or conjunctivitis.

CONCLUSIONS

Allergen-triggered IL-9 production in vitro is an excellent marker for atopy in adults given its virtual absence in allergen-stimulated PBMC from non-atopic individuals and its correlation with allergen-specific IgE and asthma.

The combined effects of zafirlukast, prednisone, and inhaled budesonide on IL-13 and IFN-gamma secretion

Therapy for asthma often includes the combined use of glucocorticoids and leukotriene receptor antagonists. The short-term, combined effects of these drugs on cytokine secretion and lymphocyte proliferation are ill-defined. The aim of this study was to analyze allergen and mitogen-induced cytokine secretion and lymphocyte proliferation in asthmatics and to determine the effect of combined therapy on these immune responses. Peripheral blood mononuclear cells were isolated from mild, persistent adult asthmatics (n = 28) and analyzed for cat allergen (Fel d 1) and mitogen (phytohemagglutinin) induced IL-13 and IFN-gamma secretion and lymphocyte proliferation. Samples were analyzed before and after 10 days of therapy with oral zafirlukast, prednisone (0.5 mg/kg/day), and inhaled budesonide (1600 mcg/day). Both Fel d 1 and mitogen stimulation resulted in IL-13 and IFN-gamma secretion. Combination drug therapy resulted in a significant decrease in allergen-induced IFN-gamma secretion (p = 0.018) and allergen-specific lymphocyte proliferation (p = 0.02), while IL-13 secretion was unchanged (p = 0.109). This study indicates a role for Th1 cytokines as well as Th2 cytokines in the allergic response.

Lyme borreliosis reinfection: might it be explained by a gender difference in immune response?

Lyme borreliosis is a tick-borne disease often manifesting as a circular skin lesion. This cutaneous form of the disease is known as erythema migrans. In a 5-year follow-up study in southern Sweden, 31 of 708 individuals initially diagnosed with erythema migrans and treated with antibiotics were found to be reinfected with Borrelia burgdorferi. Although men and women were tick-bitten to the same extent, 27 of the 31 reinfected individuals were women, all of whom were over 44 years of age. The aim of this study was to determine whether this discrepancy in gender distribution could be a result of differences in immunological response. Twenty single-infected and 21 reinfected women and 18 single-infected and three reinfected men were included in the study. None of the participants showed any sign of an ongoing B. burgdorferi infection, and thus the habitual response was captured. Lymphocytes were separated from blood and stimulated with antigens. The secretion of interleukin (IL)-4, IL-6, IL-10, interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha was measured by enzyme-linked immunosorbent assay (ELISA), enzyme-linked immunosorbent spot-forming cell assay (ELISPOT) or Immulite. No difference was detected in cytokine secretion between single-infected and reinfected individuals. We also compared the immunological response in men and women, regardless of the number of B. burgdorferi infections. Women displayed a significantly higher spontaneous secretion of all cytokines measured. The ratios of IL-4:IFN-gamma and IL-10:TNF-alpha were significantly higher in women. Gender differences in immune reactivity might in part explain the higher incidence of reinfection in women. The higher IL-4:IFN-gamma and IL-10:TNF-alpha ratios seen in women indicate that postmenopausal women have T helper type 2 (Th2)-directed reactivity with impaired inflammatory responses which might inhibit the elimination of spirochetes.

Unique cytokine secretion profile in children with both type I diabetes and asthma distinct from that of solely diabetic or asthmatic children

Asthma and type I diabetes are major causes of chronic illness in childhood which, according to the current paradigm, have mutually antagonistic immunopathologies. Nonetheless, the disorders appear to preferably coexist both on population and individual levels. To assess whether children with asthma and type I diabetes might have a common immunoregulatory defect. The spontaneous and anti-CD3+ anti-CD28-stimulated cytokine production patterns by peripheral blood mononuclear cells of 13 children with both asthma and diabetes, nine children with diabetes, 11 children with asthma and nine healthy children were assessed using cytometric bead assay. The spontaneous production of IFN-gamma, TNF-alpha and IL-10 by mononuclear cells in children with both asthma and diabetes was elevated compared to the other study groups (p=0.02, p=0.001 and p=0.04, respectively). Stimulation in vitro increased IL-10 secretion in solely diabetic (p=0.008), asthmatic (p=0.008) and healthy children (p=0.01), but not in children with both diseases (p=0.22). Children suffering from both diabetes and asthma display a unique cytokine secretion pattern, distinct from those of solely diabetic, asthmatic and healthy children. In particular, these children appear to have a defect in regulation of IL-10 secretion.

Cytokine responses to allergens during the first 2 years of life in Estonian and Swedish children

BACKGROUND

The prevalence of atopic disease among children in the formerly socialist countries in Europe, with a life style similar to that prevailing in Western Europe 30-40 years ago, is low, whereas there has been a pronounced increase in industrialized countries over the last decades. The environment during infancy influences the risk of developing allergy for many years, perhaps even for life.

OBJECTIVE

To investigate the development of allergen-specific cytokine responses during the first 2 years of life in two geographically adjacent countries with marked differences in living conditions and incidence of atopic diseases, i.e. Estonia and Sweden.

METHODS

The development of immune responses to food (beta-lactoglobulin (BLG) and ovalbumin (OVA)) and inhalant (cat and birch) allergens was studied from birth up to the age of 2 years in 30 Estonian and 76 Swedish infants. Clinical investigation and skin prick tests were performed and blood samples were obtained at birth and at 3, 6, 12 and 24 months.

RESULTS

The levels of IL-5, IL-10 and IL-13 secreted by peripheral blood mononuclear cells stimulated with BLG, OVA and cat allergen in Estonian and Swedish infants declined during the first 3 months of life. All cytokines then progressively increased in the Swedish infants, indicating the replacement of non-specifically responding immature cord blood T cells with specific T memory cells, which are primed postnatally. The resurgence of allergen-specific responses in the Estonian infants was less marked. These differences were particularly notable for birch-specific T cell responses, which correlated with development of atopic disease in the Swedish children.

CONCLUSIONS

The development of specific T cell memory to food and inhalant allergens during the first 2 years of life differs between infants living in Sweden and Estonia, and mirrors the disparate patterns of expression of allergic disease which subsequently develops in the respective populations.

Patterns of food allergen-specific cytokine production by T lymphocytes of children with multiple allergies

BACKGROUND

The contribution of different T cell subsets to the overall measured cytokine response to food allergens is largely unexplored.

METHOD

The patterns of cytokine production of peripheral blood-derived T cells after allergen stimulation were studied in 22 children with multiple food allergies and in 20 non-allergic children as controls, using flow cytometry.

RESULTS

Proportions of T cells of food-sensitized children spontaneously secreting IFN-gamma and IL-10 (without antigen stimulation) were lower than non-atopic children and adult controls (P<or=0.001). The proportions of IL-4-producing cells in vitro were significantly increased (P<or=0.04) and IFN-gamma-producing cells were significantly reduced (P<or=0.05) in sensitized children after incubation with and without dendritic cell presentation of peanut extract, beta-lactoglobulin and ovalbumin. The reverse pattern was found in non-sensitized children and adult controls. IL-4 secretion in allergic children to sensitizing allergens was mainly restricted to the CD4(+) CD45 RO(+) population while in non-atopic controls both CD4(+) and CD8(+) CD45 RO(+) cells produced mostly IFN-gamma. Food-specific IgE values did not correspond with cytokine responses but IL-4 production and IFN-gamma reduction relative to normal children were closely associated with total IgE levels.

CONCLUSION

Food-allergic children's IL-4 cytokine response to their relevant allergens is predominantly from a memory population of CD4(+) CD45 RO(+) cells, whereas IL-4 and IFN-gamma secretion of non-allergic controls was predominantly from mixed CD4(+) and CD8(+) CD45 RO(+) populations.

Atopic dermatitis in young children is associated with impaired interleukin-10 and interferon-gamma responses to allergens, vaccines and colonizing skin and gut bacteria

BACKGROUND

A significant proportion of children with food allergy and more severe forms of atopic dermatis (AD) go on to develop persistent forms of allergic disease such asthma. Defining immune dysregulation in these children will be of great value in understanding disease pathogenesis.

OBJECTIVE

In this study we characterized the immune responses of young infants (6-18 months of age) with moderate-to-severe AD (a modified SCORAD>or=25) and compared these (n=53) with responses of non-allergic children with no history of dermatitis or sensitization of the same age (n=20).

METHODS

Mononuclear cell cytokine responses to allergens (egg ovalbumin (OVA), beta-lactoglobulin (BLG), house dust mite (HDM)), vaccines (tetanus toxoid (TT), diphtheria toxoid (DT)), intestinal flora (heat-killed Lactobacillus species (HKLB)), heat-killed Staphylococcus aureus (HKSA), S. aureus enterotoxin B (SEB) and mitogen (phytohaemaglutinin (PHA)) were compared in children with AD with unaffected children.

RESULTS

Children with AD had significantly lower spontaneous (unstimulated) production of regulatory cytokine IL-10 (P<0.001), as well as IFN-gamma (P<0.001) and TNF-alpha (P<0.001) compared with the unaffected children. After allowing for differences in baseline levels IL-10 responses to virtually all stimuli (food allergens (P=0.003), vaccines P=0.01, intestinal flora (heat-killed Lactobacillus species (HKLB), P=0.005) and skin flora (heat-killed Staphylococcus aureus (HKSA), P=0.003)) were also significantly attenuated in children with AD. The only exception was HDM, to which responses were stronger in children with AD [P=0.05]. Although there were no significant correlations between HDM IgE and HDM cytokine responses at this age, T-helper type 2 (Th2) IL-5 (P=0.014) and IL-13 (P=0.004) responses to HDM were significantly more frequent in the children with AD. However, while children with AD showed significantly attenuated Th1 IFN-gamma responses to food allergens (OVA, P=0.007 and BLG, P<0.001) and vaccines (DT, P=0.008 and TT, P<0.001), these children showed no difference in Th1 IFN-gamma responses to HDM or microbial agents (HKSA and HKLB).

CONCLUSION

A increase in propensity for Th2 responses to aeroallergens in children with AD is associated with early impaired production of IL-10 regulatory cytokine to a broad range of environmental stimuli including foods, intestinal flora, S. aureus, and vaccines.

Different cytokine profiles in patients with a history of gangrenous or phlegmonous appendicitis

Appendicitis is one of the most common and costly acute abdominal states of illnesses. Previous studies suggest two types of appendicitis which may be different entities, one which may resolve spontaneously and another that progresses to gangrene and perforation. Gangrenous appendicitis has a positive association to states of Th1 mediated immunity whereas Th2 associated immune states are associated with lower risk of appendicitis. This study investigated the inflammatory response pattern in patients previously appendicectomized for gangrenous (n = 7), or phlegmonous appendicitis (n = 8) and those with a non-inflamed appendix (n = 5). Peripheral blood mononuclear cells were analysed with ELISPOT analysis for number of spontaneous or antigen/mitogen stimulated IFN-gamma, IL-4, IL-10 and IL-12 secreting cells or with ELISA for concentration of spontaneous or antigen/mitogen stimulated IFN-gamma, IL-5 and IL-10. Spontaneously IL-10 secreting cells/100,000 lymphocytes were increased in the gangrenous group compared to the phlegmonous group (P = 0.015). The median concentration of IL-10 secreted after Tetanus toxoid (TT)-stimulation were higher in the gangrenous group and the control group, than the phlegmonous group (P = 0.048 and P = 0.027, respectively). The median concentration of TT induced IFN-gamma secretion was higher for the gangrenous group compared to both the phlegmonous group and the control group (P = 0.037 and P = 0.003). Individuals with a history of gangrenous appendicitis demonstrated ability to increased IL-10 and IFN-gamma production. The increased IFN-gamma may support the notion of gangrenous appendicitis as an uncontrolled Th1 mediated inflammatory response and increased IL-10 may speculatively indicate the involvement of cytotoxic cells in the progression to perforation.

Indications of an altered immune balance in preeclampsia: A decrease in in vitro secretion of IL-5 and IL-10 from blood mononuclear cells and in blood basophil counts compared with normal pregnancy

It has been suggested that maladaptation of the maternal immune response during pregnancy might be a causal factor for preeclampsia. This study was designed to examine the systemic immune status at both the innate level and the adaptive level in pregnancies complicated by preeclampsia (n=15) and normal pregnancies (n=15). Spontaneous and in vitro-induced secretion of IL-5, IL-6, IL-10, IL-12, IL-13 and TNF-alpha, in response to paternal blood cells and the vaccination antigens purified protein derivate of tuberculin (PPD) and tetanus toxoid (TT), was detected in cell culture supernatants from blood mononuclear cells by ELISA. Preeclamptic women showed reduced numbers of basophil granulocytes in the blood (p=0.004) and lower spontaneous secretion of IL-5 from blood mononuclear cells (p=0.016). In addition, paternal antigen-induced secretion of IL-10 was decreased in preeclampsia compared with normal pregnancy (p=0.012). No further differences between preeclampsia and normal pregnancy were found for any stimuli or cytokines. The present findings of reduced basophil numbers and lower spontaneous in vitro secretion of IL-5 in preeclampsia compared with normal pregnancy indicate a decrease in systemic Th2 immunity in preeclampsia. Furthermore, the decrease in paternal antigen-induced secretion of the immunosuppressive cytokine IL-10 in preeclampsia indicates a fetus-specific decrease in immunosuppression mediated by blood mononuclear cells. Whether these systemic changes are a cause or a consequence of preeclampsia remains to be elucidated.

Suppressive effect of IL-4 on IL-13-induced genes in mouse lung

Although IL-4 signals through two receptors, IL-4R alpha/common gamma-chain (gamma(c)) and IL-4R alpha/IL-13R alpha1, and only the latter is also activated by IL-13, IL-13 contributes more than IL-4 to goblet cell hyperplasia and airway hyperresponsiveness in murine asthma. To determine whether unique gene induction by IL-13 might contribute to its greater proasthmatic effects, mice were inoculated intratracheally with IL-4 or IL-13, and pulmonary gene induction was compared by gene microarray and real-time PCR. Only the collagen alpha2 type VI (Ca2T6) gene and three small proline-rich protein (SPRR) genes were reproducibly induced > 4-fold more by IL-13 than by IL-4. Preferential IL-13 gene induction was not attributable to B cells, T cells, or differences in cytokine potency. IL-4 signaling through IL-4R alpha/gamma(c) suppresses Ca2T6 and SPRR gene expression in normal mice and induces these genes in RAG2/gamma(c)-deficient mice. Although IL-4, but not IL-13, induces IL-12 and IFN-gamma, which suppress many effects of IL-4, IL-12 suppresses only the Ca2T6 gene, and IL-4-induced IFN-gamma production does not suppress the Ca2T6 or SPRR genes. Thus, IL-4 induces genes in addition to IL-12 that suppress STAT6-mediated SPRR gene induction. These results provide a potential explanation for the dominant role of IL-13 in induction of goblet cell hyperplasia and airway hyperresponsiveness in asthma.

Dexamethasone inhibits IL-9 production by human T cells

BACKGROUND

Interleukin 9 (IL-9) is produced by activated CD4+ T cells. Its effects include stimulation of mucus production, enhanced mast cell proliferation, enhanced eosinophil function, and IgE production. These effects are consistent with a role in allergic diseases. Glucocorticoids have potent anti-inflammatory effects, including suppression of cytokine synthesis, and are widely used in the treatment of allergic conditions.

METHODS

We examined the effect of the glucocorticoid dexamethasone (Dex) on IL-9 mRNA expression and protein secretion with real-time RT-PCR and ELISA. Peripheral blood mononuclear cells (PBMC) were prepared from human volunteers and activated with OKT3. CD4+ T cells were purified from PBMC and activated with OKT3 plus PMA.

RESULTS

IL-9 mRNA abundance and protein secretion were both markedly reduced following treatment of activated PBMC with Dex. mRNA levels were reduced to 0.7% of control values and protein secretion was reduced to 2.8% of controls. In CD4+ T cells, Dex reduced protein secretion to a similar extent. The IC50 value of Dex on mRNA expression was 4 nM.

CONCLUSION

These results indicate that IL-9 production is very markedly inhibited by Dex. The findings raise the possibility that the beneficial effects of glucocorticoids in the treatment of allergic diseases are in part mediated by inhibition of IL-9 production.

Effect of cryopreservation on expression of Th1 and Th2 cytokines in blood mononuclear cells from patients with different cytokine profiles, analysed with three common assays: an overall decrease of interleukin-4

Studies on cytokine expression in blood cells are commonly performed on cryopreserved cells. Previous studies show that cryopreservation affects cytokine expression, but the findings are not consistent. This may be due to divergent effects of freezing on different cytokines, different stimuli, and different patient groups or to the use of different assays in the studies. This study was designed to investigate the effect of freezing on spontaneous, auto-antigen, allergen, and mitogen induced cytokine secretion from peripheral blood mononuclear cells from several groups of patients expressing different cytokine profiles; multiple sclerosis, atopic children, non-atopic children, and pregnant women. The expression of IFN-gamma, IL-4, IL-5, IL-9, IL-10, and IL-13 was analysed with ELISA, ELISPOT and/or real time RT-PCR. Our data provide evidence that the process of cryopreservation and thawing does affect the expression of cytokines, both at the protein and the mRNA level. Moreover, the effect varied among different cytokines, different stimuli, and different patient groups, which partly may be explained by differences in optimal freezing conditions for non-activated and activated cells. An increase of allergen and PHA stimulated IFN-gamma secretion in atopic children was found following cryopreservation, but no such increase in auto-antigen induced IFN-gamma was seen in MS-patients. The most consistent finding was that expression of IL-4 was generally decreased in spontaneous and auto-antigen/allergen induced expression in cryopreserved cells. In conclusion, this study points out the importance of investigation of the effects of freezing for each cytokine, stimuli and patient group before using frozen cells in studies of in vitro cytokine secretion.

Antigen specific cytokine response in pediatric patients with atopic dermatitis

The physiopathology of atopic dermatitis (AD) has still to be elucidated. T effector cells with cutaneous homing receptors or T-cell derived cytokines have been assumed to be implicated in the pathogenetic mechanisms in AD and to be responsible for the different immunologic responses of patients. In fact, the large majority of AD patients display high IgE levels while others do not develop an abnormal IgE response. Although, there are not significant clinical features characterizing the two different groups, patients with normal IgE belong to a younger age range, raising the possibility that the hypothesized dichotomy of AD might be due to age. In the present study we included 172 outpatient children attending the Pediatric Department of our institution. Serum IgE levels and percentages of peripheral T lymphocytes expressing the cutaneous homing antigen (CLA) were evaluated and results were analyzed in relation to the activity of the disease (SCORAD index) or age. In the overall patients, the IgE levels increased significantly with age (0-1 yr: 19.50 IU/ml; 1-3 yr: 62.0 IU/ml; 3-8 yr: 96.0 IU/ml; >8 yr: 148.5 IU/ml; p<0.001) and with the severity of the disease (SCORAD low: 46.80 IU/ml; medium: 42.90 IU/ml; high: 148.5 IU/ml; p=0.01). Percentages of CLA+ peripheral T lymphocytes also increased with age (0-1 yr: 3.3; 1-3 yr: 4.85; 3-8 yr: 10.6; >8 yr: 12.5; p<0.001), although they were not significantly different in patients with different SCORAD (p=0.89). We further investigated the cellular immune response to a specific antigen in 25 subjects, matched for age, SCORAD, and CLA+ T-cell percentages. Among them, 13 patients had casein serum specific IgE and 12 had no evidence of casein sensitization. Peripheral blood mononuclear cells were kept in short-term culture with endotoxin-free casein fractions and IFN-gamma, TNF-alpha, IL-5, IL-10 cytokine-producing cells were detected by ELISpot. Statistical analysis showed significant higher numbers of TNF-alpha- or IL-10-producing cultures (stimulation index >3) in the 'allergic' patients than in the milk tolerant subjects (p=0.01 and 0.05). The analysis of individual responses confirmed this finding but also provide evidence of a significant increase in IFN-gamma-producing cells (p=0.05) induced by casein stimulation in the group of 'non-allergic' children. Our data showed that immunologic parameters as IgE levels or CLA+ T cells in AD pediatric patients are influenced by the age, confirming that age could represent a bias in the analysis of immune response in those patients. Although, we demonstrated in children with AD the existence of different cytokine patterns of the lymphocyte response that could account for the different immunologic features between the two hypothesized forms of AD, which are not dependent on age.

Autonomic dysfunction may be an under-recognized cause of female fertility disorders

Female conditions of impaired fertility comprise a heterogeneous group of disorders that are attributed to various anatomic, hormonal and immunologic disturbances. We hypothesize that autonomic dysfunction may be a previously unrecognized factor in female fertility disorders. Emerging physiologic and molecular evidence suggests that autonomic balance varies during normal menstrual cycles with a shift to sympathetic bias during the luteal phase. Furthermore, many diseases associated with autonomic dysfunction show catamenial variations in patterns consistent with a shift to sympathetic bias occurs during the second half of normal menstrual cycles. The shift to sympathetic bias during the normal luteal phase may be an evolutionary adaptation to address the immunologic and physiologic demands for successful implantation and gestation. Through direct modulation of the lymphoid system and activation of the cortisol pathway, sympathetic bias promotes a shift to relative T helper (Th)-2 biased immunity which may favor maternal tolerance of the embryo by attenuating Th-1 mediated interference of implantation. Indeed, a growing body of evidence has implicated abnormal Th balance in fertility disorders, but the link has been attributed to factors other than autonomic function, such as hormonal factors. After implantation, maternal sympathetic bias may further support gestation through physiologic changes necessary to maintain placental perfusion pressure. We propose that insufficient shift to sympathetic bias during the luteal phase, which manifests in inadequate shift towards Th-2 bias and down-regulation of Th-1 function, may be the mechanism of impaired fertility in certain patients. Our hypothesis portends new potential methods to treat fertility disorders by modulating autonomic balance.

Diminished dendritic cell interleukin 10 production in atopic children

BACKGROUND

Diminished interleukin 10 (IL-10) and/or IL-12 production may contribute to the pathogenesis of asthma and atopy. Dendritic cells (DCs) produce these cytokines and have been implicated in the pathogenesis of these disorders.

OBJECTIVE

To determine whether DC IL-10 and/or IL-12 production is diminished in children aged 6 to 12 years with allergic rhinitis (AR) and with or without asthma.

METHODS

Monocyte-derived DCs were isolated from 20 subjects without AR or asthma (group 1), 20 subjects with AR without asthma (group 2), and 20 subjects with AR and asthma (group 3). Asthma was defined as a history of physician-diagnosed disease, and AR was defined as a positive history and positive puncture skin test responses (wheal > or = 5 mm) to relevant inhalant allergens. DCs were stimulated with either lipopolysaccharide (LPS) or diluent and cultured for 24 hours. Supernatants were assayed for IL-10 and IL-12 levels by enzyme-linked immunosorbent assay.

RESULTS

DC IL-10 production was diminished in groups 2 and 3 compared with group 1. Median LPS-induced IL-10 levels were 11.0 pg/mL in group 1, 6.1 pg/mL in group 2, and 1.5 pg/mL in group 3. The frequencies of subjects with detectable IL-10 levels were 85%, 20%, and 20% in groups 1, 2 and 3, respectively. Median LPS-induced IL-12 levels were similar in all groups.

CONCLUSIONS

These data support the hypothesis that atopic subjects have an intrinsic inability to up-regulate DC IL-10 production. Future studies in this area could lead to a better understanding of the pathogenesis of atopy.

IL-9 in allergic inflammation

Th2 type cytokines such as interleukin (IL)-4, IL-5, IL-9, and IL-13 are important mediators in allergic inflammation. The present review will focus on the role of IL-9 in allergic inflammation. The structure and genomic architecture of IL-9 and its receptor, the source of IL-9 and its regulation as well as its effects on different cell types will be reviewed. Furthermore, the specific role of IL-9 in allergic diseases and the potential therapeutic approach of blocking IL-9 will be discussed.

Increased serum levels of interleukin-9 correlate to negative prognostic factors in Hodgkin's lymphoma

Hodgkin's lymphoma (HL) is characterised by an unbalanced cytokine secretion. Many of these cytokines have been implicated in the regulation of malignant and infiltrating cells. Interleukin-9 (IL-9) has been described to act in an autocrine fashion in HL, stimulating proliferation of the malignant cells. To investigate the potential clinical implication of this observation, a novel ELISA method was used to examine the serum levels of IL-9 in lymphoma patients. High levels of IL-9 were found in the sera from patients with HL (18/44), but not in the sera from non-Hodgkin's lymphoma patients (3/21) or healthy controls. The highest serum IL-9 levels, up to 3350 pg/ml, were observed in the nodular sclerosis subtype, and there was a correlation between IL-9 levels and the negative prognostic factors advanced stage, B-symptoms, low blood Hb and high erythrocyte sedimentation rate. Furthermore, there was no correlation between serum levels of IL-9 and IL-13, a cytokine where serum levels have been speculated to be of clinical importance. This is the first report showing that IL-9 can be measured in serum samples. A novel correlation between increased serum IL-9 levels, HL and clinical features is shown, suggesting that IL-9 is a candidate factor contributing to the development of HL.

Menstrual variation of autonomic balance may be a factor in exacerbations of certain diseases during the menstrual cycle

Exacerbation of certain medical conditions during specific phases of the menstrual cycle has long been recognized. Mechanisms of the cyclic variations are poorly understood, but are often attributed to fluctuations in reproductive hormones. We hypothesize that normal variations in autonomic balance during the menstrual cycle, which likely evolved as adaptations for reproduction, may contribute to catamenial variations in diseases independent of hormonal variations. Emerging evidence suggests that autonomic balance shifts towards sympathetic bias during the second half of the menstrual cycle. This shift can be seen as an evolutionary adaptation to address the immunologic and physiologic demands for successful implantation and gestation. Through direct modulation of lymphoid system and activation of the cortisol pathway, sympathetic bias promotes a shift to relative T helper (Th)-2-biased immunity which may favor maternal tolerance of the embryo by attenuating Th-1-mediated interference of implantation. Immune variance during the menstrual cycle has been implicated in menstrual fluctuations of many diseases, but until now the immune variance has been attributed to female hormonal changes. We propose that shifts in autonomic balance independently contribute to fluctuations in diseases by modulating the immune system. Still further, we propose that many other diseases fluctuate due to the direct nervous system actions of shifts in autonomic balance. Our hypothesis portends new therapeutic paradigms based on cyclical modulation of autonomic balance to address catamenial variations of medical conditions.

New concepts of cytokines in asthma: is the Th2/Th1 paradigm out the window?

Although asthma is clearly associated with a systemic propensity for allergic T helper type 2 (Th2) cell cytokine responses, independent local immune events appear to be responsible for the development of allergic airways inflammation. There is growing interest in how local immune networks interact with resident airway cell populations such as epithelial cells, which are now also recognized as key producers of cytokines, chemokines and growth factors. As well as their recognized role in airway remodelling, epithelial cells are now thought to have a role in initiating events. This review examines the role of cytokines produced by these and other cells in the development of asthma. It also highlights emerging concepts that the excessive and inappropriate immune responses seen in allergic disease may be related to dysfunction of various interleukin-10 producing regulatory cell populations.

Allergen-induced cytokine secretion in atopic and non-atopic asthmatic children

Atopic asthma is characterized by excessive T helper 2 (Th2)-like immunity to allergens in the bronchial mucosa. The Th2-cytokine interleukin (IL)-4 induces IgE production, while the Th2-cytokine IL-5 promotes eosinophilic inflammation in the airways of asthmatics. Most asthmatics are atopic, but a subgroup is non-atopic. We hypothesize that allergen-induced Th2, particularly IL-5, responses can be observed in peripheral blood in both atopic and non-atopic asthmatic children but not in healthy control children. The aim of the present study was to determine IL-4, IL-5, IL-9, IL-10, IL-13 and IFN-gamma secretion induced from peripheral blood mononuclear cells (PBMC) by a broad panel of inhalant allergens (timothy, cat, birch, dog and house dust mite) in asthmatic children with and without sensitization. The study included 13 atopic asthmatic, 5 non-atopic asthmatic, and 12 non-atopic non-asthmatic children. PBMC were stimulated with allergens and cytokine production was measured with enzyme-linked immunosorbent assay (ELISA). Higher levels of cat and dog antigen-induced IL-5 release were more commonly observed in both atopic and non-atopic asthmatics than in controls. Children with atopic, but not non-atopic, asthma produced higher levels of allergen-induced IL-4 and IL-9 than controls. Non-atopic asthmatics produced more IL-10 than atopic asthmatics after cat stimulation. High levels of eosinophilia-associated IL-5 responses are induced by cat and dog allergen in both atopic and non-atopic asthmatic children. The Th2 cytokines IL-4 and IL-9 were associated only with atopic asthma, probably due to their IgE-inducing properties.

Asthma, lung function and allergy in 12-year-old children with very low birth weight: a prospective study

We assessed the relationship between very low birth weight (VLBW) (<or=1500 g) and the development of asthma, lung function and atopy. The study groups comprised 74 of all 86 (86%) VLBW and 64 of all 86 (74%) matched term children who were prospectively followed for 12 years. A questionnaire on asthmatic and allergic symptoms was completed and skin prick tests, spirometry and hypertonic saline provocation tests were performed at 12 years of age. Cytokine secretion was analysed in stimulated blood leukocyte cultures in 28 VLBW and 23 term children. A history of asthma was more frequent among the VLBW children, as compared with the term children at age 12 (22% vs. 9%, p = 0.046). Among the VLBW children, very preterm birth (gestational age: week 25 to 29) (RR 2.5, 95%CI 1.1-5.8), neonatal mechanical ventilation (RR 2.8, 95%CI 1.2-6.4) and neonatal oxygen supplementation (RR 4.3, 95%CI 1.3-14.0) were significantly associated with a history of asthma by the age of 12 years in univariate analyses. In multivariate logistic regression, neonatal oxygen supplementation >or= 9 days was the only remaining significant risk factor for a history of asthma (adjusted OR 6.7, 95%CI 1.0-44). The VLBW children who required mechanical ventilation during the neonatal period were more likely to have bronchial hyperresponsiveness than those not requiring mechanical ventilation (60% vs. 28%, p = 0.050). The spirometric values were similar among the VLBW and the term children at 12 years. Very low birth weight was not significantly related to allergic rhinoconjunctivitis, eczema or positive skin prick tests. Furthermore, the levels of IL-4, IL-5 and IFN-gamma in stimulated cell cultures were similar in the VLBW and the term children. A history of asthma by 12 years of age was twice as common among the VLBW as the term children, and neonatal oxygen supplementation seemed to be associated with the increased risk. Furthermore, mechanical ventilation during the neonatal period was associated with bronchial hyperresponsiveness at age 12. Very low birth weight per se was not, however, related to atopy.

Segmental allergen challenge in patients with atopic asthma leads to increased IL-9 expression in bronchoalveolar lavage fluid lymphocytes

BACKGROUND

IL-9 is a T(H)2 cell-derived cytokine that might be involved in the pathophysiology of allergic diseases. Little is known about its expression and release during the allergic response in the human lung.

OBJECTIVE

The expression of IL-9 was measured in 10 atopic subjects with mild asthma and 5 nonatopic healthy control subjects at baseline and 24 hours after segmental sham and allergen challenge.

METHODS

IL-9 protein was measured in bronchoalveolar lavage (BAL) fluid by means of ELISA and detected within the BAL cells by means of immunocytochemistry. Furthermore, IL9 mRNA expression of BAL cells was detected by means of real-time PCR.

RESULTS

Although only low or undetectable amounts of IL9 mRNA and IL-9 protein were present in nonatopic control subjects and atopic asthmatic patients at baseline, there was an increase after segmental allergen challenge in the atopic subjects. Lymphocytes were identified as major cellular sources of IL-9 production by means of immunocytochemistry. Furthermore, IL-9 protein and IL9 mRNA expression correlated with eosinophil numbers in BAL fluid.

CONCLUSIONS

These findings demonstrate that IL-9 is specifically upregulated after local allergen challenge in the lungs of atopic asthmatic patients. Lymphocytes are the major cellular source of IL-9. The increased expression and its correlation with eosinophil numbers suggest a potential role for IL-9 in the late phase of the allergic response.

Cytokine production by cord blood mononuclear cells stimulated with cows milk proteins in vitro: interleukin-4 and transforming growth factor beta-secreting cells detected in the CD45RO T cell population in children of atopic mothers

BACKGROUND

Food antigens from the maternal circulation may sensitize fetal T cells in utero and be an important determinant in the development of food allergy.

METHODS

Here we have examined the spontaneous and recall response to cow's milk proteins of cord blood mononuclear cells (CBMC) of newborn children, using single cell ELISPOT assays.

RESULTS

In term newborns, confirming previous studies, the spontaneous cytokine response of CBMC is dominated by IL-4, IL-5, IL-10, and as shown here for the first time, TGF-beta. For TGF-beta only, the response of samples from infants of atopic mothers was significantly lower than samples from infants of non-atopic mothers. In vitro stimulation of CBMC with bovine serum albumin, casein and beta-lactoglobulin resulted in a significant increase of all cytokine-secreting cells, again dominated by T helper type 2 (Th2) cytokines. There was a clear tendency for samples from infants of atopic mothers to have lower Th2 responses than samples from infants of non-atopic mothers, which was particularly significant for both IL-4 and TGF-beta. Spontaneous cytokine secreting cells were virtually absent in cord blood from infants < 34 weeks gestation, as were cows milk protein-induced responses, although they were readily detectable in samples from infants aged > 34 weeks. To explore whether the cytokine secreting cells were in the naive CD4+ CD45RA population or memory CD4+ CD45RO T cells, these subsets were purified by positive and negative selection and tested for spontaneous and cows milk protein-induced cytokine responses. Strikingly, although the responses were small, the CD45RO+ cells from children of atopic mothers showed significant spontaneous and antigen-specific IL-4 and TGF-beta responses, whereas the same population from infants of non-atopic mothers showed virtually no response. In addition CD45RA+ cells from infants of mothers with maternal atopy showed decreased IL-4 and TGF-beta responses, especially the latter.

CONCLUSIONS

The cows milk antigen-specific IL-4 and TGF-beta responses preferentially seen in the memory cell subset of infants with a maternal history of atopy strongly suggests Th2 skewing to dietary antigens in utero.

Effects of breast milk from allergic and non-allergic mothers on mitogen- and allergen-induced cytokine production

Breast milk contains several components that provide specific immunity and affect the maturation of the infant's immune system. The aim of this study was to analyze the effects of breast milk, on mitogen- and allergen-induced cytokine production from cord blood mononuclear cells (CBMC), and if those effects differ between allergic and non-allergic mothers. The cells were incubated for 96 h with phytohemagglutinin (PHA), ovalbumin or cat dander in the presence of various dilutions of colostrum. Colostrum inhibited both mitogen- and cat-induced IFN-gamma and mitogen-induced interleukin-4 (IL-4) production. The inhibition on IFN-gamma production was to some extent caused by TGF-beta, as the effect was modified when an anti-TGF-beta antibody was added to the cultures. In contrast, colostrum enhanced allergen-induced production of the Th2-like cytokines IL-5 and IL-13, and this was accompanied with increased production of IL-10. No differences were found between allergic and non-allergic mothers. The inhibitory effect of breast milk on IFN-gamma production, which was partly due to the high levels of TGF-beta, together with the enhancing effect on IL-10 secretion, confirm that breast milk is anti-inflammatory. Although the production of IL-5 and IL-13 was enhanced by colostrum, this was accompanied with an increased production of IL-10. Together with the high levels of TGF-beta in breast milk and inhibitory effect of colostrum on IL-4 production, this suggests a possible mechanism whereby breast-feeding may protect against the development of allergy. Despite differences in the composition of breast milk between allergic and non-allergic mothers, the effects of breast milk on cytokine production from CBMC were independent of the atopic status of the mothers.