Dendritic cells (DCs) play a crucial role in the immune responses against infections by sensing microbial invasion through toll-like receptors (TLRs). In humans, two distinct DC subsets, CD11c− plasmacytoid DCs (PDCs) and CD11c+ myeloid DCs (MDCs), have been identified and can respond to different TLR ligands, depending on the differential expression of cognate TLRs. In this study, we have examined the effect of TLR-7 ligands on human DC subsets. Both subsets expressed TLR-7 and could respond to TLR-7 ligands, which enhanced the survival of the subsets and upregulated the surface expression of costimulatory molecules such as CD40, CD80, and CD86. However, the cytokine induction pattern was distinct in that PDCs and MDCs produced interferon (IFN)-α and interleukin (IL)-12, respectively. In response to TLR-7 ligands, the Th1 cell supporting ability of both DC subsets was enhanced, depending on the cytokines the respective subsets produced. This study demonstrates that TLR-7 exerts its biological effect in a DC subset-specific manner.
Abstract-Peripheral blood (PB)-derived CD14ϩ monocytes were shown to transdifferentiate into endothelial cell (EC) lineage cells and contribute to neovascularization. We investigated whether bone marrow (BM)-or PB-derived CD34 Ϫ /CD14 ϩ cells are involved in reendothelialization after carotid balloon injury. Although neither hematopoietic nor mesenchymal stem cells were included in human BM-derived CD34 Ϫ /CD14 ϩ monocyte lineage cells (BM-MLCs), they expressed EC-specific markers (Tie2, CD31, VE-cadherin, and endoglin) to an extent identical to mature ECs. When BM-MLCs were cultured with vascular endothelial growth factors, hematopoietic markers were drastically decreased and new EC-specific markers (Flk and CD34) were induced. BM-MLCs were intra-arterially transplanted into balloon-injured arteries of athymic nude rats. When BM-MLCs were activated by monocyte chemoattractant protein-1 (MCP-1) in vivo or in vitro, they adhered onto injured endothelium, differentiated into EC-like cells by losing hematopoietic markers, and inhibited neointimal hyperplasia. Ability to prevent neointimal hyperplasia was more efficient than that of BM-derived CD34
Diffuse large B cell lymphoma (DLBL) constitutes the greatest percentage of adult non-Hodgkin's lymphomas and represents a diverse spectrum of lymphoid neoplasms. Clinicopathologic, phenotypic and genotypic findings were correlated and compared for 63 DLBL cases to investigate whether they represent clinically relevant subtypes. They were all cyclin D1 negative and were phenotypically divided into three groups, ie group I (CD5 + type, n = 11), group II (CD5 − CD10 + type, n = 19), and group III (CD5 − CD10 − type, n = 33). Data were correlated by observing the respective gene rearrangement and expression of BCL2 and BCL6. In clinical aspects, the group I cases demonstrated a significantly inferior survival than those of the other two groups (log-rank test, P = 0.016). Although rearrangement of BCL2 and BCL6 did not show any inclination to a specific subgroup, the immunohistochemical detection of BCL2 was less frequent, at a statistically significant level (P = 0.011), in group II (50%) than in group I (82%) and III (82%) cases. This appears to confirm the unique aspect of the CD5 − CD10 + type DLBL, indicating a certain relationship with the normal germinal center cells which usually lack BCL2 expression. The BCL6 protein expression was detected in most of the present DLBL cases (92%) irrespective of this grouping. These data suggest that the phenotypic delineation by the detection of CD5 and CD10 will improve our understanding of DLBL and be helpful in a future subgrouping of DLBL.
Background: Sarcoidosis is a systemic granulomatous disease of unknown aetiology. It has been suggested that T helper type 1 (Th1) polarisation is associated with the pathophysiology of sarcoidosis, but the mechanism of skewing towards Th1 has not been elucidated. Dendritic cells (DCs) are known to regulate immune responses. This study was performed to determine whether DCs are involved in the aetiology of sarcoidosis. Methods: The numbers of peripheral blood DCs in 24 patients with sarcoidosis were analysed and biopsy specimens from four patients were stained immunohistochemically using monoclonal antibodies. Results: The numbers of both myeloid and lymphoid DC subsets were significantly decreased in the blood and mature DCs were found in the granulomas of patients with sarcoidosis. A number of interferon-c (IFNc) producing T cells were also detected in the sarcoid granuloma, as well as many interleukin (IL)-4 producing T cells. Double staining of the biopsy specimen using anti-fascin and anti-CD3 antibodies showed an anatomical interaction between DCs and T cells. Conclusions: These findings suggest that the blood DC subsets may migrate into the affected tissues, contributing to the formation of the granulomas in sarcoidosis. It is hypothesised that the migrating DCs may regulate the T cell response in sarcoidosis, at least in the granulomatous lesions.
This combination chemotherapy is highly active and well tolerated in previously treated patients with non-small cell lung cancer. These results are encouraging and warrant additional investigation.
A recent report revealed that a large population of Hodgkin's lymphoma-infiltrating lymphocytes (HLILs) consisted of regulatory T cells. In this study, we cocultured CD4+ naive T cells with KM-H2, which was established as a Hodgkin's Reed-Sternberg cell line, to clarify their ability to induce CD25+ Forkhead box P3+ (Foxp3+) T cells. The characteristic analyses of T cells cocultured with KM-H2 revealed the presence of CD4+CD25+ T cells. They expressed CTLA-4, glucocorticoid-induced TNFR family-related gene, and Foxp3 and could produce large amounts of IL-10. Conversely, KM-H2 also generated CD4+ CTLs, which expressed Granzyme B and T cell intracellular antigen-1 in addition to Foxp3+ T cells. They exhibit a strong cytotoxic effect against the parental KM-H2. In conclusion, KM-H2 promotes a bidirectional differentiation of CD4+ naive T cells toward Foxp3+ T cells and CD4+ CTLs. In addition to KM-H2, several cell lines that exhibit the APC function were able to generate Foxp3+ T cells and CD4+ CTLs. Conversely, the APC nonfunctioning cell lines examined did not induce both types of cells. Our findings suggest that the APC function of tumor cells is essential for the differentiation of CD4+ naive T cells into CD25+Foxp3+ T cells and CD4+ CTLs and at least partly explains the predominance of CD25+Foxp3+ T cells in HLILs and their contribution to a better prognosis. Therefore, in APC-functioning tumors, including classical Hodgkin lymphomas, which generate Foxp3+ T cells and CD4+ CTLs, these T cell repertories play a beneficial role synergistically in disease stability.
Objective. We recently identified 3 fractions of human peripheral blood (PB) dendritic cells (DC), including the monocyte-associated fractions 1 and 2 (CD1a؉,CD11c؉ and CD1a؊,CD11c؉, respectively) and the lymphoid-associated fraction 3 (CD1a؊,CD11c؊). We attempted to determine whether these fractions were altered in Sjögren's syndrome (SS).Methods. We examined 23 patients with primary SS and 22 normal control subjects. DC were purified from PB and analyzed by flow cytometry. Immunohistochemical staining of labial salivary glands of SS patients was performed with monoclonal antibodies against fascin, which is known to be specific for DC.
Results. The total numbers of PB DC and fraction 1 DC were decreased in SS. Immunohistochemical staining demonstrated that fascin؉,CD11c؉,HLA-DR؉ mononuclear cells were present and scattered among numerous fascin-hyperfiltrating cells in SS patients. Interferon-␥ (IFN␥)-producing Th1 cells were shown to be increased in both PB and salivary glands of patients, indicating the presence of general IFN␥producing Th1 polarization in SS. Furthermore, numbers of Th1 cells were increased when naive T cells were cocultured with fraction 1 DC in vitro.Conclusion. These findings suggest selective trafficking of fraction 1 DC into focal sites of inflammation and subsequent promotion of Th1 balance, suggesting a novel pathogenesis of SS.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.