Plasmacytoid dendritic cells (pDCs) are involved in innate immunity (eg, by secreting interferons) and also give rise to CD4 + CD56 + hematodermic neoplasms. Dendritic Cell Isolation and Detection Kits, Interactive Pathway: Dendritic Cells Developmental Lineage Pathway, Custom Services for Cell & Gene Therapies, Inflammatory/Monocyte-derived Dendritic Cells.

They develop from bone marrow hematopoietic stem cells and constitute 0.4% of peripheral blood mononuclear cells (PBMC).

The immature cDCs capture and process antigen then transit from these tissues to lymphoid organs such as spleen and lymph nodes where they mature, up-regulate co-stimulatory molecules and present the antigen in the context of a MHC-II-peptide complex to lymphocytes (Geissmann et al. The expression of leukocyte-associated molecules involved in intracellular signaling was also explored and this revealed the presence of 5 B cell–associated molecules (the adaptor protein BLNK; the kinases BTK, Lyn, and Syk; and the PLCγ2 phospholipase) and also the transmembrane adaptor protein LIME (Lck-interacting membrane protein, which is found in T cells and plasma cells; Figure 2, Table 3). (2010). Dendritic cells (DCs) are a functionally, developmentally and phenotypically diverse group of cells. in the T-cell–rich region are strongly stained for the adaptor protein CD2AP (immunoperoxidase technique, hematoxylin counterstain). Blastic NK-cell lymphomas (agranular CD4+CD56+ hematodermic neoplasms): a review. Peripheral blood mononuclear cells were isolated from buffy coats by Ficoll gradient (GE Healthcare, Little Chalfont, United Kingdom), and pDCs were magnetically sorted with blood dendritic cell (DC) Ag BDCA-4 cell isolation kits (Miltenyi Biotec, Bergisch Gladbach, Germany), as described previously.15  More than 90% of the purified cells expressed CD123 (assessed by flow cytometry, data not shown), confirming the plasmacytoid DC nature of the great majority of the isolated cells.

The IgM-associated protein mb-1 as a marker of normal and neoplastic B cells. In contrast, 11 other transcription factors (eg, BCL-6, BOB.1, and PAX-5; Table 4), all but 3 of which are associated with the B-cell lineage, were absent (Figure 1). Nodular lesions of monocytic component in myelodysplastic syndrome. (2013). Viral infection and Toll-like receptor agonists induce a differential expression of type I and lambda interferons in human plasmacytoid and monocyte-derived dendritic cells. It should be added that the frequency of CD2AP and ICSBP/IRF8 expression on myeloid neoplasms was comparable to, or lower than, that of the 2 recently proposed diagnostic markers TCL1 and CLA.11,12,57. “Agranular CD4+ CD56+ hematodermic neoplasm” (blastic NK-cell lymphoma) originates from a population of CD56+ precursor cells related to plasmacytoid monocytes. (2011). CMS: an adapter molecule involved in cytoskeletal rearrangements. designed the project, analyzed and interpreted the data, and wrote the paper.

Cutting edge: selective usage of chemokine receptors by plasmacytoid dendritic cells. Roles of toll-like receptors in natural interferon-producing cells as sensors in immune surveillance.

(Images were acquired on a Nikon Eclipse E800 microscope [Nikon, Tokyo, Japan] equipped with 20×/0.7, 40×/0.95, and 60×/1.4 Plan Fluor objective lenses [Zeiss]), using a Zeiss Axiocam digital camera [Zeiss, Oberkochen, Germany], Axiovision 3 image acquisition software [Zeiss], and Adobe Photoshop 7 image processing and manipulation software [Adobe, San Jose, CA]). All the facts at your fingertips from cell lineage to marker proteins, discover for yourself. However only a minority of leukemia cutis samples (the neoplasms most likely to be confused with the CD4+CD56+ hematodermic neoplasm) expressed BCL11A and BLNK, while CD2AP and ICSBP/IRF8 were even less commonly expressed (Table 5), indicating their potential value for the diagnosis of hematodermic neoplasms. Furthermore, although some of the numerous pDCs present in Kikuchi disease showed a slightly more voluminous cytoplasm, for the most part they lacked dendritic surface processes (Figure 3), and we detected no acquired novel phenotypic features. Originally, pDCs were named “plasmacytoid monocytes” and characterized as CD4 + CD123 + cells that were negative for lineage markers of B cells, T cells, NK cells, and monocytes . contributed to the design of the study, interpreted the data, and wrote the paper. In addition to being potent stimulators/activators of an adaptive immune response DCs can also initiate an innate immune response and even have a role in immune tolerance (Schraml & Sousa 2015). CD56+ hematological neoplasms presenting in the skin: a retrospective analysis of 23 new cases and 130 cases from the literature. The authors thank all the members of the French Study Group on Cutaneous Lymphomas for their collaboration. “Plasmacytoid T cells” in Castleman's disease. Characterization of Siglec-H as a novel endocytic receptor expressed on murine plasmacytoid dendritic cell precursors. We report extensive characterization of human pDCs in routine tissue samples, documenting the expression of 19 immunohistologic markers, including signaling molecules (eg, BLNK), transcription factors (eg, ICSBP/IRF8 and PU.1), and Toll-like receptors (TLR7, TLR9).

CD2AP is described in the literature as a component of normal T cells (and we expected to see expression in these cells when assessing its immunohistologic reactivity in peripheral lymphoid tissues). Expression of pDC-associated molecules in pDC neoplasms and in myeloid and lymphoid leukemias. Plasmacytoid T cells: immunohistochemical evidence for their monocyte/macrophage origin. Plasmacytoid dendritic cells activate lymphoid-specific genetic programs irrespective of their cellular origin. Dendritic Cells: Cellular Mediators for Immunological Tolerance. We therefore evaluated the most selective pDC markers on 24 cases of this sort. Although all dendritic cells (DCs) are capable of pathogen recognition and antigen presentation, they are a heterogeneous cell population in terms of locations, phenotypes, and immunological functions. Create mode – the default mode when you create a requisition and PunchOut to Bio-Rad. The pDCs that are known to accumulate in non-neoplastic conditions (Kikuchi lymphadenitis,25,26  Castleman disease,27,28  lupus erythematosus,29,30  and lichen planus31 ) were all sharply delineated (mainly in the form of nodular aggregates but also as scattered cells) by immunostaining for CD2AP (Figure 3). The other molecules evaluated were randomly selected known leukocyte-associated markers.

Innate immune recognition of viral infection. Additional human DC subsets that have been characterized include human plasmacytoid DCs, which are present in blood and lymphoid tissue, as well as two types of human dermal DCs, CD1a+CD14- DCs and CD1a-CD14+ DCs and Langerhans cells. The Wiskott-Aldrich syndrome protein acts downstream of CD2 and the CD2AP and PSTPIP1 adaptors to promote formation of the immunological synapse. CD2AP was originally cloned from T cells,18-20  but in the present study peripheral T cells were consistently CD2AP negative (using 3 different antibodies) regardless of antibody dilution or whether the tissue section came from a paraffin-embedded or cryostat sample. TBC domain family, member 15 is a novel mammalian Rab GTPase-activating protein with substrate preference for Rab7.

Plasmacytoid dendritic cell-specific receptor ILT7-Fc epsilonRI gamma inhibits Toll-like receptor-induced interferon production.

CD56(+) TdT(+) blastic natural killer cell tumor of the skin: a primitive systemic malignancy related to myelomonocytic leukemia.

Dendritic Cell Subsets and Lineage-specific Markers View Dendritic Cell Subset Schematic Although all dendritic cells (DCs) are capable of pathogen recognition and antigen presentation, they are a heterogeneous cell population in terms of locations, phenotypes, and immunological functions. One of the 16 pDC-associated molecules, CD2AP, appeared to have particular potential diagnostic value, since it was present in neoplastic pDCs in most cases (41 of 43), but absent in all but one of the 24 leukemia cutis cases analyzed (and in all other myeloid neoplasms studied).

Neoplastic nature of nodal plasmacytoid monocytes associated with acute myeloid leukemia.