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.     

Complement C5a anaphylatoxin is an innate determinant of dendritic cell-induced Th1 immunity to Mycobacterium bovis BCG infection in mice

During acquired immunity to Mycobacterium bovis bacillus Calmette-Guerin (BCG) infection in mice, dendritic cells (DCs) present mycobacterial antigens to naive T cells to prime an immune response. Complement C5a (anaphylatoxin) secreted by mycobacteria-infected macrophages regulates IL-12p70 production. As IL-12p70 regulates Th1 immunity against mycobacteria in mice, we examined the effects of C5a on IL-12p70 secretion by murine DCs and Th1 immunity. DCs cultured from C5-deficient (C5(-/-)) and -sufficient (C5(+/+)) mice were infected with BCG in the presence or absence of the C5a peptide. ELISA showed that C5(-/-) DCs secreted less IL-12p70 (600 pg/mL vs. 100 pg/mL) than C5(+/+) DCs, and they secreted more IL-10. Using immunophenotyping, reduced CD40 expression was found on C5(-/-) DCs after BCG infection. BCG-primed DCs were then cocultured with naive or BCG-immune T cells to differentiate them into IFN-gamma-secreting Th1 T cells. Coincident with increased IL-12p70 levels, BCG-primed C5(+/+) DCs cocultured with naive or immune C5(+/+) T cells showed a larger increase in CD4+ IFN-gamma/CD8+ IFN-gamma+ T cells compared with cocultured DCs and T cells from C5(-/-) mice. Thus, BCG-primed C5(+/+) DCs were better able to drive a Th1 response. Furthermore, BCG aerosol-infected C5(-/-) mice showed reduced CD4 and CD8 IFN-gamma-secreting T cells in the lungs, concurrent with an increased growth of BCG. Thus, C5a, an innate peptide, appears to play an important role in the generation of acquired immune responses in mice by regulating the Th1 response through modulation of IL-12p70 secretion from DCs.     

IFN-gamma plays a dominant role in upregulation of Candida-specific IgE synthesis in patients with atopic dermatitis

BACKGROUND: Although Candida albicans (CA) is known to induce Th1 clones that suppress IgE synthesis, serum IgE antibody against CA is often increased in atopic patients. This study aims to elucidate the mechanism of IgE synthesis against CA in atopic patients. METHODS: We measured the production of IL-4 and IFN-gamma by peripheral blood mononuclear cells (PBMCs) from atopic patients upon stimulation with CA and examined the correlation with the level of serum IgE antibody against CA. Results: The level of serum CA-specific IgE antibody (CA-IgE) was significantly higher in patients with atopic dermatitis (AD) than in patients with bronchial asthma (BA) (geometric mean = 3.6 vs. 0.27 U(A)/ml, p < 0.02) (U(A) = unit allergen), while there was no difference in the level of house dust mite-specific IgE antibody between them (67.6 vs. 87.1 U(A)/ml). Although IL-4 production by PBMCs upon stimulation with CA in patients with AD was not significantly different from that in patients with BA (mean = 359.1 vs. 515.3 fg/ml), IFN-gamma production was significantly lower in the former than in the latter group (8.1 vs. 56.2 pg/ml, p < 0.001). Consequently, the ratio of IL-4/IFN-gamma production was apparently higher in patients with AD than in those with BA, which corresponds to the difference between them in the level of serum CA-IgE. A significant negative correlation was seen in patients with AD between IFN-gamma production by CA-stimulated PBMCs and the level of serum CA-IgE (p < 0.05). CONCLUSIONS: IgE synthesis against CA in atopic patients may be precipitated not by enhancing IL-4 production, but by reducing IFN-gamma secretion.     

IL-16 inhibits IL-5 production by antigen-stimulated T cells in atopic subjects

BACKGROUND: We have previously shown increased expression of the CD4+ cell chemoattractant IL-16 at sites of airway allergic inflammation. Little is known about the significance of IL-16 in allergic inflammation and its role in allergen-driven T-cell cytokine responses. Because IL-16 interacts specifically with CD4+ T cells, we hypothesized that IL-16 released at sites of inflammation may modulate the pattern of cytokines produced by CD4+ T cells. OBJECTIVE: We investigated the effects of exogenous rhIL-16 on cytokine production of PBMCs from atopic and nonatopic subjects in response to antigen and PHA. METHODS: Primary cultures of freshly isolated PBMCs from ragweed-sensitive atopic subjects and nonatopic subjects were stimulated with ragweed or PHA in the presence or absence of rhIL-16. Supernatant levels of IL-4, IL-5, and IFN-gamma were determined by means of ELISA at different time points between 2 and 6 days. Effects of IL-16 on antigen-induced cellular proliferative responses were determined. RESULTS: No IL-4 protein was detected after antigen stimulation of PBMCs from atopic subjects, whereas significant levels of IL-5 were measured on day 6 (median, 534.9 pg/mL). IL-5 secretion was abolished in PBMC cultures depleted of CD4+ cells. The addition of rhIL-16 in antigen-stimulated PBMC cultures significantly reduced the amount of IL-5 released (median, 99.8 pg/mL; P <.001). Detectable levels of IFN-gamma (median, 53.3 pg/mL) were identified after antigen stimulation. The addition of rhIL-16 in antigen-stimulated PBMC cultures significantly increased IFN-gamma levels (median, 255.6 pg/mL; P <.05). Effects of rhIL-16 appear to be specific for antigen-stimulated PBMCs in atopic subjects because rhIL-16 did not alter IL-5 or IFN-gamma production in response to PHA nor did rhIL-16 alter cytokine production in nonatopic normal subjects. CONCLUSION: These studies suggest that IL-16 can play a role in regulating the production of cytokines seen in allergic states in response to antigen.     

Secretion of cytokines,histamine and leukotrienes in chronic urticaria

BACKGROUND: Approximately 35-40% of patients with chronic urticaria have an IgG autoantibody to the IgE receptor which can activate basophils and mast cells so that they release histamine. In this study we assessed the cytokine profile present in chronic urticaria sera, and then measured cytokine and leukotriene release from basophils and mast cells upon incubation with chronic urticaria sera. Finally we assessed cytokine expression at the single-cell level and characterized the T cell subpopulations involved in their production. We chose IL-4 as representative of Th2 lymphocytes and IFN-gamma for Th1 lymphocytes. METHODS: We analyzed IL-4, IL-5 and IFN-gamma in 60 chronic urticaria sera versus 51 controls. Sera were incubated with purified human basophils and cutaneous mast cells and the release of histamine, IL-4 and leukotrienes (C(4), D(4), E(4)) was quantitated. Immunoblotting was performed to identify IgG antibody to FcepsilonRIalpha, alpha subunit. We measured intracellular cytokine production in peripheral blood mononuclear cells of 17 chronic urticaria patients compared to 50 healthy controls. RESULTS: We found higher IL-4 levels (p = 0.028) in the sera of chronic urticaria patients (1.03 pg/ml) versus healthy donors (0.20 pg/ml) but no difference between urticaria sera and atopic control sera (0.52 pg/ml). We did not detect IFN-gamma or IL-5 in any serum. However, sera that activated basophils so that they released histamine also produced leukotriene and IL-4, and leukotriene production by cutaneous mast cells and basophils was closely correlated. However, there was no correlation between immunoblotting and the functional ability to induce either histamine or IL-4. After stimulating with PMA-ionomycin we found significant differences in CD4+ lymphocyte production of IL-4 and IFN-gamma with no differences in CD8+ lymphocyte production of either cytokine. CONCLUSION: Our data support the presence of basophil and mast cell activators in the sera of patients with chronic urticaria which can lead to the production of leukotrienes and IL-4 in addition to the histamine. IL-4 levels are similar to those seen in atopic subjects. We found that CD4+ T cells from patients with chronic urticaria are activated and tend to produce higher cytokine levels than CD4+ T cells from healthy controls. There were no differences when cytokine production by CD8+ lymphocytes was similarly assessed. These results are consistent with the histology found in biopsies of chronic urticaria lesions, where a CD4+-predominant infiltrate is found with cytokine production suggesting either a Th0 response or a mixture of Th1 and Th2 lymphocytes.     

解脲脲原体GrpE蛋白促进小鼠树突状细胞成熟并诱导Th1型免疫应答

目的:探讨解脲脲原体GrpE蛋白( Ureaplasma urealyticum GrpE, Uu-GrpE)对树突状细胞成熟的影响及其对T细胞极化的作用。 方法:表达纯化 Uu-GrpE蛋白并利用Western blot鉴定。分离培养小鼠骨髓来源树突状细胞(bone ma...     

Naive human T cells can be a source of IL-4 during primary immune responses

IL-4 plays a key role in driving the differentiation of CD4+ Th precursors into Th2 cells, both in mice and in humans. The source of IL-4 during primary immune responses is, however, still debated. When IL-4 consumption in in vitro T cell cultures was blocked with a MoAb to the IL-4 receptor alpha-chain (IL-4Ralpha), it became evident that freshly isolated naive (CD45RO-) CD4+ T cells from adults or cord blood produce IL-4 upon activation with anti-CD3 and CD80. IL-4 production by naive T cells is strictly IL-2-dependent. Endogenous IL-4 activity in naive CD4+ T cell cultures modulates the production of interferon-gamma (IFN-gamma) on the one hand and IL-5 and IL-13 on the other hand in opposite directions, and it is partly responsible for the low IFN-gamma production by cord blood T cells. Comparison of the ratio of IL-4/IFN-gamma in supernatants of T cell cultures reveals a skewing towards IL-4 production by cord blood T cells, while naive T cells from (non-atopic) adults predominantly produce IFN-gamma. We conclude that CD4+ naive T cells can produce IL-4 without the need for Th2 differentiation, and therefore that they can be the initial source of IL-4 required at the time of priming for T cell differentiation into Th2 cells.     

High TNF-alpha and low IL-2 producing T cells characterize active disease in Takayasu's arteritis

We have investigated intracellular production by T cells and plasma levels of TNF-alpha, IL-2 and IFN-gamma in 12 active and 10 inactive Takayasu's arteritis (TA) patients and 12 healthy controls. The active TA compared to inactive TA and controls had higher TNF-alpha (52.7 +/- 22.3% vs. 32.9 +/- 14.2% and 35.2 +/- 14.5%, respectively; P = 0. 020), lower IL-2 (19.6 +/- 13.2% vs. 36.1 +/- 10.1% and 31.2 +/- 10.3%, respectively; P = 0.010) and comparable IFN-gamma (38.6 +/- 13.9% vs. 34.2 +/- 12.4% and 34.9 +/- 11.1%, respectively; P = 0.581) producing CD3+ T cells. There was no difference in the plasma levels of the cytokines between active TA, inactive TA and controls (TNF-alpha: 79.1 +/- 94.5 vs. 72.9 +/- 120.0 and 9.5 +/- 6.7 pg/ml, P = 0.110; IL-2: 4.3 +/- 4.8 vs. 6.6 +/- 4.7 and 8.6 +/- 4.5 pg/ml, P = 0.094 and IFN-gamma: 10.1 +/- 11.3 vs. 8.8 +/- 8.7 and 8.2 +/- 6.5 pg/ml, P = 0.871, respectively). The data show an important role of these high TNF-alpha and low IL-2 producing T cells in TA.     

IL-23 promotes CD4+ T cells to produce IL-17 in Vogt-Koyanagi-Harada disease

BACKGROUND: Vogt-Koyanagi-Harada (VKH) disease is a systemic refractory autoimmune disease. IL-23 has been thought to play a critical role in autoimmune disease through inducing the development of IL-17-producing CD4(+) T cells. OBJECTIVE: To investigate the expression of IL-23 and IL-17 and the influence of IL-23 on IL-17 production in patients with VKH disease. METHODS: Blood samples were taken from 25 patients with VKH disease and 16 healthy controls. Peripheral blood mononuclear cells (PBMCs) were subjected to analysis of IL-23p19 mRNA and IL-23 protein expression using RT-PCR and ELISA, respectively. The IL-17 levels in the supernatants of PBMCs and CD4(+) T cells cultured in the absence or presence of recombinant (r)IL-23, rIL-12, or anti-IFN-gamma were determined by ELISA. RESULTS: The patients with VKH disease with active uveitis showed an elevated level of IL-23p19 mRNA in PBMCs, higher IL-23 in the serum and supernatants of PBMCs, and increased production of IL-17 by polyclonally stimulated PBMCs and CD4(+) T cells. Recombinant IL-23 significantly enhanced IL-17 production, whereas rIL-12 and IFN-gamma inhibited IL-17 production. More importantly, IL-17 production was significantly increased in patients with active uveitis in the presence of rIL-23. Both rIL-23 and rIL-12 enhanced IFN-gamma production. CONCLUSION: The results suggest that IL-23-stimulated production of IL-17 by CD4(+) T cells may be responsible for the development of uveitis seen in patients with VKH disease. CLINICAL IMPLICATIONS: This study provides a new insight into the mechanism involved in the development of VKH disease.     

Grass pollen immunotherapy for hayfever is associated with increases in local nasal but not peripheral Th1:Th2 cytokine ratios

Grass pollen immunotherapy is the only treatment for hayfever that is both effective and confers long-term benefit. Immunotherapy may act by altering the local nasal mucosal T helper type 2 (Th2) to type 1 (Th1) cytokine balance either by down-regulation and/or immune deviation of T-lymphocyte responses. There is controversy as to whether these changes are detectable in peripheral blood. We therefore examined both local nasal and peripheral T-cell responses to allergen exposure in the same subjects before and after immunotherapy. In a double-blind trial of grass pollen immunotherapy, nasal biopsies were obtained at baseline and during the peak pollen season following 2 years of immunotherapy. Placebo-treated patients showed a seasonal increase in CD3(+) T cells (P = 0.02) and in interleukin-5 (IL-5) mRNA(+) cells (P = 0.03) and no change in interferon-gamma (IFN-gamma ) mRNA(+) cells (P = 0.2) in the nasal mucosa. In contrast, in the immunotherapy-treated group, there were no changes in the number of CD3(+) T cells (P = 0.3) and IL-5 mRNA+ cells (P = 0.2) but a significant increase in the number of IFN-gamma mRNA(+) cells (P = 0.03). Furthermore, clinical improvement in the immunotherapy-treated group was accompanied by a seasonal increase in the ratio of IFN-gamma to IL-5 mRNA(+) cells in the nasal mucosa (P = 0.03). In contrast, there were no significant changes in peripheral T-cell proliferative responses or cytokine production for IFN-gamma or IL-5 in response to grass pollen either within or between the two treatment groups. We conclude that successful grass pollen immunotherapy was associated with an increase in the ratio of IFN-gamma to IL-5 mRNA(+) cells in the nasal mucosa, whereas these changes were not reflected by alterations in peripheral blood T-cell proliferative responses or cytokine production before/after treatment.     

Monophosphoryl lipid A (MPL) promotes allergen-induced immune deviation in favour of Th1 responses

BACKGROUND: Monophosphoryl lipid A (MPL) is a nontoxic derivative of the lipopolysaccharide (LPS) of Salmonella minnesota R595. MPL has been used as an adjuvant in grass and tree pollen vaccines for the treatment of seasonal allergic rhinitis. Little is known about the influence of MPL on cellular responses to allergens in man. We therefore studied the effects of MPL in vitro on peripheral blood mononuclear cells (PBMC) obtained from patients with grass pollen hay fever. METHODS: The PBMCs from 13 subjects were cultured with grass pollen Phleum pratense extract (0, 2 and 20 microg/ml) and MPL (0 and 10 microg/ml; defined as an optimal concentration in preliminary studies) and after 6 days proliferative responses were measured by thymidine incorporation and cytokine production by enzyme-linked immunosorbent assay (ELISA). RESULTS: Proliferative responses were unaffected by the presence of MPL whereas MPL induced a significant increase in allergen-induced interferon (IFN)-gamma production [allergen alone, 645 +/- 466 pg/ml (mean +/- SE) vs allergen + MPL, 3232 +/- 818 pg/ml; P < 0.001]. In addition, there was a significant decrease in interleukin (IL)-5 production (4307 +/- 1030 pg/ml vs 2997 +/- 826 pg/ml; P < 0.01). Although MPL alone could induce modest increases in IL-10 production, MPL did not influence the production of this cytokine in allergen-stimulated cultures. Addition of neutralizing antibody against IL-12 resulted in 95% inhibition of MPL-induced IFN-gamma production. Depletion of monocytes from the culture system abrogated the effects of MPL on elevated cytokine production. CONCLUSIONS: In summary, use of MPL with grass pollen extract results in immune deviation of allergen-induced peripheral Th2-cell responses in favour of 'protective' Th1 responses in an IL-12 and monocyte-dependent fashion.     

Induction of IL-10+CD4+CD25+ T cells by grass pollen immunotherapy

BACKGROUND: Immunotherapy involves the modulation of allergen-specific T-cell responses, either T(H)2-to-T(H)1 immune deviation or, in bee venom-treated patients, induction of IL-10 production by CD4+CD25+ T cells. IL-10-producing CD4+CD25+ regulatory T cells have emerged as potential mediators of immune tolerance in numerous murine models of immunopathology. OBJECTIVE: The aim of this study was to evaluate the role of IL-10 production and CD4+CD25+ T cells in the response to grass pollen immunotherapy. METHODS: PBMCs were isolated from patients after 1 year of grass pollen immunotherapy and from matched untreated atopic and healthy control subjects. After 6 days of in vitro stimulation with Phleum pratense, production of IL-10, IL-5, IL-4, and IFN-gamma and proliferation and numbers of CD4+CD25+ T cells were measured. T cells were then stimulated for a further 5 hours with phorbol 12-myristate 13-acetate and ionomycin and assessed for intracellular IL-10 by means of flow cytometry. RESULTS: Patients undergoing immunotherapy produced significantly more IL-10 than atopic control subjects (patients undergoing immunotherapy, 116 +/- 21 pg/mL [n = 11]; atopic patients, 30 +/- 5 pg/mL [n = 11]; P <.001), and the number of CD4+CD25+ cells identified after allergen stimulation was also greater in the immunotherapy group. The numbers of CD4+CD25+ T cells correlated positively with activation as measured by proliferation in both of the control groups but not in the immunotherapy group. Moreover, only T cells from patients undergoing immunotherapy were positive for intracellular IL-10, and these were almost exclusively CD4+CD25+ cells. CONCLUSION: Grass pollen immunotherapy results in a population of circulating T cells that express the IL-10(+) CD4+CD25+ phenotype in response to allergen restimulation.     

Human Th1 cells preferentially induce interleukin (IL)-1β while Th2 cells induce IL-1 receptor antagonist production upon cell/cell contact with monocytes

The role of human T cells in the induction and regulation, upon cell/cell contact, of inflammatory responses by monocytic cells was investigated. The production of interleukin (IL)-1β and IL-1 receptor antagonist (IL-1Ra) by the monocytic THP-1 cell line was measured upon contact with either Th1 or Th2 cell clones. CD4⁺ T cell clones specific for purified protein derivative of Mycobacterium tuberculosis, predominantly Th1 [high interferon (IFN)-γ and low IL-4 producers], or tetanus toxoid, predominantly Th2 (low IFN-γ and high IL-4 producers), were generated. Cell membranes from antigen-stimulated, but not from resting T cell clones induced dose-dependent cytokine production by THP-1 cells. Th1 clones induced higher levels of IL-1β production (484–806 pg/ml) than did Th2 clones (21–114 pg/ml). In contrast, Th1 clones induced lower levels of IL-1Ra (0.9–7.8 ng/ml) than did Th2 clones (7.0–49.6 ng/ml). Similar results were obtained when T cell clones were activated by cross-linked CD3 and CD28. IL-1β production by THP-1 cells correlated with IFN-γ production by T cell clones but was unaffected by IFN-γ neutralization. IL-1Ra production by THP-1 cells correlated with IL-4 production by T cells and was partially inhibited by IL-4 neutralization. These data indicate that activated Th1 and Th2 cells express different molecules on the cell surface able to induce distinct pro-inflammatory (IL-1β) or anti-inflammatory (IL-1Ra) responses in monocytes. This differential induction of molecules with opposite effects on inflammation stresses the functional heterogeneity in CD4⁺ T cells.     

Modulation of innate cytokine responses by products of Helicobacter pylori

The gastric inflammatory and immune response in Helicobacter pylori infection may be due to the effect of different H. pylori products on innate immune mechanisms. The aim of this study was to determine whether bacterial components could modulate cytokine production in vitro and thus contribute to Th1 polarization of the gastric immune response observed in vivo. The effect of H. pylori recombinant urease, bacterial lysate, intact bacteria, and bacterial DNA on proliferation and cytokine production by peripheral blood mononuclear cells (PBMCs) from H. pylori-negative donors was examined as a model for innate cytokine responses. Each of the different H. pylori preparations induced gamma interferon (IFN-gamma) and interleukin-12p40 (IL-12p40), but not IL-2 or IL-5, production, and all but H. pylori DNA stimulated release of IL-10. Addition of anti-IL-12 antibody to cultures partially inhibited IFN-gamma production. In addition, each bacterial product inhibited mitogen-stimulated IL-2 production by PBMCs and Jurkat T cells. The inhibitory effect of bacterial products on IL-2 production correlated with inhibition of mitogen-stimulated lymphocyte proliferation, although urease inhibited IL-2 production without inhibiting proliferation, suggesting that inhibition of IL-2 production alone is not sufficient to inhibit lymphocyte proliferation. The results of these studies demonstrate that Th1 polarization of the gastric immune response may be due in part to the direct effects of multiple different H. pylori components that enhance IFN-gamma and IL-12 production while inhibiting both IL-2 production and cell proliferation that may be necessary for Th2 responses.     

Induction of CD4 T cell proliferation and in vitro Th1-like cytokine responses to measles virus

Mechanisms that lead to induction of life-long immunity to measles virus (MV) are poorly understood. In the present study, we have assessed the activation, proliferation and cytokine secreting function of peripheral blood T cells from MV immune individuals. Expression of cell blastogenesis markers, such as increased forward light scatter and CD38 expression, peaked 5-7 days after infection of peripheral blood mononuclear cells (PBMC) with the live attenuated Edmonston strain of MV. Subset analysis revealed that both CD3- and CD3+ cells expressed activation markers but that the CD3+ T cells predominated late in the culture period corresponding to maximal proliferation and cell recovery. The majority of CD3+ T cells consisted of CD4+CD8- cells. IFN-gamma and IL-4 production similarly showed optimal production late in culture. Depletion of CD4 cells prior to culture and MV stimulation completely abrogated both IFN-gamma and IL-4 production, whereas depletion of CD8 cells did not diminish production, suggesting that CD4+CD8- T cells were principally involved in production of these cytokines. Finally, optimal IFN-gamma production was elicited at high MV doses and IL-4 at much lower doses. These results suggest that among MV immune individuals, in vitro responses to measles are dominated by CD4+ T cells that, depending on antigen dose, primarily produce a Th1-like and, to a lesser extent, a Th1/Th2-mixed pattern of cytokine release.     

Human γδ T cells modulate the mite allergen-specific T-helper type 2-skewed immunity

BACKGROUND: Gammadelta T cells have been described as one of immune regulators in patients with infection, malignancy, and allergy. OBJECTIVE: To elucidate the ability of gammadelta T cells as an allergen immunotherapy candidate, the effectiveness of human gammadelta T cells in allergen-specific T-helper type 2 (Th2)-type T cells was evaluated in vitro. METHODS: House dust mite-specific Th2-type T cell clones, Bacillus Calmette-Guerin (BCG)-specific Th1-type T cell clones, and gammadelta T cell lines were established from the peripheral blood mononuclear cells of two patients with allergic rhinitis. The effectiveness of gammadelta T cells and BCG-specific Th1-type T cell clones in the modulation of allergen-specific Th2 cells in terms of their cytokine productions was evaluated. RESULTS: In response to cognate antigens, the gammadelta T cell lines demonstrated a proliferation and production of IFN-gamma that exceeded that of BCG-specific Th1-type T cell clones (mean stimulation index: 14.5 vs. 2.8, mean IFN-gamma: 130.5 vs. 10.0 pg/mL). When the gammadelta T cell lines and mite-allergen-specific Th2 clones were co-cultured with each other, only the levels of IL-4 (mean, -87%) decreased, but not the levels of IL-5 and IL-13, with an increasing concentration of gammadelta T cell antigen and IFN-gamma production (mean, +730%). CONCLUSION: These results demonstrated that gammadelta T cells derived from allergic patients might thus have a partial ability to modulate allergen-specific Th2-skewed immunity.     

Heterogeneity in cytokine profiles of Babesia bovis-specific bovine CD4+ T cells clones activated in vitro.

The central role of T cells in the immune response against hemoprotozoan parasites, both as helper cells for T cell-dependent antibody production and as effector cells acting on intracellular parasites through the elaboration of cytokines, has prompted an investigation of the bovine cellular immune response against Babesia bovis antigens. CD4+ T helper (Th) cell clones generated from four B. bovis-immune cattle by in vitro stimulation with a soluble or membrane-associated merozoite antigen were characterized for reactivity against various forms of antigen and against different geographical isolates of B. bovis and B. bigemina and analyzed for cytokine production following mitogenic stimulation with concanavalin A. Biological assays to measure interleukin-2 (IL-2), IL-4, gamma interferon (IFN-gamma), and tumor necrosis factor alpha or tumor necrosis factor beta and Northern (RNA) blot analysis to verify the expression of IL-2, IL-4, IFN-gamma, and tumor necrosis factor alpha revealed differential production of cytokines by the Th cell clones. The majority of clones expressed the Th0 pattern of cytokines: IFN-gamma, IL-4, and IL-2. One clone expressed the Th1 profile (IFN-gamma and IL-2 but not IL-4), whereas none of the clones expressed the Th2 profile. All of the Th cell clones examined expressed the low-molecular-weight isoform of the leukocyte common antigen associated with a memory cell phenotype (CD45RO), and all expressed the lymph node homing receptor (L-selectin). These results extend our previous finding of differential cytokine expression by B. bovis-specific Th cell clones and confirm the identity of the specific cytokines produced, showing that a Th0 response is preferentially induced in a panel of 20 CD4+ T cell clones obtained from immune cattle.     

Immunomodulatory effects of the pentapeptide YGSRS on human peripheral-blood mononuclear cells

Abstract

Context: The pentapeptide YGSRS is originated from coffee bean, while its pharmacological features have little been examined.

Objectives: We investigated the effects of YGSRS on proliferation, cytokine production and CD4+ CD25+ Foxp3+ regulatory T (Treg) cell frequency of human peripheral blood mononuclear cells (PBMCs) activated by T-cell mitogen.

Materials and methods: The effects of YGSRS on T-cell mitogen-activated PBMCs were assessed by WST assay procedures. Concentrations of Th1/Th2/Th17 cytokines in the PBMCs culture medium were analyzed with beads-array procedures followed by analysis with flow cytometry. The CD4+ CD25+ Foxp3+ Treg cells in mitogen-activated PBMCs were stained with fluorescence-labeled specific antibodies followed by flow cytometry.

Results: YGSRS at 1–10?000?ng/ml (1.56–15?600?nM) has a tendency to promote the mitogen-activated proliferation of PBMCs, but the effects were not statistically significant. YGSRS affect the production of tumor necrosis factor (TNF) α, interleukin (IL)-4, IL-6 and IL-10 from the activated PBMCs, and statistically significant increase in the concentrations of IL-6 and IL-10 in the medium were observed at 1–1000?ng/ml (1.56–1560?nM) (p?<?0.05). YGSRS has a tendency to decrease the frequency of Treg cells in the activated PBMCs, but the difference was not statistically significant.

Discussion and conclusions: The data suggest that the pentapeptide YGSRS affects the production of several types of cytokines from activated human peripheral T cells, which may modulate Th2 type immunity.     

环孢素A抑制正常人外周血记忆CD4~＋T细胞产生IL-22的实验研究

目的探讨环孢素A（CsA）是否能够抑制正常人CD4＋T细胞产生白细胞介素22（IL-22）。方法使用密度梯度离心法制备正常人外周血单个核淋巴细胞（PBMCs）,加入PMA＋Inomycin刺激细胞后,做细胞内细胞因子染色,流式细胞仪检测正常人外周血PBMCs中产生IL-22的T细胞亚群,以及IL-17-IFN-γ-IL-22＋CD4＋T细胞亚群（Th22）;PMA＋Inomycin刺激正常人PBMCs,同时加或不加环孢素A（CsA）后,做细胞内细胞因子染色,流式细胞仪检测IL-22＋CD4＋T细胞和IFN-γ＋CD4＋T细胞的比例,以及IL-22＋CD4＋T细胞表达记忆表型分子CD45RO情况。结果正常人外周血中产生IL-22的T细胞以CD4＋T细胞为主,且存在仅分泌IL-22,不分泌IL-17和IFN-γ的Th22亚群;CsA以剂量依赖方式抑制CD4＋T细胞产生IL-22和IFN-γ;CsA抑制外周血PBMCs中记忆CD4＋T细胞产生IL-22。结论 CsA能抑制正常人外周血中记忆CD4＋T细胞产生IL-22。