Grass pollen immunotherapy inhibits seasonal increases in basophils and eosinophils in the nasal epithelium

BACKGROUND: Symptoms of allergic rhinitis are accompanied by infiltration of the nasal mucosa with inflammatory cells, predominantly eosinophils and metachromatic cells (basophils and mast cells). Specific immunotherapy (IT) reduces mucosal eosinophilia and numbers of metachromatic cells in the epithelium. A specific marker distinguishing basophils from mast cells was recently developed. OBJECTIVES: The basophil-specific monoclonal antibody 2D7 was used to determine the influence of subcutaneous IT on numbers of nasal mucosal basophils compared with the effects of IT on neutrophils, eosinophils and mast cells. METHOD: During a randomized, placebo-controlled trial of grass pollen IT in 44 adults with severe summer hay fever, nasal biopsies were taken at baseline, out of the pollen season, and at the peak of the pollen season following 2 years treatment. Biopsies were processed for immunohistochemistry for basophils (2D7+), mast cells (AA1+), eosinophils (MBP+) and neutrophils (neutrophil elastase+). RESULTS: In placebo-treated (PL) patients there were significant seasonal increases in basophils (P < 0.01), mast cells (P < 0.05) and eosinophils (P = 0.002) in the nasal submucosa. In IT-treated patients significant increases in 2D7+ cells (P < 0.01) and eosinophils (P = 0.01) but not AA1+ cells (P = 0.9) were observed. These differences were significant between groups for eosinophils (P < 0.05). In the epithelium there were seasonal increases in AA1+ cells and eosinophils in both groups (PL: P < 0.01, IT: P < 0.05 for both). The between-group difference was significant for eosinophils (P = 0.05). Basophils were observed in the epithelium of six out of 17 in the placebo group and one out of 20 in the IT group (P = 0.03). Neutrophil numbers remained constant in both epithelium and submucosa. CONCLUSION: Successful grass pollen immunotherapy was associated with inhibition of seasonal increases in basophils and eosinophils, but not mast cells or neutrophils within the nasal epithelium. Immunotherapy may act, at least in part, by reducing seasonal recruitment of basophils and eosinophils into the epithelium.     

Short-term preseasonal birch pollen allergoid immunotherapy influences symptoms, specific nasal provocation and cytokine levels in nasal secretions, but not peripheral T-cell responses, in patients with allergic rhinitis

BACKROUND: Birch pollen allergic rhinitis can be sufficiently treated with specific subcutaneous allergoid immunotherapy (IT). However, little is known about the clinical and immunological effects of short-term therapy protocols. OBJECTIVE: To investigate the clinical efficacy of a birch pollen allergoid IT using seven preseasonal injections and to evaluate immunological parameters that might explain clinical findings. METHODS: Thirty-seven patients were included into the study and randomized to either a symptomatic treatment or allergoid IT plus symptomatic treatment. Patients were examined during the pre-IT season, at two extraseasonal visits both before and after IT and during the post-IT season. At each visit, nasal secretion samples were taken and analysed for levels of IL-4, IL-5 and IFNgamma. In addition, short-term birch-specific T-cell lines (TCLs) were cultured from peripheral blood mononuclear cells of 10 patients of the IT group, both before and after IT, and the ratios of lymphocyte subpopulations were determined. Cytokine production by TCLs (IL-4, IL-5, IFNgamma, IL-10) and proliferation of TCLs in response to stimulation with birch pollen allergen were measured. RESULTS: It was possible to evaluate 27 patients in accordance with the study protocol. Clinical symptoms and medication intake were reduced as a result of the IT as were nasal secretion levels of IL-5 (P = 0.007). IFNgamma was increased in nasal secretions (P = 0.01), while IL-4 was not measurable in most samples. No effect was found on proliferation of birch pollen-reactive TCLs, cytokine production by TCLs and the frequency and ratio of CD4+ and CD8bright or CD45RA+ and CD45RO+ cells in peripheral blood (all P > 0.05). Conclusion Preseasonal IT with a birch pollen allergoid is clinically effective in allergic rhinitis and influences cytokine production in the nose, but does not modulate the measured responses of peripheral blood T cells.     

Anergy in vivo: down-regulation of antigen-specific CD4+ Th1 but not Th2 cytokine responses

Efficient immunologic tolerance, defined as antlgen-speclflcunresponslveness, can be peripherally induced by the l.v. Injectionof syngenelc splenocytes coupled with antigen using ethylenecarbodilmlde (ECDI). We have previously reported that unresponslvenessinduced via l.v. Injection of syngenelc splenocytes coupledwith intact, UV-lnactlvated Theiler's murine encephalomyelitisvirus (TMEV-SP) resulted in ‘split tolerance’. Bothvtrus-speclflc delayed-type hypersensltlvlty and lgG2a levelswere inhibited, whereas lgG1 levels were increased when comparedwith sham tolerized controls. In the present report we demonstratethat tolerance induced by l.v. Injection of TMEV-coupled splenocytesresulted in antigen-specific inhibition of T cell proliferation,as well as IL-2 and IFN- production in response to both wholeTMEV and the immunodomlnant viral epitope. Additionally, toleranceinduction resulted in abrogation of T_h1 -derived [IL-2, IFN-and LT/tumor necrosis factor-ß (TNF-ß)]cytokine mRNA expression in response to In vitro stimulationwith UV-inactlvated TMEV as determined by reverse transcrlptasepolymerase chain reaction. In contrast, expression of T_h2-derived(IL-4, IL-6 and IL-10) cytokine mRNA was not affected in tolerizedmice. Tolerance functioned directly at the level of CD4⁺ T_h1cells at both the induction and effector limbs as depletionof CD8⁺ T cells both prior to in vivo tolerizatlon or in vitroculture had no effect on inhibition of T_h1-specific responses.The mechanism of In vivo tolerance induction appeared to beanergy of CD4⁺ T_h1 cells since IL-2, IFN- and LT/TNF-ßmRNA expression as well as virus-specific prollferatlve responsescould be restored by addition of rlL-2 to In vitro culturesof tolerant, CD4⁺ T_h1 populations. These results suggest thatin vivo ‘split tolerance’ Induced by l.v. Injectionof ECDI-flxed, antigen-coupled splenocytes involves anergy ofTMEV-speclflc, CD4⁺ T_h1 lymphocytes and concomitant primingof T_h2 cells. The induction of antlgen-speclflc, in vivo anergyhas important implications in the design of therapeutic strategiesfor immunopathologic diseases mediated by T_h1 lymphocytes, especiallyT cell-mediated autoimmune disorders.     

Association of polymorphisms in Th1, Th2 cytokine genes with hayfever and atopy in a subsample of EPIC-Heidelberg

BACKGROUND: Hayfever is determined by an interaction of environmental and genetic factors and biologically characterized by an imbalanced T helper cell 1 (Th1) and Th2 immune response and elevated IgE levels against inhalant allergens. Indications exist that polymorphisms in cytokine genes involved in the regulation of the Th1/Th2 balance may contribute to the allergic phenotype. OBJECTIVE: We investigate whether polymorphisms in genes directly or indirectly involved in Th1, Th2 immune response are associated with hayfever and elevated IgE levels against inhalant allergens. METHODS: From a subsample of the European Prospective Investigation into Cancer and Nutrition-Heidelberg, 322 subjects with hayfever and 322 age- and sex-matched non-allergic controls were selected and genotypes determined for 15 polymorphisms in 13 genes. Plasma IgE against inhalant allergens was measured via CAPSX1 (Phadiatop) test. We computed odds ratios (ORs) by logistic regression, tests on group differences of IgE-levels in dependence upon genotype and tests for trend by means of non-parametric methods. RESULTS: We found decreased OR for hayfever (OR=0.60, 95%CI=0.4-0.9) and sensitization to inhalant antigens (OR=0.5, 95%CI=0.4-0.8) in heterozygotes of the IL-6 -174 G/C polymorphism. Homozygotes of the G-allele in IL-2 -330 T/G were at increased risk of hayfever (OR=2.6, 95%CI=1.3-5.2). Moreover, we found indications for differences in IgE levels against inhalant allergens in dependence upon genotypes of polymorphisms in IL-4R, IL-6, IL-13, and IL-18. CONCLUSION: Our data suggest an association of genetic variants in IL-6 and IL-2 with hayfever, confirm a role of polymorphisms in IL-4R, IL-13, and IL-18 for the elevated IgE phenotype, and add IL-6 to the list of candidate genes.     

B cells express Ly-6C in a Th1 but not Th2 cytokine environment.

Interferon-alpha (IFN-alpha) is the primary regulator of transient Ly-6C expression on T cells. B cells, which do not express Ly-6C in the resting state, have been reported to express Ly-6C following exposure to proinflammatory stimuli. This study examined the factors controlling Ly-6C expression on B cells and the kinetics of Ly-6C expression in the presence of these factors. In vivo studies demonstrated that proinflammatory (Th1) cytokines transiently upregulate B cell Ly-6C expression. In vitro studies identified Th1 cytokines, particularly IFN-alpha and IFN-gamma, as the principal cytokines responsible for this induction. Polyclonal B cell activators (anti-IgM and recombinant CD40 ligand trimer) showed minimal ability to independently induce Ly-6C expression on B cells but did enhance the ability of IFNs to induce expression. Th2 cytokine environments did not result in B cell Ly-6C expression, and interleukin-4 (IL-4) actually antagonized the IFN-driven induction of Ly-6C. Ly6.1 strains of mice consistently demonstrated a greater ability to express Ly-6C on B cells than did Ly-6.2 strains. Together, these studies demonstrate the ability of Th1 but not Th2 cytokine environments to transiently induce the expression of Ly-6C on B cells and provide additional evidence for differences in the regulation of Ly-6C expression in Ly6.1 and Ly6.2 strains.     

Nickel-induced IL-10 down-regulates Th1- but not Th2-type cytokine responses to the contact allergen nickel

Whereas the involvement of Th1- and Th2-type cytokines in contact allergy to nickel (Ni) is well documented, the role of the regulatory cytokine IL-10 is less clear. We therefore investigated the impact of IL-10 on Ni-induced Th1- (IFN-gamma) and Th2-type (IL-4 and IL-13) cytokine responses in human peripheral blood mononuclear cells (PBMC). PBMC from 15 blood donors with reactivity to Ni (Ni-PBMC) and 8 control donors devoid of reactivity (control PBMC) were stimulated with Ni and the frequency of cytokine-producing cells and the levels of secreted cytokines were analysed by ELISpot (IL-4, IL-13 and IFN-gamma) and ELISA (IL-10, IL-13 and IFN-gamma), respectively. The Ni-induced response was further assessed in the presence of recombinant IL-10 (rIL-10) or neutralizing antibody to IL-10 and the phenotype of the Ni-specific cytokine-producing cells regulated by IL-10 was determined by cell depletion experiments. Ni induced IL-10 production in Ni-PBMC (mean, (range); 33.1 pg/ml (0-93.4 pg/ml)) but not control PBMC (2.2 pg/ml (0-14.9 pg/ml)) (P = 0.002). Ni also induced significant production of IL-4, IL-13 and IFN-gamma that correlated with the IL-10 response. Addition of rIL-10 down-regulated the Ni-induced production of all cytokines but with a more pronounced effect on IFN-gamma. However, neutralization of Ni-induced IL-10 enhanced the levels of IFN-gamma induced by Ni (P = 0.004) but did not affect the number of IFN-gamma-producing cells or the production of other cytokines. Cell depletion experiments suggested that the Ni-specific IFN-gamma (and Th2-type cytokine) producing cells were CD4(+) T cells. The impact of IL-10 on Ni-induced IFN-gamma responses by CD4(+) T cells suggests that an important role of IL-10 in vivo is to counteract the allergic reactions mediated by Th1-type cytokines.     

Grass pollen immunotherapy: symptomatic improvement correlates with reductions in eosinophils and IL-5 mRNA expression in the nasal mucosa during the pollen season

BACKGROUND: Tissue eosinophilia and infiltration by T(H)2-type T cells are characteristic features of allergic rhinitis both after allergen challenge and during natural allergen exposure. Specific immunotherapy inhibits allergen-induced nasal eosinophilia. OBJECTIVES: We sought to assess, in the context of a randomized trial, the relationships between symptomatic improvement after immunotherapy and eosinophil numbers and IL-5 expression in the nasal mucosa during the pollen season. METHODS: Nasal biopsy specimens were taken from 37 adults with severe summer hay fever at baseline (out of season) and at peak season after 2 years of treatment with a depot grass pollen extract or placebo. Biopsy specimens were processed for immunohistochemistry by using mAbs against eosinophils (EG2), T cells (CD3), and IL-2 receptor-positive cells (CD25), as well as for in situ hybridization by using a sulfur 35-labeled antisense riboprobe directed against IL-5. RESULTS: Immunotherapy significantly reduced symptoms (49%, P =.01) and medication requirements (80%, P =.007) compared with placebo. There was a 400% increase (P =.004) in eosinophils during the pollen season in placebo-treated patients, which was inhibited in the immunotherapy group (20% increase, P =.04 between groups). Seasonal increases were also observed for CD25(+) cells (P =.002), CD3(+) cells (P =.02), and IL-5 mRNA-expressing cells (P =.03) in the placebo group but not in the immunotherapy group. A significant correlation was observed between eosinophils and IL-5 expression (r = 0.5, P <.05). Both eosinophils (r = 0.6, P <.02) and IL-5 (r = 0.6, P <.02) correlated with symptoms after immunotherapy. CONCLUSION: Improvement in symptoms after grass pollen immunotherapy may result, at least in part, from inhibition of IL-5-dependent tissue eosinophilia during the pollen season.     

Reduced Th1, but not Th2, cytokine production by lymphocytes after in vivo exposure of healthy subjects to endotoxin

Endotoxin (lipopolysaccharide [LPS]) tolerance is characterized by a reduced capacity of monocytes to produce proinflammatory cytokines upon restimulation in vitro. To determine whether LPS exposure induces a change in lymphocyte cytokine production and whether this results in a shift in the T-helper 1 (Th1)/Th2 balance, whole blood obtained from seven healthy subjects before and after an intravenous injection of LPS (4 ng/kg) was stimulated in vitro with the T-cell stimulus anti-CD3/CD28 or staphylococcal enterotoxin B. Whole-blood production of the Th1 cytokines gamma interferon (IFN-gamma) and interleukin-2 (IL-2) was markedly reduced at 3 and 6 h, while the production of the Th2 cytokines IL-4 and IL-5 was not influenced or was slightly increased. The IFN-gamma/IL-4 ratio was strongly decreased at 6 h. Serum obtained after LPS exposure could slightly inhibit the release of IFN-gamma but increased IL-4 production during stimulation of blood drawn from subjects not previously exposed to LPS. Normal serum also inhibited IFN-gamma production, albeit to a lesser extent. LPS exposure influences lymphocyte cytokine production, resulting in a shift toward a Th2 cytokine response, an effect that may be mediated in part by soluble factors present in serum after LPS administration in vivo.     

Apoptosis is related to imbalance of Th1/Th2-type cytokine in peripheral blood mononuclear cells of patients with chronic hepatitis B

Keywords: peripheral blood mononuclear cells; apoptosis; cytokine; hepatitis B virus.     

Distribution of Th1, Th2, and Th0 and the Th1/Th2 cell ratios in human peripheral and endometrial T cells

PROBLEM: To examine whether normal pregnancy involves type 2 T-helper (Th2) immune condition or not. METHOD OF STUDY: We measured the percentage of Th0, Th1, and Th2 and the Th1/Th2 cell ratios of human peripheral blood and endometrial T cells using flow cytometry, which can analyze both the surface marker CD3, and intracellular cytokines, interleukin 4 (IL-4) and interferon gamma (IFNgamma). RESULTS: No significant differences were found in the percentages of Th1, Th2, and Th0 and the Th1/Th2 cell ratios in the peripheral blood T cells of nonpregnant women and women in early pregnancy. On the other hand, the percentage of Th1 cells was highest during the proliferative phase of the endometrium, followed by the secretory phase and early pregnancy decidua. The percentage of Th2 cells was highest in early pregnancy decidua and lowest during the proliferative phase of the endometrium. The Th1/Th2 ratio was 147.48+/-96.68 during the proliferative phase of the endometrium, 37.74+/-21.33 during the secretory phase, and 1.31+/-0.48 in the early pregnancy decidua. CONCLUSIONS: These data indicate that Th1 cells predominate in the nonpregnant endometrium, especially during the proliferative phase, while Th2 cells predominate in early pregnancy decidua.     

Sublingual immunotherapy with grass pollen is not effective in symptomatic youngsters in primary care

BACKGROUND: Sublingual immunotherapy (SLIT) is considered safer and more convenient than subcutaneous therapy and therefore has been proposed as especially suitable for children and in primary care. Most efficacy studies in children lack power to be conclusive, and all have been performed in referral centers. OBJECTIVE: To investigate the efficacy of SLIT with grass pollen allergen in children and adolescents with rhinoconjunctivitis in a primary care setting. METHODS: Youngsters aged 6-18 years with hay fever were enrolled from general practices and randomly assigned to receive placebo or grass pollen mix for 2 years. The primary outcome was the mean daily total symptom score (scale 0-15) comprising sneezing, itching nose, watery running nose, nasal blockage, and itching eyes during the months May-August of the second treatment year. RESULTS: Out of 204 youngsters randomized, 168 entered the intention-to-treat analysis (91 verum, 77 placebo). The mean daily total symptom score did not differ between participants allocated to verum and those allocated to placebo (difference for verum minus placebo: -0.08, 95%CI, -0.66-0.50; P = .78). No differences were found for rescue medication-free days, disease-specific quality of life, and overall evaluation of the treatment effect. Local side effects were more frequent in the verum group (39% vs 17% of participants; P = .001). CONCLUSION: Sublingual immunotherapy with grass pollen in a primary care setting is not effective in children and adolescents. CLINICAL IMPLICATIONS: Currently, SLIT cannot be recommended for general practitioners as a therapeutic modality in youngsters with grass pollen allergy.     

Moderate exercise is associated with enhanced antigen-specific cytokine, but not IgM antibody production in aged mice

It has been suggested that moderate exercise may modulate the immune response in the elderly. We investigated whether moderate exercise had an effect on the immune response to viral infection in both young (2-4 months) and older (16-18 months) male BALB/cJ mice. Exercised (EX) mice ran on a treadmill for 8 weeks at a gradually increasing speed and duration whereas control (CON) mice were only handled briefly during each exercise session and then returned to their cages. Mice were infected with herpes simplex virus type 1 (HSV-1) 24 h post-exercise. Serum IgM anti-HSV antibody, HSV-1 specific Th1/Th2 cytokine production by spleen cells, and cytokine production by alveolar cells were measured 7 days post-infection. In the aged mice, exercise was associated with an enhanced production of the HSV-1 specific Th1-associated cytokines, interleukin (IL)-2 and interferon (IFN)-gamma, but had no effect on the Th2-associated cytokine IL-10 or IgM antibody. No effect of exercise was observed in young mice. IL-12 production was not altered by exercise, but aging was associated with altered IL-12 production in a tissue-specific manner. In conclusion, moderate exercise was associated with increased antigen-specific IL-2 and IFN-gamma production in response to viral challenge in older mice.     

Interleukin-12/T cell stimulating factor,a cytokine with multiple effects on T helper type 1 (Th1) but not on Th2 cells

At least two subsets of CD4⁺ T helper cell lymphocytes termed T_h1 and T _h, 2 exist in the mouse and probably in humans. They are characterized by the secretion of different lymphokines and by their functional behavior. Dysregulated expansion of one or the other subset may be one reason for the development of certain diseases. Thus, it is of importance to define the signals involved in the differentiation and activation of the two T_h cell subsets. It is known and has been confirmed in this report that the cytokine interleukin (IL)-1 acts onT_h2 cells but not on T_h1 cells. We now report that a previously identified cytokine which was provisionally termed T cell stimulating factor is identical with IL-12 and exhibits a reciprocal behaviour to IL-1. IL-12 has several effects on T_h1 cells. It can induce the proliferation of certain T_h1 cells in combination with IL-2. Synthesis of interferon (IFN)-γ by T_h1 cells can be triggered by IL-2 plus IL-12. In contrast to the IFN-γ production observed after T cell receptor (TcR) CD3 stimulation of T_h1 cells with lectin Concanavalin A the IFN-γ production induced by IL-12+IL-2 is insensitive to the immunosuppressive drug cyclosporin A. Furthermore, IL-12 enhances the TcR/CD3-induced synthesis of IFN-γ of several T_h1 clones. Finally, IL-12 (+ IL-2) induces homotypic cell aggregation of T_h1 clones. This type of cell aggregation depends on the participation of LFA-1 and ICAM-1 molecules. In all activation systems with T_h1 cells no effect of IL-1 was demonstrable. In contrast, only IL-1 but not IL-12 served as a co-stimulatory signal for several T_h2 cell lines activated via the TcR/CD3 complex.     

Macrophage migration inhibitory factor is essential for allergic asthma but not for Th2 differentiation

Macrophage migration inhibitory factor (MIF) is increased in asthmatic patients and plays a critical role in the pathogenesis of asthma. We show here that mice lacking MIF failed to develop airway hyper-responsiveness (AHR), tissue eosinophilia, and mucus metaplasia. Analysis of the bronchoalveolar fluids revealed a substantial reduction of IL-13, eotaxin and cysteinyl-leukotrienes. The lack of these cardinal features of asthma in MIF(-/-) mice occurs regardless of high concentrations of IL-4 in the lung and OVA-specific IgE in the serum. Antigen-specific lymphocyte proliferation and IL-13 production were similarly increased in the draining lymph nodes of OVA-immunized and challenged MIF(-/-) mice compared to WT, but were reduced in the spleen of MIF(-/-), thus indicating differential roles of MIF in these compartments. Stimulation of naive CD4(+) cells with anti-CD3 antibody demonstrated that MIF(-/-) cells produced increased amounts of IFN-gamma and IL-4 compared to WT CD4(+) cells. Finally, treatment of sensitized BALB/c mice with neutralizing anti-MIF antibody abrogated the development of ARH and airway inflammation without affecting the production of Th2 cytokines or IgE. The present study demonstrates that MIF is required for allergic inflammation, adding important elements to our knowledge of asthma pathogenesis and suggesting that neutralization of MIF might be of therapeutic value in asthma.     

Intravenous immunoglobulin treatment in women with recurrent abortions: increased cytokine levels and reduced Th1/Th2 lymphocyte ratio in peripheral blood

PROBLEM: The aim of this study was to investigate changes in peripheral blood Th1/Th2 cytokine levels and lymphocyte ratios after massive intravenous immunoglobulin (MIVIg) treatment for women with recurrent spontaneous abortion (RSA) of unexplained etiology. METHOD OF STUDY: Serum Th1 (IFN-gamma, TNF-alpha) and Th2 cytokine (IL-4, IL-10) levels were assessed by ELISA methods (n = 9) and peripheral blood Th1/Th2 lymphocyte ratios (n = 4) by flow cytometry before and after MIVIg treatments in women with four or more consecutive RSA. RESULTS: Pre-treatment serum IFN-gamma (0.06 +/- 0.09 pg/mL, mean +/- SD), TNF-alpha (0.21 +/- 0.45 pg/mL), IL-4 (0.70 +/- 1.16 pg/mL), and IL-10 (1.12 +/- 1.67 pg/mL) increased to 0.17 +/- 0.16 pg/mL, 0.77 +/- 0.28 pg/mL, 1.82 +/- 0.89 pg/mL, and 3.44 +/- 0.48 pg/mL, respectively, after MIVIg treatments (P < 0.05). CD4-positive IFN-gamma/IL-4 lymphocyte ratios (17.3 +/- 9.1) were reduced to 11.5 +/- 7.1 after treatment (P < 0.05). CONCLUSIONS: Massive intravenous immunoglobulin treatments increased peripheral blood cytokine levels and decreased Th1/Th2 lymphocyte ratios; thus, MIVIg treatments modify the peripheral Th1/Th2 balance.