Phenotypic Characterization of Five Dendritic Cell Subsets in Human Tonsils

Abstract

Dendritic cells (DCs) have a central role in the initiation and regulation of immune responses in both lymphoid and nonlymphoid tissues. They share a number of common features, notably MHC class II expression, in combination with an absence of the lineage-specific markers CD3, CD14, CD16, and CD19 (lin Ϫ ). [1][2][3] There is however considerable intra-and intertissue variation in the phenotype, morphology, function, and tissue localization of different DC populations. [1][2][3][4][5][6][7] After the identification of distinct myeloid DC and lymphoid DC subsets in mice 3 there has been increasing interest in the characterization of human DC subsets. These have been categorized on the basis of differential expression of myeloid and lymphoid lineage-associated markers, as well as their responsiveness to maturation or differentiation stimuli. 8 -13 There is evidence that myeloid DCs and lymphoid DCs direct immunogenic and tolerogenic responses, respectively. 13 It is unclear whether human DC subsets represent distinct cell lineages 10,12 or differing maturation states. 9,14 As a result, the ontogeny and interrelationship of human DC subsets requires further investigation.Tonsils have been used as a readily available source of lymphoid tissue to characterize human DCs. 15 Three tonsil DC subsets have been identified: interdigitating DCs (IDCs), 16 plasmacytoid DCs, 17 and germinal center DCs (GCDCs). 18 These DC subsets were isolated after a period of in vitro culture, which is likely to alter cell phenotype and morphology. 19 They were also positively selected from lin Ϫ cells based on their expression of the CD4, CD11c, or CD40 antigens, which would exclude any DC subsets lacking these antigens and would incorporate all DC subsets expressing those antigens into one population. The observation that both IDCs and GCDCs were heterogeneous with regard to CD11c, CD83, HLA-DR, and CD13 intensity raised the possibility that these tonsil DC populations might contain additional subsets. This is the first study to analyze the composition of tonsil DC subsets within the entire lin Ϫ HLA-DR ϩ DC population isolated using a new method that maintains the cells at 4°C to minimize changes in cellular differentiation/activation induced by the isolation procedure. We report the presence of five distinct DC subsets within human tonsils. The phenotype of each tonsil DC subset was analyzed by threecolor flow cytometry and two-color immunohistochemistry using an extensive panel of antigens relevant to DC lineage, activation state, and function. Materials and Methods Patients and SamplesAfter approval by the Canterbury Ethics Committee and appropriate informed consent, tonsils were obtained from 68 patients undergoing routine tonsillectomies, which were excised in a noninflamed state. They were trans-

Parallel Loss of Myeloid and Plasmacytoid Dendritic Cells from Blood and Lymphoid Tissue in Simian AIDS

“…2D), consistent with findings in humans (32). Collectively, these findings demonstrate that in superficial lymph nodes from SIV-naive monkeys pDC are phenotypically immature and likely derive from blood, whereas the majority of mDC are mature, epidermisderived cells, consistent with studies of lymph node DC in mice and humans (3,8,9,33).…”

Expression of the plasmacytoid dendritic cell marker BDCA-2 supports a spectrum of maturation among CD4+ CD56+ hematodermic neoplasms

“…11,30,31 BDCA-2 immunoreactivity was noted in clusters of cells adjacent to germinal centers ( Figure 2d) that overlapped with anti-CD123 staining patterns (Figure 2e), and was concentrated in the CD3 þ T-cell-rich interfollicular areas ( Figure 2F) where plasmacytoid dendritic cells are most abundant. 11,20,[30][31][32] Therefore, cyto-BDCA-2 antibodies allow selective plasmacytoid dendritic cell staining in formalin-fixed, paraffin-embedded and fresh tissues.…”

A critical role of T follicular helper cells in human mucosal anti-influenza response that can be enhanced by immunological adjuvant CpG-DNA

“…Considering that tonsillar tissue contains a prominent number of pDC (Polak et al, 2008;Rescigno, 2013) (Summers et al, 2001), this contribution by pDC to T FH -mediated antibody response in NALT tissue may be explored in future vaccination strategy against respiratory infection.…”