Cytoplasmic CCR7 (CCR7c) immunoexpression is associated with local tumor recurrence in triple-negative breast cancer.

BACKGROUND: Triple-negative breast cancer (TNBC) is a subtype of cancer, which tests negative for estrogen receptors, progesterone receptors, and lacks overexpression of the human epidermal growth factor 2 (C-erbB2, HER2/neu) gene. The expression of chemokines and their receptors, including CCR7, has been described in several types of cancer, contributing to tumor progression. AIM OF THE STUDY: This study investigated the association between the membrane and cytoplasmic CCR7 expression and the prognosis of TNBC. MATERIALS AND METHODS: Surgical paraffin histopathology blocks and clinico-pathological data were assessed from 133 patients. Samples were analyzed by immunohistochemistry and immunofluorescence using the Tissue Microarray technique for scoring the intensity of CCR7 expression. RESULTS: TNBC patients in which the CCR7 labeling was predominantly in the cytoplasm of tumor cells presented increased local tumor recurrence (P = 0.033). Conversely, there was no statistical difference in five-year overall survival between the patients with low (77%) versus high (80%) cytoplasmic CCR7 expression (P = 0.7104). Additionally, the risk of death between these groups was 1.19 (95% CI = 0.48-2.91). CONCLUSION: The cytoplasmic CCR7 expression associates with an increased incidence of tumor relapse in TNBC, not affecting patients survival. Consequently, the cell compartment in which the CCR7 localizes could serve as a prognostic marker in this cancer subtype.

The Diagnostic Value of Chemokine/Chemokine Receptor Pairs in Hepatocellular Carcinoma and Colorectal Liver Metastasis.

Chemokines and their receptors have been proposed to play important roles in tumor progression and metastasis. To investigate their roles in the progression of primary and metastatic malignant liver tumors and their prognosis, we compared expression profiles of CXCL12/CXCR4, CCL20/CCR6, and CCL21/CCR7 in hepatocellular carcinoma (HCC) and colorectal liver metastases (CRLM). Immunohistochemistry was used to analyze the expression levels of the chemokine/chemokine receptor pairs in 29 HCC and 11 CRLM specimens and adjacent non-cancerous tissues, and correlations with clinicopathological variables and overall survival were determined. CCL20/CCR6 expression was higher in HCC than in adjacent non-cancerous tissues. High CCR6 expression in HCC was negatively associated with 5-year survival rate and was an independent prognostic factor for overall survival of HCC patients, whereas differences were not observed between CRLM and adjacent tissues. Furthermore, significantly higher expression of CCL21/CCR7 was found in CRLM than in HCC. In summary, the CCL20/CCR6 axis was elevated in HCC but not in CRLM, whereas the CCL21/CCR7 axis was elevated in CRLM but not in HCC.

Clonal analysis of Salmonella-specific effector T cells reveals serovar-specific and cross-reactive T cell responses.

To tackle the complexity of cross-reactive and pathogen-specific T cell responses against related Salmonella serovars, we used mass cytometry, unbiased single-cell cloning, live fluorescence barcoding, and T cell-receptor sequencing to reconstruct the Salmonella-specific repertoire of circulating effector CD4+ T cells, isolated from volunteers challenged with Salmonella enterica serovar Typhi (S. Typhi) or Salmonella Paratyphi A (S. Paratyphi). We describe the expansion of cross-reactive responses against distantly related Salmonella serovars and of clonotypes recognizing immunodominant antigens uniquely expressed by S. Typhi or S. Paratyphi A. In addition, single-amino acid variations in two immunodominant proteins, CdtB and PhoN, lead to the accumulation of T cells that do not cross-react against the different serovars, thus demonstrating how minor sequence variations in a complex microorganism shape the pathogen-specific T cell repertoire. Our results identify immune-dominant, serovar-specific, and cross-reactive T cell antigens, which should aid in the design of T cell-vaccination strategies against Salmonella.

Clinical significance of CCR7+CD8+ T cells in kidney transplant recipients with allograft rejection.

The regulatory function of CCR7+CD8+ T cells against effector T-cells involved in T-cell mediated rejection (TCMR) in kidney transplant recipients was investigated. In vitro experiments explored the ability of CCR7+CD8+ T cells to suppress T-cell proliferation under T-cell activation conditions or during coculture with human renal proximal tubular epithelial cells (HRPTEpiC). In an ex vivo experiment, the proportion of CCR7+/CD8+, FOXP3+/CCR7+CD8+ T and effector T-cell subsets were compared between the normal biopsy control (NC, n = 17) and TCMR group (n = 17). The CCR7+CD8+ T cells significantly suppressed the proliferation of CD4+ T cells and significantly decreased the proportion of IFN-γ+ and IL-17+/CD4+ T cells and inflammatory cytokine levels (all p < 0.05). After coculturing with HRPTEpiC, CCR7+CD8+ T cells also suppressed T-cell differentiation into IL-2+, IFN-γ+, and IL-17+/CD4+ T cells (all p < 0.05). The TCMR group had significantly fewer CCR7+/CD8+ and FOXP3+/CCR7+CD8+ T in comparison with the NC group, but the proportions of all three effector T-cell subsets were increased in the TCMR group (all p < 0.05). The proportion of CCR7+/CD8+ T was inversely correlated with those of effector T-cell subsets. The results indicate that CCR7+CD8+ T cells may regulate effector T-cells involved in TCMR in an in vitro and in an ex vivo transplant model.

Alterations of CCR5 and CCR7 expression on donor peripheral blood T cell subsets after mobilization with rhG-CSF correlate with acute graft-versus-host disease.

To investigate the effects of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on chemokine receptors and explore the potential mechanism of rhG-CSF inducing immune tolerance, ninety-seven donor and recipient pairs undergoing family-donor allogeneic hematopoietic stem cell transplantation were studied. The results indicated that different donors showed great disparities in expression changes after mobilization. Multivariate analysis revealed that both HLA mismatching and CCR7 downregulation on donors' CD4+ T cells after mobilization were independent risk factors for acute graft-versus-host disease (GVHD). In contrast, CCR5 downregulation on CD4+ T cells was associated with reduced incidence of acute GVHD. In conclusion, rhG-CSF mobilization could lead to differential regulation of chemokine receptors expression on T cell subsets in different donors. Downregulation of CCR5 and upregulation of CCR7 expression on donor CD4+ T cells might protect recipients from acute GVHD. This finding may provide a promising new strategy for the prevention and treatment of acute GVHD.

High Expression of CCR7 Predicts Lymph Node Metastasis and Good Prognosis in Triple Negative Breast Cancer.

BACKGROUND/AIMS: Previous preclinical and clinical studies have reported a positive correlation between the expression of the C-C chemokine receptor 7 (CCR7) and the incidence of lymph node metastasis in breast cancer. However, the prognostic relevance of CCR7 expression in breast cancer remains contradictory till now. The aim of this study is to assess the correlation of the CCR7 expression with other clinicopathological features and prognosis in breast cancer. METHODS: The CCR7 gene amplification and mRNA expression levels from approximately 3,000 patients were retrieved from human breast cancer databases and analyzed. Furthermore, a total of 188 primary triple negative breast cancer patients were enrolled in this study (diagnosed since January 2009 to January 2013 from the Second Hospital of Dalian Medical University). The protein levels of CCR7 were examined by immunohistochemistry using paraffin-embedded tumor tissues. RESULTS: The analysis of gene amplification and mRNA levels showed the expression of CCR7 in breast cancer correlated with better prognosis. When we compared the CCR7 expressions in different subtypes, the basal-like group showed the highest expression of CCR7 and exhibited a better prognosis. Consistently, Kaplan-Meier analysis of 188 triple negative breast cancer patients showed that the prognosis of patients with positive CCR7 expression was significantly better than those with negative expression (HR=0.642, p=0.0275). Additionally, we also observed a positive correlation between lymph node metastasis and the CCR7 expression (p=0.0096). CONCLUSIONS: Our results indicated that elevated CCR7 expression as a marker for increased lymph node metastasis, in addition to serve as an independent prognostic indicator for better overall survival in triple negative breast cancer patients.

Compartment-specific immunity in the human gut: properties and functions of dendritic cells in the colon versus the ileum.

OBJECTIVE: Dendritic cells (DC) mediate intestinal immune tolerance. Despite striking differences between the colon and the ileum both in function and bacterial load, few studies distinguish between properties of immune cells in these compartments. Furthermore, information of gut DC in humans is scarce. We aimed to characterise human colonic versus ileal DC. DESIGN: Human DC from paired colonic and ileal samples were characterised by flow cytometry, electron microscopy or used to stimulate T cell responses in a mixed leucocyte reaction. RESULTS: A lower proportion of colonic DC produced pro-inflammatory cytokines (tumour necrosis factor-α and interleukin (IL)-1ß) compared with their ileal counterparts and exhibited an enhanced ability to generate CD4(+)FoxP3(+)IL-10(+) (regulatory) T cells. There were enhanced proportions of CD103(+)Sirpα(-) DC in the colon, with increased proportions of CD103(+)Sirpα(+) DC in the ileum. A greater proportion of colonic DC subsets analysed expressed the lymph-node-homing marker CCR7, alongside enhanced endocytic capacity, which was most striking in CD103(+)Sirpα(+) DC. Expression of the inhibitory receptor ILT3 was enhanced on colonic DC. Interestingly, endocytic capacity was associated with CD103(+) DC, in particular CD103(+)Sirpα(+) DC. However, expression of ILT3 was associated with CD103(-) DC. Colonic and ileal DC differentially expressed skin-homing marker CCR4 and small-bowel-homing marker CCR9, respectively, and this corresponded to their ability to imprint these homing markers on T cells. CONCLUSIONS: The regulatory properties of colonic DC may represent an evolutionary adaptation to the greater bacterial load in the colon. The colon and the ileum should be regarded as separate entities, each comprising DC with distinct roles in mucosal immunity and imprinting.

HIV-specific ADCC improves after antiretroviral therapy and correlates with normalization of the NK cell phenotype.

BACKGROUND: Natural killer (NK) cell phenotype and function have recently gained much attention as playing crucial roles in antibody-dependent cellular cytotoxicity (ADCC). We investigated NK cell function, as measured by ADCC, in HIV-1-positive individuals before and 6 months after highly active antiretroviral therapy (HAART) initiation. METHOD: The ability of antibodies and NK cells to mediate ADCC was investigated separately and in combination in an autologous model. The NK cell subset distribution and NK cell phenotype (ie, expression of maturation and activation markers within NK cell subsets) were analyzed. RESULTS: The ability of NK cells to mediate ADCC was significantly increased after only 6 months of HAART and was not explained by a normalization of NK cell subsets (CD56 CD16 and CD56 CD16 NK cells) but rather by normalization in the frequency of NK cells expressing CCR7 and CD27. For individuals with no increase in ADCC after 6 months of HAART, the frequency of NK cells expressing NKp46 was downregulated. The ability of antibodies to mediate ADCC alone and in combination in an autologous model was not improved. CONCLUSIONS: HAART improves the ability of NK cells to mediate ADCC after 6 months. This improvement does not correlate with general immune restoration, as measured by CD4 T-cell counts, but rather to a decrease in the frequency of NK cells expressing CCR7 and CD27.

CCL21/CCR7 axis activating chemotaxis accompanied with epithelial-mesenchymal transition in human breast carcinoma.

Secondary lymphoid tissue chemokine (SLC/CCL21) and its receptor CCR7 have been implicated in lymph node metastasis, whereas the mechanism of which remains unclear. Epithelial-mesenchymal transition (EMT) plays an important role in invasion and migration of cancer cells. We presumed that CCL21/CCR7 axis activates EMT process to induce cancer cell invasion and metastasis. Firstly, the expressions of CCR7 and EMT markers were examined by immunohistochemical staining in the primary breast carcinoma tissues from 60 patients who underwent radical mastectomy. Then, we investigated whether CCL21/CCR7 induces EMT process during mediating cancer cell invasion or migration in vitro. By immunohistolochemistry, high expressions of CCR7, Slug and N-cadherin were seen in 60, 65, and 76.67 % of tumors, respectively, and significantly associated with lymph node metastases as well as clinical pathological stage. Furthermore, the CCR7 expression was significantly correlated to Slug and N-cadherin. In vitro, stimulating breast cancer cell lines 1428, MCF-7 and MDA-MB-231 with CCL21, the invasion and migration of tumor cells were promoted, and simultaneously, EMT phenotype of tumor cells was enhanced, including down-regulation of E-cadherin, up-regulation of Slug, Vimentin and N-cadherin at both protein and mRNA levels. Inversely, knockdown of CCR7 by shRNA suppressed tumor cell invasion, migration and EMT phenotype induced by CCL21. These results indicated that CCL21/CCR7 axis could activate EMT process during chemotaxis of breast carcinoma cells.

CD8+ T cell responses specific for hepatitis B virus core protein in patients with chronic hepatitis B virus infection.

BACKGROUND: Chronic hepatitis B virus (HBV) infection includes a set of heterogeneous clinical patterns, and core-protein-specific T cell response is important for virus control and disease progression, yet is not well elucidated. OBJECTIVES: To analyze the phenotypic and functional profiles of HBV-core-protein-specific CD8+ T cells in different clinical patterns of chronic HBV infection. STUDY DESIGN: A total of 46 HBV patients were recruited and classified according to their clinical status. CD8+ T cell responses in different patterns of chronic HBV infections were tested with flow cytometry using overlapping 15-mer peptides covering HBV core protein. Meanwhile, the CCR7/CD27 phenotypes of these CD8+ T cells were also determined. RESULTS: Frequencies of gamma interferon (IFN-γ) positive CD8+ T cells in inactive HBV surface antigen (HBsAg) carriers in response to the core protein peptide pools were generally stronger than those of chronic HBV carriers and resolved individuals, especially with regards to peptide pool C13-C24. Moreover, phenotypic studies further highlighted the group of CD8+ CCR7-CD27+ T memory cells, which showed significantly higher levels of IFN-γ secretion in inactive HBsAg carriers than those in chronic hepatitis B patients, chronic HBV carriers and resolved individuals. CONCLUSIONS: Core-protein-specific T cell response plays an important role in chronic HBV infection. Inactive HBsAg carriers showed a much stronger core-protein-specific cytotoxic T cell response than other types of chronically infected patients. CD8+ CCR7-CD27+ T memory lymphocytes may be crucial in the immune pathogenesis of chronic HBV infection.

[The impact of donor naive and memory T cell subsets on patient outcome following allogeneic stem cell transplantation: relationship between infused donor CD4+/CCR7+ T cell subsets and acute graft-versus-host disease]. / Impact de la composition du greffon sur le devenir des patients après une allogreffe de cellules souches hématopoïétiques: corrélation entre proportion des lymphocytes T CD4+ du greffon exprimant le CCR7 et la survenue d'une GVH aiguë

In a previous prospective study on 62 patients who underwent an HLA-matched allogeneic stem cell transplantation, we have observed that proportion of donor-derived CCR7(+)/CD4(+) T cells in the graft provided a predictive indicator of acute GVHD without interfering on chronic GVHD and relapse rate. Here we present our results on a confirmatory cohort of 137 consecutive patients. Indeed patients who received more than 76% of CCR7(+)/CD4(+) T cells in the graft developed more often acute GVHD be it of low or high grade than those who did not. Determination of the CCR7(+)/CCR7(neg) ratio of CD4(+) T cells in the graft provides a predictive indicator of acute GVHD and could help to define strategies of partial selective T cell depleted transplantation.

CD45RA-Foxp3(high) activated/effector regulatory T cells in the CCR7 + CD45RA-CD27 + CD28+central memory subset are decreased in peripheral blood from patients with rheumatoid arthritis.

Human CD4+ T cells can be classified as either naïve, central memory (TCM), or effector memory (TEM) cells. To identify the CD4+ T cell subsets most important in the pathogenesis of rheumatoid arthritis (RA), we phenotypically defined human CD4+ T cells as functionally distinct subsets, and analyzed the distribution and characteristics of each subset in the peripheral blood. We classified CD4+ T cells into six novel subsets based on the expression of CD45RA, CCR7, CD27, and CD28. The CCR7 + CD45RA-CD27 + CD28+ TCM subset comprised a significantly smaller proportion of CD4+ T cells in RA patients compared to healthy controls. The frequency of TNF-α-producing cells in the CCR7-CD45RA-CD27 + CD28+ TEM subset was significantly increased in RA. Furthermore, within the CCR7 + CD45RA-CD27 + CD28+ TCM subset, which was decreased in periperal blood from RA, the proportions of total Foxp3+ Treg cells and CD45RA-Foxp3(high) activated/effector Treg cells were significantly lower in RA patients. Our findings suggest that the increased proportion of TNF-α-producing cells and the decreased proportion of CD45RA-Foxp3(high) activated/effector Treg cells in particular subsets may have critical roles in the pathogenesis of RA.

Distribution and expression of fibroblast-specific protein chemokine CCL21 and chemokine receptor CCR7 in renal allografts.

We aimed to characterize the expression and distribution of the fibroblast surface protein (FSP), the chemokine CC-ligand 21 (CCL21) secondary lymphoid tissue chemokine CC-chemokine receptor 7 (CCR7) in renal allograft biopsy specimens obtained from patients after transplantation. We recruited 165 patients who received renal transplants at our center for this study. Histological examination of the renal allograft biopsy specimens was performed using hematoxylin-eosin, periodic acid-Schiff, and Masson's trichrome staining. Distribution and expression of FSP, CCL21, and CCR7 were determined using immunohistochemistry staining. Serum creatinine levels were evaluated using an enzymatic sarcosine oxidase method. FSP was mainly localized in the cytoplasm and nucleus of renal interstitial fibroblasts and tubular epithelial cells. Compared with the normal group, an elevated number of FSP-positive fibroblasts were observed in patients with acute/active cellular rejection and chronic/sclerosing allograft nephropathy (P < .05). Patients with chronic/sclerosing allograft nephropathy also showed increased total fibroblasts as compared with borderline changes (P < .05). In a multiple regression analysis, CCR7-positive expression was a strong protective factor for acute/active cellular rejection and recurrent nephropathy (odds ratio [OR] = 0.12, P = .034, and OR = 0.08; P = .036, respectively). In contrast, CCL21-positive expression led to a high susceptibility to recurrent nephropathy among renal transplant patients (OR = 10.41, P = .029). Moreover, FSP and CCL21, or CCL21 and CCR7 were localized in the interstitial fibroblasts and renal tubular epithelium cells. In addition, FSP and CCL21 expression positively correlated with serum creatinine levels. Our results suggested that the CCL21/CCR7 signaling pathway is involved in renal fibrosis in kidney transplant patients. An increased number of FSP-positive fibroblasts may be a risk factor for acute/active cellular rejection and chronic/sclerosing allograft nephropathy after renal transplantation. These findings may help understanding of renal allograft fibrosis.

Site-specific dynamics of CD11b+ and CD103+ dendritic cell accumulations following ozone exposure.

Pulmonary dendritic cells (DCs) are among the first responders to inhaled environmental stimuli such as ozone (O(3)), which has been shown to activate these cells. O(3) reacts with epithelial lining fluid (ELF) components in an anatomically site-specific manner dictated by O(3) concentration, airway flow patterns, and ELF substrate concentration. Accordingly, the anatomical distribution of ELF reaction products and airway injury are hypothesized to produce selective DC maturation differentially within the airways. To investigate how O(3) affects regional airway DC populations, we utilized a model of O(3)-induced pulmonary inflammation, wherein C57BL/6 mice were exposed to 0.8 ppm O(3) 8 h/day for 1, 3, and 5 days. This model induced mild inflammation and no remarkable epithelial injury. Tracheal, but not more distant airway sites, and mediastinal lymph node (MLN) DC numbers were increased significantly after the third exposure day. The largest increase in each tissue was of the CD103(+) DC phenotype. After 3 days of exposure, fewer DCs expressed CD80, CD40, and CCR7, and, at this same time point, total MLN T cell numbers increased. Together, these data demonstrate that O(3) exposure induced site-specific and phenotype changes in the pulmonary and regional lymph node DC populations. Possibly contributing to ozone-mediated asthma perturbation, the phenotypic changes to DCs within pulmonary regions may alter responses to antigenic stimuli. Decreased costimulatory molecule expression within the MLN suggests induction of tolerance mechanisms; increased tracheal DC number may raise the potential for allergic sensitization and asthmatic exacerbation, thus overcoming O(3)-induced decrements in costimulatory molecule expression.

Coexpression of CCR6 and CD146 (MCAM) is a marker of effector memory T-helper 17 cells.

Effector memory T (T(EM)) cells are a subpopulation of memory T cells that express receptors mediating migration to inflamed tissues and produce various cytokines. Effector memory T-helper (Th)17 (Th17(EM)) cells are thought to be essential for inflammation in Th17-mediated diseases, but have not been studied in detail. To identify superior surface markers to isolate a homogeneous population of Th17(EM) cells from peripheral blood, CD4(+) T cells were isolated from the peripheral blood of healthy donors based on the expression of CCR7, CCR6 and CD146 using six-color flow cytometry. After 4days of culture in the presence of anti-CD3/28 beads, intracellular cytokines were determined by flow cytometric analysis. To investigate the relevance of Th17(EM) cells in Th17-mediated disease, the frequencies of T(EM) -cell subsets in psoriasis were quantified using six-color flow cytometry. An enzyme-linked immunosorbent assay was performed to confirm the interleukin (IL)-17-producing capacity of T(EM) -cell subsets from the peripheral blood of a patient with psoriasis. CCR6(+) CD146(+) T(EM) (CD4(+) CD45RA(-) CCR7(-)) cells had a greater capacity to produce IL-17 than CCR6(+) CD146(-) or CCR6(-) CD146(+) T(EM) cells. Although the percentage of CCR6(+) CD146(+) cells in T(EM) cells was not significantly different between patients with psoriasis and controls, three of eight patients had a higher percentage of CCR6(+) CD146(+) T(EM) cells than the mean +5 standard deviations of the controls. Coexpression of CCR6 and CD146 is a useful marker for Th17(EM) cells. Increasing the number of CCR6(+) CD146(+) Th17(EM) cells in peripheral blood may facilitate estimation of systemic Th17-cell activity in Th17-mediated diseases.

Mycobacterium tuberculosis culture filtrate protein 10-specific effector/memory CD4⁺ and CD8⁺ T cells in tubercular pleural fluid, with biased usage of T cell receptor Vß chains.

T cell-mediated immunity is critical for the control of Mycobacterium tuberculosis infection. Identifying the precise immune mechanisms that lead to control of initial M. tuberculosis infection and preventing reactivation of latent infection are crucial for combating tuberculosis. However, a detailed understanding of the role of T cells in the immune response to infection has been hindered. In addition, there are few flow cytometry studies characterizing the Vß repertoires of T cell receptors (TCRs) at local sites of M. tuberculosis infection in adult tuberculosis. In this study, we used culture filtrate protein 10 (CFP-10) from M. tuberculosis to characterize T cells at local sites of infection. We simultaneously analyzed the correlation of the production of cytokines with TCR Vß repertoires in CFP-10-specific CD4(+) and CD8(+) T cell subsets. For the first time, we demonstrate that CFP-10-specific CD4(+) or CD8(+) T cells from tubercular pleural fluid can produce high levels of gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) and upregulate the expression of CD107a/b on the cell surface. The CFP-10-specific cells were effector/memory cells with a CD45RO(+) CD62L(-) CCR7(-) CD27(-) expression profile. In addition, we found CFP-10-specific CD4(+) and CD8(+) T cells in tubercular pleural fluid, with biased usage of TCR Vß9, Vß12, or Vß7.2. Our findings of CFP-10-specific CD4(+) and CD8(+) T cells in tubercular pleural fluid are critical for understanding the mechanisms of the local cellular immune response and developing more effective therapeutic interventions in cases of M. tuberculosis infection.

Steady state migratory RelB+ langerin+ dermal dendritic cells mediate peripheral induction of antigen-specific CD4+ CD25+ Foxp3+ regulatory T cells.

Tolerance to self-antigens expressed in peripheral organs is maintained by CD4(+) CD25(+) Foxp3(+) Treg cells, which are generated as a result of thymic selection or peripheral induction. Here, we demonstrate that steady-state migratory DCs from the skin mediated Treg conversion in draining lymph nodes of mice. These DCs displayed a partially mature MHC II(int) CD86(int) CD40(hi) CCR7(+) phenotype, used endogenous TGF-ß for conversion and showed nuclear RelB translocation. Deficiency of the alternative NF-κB signaling pathway (RelB/p52) reduced steady-state migration of DCs. These DCs transported and directly presented soluble OVA provided by s.c. implanted osmotic minipumps, as well as cell-associated epidermal OVA in transgenic K5-mOVA mice to CD4(+) OVA-specific TCR-transgenic OT-II T cells. The langerin(+) dermal DC subset, but not epidermal Langerhans cells, mediated conversion of naive OT-II×RAG-1(-/-) T cells into proliferating CD4(+) CD25(+) Foxp3(+) Tregs. Thus, our data suggest that steady-state migratory RelB(+) TGF-ß(+) langerin(+) dermal DCs mediate peripheral Treg conversion in response to epidermal antigen in skin-draining lymph nodes.

Placental macrophage (Hofbauer cell) polarization is independent of maternal allergen-sensitization and presence of chorioamnionitis.

BACKGROUND: Macrophages can polarize in which M1/classically activated and M2/alternatively activated macrophages are considered to be the extremes. M1 macrophages are involved in inflammatory reactions, while M2 macrophages are suggested to be involved in homeostasis, parasite killing, tumor promotion, tissue remodeling and in allergic reactions. We hypothesized that polarization of placental macrophages (Hofbauer cells) is influenced by the allergen-sensitization status of the mother and/or the presence of chorioamnionitis, a placental inflammation. This Hofbauer cell polarization might be associated to the intrauterine environment and influence the risk of allergy development for the child. Therefore we aimed to determine the polarization status of Hofbauer cells in health and disease. METHODS: We determined the expression of CD68, CX3CR1, IL-7R, DC-SIGN/CD209 and CD163 in placentas of sensitized versus non-sensitized mothers (n = 17), and placentas with or without histological chorioamnionitis (n = 10) by means of immunohistochemical analysis and quantitative real-time PCR (qPCR). RESULTS: Protein expression of the M1 markers (CX3CR1, IL-7R and CCR7) could not be detected in any of the analyzed samples while the M2 markers (DC-SIGN, CD163 and mannose receptor/CD206) were readily detected. Significant differences between non-sensitized versus sensitized mothers and uncomplicated versus chorioamnionitis complicated pregnancies were not detected at protein or at mRNA expression level. CONCLUSIONS: These results suggest that Hofbauer cells have an M2 phenotype, and that their polarization is not affected by maternal allergen-sensitization or by presence of chorioamnionitis.

Prostatectomy restores the maturation competence of blood dendritic cell precursors and reverses the abnormal expansion of regulatory T lymphocytes.

OBJECTIVE: To verify the presence of deviated dendritic cell (DC) precursors and of suppressor lymphocytes (Treg) in tumor bearing prostate cancer (PCa) patients and to monitor the corrective effect of tumor ablation. METHODS: Monocytes isolated from the blood of patients before and 1 month after prostatectomy were allowed to reach complete maturation (mDC) ex vivo in a clinical grade two-step process. T-regulatory cells were identified in the lymphocyte cell fraction by the CD4(+)CD25(high)FoxP3(+)/CD4(+)CD25(high)CD127(low/-) phenotype. RESULTS: Despite loss of the monocytes marker CD14, cytokine-matured DCs of tumor bearing patients expressed lower levels of the costimulatory molecule CD80 and of the maturation markers CD83 and CCR7 compared to mDC of normal subjects (NS, P = 0.001, 0.001, and 0.008, respectively). Prostatectomy restored CD80, CD83, and CCR7 expression to values not different from those of NS (P = 0.15, 0.60, and 0.71) and significantly higher than those of the pre-surgery state (CD83, P = 0.0003 and CCR7, P = 0.002). The frequency of Tregs, identified as either CD4 + CD25(high)FoxP3(+) or CD4(+)CD25(high)CD127(low/-), was significantly higher in pre-surgery patients than in NS (P = 0.0001 and 0.0003) and significant recovery of the CD4(+)CD25(high)CD127(low/-) (P = 0.0005) was observed after surgery. CONCLUSIONS: The presence of defective DC precursors and suppressor lymphocytes in the tumor-bearing, but not tumor-free stage, positions the latter as the ideal setting for clinical success of PCa vaccine therapy.