CCR6 expression reduces mouse survival upon malarial challenge with Plasmodium berghei NK65 strain.

BACKGROUND: It has been demonstrated that proteins expressed by liver-stage Plasmodium parasites can inhibit the translocation of transcription factors to the nucleus of different cells. This process would hinder the expression of immune genes, such as the CCL20 chemokine. OBJECTIVE: Since CCR6 is the only cognate receptor for CCL20, we investigated the importance of this chemokine-receptor axis against rodent malaria. METHODS: CCR6-deficient (KO) and wild-type (WT) C57BL/6 mice were challenged with Plasmodium berghei (Pb) NK65 sporozoites or infected red blood cells (iRBCs). Liver parasitic cDNA, parasitemia and serum cytokine concentrations were respectively evaluated through reverse transcription-polymerase chain reaction (RT-PCR), staining thin-blood smears with Giemsa solution, and enzyme-linked immunosorbent assay (ELISA). FINDINGS: Although the sporozoite challenges yielded similar liver parasitic cDNA and parasitemia, KO mice presented a prolonged survival than WT mice. After iRBC challenges, KO mice kept displaying higher survival rates as well as a decreased IL-12 p70 concentration in the serum than WT mice. CONCLUSION: Our data suggest that malaria triggered by PbNK65 liver- or blood-stage forms elicit a pro-inflammatory environment that culminates with a decreased survival of infected C57BL/6 mice.

Involvement of Th1Th17 Cell Subpopulations in the Immune Responses of Mothers Who Gave Birth to Children with Congenital Zika Syndrome (CZS).

High levels of T helper 17 cell (Th17)-related cytokines have been shown in acute Zika virus (ZIKV) infection. We hypothesized that the high levels of Th17-related cytokines, associated with a regulatory environment during pregnancy, create a favorable milieu for the differentiation of CD4+Th17 cells. We present data from a cross-sectional study on mothers who confirmed ZIKV infection by qRT-PCR and their children. We also recruited non-pregnant women infected with ZIKV in the same period. ZIKV infection occurred between 2015 and 2017. We collected samples for this study between 2018 and 2019, years after the initial infection. We highlight that, after in vitro stimulation with ZIKV CD4 megapool (ZIKV MP), we found a lower frequency of IL-17-producing CD4+ T cells (Th17), especially in the mothers, confirmed by the decrease in IL-17 production in the supernatant. However, a higher frequency of CD4+ IL-17+ IFN-γ+ T cells (Th1Th17) responding to the ZIKV MP was observed in the cells of the mothers and children but not in those of the non-pregnant women. Our data indicate that the priming of CD4 T cells of the Th1Th17 phenotype occurred preferentially in the mothers who gave birth to children with CZS and in the children.

A prognostic value of CD45RA+, CD45RO+, CCL20+ and CCR6+ expressing cells as 'immunoscore' to predict cervical cancer induced by HPV.

The interplay between cervical cancer (CC) and immune cells, mainly intratumoral lymphocytes, has a pivotal role in carcinogenesis. In this context, we evaluated the distribution of CD45RA+ and CD45RO+ cells as well as CCR6+ and CCL20+ cells in intraepithelial (IE) and marginal stroma (MS) areas from cervical intraepithelial neoplasia (CIN) I-III, and CC as 'immunoscore' for HPV-induced CC outcome. We observed increased CD45RA+ and CD45RO+ cells distribution in IE and MS areas in the CC group compared to CIN groups and healthy volunteers. Interestingly, there is a remarkable reduction of CCL20+ expressing cells distribution according to lesion severity. The CC group had a significant decrease in CCL20+ and CCR6+-expressing cells distribution in both IE and MS areas compared to all groups. Using the 'immunoscore' model, we observed an increased number of women presenting high CD45RA+/CD45RO+ and low CCL20+/CCR6+ 'immunoscore' in the CC group. Our results suggested a pattern in cervical inflammatory process with increasing CD45RA+/CD45RO+, and decreasing CCL20+/CCR6+ expression in accordance with CIN severity. Taken together, these markers could be evaluated as 'immunoscore' predictors to CC response. A more comprehensive analysis of longitudinal studies should be conducted to associate CD45RA+/CD45RO+ and CCL20+/CCR6+ 'immunoscore' to CC progression and validate its value as a prognosis method.

Differential expression of CXCR3 and CCR6 on CD4+ T-lymphocytes with distinct memory phenotypes characterizes tuberculosis-associated immune reconstitution inflammatory syndrome.

Immune reconstitution inflammatory syndrome (IRIS) occurs in up to 40% of individuals co-infected with pulmonary tuberculosis (PTB) and HIV, primarily upon antiretroviral therapy (ART) initiation. Phenotypic changes in T-cells during TB-IRIS and their relationship with systemic inflammation are not fully understood. In this prospective cohort study, we followed 48 HIV-positive patients with PTB from South India before and after ART initiation, examining T-lymphocyte subsets and inflammatory biomarkers in peripheral blood. Quantification of naïve (CD27+CD45RO-) as well as effector memory CD4+ T cells (CD27-CD45RO+) at weeks 2-6 after ART initiation could distinguish TB-IRIS from non-IRIS individuals. Additional analyses revealed that ART reconstituted different quantities of CD4+ T lymphocyte subsets with preferential expansion of CXCR3+ CCR6- cells in TB-IRIS patients. Moreover, there was an expansion and functional restoration of central memory (CD27+CD45RO+) CXCR3+CCR6- CD4+ lymphocytes and corresponding cytokines, with reduction in CXCR3-CCR6+ cells after ART initiation only in those who developed TB-IRIS. Together, these observations trace a detailed picture of CD4+ T cell subsets tightly associated with IRIS, which may serve as targets for prophylactic and/or therapeutic interventions in the future.

Evaluation of parasite and host genetics in two generations of a family with Chagas disease.

Chagas disease, caused by the protozoan Trypanosoma cruzi, is considered to be a multifactorial disease associated with host and parasite genetics, which influence clinical aspects of the disease and other host conditions. In order to understand better the evolution of the disease, this study intended to evaluation of parasite and host genetics in two generations of a family with Chagas disease from the Alto Paranaiba region, Minas Gerais, Brazil, comprising a mother and her five daughters. Several features were evaluated, including the characterization of T. cruzi directly from the blood of patients, host polymorphisms of genes related to cardiomyopathy (TNF, WISP1, CCR5, and TGF-ß1) and clinical aspects of the patients. To verify the intraspecific variability of the parasite, the characterization was done directly from human blood using the PCR-LSSP technique and analyzed based on Dice coefficient and unweighted pair group analysis (UPGMA). The host polymorphism was evaluated by PCR-RFLP. The global results showed low variability of the parasites characterized from blood of patients, through Shannon index (0.492) and mean heterozygosity value per locus (0.322). All six patients presented the same genetic polymorphism profile for TNF, WISP1, and TGF-ß1, and only one patient was homozygous to CCR5, which suggests that there is no association between the clinical aspects of the patients and their genetic profiles. In conclusion, the findings confirm that the understanding of the clinical evolution of Chagas disease goes beyond the genetic aspects of the parasite and the host.

In vitro chemokine (C-C motif) receptor 6-dependent non-inflammatory chemotaxis during spermatogenesis.

BACKGROUND: Chemokine (C-C motif) receptor 6 (CCR6) is present in sperm and plays a significant role in sperm motility and chemotaxis acting in the reproductive tracts. However, the expression and functional significance of CCR6 in testis are still poorly understood, especially in the process of spermatogenesis. METHODS AND RESULTS: CCR6 was expressed in spermatogenic cell lines and its expression was shown in an age-dependent upregulation manner from puberty to adulthood in mouse testis. Immunostaining results confirmed the localization of CCR 6 in testis. Further chemotaxis assays demonstrated that spermatogenic cells GC-1 and -2 exhibited a directional movement toward CCR6-specific ligand such as CCL20 or Sertoli cells in vitro. CONCLUSIONS: The present findings indicate that CCR6 is involved in the chemotaxis of spermatogenic cells in vitro and promotes chemotaxis under non-inflammatory conditions during normal spermatogenesis.

In vitro chemokine (C-C motif) receptor 6-dependent non-inflammatory chemotaxis during spermatogenesis

BACKGROUND: Chemokine (C-C motif) receptor 6 (CCR6) is present in sperm and plays a significant role in sperm motility and chemotaxis acting in the reproductive tracts. However, the expression and functional significance of CCR6 in testis are still poorly understood, especially in the process of spermatogenesis. METHODS AND RESULTS: CCR6 was expressed in spermatogenic cell lines and its expression was shown in an age-dependent upregulation manner from puberty to adulthood in mouse testis. Immunostaining results confirmed the localization of CCR 6 in testis. Further chemotaxis assays demonstrated that spermatogenic cells GC-1 and -2 exhibited a directional movement toward CCR6-specific ligand such as CCL20 or Sertoli cells in vitro. CONCLUSIONS: The present findings indicate that CCR6 is involved in the chemotaxis of spermatogenic cells in vitro and promotes chemotaxis under non-inflammatory conditions during normal spermatogenesis.

Unbalanced expression of aryl hydrocarbon receptor in peripheral blood CCR6+CD4+ and CD4+CD25+T cells of rheumatoid arthritis.

OBJECTIVE: The goal of this study was to analyze the role of aryl hydrocarbon receptor in peripheral blood CCR6+CD4+ and CD4+CD25+T cells of patients with rheumatoid arthritis. METHODS: Flow cytometry was applied to determine the proportion of AhR positive cells in CCR6+CD4+T, CD4+CD25+T and peripheral blood peripheral mononuclear cells from each subject. AhR mRNA and CYP1A1 mRNA relative expression levels were tested by real-time PCR. RESULTS: The percentage of AhR positive cells in peripheral blood mononuclear cells was higher in RA group than that in healthy cases [(35.23±10.71)% vs. (18.83±7.32)%, p<0.01]. The expression levels of AhR and CYP1A1 were both increased in patients with RA while compared to controls [(3.71±1.63) vs. (2.00±1.27), p=0.002; (2.62±2.08) vs. (0.62±0.29), p<0.01, respectively]. In RA patients, the percentage of AhR positive cells in CD4+CD25+T cells was significantly lower than that from controls [17.90 (6.10±80.10)% vs. (52.49±19.18)%, p<0.01]; In healthy controls, the percentage of AhR positive cells in CD4+CD25+T cells was significantly higher than that in CCR6+CD4+T cells, and was also significantly higher than that in PBMCs [(52.49±19.18)% vs. (23.18±5.62)% vs. (18.06±7.80)%, X2=24.03, p<0.01]; in RA patients, the percentage of AhR positive cells in CCR6+CD4+T cells was significantly increased than that in CD4+CD25+T cells and PBMCs [(46.02±14.68)% vs. 17.90 (6.10±80.10)% vs. (34.22±10.33)%, X2=38.29, p<0.01]; Nevertheless, no statistically significant relationship was found between clinical data and AhR positive cells in CCR6+CD4+T and CD4+CD25+T cells. CONCLUSION: AhR may participate in the pathological progress of RA by controlling the differentiation of Th17 and Treg cells in peripheral blood.

Unbalanced expression of aryl hydrocarbon receptor in peripheral blood CCR6+CD4+ and CD4+CD25+T cells of rheumatoid arthritis / Expressão não equilibrada do receptor de hidrocarboneto arílico nos linfócitos T CCR6+ CD4+ e CD4+ CD25+ do sangue periférico na artrite reumatoide

ABSTRACT Objective: The goal of this study was to analyze the role of aryl hydrocarbon receptor in peripheral blood CCR6+CD4+ and CD4+CD25+T cells of patients with rheumatoid arthritis. Methods: Flow cytometry was applied to determine the proportion of AhR positive cells in CCR6+CD4+T, CD4+CD25+T and peripheral blood peripheral mononuclear cells from each subject. AhR mRNA and CYP1A1 mRNA relative expression levels were tested by real-time PCR. Results: The percentage of AhR positive cells in peripheral blood mononuclear cells was higher in RA group than that in healthy cases [(35.23 ± 10.71)% vs. (18.83 ± 7.32)%, p < 0.01]. The expression levels of AhR and CYP1A1 were both increased in patients with RA while compared to controls [(3.71 ± 1.63) vs. (2.00 ± 1.27), p = 0.002; (2.62 ± 2.08) vs. (0.62 ± 0.29), p < 0.01, respectively]. In RA patients, the percentage of AhR positive cells in CD4+CD25+T cells was significantly lower than that from controls [17.90 (6.10 ± 80.10)% vs. (52.49 ± 19.18)%, p < 0.01]; In healthy controls, the percentage of AhR positive cells in CD4+CD25+T cells was significantly higher than that in CCR6+CD4+T cells, and was also significantly higher than that in PBMCs [(52.49 ± 19.18)% vs. (23.18 ± 5.62)% vs. (18.06 ± 7.80)%, X 2 = 24.03, p < 0.01]; in RA patients, the percentage of AhR positive cells in CCR6+CD4+T cells was significantly increased than that in CD4+CD25+T cells and PBMCs [(46.02 ± 14.68)% vs. 17.90 (6.10 ± 80.10)% vs. (34.22 ± 10.33)%, X 2 = 38.29, p < 0.01]; Nevertheless, no statistically significant relationship was found between clinical data and AhR positive cells in CCR6+CD4+T and CD4+CD25+T cells. Conclusion: AhR may participate in the pathological progress of RA by controlling the differentiation of Th17 and Treg cells in peripheral blood.

RESUMO Objetivo: Analisar o papel do receptor de hidrocarboneto arílico (AhR) nos linfócitos T CCR6+ CD4+ e CD4+ CD25+ no sangue periférico de pacientes com artrite reumatoide (AR). Métodos: Foi aplicada citometria de fluxo para determinar a proporção de células AhR positivas em linfócitos CCR6+ CD4+ e CD4+ CD25+ do sangue periférico e células mononucleares periféricas de cada indivíduo. Os níveis de expressão relativa de ácido ribonucleico mensageiro (do inglês ribonucleic acid, RNAm,) de AhR e RNAm de enzima de primeiro estágio essencial para o AhR (CYP1A1) foram testados por reação em cadeia de polimerase (do inglês polymerase chain reaction, PCR,) em tempo real. Resultados: A percentagem de células AhR positivas nas células mononucleares do sangue periférico foi maior no grupo com AR do que nos indivíduos saudáveis [(35,23 ± 10,71)% vs. (18,83 ± 7,32)%, (p < 0,01)]. Os níveis de expressão de AhR e CYP1A1 estavam aumentados em pacientes com AR quando comparados com os controles [(3,71 ± 1,63) vs. (2,00 ± 1,27), p = 0,002; (2,62 ± 2,08) vs. (0,62 ± 0,29), p < 0,01, respectivamente]. Em pacientes com AR, a percentagem de células AhR positivas nos linfócitos T CD4+ CD25+ foi significativamente inferior à dos controles [17,90 (6,10 ± 80,10)]% vs. (52,49 ± 19,18)%, p < 0,01]; em controles saudáveis, a percentagem de células AhR positivas nos linfócitos T CD4+ CD25+ foi significativamente mais elevada do que nos linfócitos T CCR6+ CD4+ e também foi significativamente maior do que nas células mononucleares do sangue periférico (do inglês peripheral blood mononuclear cells, PBMC,) [(52,49 ± 19,18)% vs. (23,18 ± 5,62)% vs. (18,06 ± 7,80)%, X 2 = 24,03, p < 0,01]; em pacientes com AR, a percentagem de células AHR positivas nos linfócitos T CCR6+ CD4+ era significativamente maior em comparação com os linfócitos T CD4+ CD25+ e PBMC (46,02 ± 14,68)% vs. [17,90 (6,10 ± 80.10)]% vs. (34,22 ± 10,33)%, X2 = 38,29, p < 0,01]; no entanto, não foi encontrada correlação estatisticamente significativa entre os dados clínicos e células AhR positivas em linfócitos T CCR6+ CD4+ e CD4+ CD25+. Conclusão: O Ahr pode participar do progresso patológico da AR ao controlar a diferenciação de linfócitos Th17 e Treg no sangue periférico.

Follicular helper T cells in peripheral blood of patients with rheumatoid arthritis. / Células T helper foliculares en sangre periférica de pacientes con artritis reumatoide.

INTRODUCTION: Rheumatoid arthritis (RA) is a chronic autoimmune disease that is characterized by the presence of different autoantibodies such as rheumatoid factor (RF) and anti-citrullinated protein antibodies. CD4T cells expressing CXCR5, referred as follicular helper T cells (Tfh), collaborate with B cells to produce antibodies. Differential expression of CXCR3 and CCR6 within CD4+CXCR5+ T cells defines three mayor subsets: CXCR3+CCR6- (Tfh1), CXCR3-CCR6- (Tfh2) and CXCR3-CCR6+ (Tfh17). The aim of the study was to assess whether there is an association between the percentage of these cells and RA and whether there is a correlation with disease activity. MATERIAL AND METHODS: Twenty-four RA patients, 22 healthy controls (HC) and 16 undifferentiated arthritis (UA) patients were included. Percentage of CD4+CXCR5+ T cells and their subsets were analyzed by flow cytometry. RESULTS: No differences were found in the percentages of CD4+CXCR5+ T cells in the comparison of RA vs HC or RA vs UA patients. Tfh1, Tfh2 and Tfh17 subsets showed no differences either. There was no correlation between CD4+CXCR5+T cells, Tfh1, Tfh2 and Tfh17, and Disease Activity Score in twenty-eight joints (DAS28) or erythrocyte sedimentation rate. Surprisingly, there was a positive correlation between Tfh17 cells and C-reactive protein. Finally, there was no correlation between CD4+CXCR5+ T cells, or their subsets, and anti-mutated citrullinated vimentin, or between the cells and RF. CONCLUSION: There were no differences between the percentages of CD4+CXCR5+ T cells and their subsets in peripheral blood of RA patients and the percentages of cells in the control groups. This finding does not rule out a pathogenic role of these cells in the development and activity of RA.

CCR6 overexpression predicted advanced biological behaviors and poor prognosis in patients with gastric cancer.

BACKGROUND: CCR6 expression is deregulated in some human malignancies and may be involved in the tumor progression. The aim of the present study was to determine the CCR6 expression in gastric cancer (GC) and to clarify its clinical significance. METHODS: We used western blotting to examine CCR6 protein expression in GC tissues and matched adjacent non-tumor tissues. Immunohistochemistry was performed on a large cohort of 372 postoperative GC samples. Chi-square test, Kaplan-Meier analysis and Cox regression model were used to analyze the data. RESULTS: Upregulated CCR6 protein expression was observed in the GC tissues by western blotting compared with the adjacent non-cancerous gastric tissues. High CCR6 expression was detected in 56.5 % (210/372) samples and significantly associated with the extracapsular extension of the tumor, tumor relapse and poor overall survival in GC (P < 0.001). Further analysis demonstrated that the CCR6 expression level stratified the patient outcome in stage II, stage III, T3/4, N positive and poorly differentiated/undifferentiated tumor subgroups. The Cox regression analysis showed that high expression of CCR6 was an independent prognostic factor for GC patients. CONCLUSIONS: CCR6 expression may be a novel biomarker for predicting clinical outcomes for GC patients.

Effect of NB-UVB on levels of MCP-1 and CCR6 mRNA in patients with psoriasis vulgaris.

The aim of this study is to explore the effect of narrow band ultraviolet B (NB-UVB) on the chemokine receptor CCR6 mRNA levels in patients with psoriasis. Psoriasis area and severity index (PASI) values were recorded before and after the treatment with NB-UVB phototherapy of 30 psoriasis vulgaris patients. The reverse transcription-polymerase chain reaction method was used to detect the expression level of CCR6 mRNA in peripheral blood mononuclear cells, and compared with 30 healthy subjects. The PASI value of the 30 psoriasis vulgaris patients decreased significantly after 15 iterations of phototherapy treatment (P < 0.01). The expression level of CCR6 mRNA in psoriasis patients was significantly higher than in the healthy controls (P < 0.01), while the expression level of CCR6 mRNA decreased significantly after phototherapy (P < 0.01). Reduction of CCR6 level may be one of the mechanisms through which NB-UVB can treat psoriasis.

Regulation of CD4⁺FOXP3⁺ T cells by CCL20/CCR6 axis in early unexplained recurrent miscarriage patients.

Expression and function of CCR6/CCL20 in CD4(+)FOXP3(+) regulatory T cells (Tregs) was investigated in unexplained recurrent miscarriage (URM) patients. Flow cytometry, reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assay, western blots, and Transwell migration assays were used to analyze the expression and function of regulatory T cells in peripheral blood (PB) and decidual samples of women with URM and of healthy controls. Proportions of CD4(+)FOXP3(+) T cells and CCR6(+)CD4(+)FOXP3(+) T cells were lower in URM patients than in healthy controls for both PB lymphocytes and decidual samples (P < 0.05). Expression levels of FOXP3 and CCR6 mRNA were lower in URM patients than in control subjects for PB and decidual samples (P < 0.05). CCL20 protein levels were lower in URM patients than in controls (P < 0.05). An effect of Treg migration was significantly blocked (by 89.13%) using a neutralizing anti-CCL20 antibody in vitro. Furthermore, CCL20-stimulated Tregs exhibited a 3.21-fold increase in migration and this was blocked using a neutralizing anti-CCL20 antibody. IL-10 concentration in culture supernatants of CD4(+)CD25(+)CD127(dim/-) Tregs of URM patients was significantly lower than that in controls. Anti-CCL20 antibody inhibited IL-10 and IL-4 expression but increased IFN-r and IL-17 levels when there was cell-cell contact between PB CD4(+)CD25(+) T cells and CD4(+)CD25(-) T cells. No difference was detected when cell-cell contact was prevented by a semi-permeable Transwell membrane. CCL20-CCR6 could drive immune activity of CD4(+)FOXP3(+) Tregs, followed by their migration to the feto-maternal microenvironment. These results elucidated the mechanism by which Tregs exert this suppressive effect.

Quantitative T cell subsets profile in peripheral blood from patients with idiopathic inflammatory myopathies: tilting the balance towards proinflammatory and pro-apoptotic subsets.

The role of T cells in idiopathic inflammatory myopathies (IIM) is not yet clear. Some alterations in certain subsets have been reported in inflamed muscle cells. However, a broad quantitative assessment of peripheral T cell subsets has not been evaluated. The aim of this study was to address the quantitative profile of potential pathogenic T cell subsets, namely follicular helper T cells (Tfh), T helper type 17 (Th17), CD28(null) and regulatory T cells (Tregs ) in peripheral blood from IIM patients. Thirty IIM patients and 30 age- and gender-matched healthy donors were included. Peripheral blood mononuclear cells were isolated. T cell subsets were evaluated by flow cytometry, as follows: Tfh (CD4(+) CXCR5(+) ) and its subsets Tfh1 (CXCR3(+) CCR6(-) ), Tfh2 (CXCR3(-) CCR6(-) ), Tfh17 (CXCR3(-) CCR6(+) ), Th17 (CD4(+) IL17A(+) ), CD28(null) (CD4(+) CD28(-) CD244(+) ) and Tregs (CD4(+) CD25(high) forkhead box protein 3 (FoxP3(+) ); CD8(+) CD25(high) FoxP3(+) ). Percentage, absolute numbers and mean fluorescence intensity were analysed. We found increased numbers of total Tfh cells (28 ± 8.16 versus 6.64 ± 1.29, P=0.031) in IIM patients when compared to healthy controls. Moreover, this increment was dependent upon Tfh2 and Tfh17 (Tfh2:9.49 ± 2.19 versus 1.66 ± 0.46, P=0.005; Tfh17 9.48 ± 2.83 versus 1.18 ± 0.21, P=0.014). Also, IIM patients showed higher numbers of Th17 cells (30.25 ± 6.49 versus 13.46 ± 2.95, P=0.031) as well as decreased number of Tregs (5.98 ± 1.61 versus 30.82 ± 8.38, P=0.009). We also found an expansion of CD28(null) cells (162.88 ± 32.29 versus 64 ± 17.35, P=0.015). Our data suggest that IIM patients are characterized by an expansion of peripheral proinflammatory T cells, such as Tfh and Th17, as well as pro-apoptotic CD28 null cells and a deficiency of suppressor populations of Tregs (CD4(+) and CD8(+) ).

Variability of the dendritic cell response triggered by different serotypes of Aggregatibacter actinomycetemcomitans or Porphyromonas gingivalis is toll-like receptor 2 (TLR2) or TLR4 dependent.

BACKGROUND: Different serotypes of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis have been shown to induce differential dendritic cell (DC) responses. This study investigates whether cytokine and CC-chemokine receptor (CCR) production by DCs stimulated with different serotypes of A. actinomycetemcomitans or P. gingivalis is Toll-like receptor 2 (TLR2) and/or TLR4 dependent. METHODS: DCs were obtained from healthy individuals and primed at a multiplicity of infection (MOI) of 10(2) with different A. actinomycetemcomitans or P. gingivalis serotypes in the presence or absence of anti-TLR2 or anti-TLR4 blocking antibodies. TLR2 and TLR4 expression, CCR5 and CCR6 expression, and interleukin (IL)-1ß, IL-10, IL-12, and IL-23 expression and secretion were quantified by flow cytometry, real-time reverse-transcription polymerase chain reaction, and enzyme-linked immunosorbent assay. RESULTS: When DCs were stimulated with serotype b of A. actinomycetemcomitans or serotype K1 of P. gingivalis, higher levels of TLR2 or TLR4, respectively, were detected compared to DCs stimulated with the other serotypes. Similarly, higher levels of cytokines and CCRs were detected in serotype b- or serotype K1-primed DCs compared to the others, and these increased levels positively correlated with levels of TLR2 or TLR4. When TLR2 signaling was blocked using a specific anti-TLR2 monoclonal antibody, serotype b-induced cytokine and CCR expression was inhibited; when TLR4 signaling was blocked, serotype K1-induced response was inhibited. CONCLUSIONS: These results demonstrate that the variability of secretion of cytokines and expression of CCRs detected in DCs stimulated with different serotypes of A. actinomycetemcomitans or P. gingivalis is TLR2 or TLR4 dependent, respectively.

Enrichment of regulatory T cells in invasive breast tumor correlates with the upregulation of IL-17A expression and invasiveness of the tumor.

Breast cancer is a leading cause of neoplasia-associated death in women worldwide. Regulatory T (Treg) and Th17 cells are enriched within some tumors, but the role these cells play in invasive ductal carcinoma (IDC) of the breast is unknown. We show that CD25(+) CD4(+) T cells from PBMCs and tumor express high levels of Foxp3, GITR, CTLA-4, and CD103, indicating that tumor-infiltrating Treg cells are functional and possibly recruited by CCL22. Additionally, we observed upregulation of Th17-related molecules (IL-17A, RORC, and CCR6) and IL-17A produced by tumor-infiltrating CD4(+) and CD8(+) T lymphocytes. The angiogenic factors CXCL8, MMP-2, MMP-9, and vascular endothelial growth factor detected within the tumor are possibly induced by IL-17 and indicative of poor disease prognosis. Treg and Th17 cells were synchronically increased in IDC patients, with positive correlation between Foxp3, IL-17A, and RORC expression, and associated with tumor aggressiveness. Therefore, Treg and Th17 cells can affect disease progression by Treg-cell-mediated suppression of the effector T-cell response, as indicated by a decrease in the proliferation of T cells isolated from PBMCs of IDC patients and induction of angiogenic factors by IL-17-producing Th17. The understanding of regulation of the Treg/Th17 axis may result in novel perspectives for the control of invasive tumors.

CCL25 induces α4ß7 integrin-dependent migration of IL-17⁺ γδ T lymphocytes during an allergic reaction.

Herein, we provide evidence that during allergic inflammation, CCL25 induces the selective migration of IL-17(+) γδ T cells mediated by α(4) ß(7) integrin. Intrapleural injection of CCL25 into ovalbumin (OVA)-immunized C57BL/6 mice triggered the accumulation of γδ T lymphocytes expressing CCR9 (CCL25 receptor) and α(4) ß(7) integrin in the pleura, but failed to attract αß T lymphocytes. CCL25 attracted CCR6(+) γδ T cells producing IL-17 (but not IFN-γ or IL-4). OVA challenge triggered increased production of CCL25 followed by the accumulation of CCR9(+) , α(4) ß(7) (+) , and CCR6(+) /IL-17(+) γδ T cells into the pleural cavities of OVA-immunized mice, which was inhibited by the in vivo neutralization of CCL25. The in vivo blockade of α(4) ß(7) integrin also inhibited the migration of IL-17(+) γδ T lymphocytes (but not of αß T lymphocytes) into mouse pleura after OVA challenge, suggesting that the CCL25/α(4) ß(7) integrin pathway is selective for γδ T cells. In addition, α(4) ß(7) integrin blockade impaired the in vitro transmigration of γδ T cells across endothelium (which expresses α(4) ß(7) ligands VCAM-1 and MadCAM-1), which was induced by CCL25 and by cell-free pleural washes recovered from OVA-challenged mice. Our results reveal that during an allergic reaction, CCL25 drives IL-17(+) γδ T-cell mobilization to inflamed tissue via α(4) ß(7) integrin and modulates IL-17 levels.

Human mucosal leishmaniasis: neutrophils infiltrate areas of tissue damage that express high levels of Th17-related cytokines.

Mucosal leishmaniasis (ML) is characterised by severe tissue destruction. Herein, we evaluated the involvement of the IL-17-type response in the inflammatory infiltrate of biopsy specimens from 17 ML patients. IL-17 and IL-17-inducing cytokines (IL-1ß, IL-23, IL-6 and TGF-ß) were detected by immunohistochemistry in ML patients. IL-17(+) cells exhibited CD4(+), CD8(+) or CD14(+) phenotypes, and numerous IL-17(+) cells co-expressed the CC chemokine receptor 6 (CCR6). Neutrophils, a hallmark of Th17-mediated inflammation, were regularly detected in necrotic and perinecrotic areas and stained positive for neutrophil elastase, myeloperoxidase and MMP-9. Taken together, these observations demonstrate the existence of Th17 cells in ML lesions associated with neutrophils in areas of tissue injury and suggest that IL-17 is involved in ML pathogenesis.

Simian immunodeficiency virus dramatically alters expression of homeostatic chemokines and dendritic cell markers during infection in vivo.

Dendritic cells (DCs) are potent antigen-presenting cells that likely play multiple roles in human immunodeficiency virus type 1 (HIV-1) pathogenesis. We used the simian immunodeficiency virus (SIV)/macaque model to study the effects of infection on homeostatic chemokine expression and DC localization directly in secondary lymphoid tissues. SIV infection altered the expression of chemokines (CCL19/MIP-3beta, CCL21/ 6Ckine, and CCL20/MIP-3alpha) and of chemokine receptors (CCR7 and CCR6) that drive DC trafficking. CCL19/MIP-3beta, CCL20/MIP-3alpha, CCR6, and CCR7 expression increased in lymph nodes during the early systemic burst of viral replication (acute infection), whereas CCL21/6Ckine expression progressively decreased throughout disease to AIDS. Parallel with the SIV-induced perturbations in chemokine expression were changes in the expression of the DC-associated markers, DC-SIGN, DC-LAMP, and DECTIN-1. During AIDS, DC-LAMP mRNA expression levels were significantly reduced in lymph nodes and spleen, and DC-SIGN levels were significantly reduced in spleen. These findings suggest that the disruption of homeostatic chemokine expression is responsible, in part, for alterations in the networks of antigen-presenting cells in lymphoid tissues, ultimately contributing to systemic immunodeficiency.

Early inflammatory markers in elicitation of allergic contact dermatitis.

BACKGROUND: Allergic Contact Dermatitis (ACD) is regarded as a T-cell-mediated delayed-type hypersensitivity reaction. We studied the kinetics of the expression of CS-1 fibronectin, thymus and activation-regulated chemokine (CCL17/ TARC) and different chemokine receptors (CR) in skin biopsies from individuals suffering from back problems, with the antigen responsible of their contact dermatitis and an irrelevant antigen. METHODS: Samples were taken at 2, 10, and 48 hours for histological and immunohistochemical studies using monoclonal antibodies against human CS-1 fibronectin, CCL17, CD3, CD68, CD49d, CXCR3, CCR5, and CCR3. RESULTS: At positive antigen stimulated sites there was an early expression of CS-1 fibronectin (2 hours), followed by CCL17 and a later accumulation of alplha4/beta1+ (CD49d), CD3+, CD68+, CXCR3+ and CCR5+ mononuclear cells. At 48 hours, approximately 59 % of infiltrating cells were CXCR3+, 42% CCR5+, and only 14 % CCR3+. CONCLUSIONS: These results showed for the first time a very early expression of CS-1 fibronectin which preceded production of CCL17 in blood endothelial cells (BCEs) from patients' skin with ACD. The role of these molecules in recruitment of monocytes and effector T cells in ACD is discussed.