90 resultados para TGF-ß, IL-10, asthma, Treg
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Background Previous studies have established that mycobacterial infections ameliorate allergic inflammation. However, a non-infectious approach that controls allergic responses might represent a safer and more promising strategy. The 60-65 kDa heat shock protein (Hsp) family is endowed with anti-inflammatory properties, but it is still unclear whether and how single mycobacterial Hsp control allergic disorders. Objective Therefore, in this study we determined whether the administration of Mycobacterial leprae Hsp65 expressed by recombinant a DNA plasmid could attenuate a previously established allergic response. Methods We used an experimental model of airway allergic inflammation to test the effects of immunotherapy with DNA encoding Hsp65. Allergic mice, previously sensitized and challenged with ovalbumin, were treated with tree intramuscular doses of recombinant DNA encoding Hsp65. After treatment, mice received a second allergen challenge and the allergic response was measured. Results We found that immunotherapy attenuated eosinophilia, pulmonary inflammation, Th2 cytokine and mucus production. Moreover, we showed that the inhibition of allergic response is dependent on IL-10 production. Both Hsp65 and allergen-specific IL-10-producing cells contributed to this effect. Cells transferred from DNA-immunized mice to allergic mice migrated to allergic sites and down-modulated the Th2 response. Conclusions and Clinical Relevance Our findings clearly show that immunotherapy with DNA encoding Hsp65 can attenuate an established Th2 allergic inflammation through an IL-10-dependent mechanism; moreover, the migration of allergen-and Hsp65-specific cells to the allergic sites exerts a fundamental role. This work represents a novel contribution to the understanding of immune regulation by Hsp65 in allergic diseases.
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We performed a comparative study and evaluated cellular infiltrates and anti-inflammatory cytokine production at different time-points after syngeneic or allogeneic skin transplantation. We observed an early IL-10 production in syngeneic grafts compared with allografts. This observation prompted us to investigate the role of IL-10 in isograft acceptance. For this, we used IL-10 KO and WT mice to perform syngeneic transplantation, where IL-10 was absent in the graft or in the recipient. The majority of syngeneic grafts derived from IL-10 KO donors did not engraft or was only partially accepted, whereas IL-10 KO mice transplanted with skin from WT donors accepted the graft. We evaluated IL-10 producers in the transplanted skin and observed that epithelial cells were the major source. Taken together, our data show that production of IL-10 by donor cells, but not by the recipient, is determinant for graft acceptance and strongly suggest that production of this cytokine by keratinocytes immediately upon transplantation is necessary for isograft survival. J. Leukoc. Biol. 92: 259-264; 2012.
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Background In human malaria, the naturally-acquired immune response can result in either the elimination of the parasite or a persistent response mediated by cytokines that leads to immunopathology. The cytokines are responsible for all the symptoms, pathological alterations and the outcome of the infection depends on the reciprocal regulation of the pro and anti-inflammatory cytokines. IL-10 and IFN-gamma are able to mediate this process and their production can be affected by single nucleotide polymorphisms (SNPs) on gene of these cytokines. In this study, the relationship between cytokine IL-10/IFN-gamma levels, parasitaemia, and their gene polymorphisms was examined and the participation of pro-inflammatory and regulatory balance during a natural immune response in Plasmodium vivax-infected individuals was observed. Methods The serum levels of the cytokines IL-4, IL-12, IFN-gamma and IL-10 from 132 patients were evaluated by indirect enzyme-linked immunosorbent assays (ELISA). The polymorphism at position +874 of the IFN-gamma gene was identified by allele-specific polymerase chain reaction (ASO-PCR) method, and the polymorphism at position -1082 of the IL-10 gene was analysed by PCR-RFLP (PCR-Restriction Fragment Length Polymorphism). Results The levels of a pro- (IFN-gamma) and an anti-inflammatory cytokine (IL-10) were significantly higher in P. vivax-infected individuals as compared to healthy controls. The IFN-gamma levels in primoinfected patients were significantly higher than in patients who had suffered only one and more than one previous episode. The mutant alleles of both IFN-gamma and IL-10 genes were more frequent than the wild allele. In the case of the IFNG+874 polymorphism (IFN-gamma) the frequencies of the mutant (A) and wild (T) alleles were 70.13% and 29.87%, respectively. Similar frequencies were recorded in IL-10-1082, with the mutant (A) allele returning a frequency of 70.78%, and the wild (G) allele a frequency of 29.22%. The frequencies of the alleles associated with reduced production of both IFN-gamma and IL-10 were high, but this effect was only observed in the production of IFN-gamma. Conclusions This study has shown evidence of reciprocal regulation of the levels of IL-10 and IFN-gamma cytokines in P. vivax malaria, which is not altered by the presence of polymorphism in the IL-10 gene.
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Activation of the platelet-activating factor receptor (PAFR) in macrophages is associated with suppressor phenotype. Here, we investigated the PAFR in murine dendritic cells (DC). Bone marrow-derived dendritic cells (BALB/c) were cultured with GM-CSF and maturation was induced by LPS. The PAFR antagonists (WEB2086, WEB2170, PCA4248) and the prostaglandin (PG) synthesis inhibitors (indomethacin, nimesulide and NS-398) were added before LPS. Mature and immature DCs expressed PAFR. LPS increased MHCII, CD40, CD80, CD86, CCR7 and induced IL-10, IL-12, COX-2 and PGE2 expression. IL-10, COX-2 and PGE2 levels were reduced by PAFR antagonists and increased by cPAF. The IL-10 production was independent of PGs. Mature DCs induced antigen-specific lymphocyte proliferation. PAFR antagonists or PG-synthesis inhibitors significantly increased lymphocyte proliferation. It is proposed that PAF has a central role in regulatory DC differentiation through potentiation of IL-10 and PGE2 production.
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BACKGROUND: Cellular immunity is the main defense mechanism in paracoccidioidomycosis (PCM), the most important systemic mycosis in Latin America. Th1 immunity and IFN-γ activated macrophages are fundamental to immunoprotection that is antagonized by IL-10, an anti-inflammatory cytokine. Both in human and experimental PCM, several evidences indicate that the suppressive effect of IL-10 causes detrimental effects to infected hosts. Because direct studies have not been performed, this study was aimed to characterize the function of IL-10 in pulmonary PCM. METHODOLOGY/PRINCIPAL FINDINGS: Wild type (WT) and IL-10(-/-) C57BL/6 mice were used to characterize the role of IL-10 in the innate and adaptive immunity against Paracoccidioides brasiliensis (Pb) infection. We verified that Pb-infected peritoneal macrophages from IL-10(-/-) mice presented higher phagocytic and fungicidal activities than WT macrophages, and these activities were associated with elevated production of IFN-γ, TNF-α, nitric oxide (NO) and MCP-1. For in vivo studies, IL-10(-/-) and WT mice were i.t. infected with 1×10(6) Pb yeasts and studied at several post-infection periods. Compared to WT mice, IL-10(-/-) mice showed increased resistance to P. brasiliensis infection as determined by the progressive control of pulmonary fungal loads and total clearance of fungal cells from dissemination organs. This behavior was accompanied by enhanced delayed-type hypersensitivity reactions, precocious humoral immunity and controlled tissue pathology resulting in increased survival times. In addition, IL-10(-/-) mice developed precocious T cell immunity mediated by increased numbers of lung infiltrating effector/memory CD4(+) and CD8(+) T cells. The inflammatory reactions and the production of Th1/Th2/Th17 cytokines were reduced at late phases of infection, paralleling the regressive infection of IL-10(-/-) mice. CONCLUSIONS/SIGNIFICANCE: Our work demonstrates for the first time that IL-10 plays a detrimental effect to pulmonary PCM due to its suppressive effect on the innate and adaptive immunity resulting in progressive infection and precocious mortality of infected hosts.
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Macrophage interaction with oxidized low-density lipoprotein (oxLDL) leads to its differentiation into foam cells and cytokine production, contributing to atherosclerosis development. In a previous study, we showed that CD36 and the receptor for platelet-activating factor (PAFR) are required for oxLDL to activate gene transcription for cytokines and CD36. Here, we investigated the localization and physical interaction of CD36 and PAFR in macrophages stimulated with oxLDL. We found that blocking CD36 or PAFR decreases oxLDL uptake and IL-10 production. OxLDL induces IL-10 mRNA expression only in HEK293T expressing both receptors (PAFR and CD36). OxLDL does not induce IL-12 production. The lipid rafts disruption by treatment with βCD reduces the oxLDL uptake and IL-10 production. OxLDL induces co-immunoprecipitation of PAFR and CD36 with the constitutive raft protein flotillin-1, and colocalization with the lipid raft-marker GM1-ganglioside. Finally, we found colocalization of PAFR and CD36 in macrophages from human atherosclerotic plaques. Our results show that oxLDL induces the recruitment of PAFR and CD36 into the same lipid rafts, which is important for oxLDL uptake and IL-10 production. This study provided new insights into how oxLDL interact with macrophages and contributing to atherosclerosis development.
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Regulatory T (Treg) cells are fundamental in the control of immunity and excessive tissue pathology. In paracoccidioidomycosis, an endemic mycosis of Latin America, the immunoregulatory mechanisms that control the progressive and regressive forms of this infection are poorly known. Due to its modulatory activity on Treg cells, we investigated the effects of anti-CD25 treatment over the course of pulmonary infection in resistant (A/J) and susceptible (B10.A) mice infected with Paracoccidioides brasiliensis. We verified that the resistant A/J mice developed higher numbers and more potent Treg cells than susceptible B10.A mice. Compared to B10.A cells, the CD4(+)CD25(+)Foxp3(+) Treg cells of A/J mice expressed higher levels of CD25, CTLA4, GITR, Foxp3, LAP and intracellular IL-10 and TGF-beta. In both resistant and susceptible mice, anti-CD25 treatment decreased the CD4(+)CD25(+)Foxp3(+) Treg cell number, impaired indoleamine 2,3-dioxygenase expression and resulted in decreased fungal loads in the lungs, liver and spleen. In A/J mice, anti-CD25 treatment led to an early increase in T cell immunity, demonstrated by the augmented influx of activated CD4(+) and CD8(+) T cells, macrophages and dendritic cells to the lungs. At a later phase, the mild infection was associated with decreased inflammatory reactions and increased Th1/Th2/Th17 cytokine production. In B10.A mice, anti-CD25 treatment did not alter the inflammatory reactions but increased the fungicidal mechanisms and late secretion of Th1/Th2/Th17 cytokines. Importantly, in both mouse strains, the early depletion of CD25(+) cells resulted in less severe tissue pathology and abolished the enhanced mortality observed in susceptible mice. In conclusion, this study is the first to demonstrate that anti-CD25 treatment is beneficial to the progressive and regressive forms of paracoccidioidomycosis, potentially due to the anti-CD25-mediated reduction of Treg cells, as these cells have suppressive effects on the early T cell response in resistant mice and the clearance mechanisms of fungal cells in susceptible mice.
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OBJECTIVES: FTY720 modulates CD4(+)T cells by the augmentation of regulatory T cell activity, secretion of suppressive cytokines and suppression of IL-17 secretion by Th17 cells. To further understand the process of graft rejection/acceptance, we evaluated skin allograft survival and associated events after FTY720 treatment. METHODS: F1 mice (C57BL/6xBALB/c) and C57BL/6 mice were used as donors for and recipients of skin transplantation, respectively. The recipients were transplanted and either not treated or treated with FTY720 by gavage for 21 days to evaluate the allograft survival. In another set of experiments, the immunological evaluation was performed five days post-transplantation. The spleens, axillary lymph nodes and skin allografts of the recipient mice were harvested for phenotyping (flow cytometry), gene expression (real-time PCR) and cytokine (Bio-Plex) analysis. RESULTS: The FTY720 treatment significantly increased skin allograft survival, reduced the number of cells in the lymph nodes and decreased the percentage of Tregs at this site in the C57BL/6 recipients. Moreover, the treatment reduced the number of graft-infiltrating cells and the percentage of CD4(+) graft-infiltrating cells. The cytokine analysis (splenocytes) showed decreased levels of IL-10, IL-6 and IL-17 in the FTY720-treated mice. We also observed a decrease in the IL-10, IL-6 and IL-23 mRNA levels, as well as an increase in the IL-27 mRNA levels, in the splenocytes of the treated group. The FTY720-treated mice exhibited increased mRNA levels of IL-10, IL-27 and IL-23 in the skin graft. CONCLUSIONS: Our results demonstrated prolonged but not indefinite skin allograft survival by FTY720 treatment. This finding indicates that the drug did not prevent the imbalance between Tr1 and Th17 cells in the graft that led to rejection.
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T regulatory cells (Tregs) play an important role in the mechanism of host's failure to control pathogen dissemination in severe forms of different chronic granulomatous diseases, but their role in leprosy has not yet been elucidated; 28 newly diagnosed patients (16 patients with lepromatous leprosy and 12 patients with tuberculoid leprosy) and 6 healthy Mycobacterium leprae-exposed individuals (contacts) were studied. Tregs were quantified by flow cytometry (CD4+ CD25+ Foxp3+) in peripheral blood mononuclear cells stimulated in vitro with a M. leprae antigenic preparation and phytohemagglutinin as well as in skin lesions by immunohistochemistry. The lymphoproliferative (LPR), interleukin-10 (IL-10), and interferon-gamma (IFN-gamma) responses of the in vitro-stimulated peripheral blood mononuclear cells and the in situ expression of IL-10, transforming growth factor-beta (TGF-beta), and cytotoxic T-lymphocyte antigen 4 (CTLA-4) were also determined. We show that M. leprae antigens induced significantly lower LPR but significantly higher Treg numbers in lepromatous than tuberculoid patients and contacts. Mitogen-induced LPR and Treg frequencies were not significantly different among the three groups. Tregs were also more frequent in situ in lepromatous patients, and this finding was paralleled by increased expression of the antiinflammatory molecules IL-10 and CTLA-4 but not TGF-beta. In lepromatous patients, Tregs were intermingled with vacuolized hystiocyte infiltrates all over the lesion, whereas in tuberculoid patients, Tregs were rare. Our results suggest that Tregs are present in increased numbers, and they may have a pathogenic role in leprosy patients harboring uncontrolled bacillary multiplication but not in those individuals capable of limiting M. leprae growth.
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Objective This study investigated environmental endotoxin exposure during early life, sensitization to aeroallergens, the production of cytokines by LPS-stimulated leukocytes, and the development of a wheezing phenotype in a prospective cohort of infants with high risk of developing allergic diseases. Materials and Methods Eighty-four infants were followed from birth until 30 months of age. We assessed endotoxin concentration in house dust of their homes during the first 6 months of life. At age 30 months they were clinically evaluated to determine the development of wheezing and other clinical events, were skin prick tested, and had blood samples collected for the evaluation of cytokine release by LPS-stimulated peripheral blood mononuclear cells (PBMC). Results The level of endotoxin exposure during early life was not associated with development of a wheezing phenotype. On the other hand a higher incidence of respiratory infections occurred among recurrent wheezing (RW) infants. PBMC from RW children exposed to higher levels of environmental endotoxin (above 50?EU/mg) released less Interleukin (IL)-12p70 and IFN-? compared to the non-RW group. TNF-a, IL-10, IL-4, IL-5, and IL17 production by LPS-stimulated PBMC from RW and non-RW children was equivalent in both groups of environmental endotoxin exposure. Conclusion In this prospective cohort of infants with high risk of developing allergic diseases we observed that RW and non-RW children were exposed to similar levels of endotoxin early in life. LPS-stimulated PBMC from RW infants exposed to higher levels of endotoxin released significantly less IL-12 and IFN-? compared to non-RW infants. Pediatr Pulmonol. 2012. 47:10541060. (C) 2012 Wiley Periodicals, Inc.
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Problem To evaluate CD4+CD25highFoxp3+ cells and IL-6, IL-10, IL-17, and TGF-beta in the peritoneal fluid of women with endometriosis. Method of study A total of ninety-eight patients were studied: endometriosis (n = 70) and control (n = 28). First, peritoneal fluid lymphocytes were isolated, and CD4+CD25high cells were identified using flow cytometry. Then, RT-PCR was performed to verify Foxp3 expression in these cells. Also, IL-6, IL-10, IL-17, and TGF-beta concentration was determined. Results Of all the lymphocytes in the peritoneal fluid of women with endometriosis, 36.5% (median) were CD4+CD25high compared to only 1.15% (median) in the control group (P < 0.001). Foxp3 expression was similarly elevated in patients with the disease compared to those without (median, 50 versus 5; P < 0.001). IL-6 and TGF-beta were higher in endometriosis group (IL-6: 327.5 pg/mL versus 195.5 pg/mL; TGF-beta: 340 pg/mL versus 171.5 pg/mL; both P < 0.001). IL-10 and IL-17 showed no significant differences between the two groups. Conclusion The peritoneal fluid of patients with endometriosis had a higher percentage of CD4+CD25highFoxp3+ cells and also higher levels of IL-6 and TGF-beta compared to women without the disease. These findings suggest that CD4+CD25highFoxp3+ cells may play a role in the pathogenesis of endometriosis.
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DCs orchestrate immune responses contributing to the pattern of response developed. In cancer, DCs may play a dysfunctional role in the induction of CD4(+)CD25(+) Foxp3(+) Tregs, contributing to immune evasion. We show here that Mo-DCs from breast cancer patients show an altered phenotype and induce preferentially Tregs, a phenomenon that occurred regardless of DC maturation stimulus (sCD40L, cytokine cocktail, TNF-alpha, and LPS). The Mo-DCs of patients induced low proliferation of allogeneic CD3(+)CD25(neg)Foxp3(neg) cells, which after becoming CD25(+), suppressed mitogen-stimulated T cells. Contrastingly, Mo-DCs from healthy donors induced a stronger proliferative response, a low frequency of CD4(+)CD25(+)Foxp3(+) with no suppressive activity. Furthermore, healthy Mo-DCs induced higher levels of IFN-gamma, whereas the Mo-DCs of patients induced higher levels of bioactive TGF-beta 1 and IL-10 in cocultures with allogeneic T cells. Interestingly, TGF-beta 1 blocking with mAb in cocultures was not enough to completely revert the Mo-DCs of patients' bias toward Treg induction. Altogether, these findings should be considered in immunotherapeutic approaches for cancer based on Mo-DCs. J. Leukoc. Biol. 92: 673-682; 2012.
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Objective:3,4-Methylenedioxymethamphetamine(MDMA), or ecstasy, is a synthetic drug used recreationally, mainly by young people. It has been suggested that MDMA has a Th cell skewing effect, in which Th1 cell activity is suppressed and Th2 cell activity is increased. Experimental allergic airway inflammation in ovalbumin (OVA)-sensitized rodents is a useful model to study Th2 response; therefore, based on the Th2 skewing effect of MDMA, we studied MDMA in a model of allergic lung inflammation in OVA-sensitized mice. Methods: We evaluated cell trafficking in the bronchoalveolar lavage fluid, blood and bone marrow; cytokine production; L-selectin expression and lung histology. We also investigated the effects of MDMA on tracheal reactivity in vitro and mast cell degranulation. Results: We found that MDMA given prior to OVA challenge in OVA-sensitized mice decreased leukocyte migration into the lung, as revealed by a lower cell count in the bronchoalveolar lavage fluid and lung histologic analysis. We also showed that MDMA decreased expression of both Th2-like cytokines (IL-4, IL-5 and IL-10) and adhesion molecules (L-selectin). Moreover, we showed that the hypothalamus-pituitary-adrenal axis is partially involved in the MDMA-induced reduction in leukocyte migration into the lung. Finally, we showed that MDMA decreased tracheal reactivity to methacholine as well as mast cell degranulation in situ. Conclusions:Thus, we report here that MDMA given prior to OVA challenge in OVA-sensitized allergic mice is able to decrease lung inflammation and airway reactivity and that hypothalamus-pituitary-adrenal axis activation is partially involved. Together, the data strongly suggest an involvement of a neuroinnmune mechanism in the effects of MDMA on lung inflammatory response and cell recruitment to the lungs of allergic animals. Copyright (C) 2012 S. Karger AG, Basel
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Background: Myocardium damage during Chagas' disease results from the immunological imbalance between pro-and production of anti-inflammatory cytokines and has been explained based on the Th1-Th2 dichotomy and regulatory T cell activity. Recently, we demonstrated that IL-17 produced during experimental T. cruzi infection regulates Th1 cells differentiation and parasite induced myocarditis. Here, we investigated the role of IL-17 and regulatory T cell during human Chagas' disease. Methodology/Principal Findings: First, we observed CD4(+)IL-17(+) T cells in culture of peripheral blood mononuclear cells (PBMC) from Chagas' disease patients and we evaluated Th1, Th2, Th17 cytokine profile production in the PBMC cells from Chagas' disease patients (cardiomyopathy-free, and with mild, moderate or severe cardiomyopathy) cultured with T. cruzi antigen. Cultures of PBMC from patients with moderate and severe cardiomyopathy produced high levels of TNF-alpha, IFN-gamma and low levels of IL-10, when compared to mild cardiomyopathy or cardiomyopathy-free patients. Flow cytometry analysis showed higher CD4(+)IL-17(+) cells in PBMC cultured from patients without or with mild cardiomyopathy, in comparison to patients with moderate or severe cardiomyopathy. We then analyzed the presence and function of regulatory T cells in all patients. All groups of Chagas' disease patients presented the same frequency of CD4(+)CD25(+) regulatory T cells. However, CD4(+)CD25(+) T cells from patients with mild cardiomyopathy or cardiomyopathy-free showed higher suppressive activity than those with moderate and severe cardiomyopathy. IFN-gamma levels during chronic Chagas' disease are inversely correlated to the LVEF (P = 0.007, r = -0.614), while regulatory T cell activity is directly correlated with LVEF (P = 0.022, r = 0.500). Conclusion/Significance: These results indicate that reduced production of the cytokines IL-10 and IL-17 in association with high levels of IFN-gamma and TNF-alpha is correlated with the severity of the Chagas' disease cardiomyopathy, and the immunological imbalance observed may be causally related with deficient suppressor activity of regulatory T cells that controls myocardial inflammation.
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Background: Patients with X-linked hyper-IgM syndrome (X-HIGM) due to CD40 ligand (CD40L) mutations are susceptible to fungal pathogens; however, the underlying susceptibility mechanisms remain poorly understood. Objective: To determine whether monocyte-derived dendritic cells (DCs) from patients with X-HIGM exhibit normal responses to fungal pathogens. Methods: DCs from patients and controls were evaluated for the expression of costimulatory (CD80 and CD86) and MHC class II molecules and for their ability to produce IL-12 and IL-10 in response to Candida albicans and Paracoccidioides brasiliensis. We also evaluated the ability of C albicans- and P brasiliensis-pulsed mature DCs to induce autologous T-cell proliferation, generation of T helper (T-H) 17 cells, and production of IFN-gamma, TGF-beta, IL-4, IL-5, and IL-17. Results: Immature DCs from patients with X-HIGM showed reduced expression of CD80, CD86, and HLA-DR, which could be reversed by exogenous trimeric soluble CD40L. Most important, mature DCs from patients with X-HIGM differentiated by coculturing DCs with fungi secreted minimal amounts of IL-12 but substantial amounts of IL-10 compared with mature DCs from normal individuals. Coculture of mature DCs from X-HIGM patients with autologous T cells led to low IFN-g production, whereas IL-4 and IL-5 production was increased. T-cell proliferation and IL-17 secretion were normal. Finally, in vitro incubation with soluble CD40L reversed the decreased IL-12 production and the skewed T-H(2) pattern response. Conclusion: Absence of CD40L during monocyte/DC differentiation leads to functional DC abnormalities, which may contribute to the susceptibility to fungal infections in patients with X-HIGM. (J Allergy Clin Immunol 2012; 129: 778-86.)