Frequency Of CD11c Research Articles

CD11c+ B Cells Participate in the Pathogenesis of Graves' Disease by Secreting Thyroid Autoantibodies and Cytokines.

Graves’ disease (GD) is a common autoimmune disorder with an elevation in pathogenic autoantibodies, specifically anti-thyrotropin receptor antibodies (TRAbs), which are secreted by autoreactive B cells. To date, there has been little research on self-reactive B cells in GD. In the current study, we reported that a unique B-cell subset, CD11c+ B cells, was expanded in the peripheral blood (PB) of GD patients, as detected by flow cytometry. The frequency of CD11c+ B cells was positively correlated with serum TRAb levels. The flow cytometry data showed that CD11c expression was higher in a variety of B-cell subsets and that CD11c+ B cells presented a distinct immunophenotype compared to paired CD11c- B cells. Immunohistochemical and immunofluorescence staining indicated the presence of CD11c+CD19+ B cells in lymphocyte infiltration areas of the GD thyroid. Flow cytometric analysis of PB and fine-needle aspiration (FNA) samples showed that compared to PB CD11c+ B cells, CD11c+ B cells in the thyroid accumulated and further differentiated. We found that CD11c+ B cells from the PB of GD patients were induced to differentiate into autoreactive antibody-secreting cells (ASCs) capable of secreting TRAbs in vitro. Luminex liquid suspension chip detection data showed that CD11c+ B cells also secreted a variety of cytokines, including proinflammatory cytokines, anti-inflammatory cytokines, and chemokines, which might play roles in regulating the local inflammatory response and infiltration of lymphocytes in the thyroid. In addition, we performed a chemotaxis assay in a Transwell chamber to verify that CD11c+ B cells were recruited by thyroid follicular cells (TFCs) via the CXCR3-CXCL10 axis. In conclusion, our study determined that CD11c+ B cells were involved in the pathogenesis of GD in multiple ways and might represent a promising immunotherapeutic target in the future.

A4 HELMINTH-DERIVED METABOLITES INDUCE A TOLEROGENIC PROFILE IN DENDRITIC CELLS AND ALLEVIATE EXPERIMENTAL COLITIS

BackgroundInflammatory bowel diseases (IBD) are chronic inflammatory diseases characterized by abdominal pain, bloody diarrhea, fatigue, weight loss, and diminished quality of life. The morbidity associated with IBD is a result of loss of tolerance towards the gastrointestinal commensal microbiota. The high incidence of IBD in Western societies is inversely correlated with the low incidence of intestinal helminth parasite infections, potentially due to the ability of the helminth parasite to induce tolerance by inducing tolerogenic dendritic cells (tolDC) polarization. Although macromolecules from helminth such as proteins and polysaccharides have been shown to polarize tolDCs, to characterize a novel pathway, in this study we focused on small molecules such as metabolites in the helminth secretome. We hypothesized that helminth-derived metabolites (HDMs) polarize DCs towards a tolerogenic phenotype, which alleviates colitis.AimsTo evaluate and characterize the tolerogenic response induced by HDMs in DCs, and its ability to alleviate colitis.Methods Heligmosomoides polygyrus worms were culture for 24 h and HDMs were isolated from conditioned media by chromatography. Bone marrow dendritic cells (BMDCs) were differentiated with GM-CSF for 8 days and then incubated with HDM for 4 h before LPS stimulation for 20 h. Cytokine secretion was measured by ELISA. The transcriptome of DCs treated with HDMs was assessed by RNAseq. Colitis was induced by giving 3% DSS in drinking water for 5 days followed by 3 days of tap water. The anti-colitic effect of HDMs was assessed by daily treatment with HDM or DCs treated with HDM in the 3 days of tap water.ResultsPre-treatment with HDM decreased LPS-induced TNF and increased IL-10 release by BMDCs, compared to control BMDCs. Colitic mice treated with HDM presented lower disease activity scores, less colon shortening, decreased weight loss, and healthier histopathology compared to vehicle-treated colitic mice. Importantly, there was an increased frequency of CD11c+ CD103+ DCs in the colon of HDM-treated mice, suggesting that HDM alleviates colitis by increasing the abundance of tolDCs in the colon. Adoptive transfer of HDM-treated DCs also reduced the severity of colitis compared with vehicle-treated mice or mice that received naïve DCs. These results indicate that HDM induced tolerogenic DCs, which in turn ameliorates DSS colitis. RNAseq showed that HDM upregulated 183 and downregulated 76 genes. These differentially expressed genes may indicate a novel mechanism by which helminths induce a tolerogenic profile in DCs.ConclusionsHDMs induce tolerogenic DCs and alleviate DSS-induced colitis.Funding AgenciesNSERC and FRQNT

Disruption of Glucocorticoid Action on CD11c+ Dendritic Cells Favors the Generation of CD4+ Regulatory T Cells and Improves Fetal Development in Mice.

A wealth of innate and adaptive immune cells and hormones are involved in mounting tolerance towards the fetus, a key aspect of successful reproduction. We could recently show that the specific cross talk between the pregnancy hormone progesterone and dendritic cells (DCs) is significantly engaged in the generation of CD4+ FoxP3+ regulatory T (Treg) cells while a disruption led to placental alterations and intra-uterine growth restriction. Apart from progesterone, also glucocorticoids affect immune cell functions. However, their functional relevance in the context of pregnancy still needs clarification. We developed a mouse line with a selective knockout of the glucocorticoid receptor (GR) on DCs, utilizing the cre/flox system. Reproductive outcome and maternal immune and endocrine adaptation of Balb/c-mated C57Bl/6 GRflox/floxCD11ccre/wt (mutant) females was assessed on gestation days (gd) 13.5 and 18.5. Balb/c-mated C57Bl/6 GRwt/wtCD11ccre/wt (wt) females served as controls. The number of implantation and fetal loss rate did not differ between groups. However, we identified a significant increase in fetal weight in fetuses from mutant dams. While the frequencies of CD11c+ cells remained largely similar, a decreased expression of co-stimulatory molecules was observed on DCs of mutant females on gd 13.5, along with higher frequencies of CD4+ and CD8+ Treg cells. Histomorphological and gene expression analysis revealed an increased placental volume and an improved functional placental capacity in mice lacking the GR on CD11c+ DCs. In summary, we here demonstrate that the disrupted communication between GCs and DCs favors a tolerant immune microenvironment and improves placental function and fetal development.

Th1 ‐ CD11c+ B Cell Axis Associated with Response to Plasmapheresis in Multiple Sclerosis

ObjectiveAlthough plasmapheresis is a treatment option for patients with autoimmune neurological diseases, treatment response varies greatly among patients. The main objective of this study was to find out if biological/immune traits correlate with a beneficial response.MethodsWe thoroughly analyzed immune phenotypes in paired blood samples from a cohort of 31 patients with multiple sclerosis before and after plasmapheresis, in parallel with clinical evaluation of treatment response.ResultsThe frequency of IFN‐γ+ Th1 cells was persistently higher in those who obtained benefit from plasmapheresis (responders) than nonresponders. The Th1 cell frequency before plasmapheresis provided a high predictive value for beneficial response, achieving area under the curve (AUC) of 0.902. Plasmapheresis treatment decreased inflammation‐related gene expressions in Th1 cells. Meanwhile, IFNG expression in Th1 cells positively correlated with the frequency of CD11c+ B cells, of which a pathogenic role has been suggested in several autoimmune diseases. In line with this, in vitro experiments showed that CD11c+ B cells would increase in response to exogenous IFN‐γ compared to IL‐4, and secrete high amounts of IgG. B cell receptor analysis indicated that clonal expansion of CD11c+ B cells takes place in patients with multiple sclerosis. Interestingly, CD11c+ B cells, which showed unique gene expression profile, decreased after plasmapheresis treatment along with all the immunoglobulin subsets in the circulation.InterpretationTaken together, we postulate that Th1 cell ‐ CD11c+ B cell axis is involved in treatment response to plasmapheresis, giving us clues to better understanding of complicated pathogenesis of autoimmune diseases, and getting closer to a personalized therapy. ANN NEUROL 2021;90:595–611

Indoleamine 2,3-dioxygenase 1 limits hepatic inflammatory cells recruitment and promotes bile duct ligation-induced liver fibrosis

Liver fibrosis is a course of chronic liver dysfunction, can develop into cirrhosis and hepatocellular carcinoma. Inflammatory insult owing to pathogenic factors plays a crucial role in the pathogenesis of liver fibrosis. Indoleamine 2,3-dioxygenase 1 (IDO1) can affect the infiltration of immune cells in many pathology processes of diseases, but its role in liver fibrosis has not been elucidated completely. Here, the markedly elevated protein IDO1 in livers was identified, and dendritic cells (DCs) immune-phenotypes were significantly altered after BDL challenge. A distinct hepatic population of CD11c+DCs was decreased and presented an immature immune-phenotype, reflected by lower expression levels of co-stimulatory molecules (CD40, MHCII). Frequencies of CD11c+CD80+, CD11c+CD86+, CD11c+MHCII+, and CD11c+CD40+ cells in splenic leukocytes were reduced significantly. Notably, IDO1 overexpression inhibited hepatic, splenic CD11c+DCs maturation, mature DCs-mediated T-cell proliferation and worsened liver fibrosis, whereas above pathological phenomena were reversed in IDO1−/− mice. Our data demonstrate that IDO1 affects the process of immune cells recruitment via inhibiting DCs maturation and subsequent T cells proliferation, resulting in the promotion of hepatic fibrosis. Thus, amelioration of immune responses in hepatic and splenic microenvironment by targeting IDO1 might be essential for the therapeutic effects on liver fibrosis.

Neurogenic tachykinin mechanisms in experimental nephritis of rats

We demonstrated earlier that renal afferent pathways combine very likely “classical” neural signal transduction to the central nervous system and a substance P (SP)–dependent mechanism to control sympathetic activity. SP content of afferent sensory neurons is known to mediate neurogenic inflammation upon release. We tested the hypothesis that alterations in SP-dependent mechanisms of renal innervation contribute to experimental nephritis. Nephritis was induced by OX-7 antibodies in rats, 6 days later instrumented for recording of blood pressure (BP), heart rate (HR), drug administration, and intrarenal administration (IRA) of the TRPV1 agonist capsaicin to stimulate afferent renal nerve pathways containing SP and electrodes for renal sympathetic nerve activity (RSNA). The presence of the SP receptor NK-1 on renal immune cells was assessed by FACS. IRA capsaicin decreased RSNA from 62.4 ± 5.1 to 21.6 ± 1.5 mV s (*p < 0.05) in controls, a response impaired in nephritis. Suppressed RSNA transiently but completely recovered after systemic administration of a neurokinin 1 (NK1-R) blocker. NK-1 receptors occurred mainly on CD11+ dendritic cells (DCs). An enhanced frequency of CD11c+NK1R+ cell, NK-1 receptor+ macrophages, and DCs was assessed in nephritis. Administration of the NK-1R antagonist aprepitant during nephritis reduced CD11c+NK1R+ cells, macrophage infiltration, renal expression of chemokines, and markers of sclerosis. Hence, SP promoted renal inflammation by weakening sympathoinhibitory mechanisms, while at the same time, substance SP released intrarenally from afferent nerve fibers aggravated immunological processes i.e. by the recruitment of DCs.

Mutual antagonism between indoleamine 2,3-dioxygenase 1 and nuclear factor E2-related factor 2 regulates the maturation status of DCs in liver fibrosis

Liver fibrosis can develop into liver cirrhosis and hepatocellular carcinoma substantially without effective available treatment currently due to rarely characterized molecular pathogenesis.Indoleamine 2,3-dioxygenase 1(IDO1) can be detected on antigen-presenting cells (APCs) and modulates various immune responses. However, the role of IDO1 in the regulation of dendritic cells (DCs) during liver fibrosis is rarely reported. Here, we found that hepatic IDO1 was up-regulated during CCL4-induced liver fibrosis, which accompanied by a significant decrease in the frequencies of CD11c+CD80+, CD11c+CD86+, CD11c+CD40+ and CD11c+MHCII+ cells and a reduction in the subsequent T cell proliferation rate, whereas these changes were reversed significantly in IDO1−/− mice. Overexpressing IDO1 by adeno-associated viral vector serotype 9 (AAV9) significantly inhibited the maturation status of DCs, worsened fibrosis. In vitro studies showed that significantly elevated CD80, CD86, CD40 and MHCII expression were observed in BMDCs derived from IDO1−/− mice. Moreover, the maturation of BMDCs derived from WT mice were significantly increased after stimulated with IDO1 inhibitor (1-methyl- D -tryptophan). Nuclear factor E2-related factor 2 (Nrf2), a key regulator of the cellular adaptive response to oxidative insults and inflammation, exhibited a markedly decrease in the liver of WT fibrotic mice, nevertheless, knockout of IDO1 enhanced the protein level of Nrf2. Moreover, the expression of IDO1 and Nrf2 exhibited inverse colocalization pattern suggesting that ectopically expressed IDO1 down-regulated Nrf2. Additionally, up-regulation of IDO1 was also observed in the livers of Nrf2−/− fibrotic mice. Taken together, these data uncovered mutual antagonism between IDO1 and Nrf2 on the maturation status of DCs during hepatic fibrosis.

PD-1hiCXCR5- T peripheral helper cells promote B cell responses in lupus via MAF and IL-21.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by pathologic T cell-B cell interactions and autoantibody production. Defining the T cell populations that drive B cell responses in SLE may enable design of therapies that specifically target pathologic cell subsets. Here, we evaluated the phenotypes of CD4+ T cells in the circulation of 52 SLE patients drawn from multiple cohorts and identified a highly expanded PD-1hiCXCR5-CD4+ T cell population. Cytometric, transcriptomic, and functional assays demonstrated that PD-1hiCXCR5-CD4+ T cells from SLE patients are T peripheral helper (Tph) cells, a CXCR5- T cell population that stimulates B cell responses via IL-21. The frequency of Tph cells, but not T follicular helper (Tfh) cells, correlated with both clinical disease activity and the frequency of CD11c+ B cells in SLE patients. PD-1hiCD4+ T cells were found within lupus nephritis kidneys and correlated with B cell numbers in the kidney. Both IL-21 neutralization and CRISPR-mediated deletion of MAF abrogated the ability of Tph cells to induce memory B cell differentiation into plasmablasts in vitro. These findings identify Tph cells as a highly expanded T cell population in SLE and suggest a key role for Tph cells in stimulating pathologic B cell responses.

Kinetics of Corneal Antigen Presenting Cells in Experimental Dry Eye Disease

ObjectiveTo evaluate dry eye disease (DED)-induced alterations in subsets of corneal antigen presenting cells (APCs) in a mouse model of experimental DED.Methods and AnalysisSeven to 8-week-old female C57BL/6 mice were...

Transient decrease in human peripheral blood myeloid dendritic cells following influenza vaccination correlates with induction of serum antibody

Dendritic cells (DC) are critical inducers of the adaptive immune response. Extensive characterization of tissue-resident and monocyte-derived DC has revealed diverse stimulatory and regulatory actions, although the role of peripheral blood dendritic cells (PBDC) in maintaining homeostasis remains unclear. Examination of various myeloid (CD11c+CD303-) and plasmacytoid (CD11c-CD303+) DC populations in the peripheral blood of seasonal trivalent inactivated influenza vaccine recipients revealed a transient decrease in the frequency of CD11c+CD1c- myeloid DC subsets 5-10 days following vaccination, including both CD141+ and CD141- myeloid DC subsets of this population. These populations rebounded by 1 month, while plasmacytoid DC remained stable. The magnitude of the decrease in the CD141+ myeloid DC subset at d5-7 significantly correlated with the induction of influenza specific serum antibodies measured at 1 month following vaccination. These results demonstrate a mobilization of peripheral blood myeloid DC following vaccination and indicate these cells are potential biomarkers of immune response.

Abstract 1258: The frequency of CD11c+ cells within the gastric cancer tissue is associated with favorable prognosis.

Abstract Aim: CD11c is a marker for dendritic cells which help initiating adaptive antitumor immunity. The study was designed to investigate correlation between the frequency of CD11c+ cells in the gastric cancer tissue and the clinical and pathological parameters of gastric cancer patients. Methods: CD11c expression in gastric cancer tissues was examined by immunohistochemistry. Surface CD11c expression on the leukocytes within cancer tissues was examined by flow cytometry. Results: The number of CD11c+ cells was higher in gastric cancer tissues than that in gastritis or gastric polyps tissues. The number of CD11c+ cells in tumor specimens from the early-stage gastric cancer was significantly higher than that in specimens from the late-stage gastric cancer (t=2.77,P=0.0064). Flow cytometry found that CD11c surface expression was stronger in specimens from the early stages than those from the late stages of gastric cancer. The Univariate analysis revealed that the frequency of intratumoral CD11c+ cells showed association with gender and tumor location, and was reversely correlated with tumor size, depth of infiltration, nodal metastasis, tumor histological grade and cancer stages. The median survival time (MST) for the subgroups of patients with stronger and weaker CD11c expression were 67.0 months (95%CI, 39.0-112.0 months) and 29.0 months (95%CI, 21.0-39.0 months), respectively. And MSTs were significantly different between the CD11c higher and lower subgroups (χ2=11.6425,P=0.0006). Among patients who suffered from late-stage diseases, those with higher numbers of intratumoral CD11c cells had a significantly lower risk of death than those with lower numbers of CD11c cells (χ2=8.549,P=0.0035), and the lowered risk of death was statistically significant after adjusting gender, age, tumor size and infiltrating depth (RR=0.52,95%CI=0.29-0.94). Conclusions: The number of CD11c+ cells within gastric cancer tissue is a favorable prognostic marker for gastric cancer. Our study suggests gradual elimination of dendritic cells is characteristic of gastric cancer progression. Citation Format: Jingting Jiang, Changping Wu, Binfeng Lu. The frequency of CD11c+ cells within the gastric cancer tissue is associated with favorable prognosis. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1258. doi:10.1158/1538-7445.AM2013-1258 Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.

Assessing the Role of CD103 in Immunity to an Intestinal Helminth Parasite

BackgroundIn the intestine, the integrin CD103 is expressed on a subset of T regulatory (Treg) cells and a population of dendritic cells (DCs) that produce retinoic acid and promote immune homeostasis. However, the role of CD103 during intestinal helminth infection has not been tested.Methodology/Principal FindingsWe demonstrate that CD103 is dispensable for the development of protective immunity to the helminth parasite Trichuris muris. While we observed an increase in the frequency of CD103+ DCs in the lamina propria (LP) following acute high-dose infection with Trichuris, lack of CD103 had no effect on the frequency of CD11c+ DCs in the LP or mesenteric lymph nodes (mLN). CD103-deficient (CD103−/−) mice develop a slightly increased and earlier T cell response but resolve infection with similar kinetics to control mice. Similarly, low-dose chronic infection of CD103−/− mice with Trichuris resulted in no significant difference in immunity or parasite burden. Absence of CD103 also had no effect on the frequency of CD4+CD25+Foxp3+ Treg cells in the mLN or LP.Conclusions/SignificanceThese results suggest that CD103 is dispensable for intestinal immunity during helminth infection. Furthermore, lack of CD103 had no effect on DC or Treg recruitment or retention within the large intestine.

Induction of Targeted Cell Migration by Cutaneous Administration of a DNA Vector Encoding a Biologically Active Chemokine CCL21

Skin inflammation can induce local expression of CCL21, which is subsequently drained to lymph nodes (LNs) influencing their cellular composition. To determine whether the same can be achieved by dermal administration of a plasmid DNA (pDNA) encoding CCL21, we generated a pDNA-based gene construct allowing high-level expression of CCL21. Expression and secretion of biologically active CCL21 were confirmed in vitro by immunohistochemistry, western blot analysis, ELISA, and transwell chemotactic assays. In vivo experiments showed cellular expression of transgenic CCL21 after particle-mediated gene gun delivery of pDNA into skin. CCL21 was expressed in the epidermis, consequently secreted into the upper dermis, and transported into the draining LNs, which resulted in increased CCL21 concentration, total cell number, and frequencies of CD11c(+) DCs and CD4(+)/CD62L(+) naïve, CD4(+)/CD62L(-), and CD8(+)/CD62L(-) effector memory T-cells (expressing CCL21 receptors CCR7 or CXCR3), as well as retention of adoptively transferred T-lymphocytes, in the draining LNs of plt/plt mice (lacking endogenous expression of CCL21). Our studies show that biologically active CCL21 can be overexpressed by genetic means in vitro and in vivo. This strategy allows reconstitution of a genetic defect and colocalization of different cell types in the secondary lymphoid organs, an important prerequisite for targeted cell migration.

Effects of TCDD on the Fate of Naive Dendritic Cells

The environmental contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), causes immune suppression via activation of the aryl hydrocarbon receptor. Dendritic cells (DCs), the professional antigen-presenting cells in the immune system, are adversely affected by TCDD. We hypothesized that TCDD alters DC homeostasis, resulting in a loss of DCs in naive mice. To test this hypothesis, C57Bl/6 mice were gavaged with either vehicle or an immunosuppressive dose of TCDD (15 microg/kg). TCDD exposure decreased the frequency and number of splenic CD11c(high) DCs on day 7 when compared with vehicle-treated controls. TCDD increased the expression of CD86 and CD54, while decreasing the frequency of splenic CD11c(high) DCs expressing CD11a and major histocompatibility complex (MHC) class II. Moreover, TCDD selectively decreased the CD11c(high)CD8alpha(-)33D1(+) splenic DCs specialized at activating CD4(+) T cells but did not affect the regulatory CD11c(high)CD8alpha(+)DEC205(+) splenic DCs. TCDD did not alter the number or frequency of CD11c(low) splenic DCs but decreased their MHC class II and CD11a expression. Loss of splenic CD11c(high) DCs was independent of Fas-mediated apoptosis and was not due to alterations in the numbers of common DC precursors in the bone marrow or their ability to generate steady-state DCs in vitro. Instead, increased CCR7 expression on CD11c(high) DCs suggested involvement of a migratory event. Popliteal and brachial lymph node CD11c(+) cells showed elevated levels of MHC class II and CD40 following TCDD exposure. Collectively, this study shows the presence of a TCDD-sensitive splenic DC subpopulation in naive mice, suggesting that TCDD may induce suppression of T-cell-mediated immunity by disrupting DC homeostasis.

Aberrant dendritic cell differentiation initiated by theMll-Eenfusion gene does not require leukemic transformation

Dendritic cells (DCs), as specialized APCs, play a key role in the induction of anti-tumor immunity. They originate from bone marrow (BM) progenitors, which are frequently the targets of chromosomal translocations leading to development of leukemia. Aberrant DC differentiation and functions have been observed and are widely reported in patients with leukemia. It is not clear, however, whether such defects are a direct effect of a leukemic fusion gene or simply an outcome of the clinical disease. In this study, we demonstrate for the first time that knockin of the Mll-Een fusion gene can affect myeloid DC differentiation and functions directly, independent of the leukemic disease activities. We showed that the Mll-Een-expressing BM cells [enhanced green fluorescent protein+ (EGFP+)] from leukemic and nonleukemic mice had similarly impaired DC differentiation capacities with functional abnormalities. In contrast, BM cells without Mll-Een expression (EGFP(-)) showed normal DC differentiation and functions. A reduction in the frequency of CD11c+ DCs was also observed within the EGFP+ population in spleen and lymph nodes, and these cells were dysfunctional. Taken together, our findings suggest that the Mll-Een fusion gene can affect myeloid DC differentiation directly and functions in a cell-autonomous manner, where fully leukemic transformation of the hematopoietic progenitors is not required exclusively. Therefore, the study provides evidence for a direct causal relationship between leukemic gene fusion and abnormal DC differentiation, possibly contributing to the development of leukemia.

Nasal Flt3 ligand cDNA elicits CD11c+CD8+ dendritic cells for enhanced mucosal immunity.

Nasal immunization is an effective way to induce both mucosal and systemic immune responses. In this study, we assessed a cDNA vector for Flt3 ligand (FL) for its potential to enhance mucosal immunity or tolerance. Interestingly, tolerance was avoided and elevated levels of OVA-specific Ab responses were induced in nasal washes, fecal extracts, and saliva as well as in plasma when compared with mice given nasal OVA plus DNA plasmid without the FL gene. In addition, significant levels of OVA-specific CD4+ T cell proliferative responses and OVA-induced IL-4 and IL-2 production were noted in spleen and cervical lymph nodes. Further, marked increases in FL protein occurred in the nasal lamina propria and submandibular glands and the frequencies of CD11c+CD8+ dendritic cells (DCs) significantly increased in the mucosal tissues. Moreover, these DCs expressed high levels of CD40, CD80, CD86, and MHC class II molecules. Nasal delivery of plasmid FL with OVA resulted in FL expression in both mucosal inductive and effector sites and resulted in expanded activated lymphoid DCs. Thus, nasal plasmid FL prevents mucosal tolerance and enhances active immunity when given by a mucosal route.

Estrogen inhibition of EAE involves effects on dendritic cell function.

Estrogen has been found to have suppressive effects on the induction of experimental autoimmune encephalomyelitis (EAE), an animal model for the human disease multiple sclerosis. We have investigated the effects of 17beta-estradiol (E2) treatment on dendritic cells (DCs) in two different mouse models of EAE. The frequency of CD11b(+)/CD11c(+) DCs was significantly decreased in the brain of mice protected from EAE induction by E2 treatment. In addition, the frequency of CD11c(+)/CD8alpha(+) DCs producing tumor necrosis factor (TNF)alpha and interferon (IFN)gamma in the spleen of E2-treated mice was dramatically decreased compared to that in control mice with EAE, demonstrating an effect of E2 on DC function. In order to examine E2 effects on DCs in more detail, splenic DCs were cultured in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-4 to promote maturation. E2 pretreatment was found to suppress the ability of cultured DCs bearing a mature phenotype to present Ag to myelin basic protein (MBP)-specific T cells. Analysis of cytokine production demonstrated that E2 decreased TNFalpha, IFNgamma and IL-12 production in mature DCs. In addition, MBP-specific T cells cocultured with E2-pretreated mature DCs in the presence of antigen demonstrated a shift towards production of Th2 cytokines IL-4 and IL-10 and a concomitant decrease in the production of Th1 cytokines TNFalpha and IFNgamma. Thus, E2 treatment appears to have multiple effects on the DC population, which may contribute to a down-regulation or block in the activation of Th1 cells involved in the induction of EAE.