title: Leu-6-expressing cells in lymph nodes: dendritic cells phenotypically similar to interdigitating cells.
abstract: Leu-6 is an antigen expressed by immature T cells, Langerhans cells, and indeterminate cells, the latter two of which are dendritic cells found predominantly within the skin. In dermatopathic lymphadenopathy, the paracortex is expanded by T cells and dendritic cells, including Langerhans cells. While the paracortex also contains Leu-6+ cells, the nature of such cells in lymph nodes has been controversial. To determine the characteristics of Leu-6+ paracortical cells, their morphologic, antigenic, and enzymatic features were studied in lymph nodes showing dermatopathic lymphadenopathy or reactive follicular hyperplasia. Immunologic studies with plastic, frozen, and paraffin sections demonstrated a dendritic cell morphology, a dendritic cell lineage phenotype (L3B12+, HLA-A,B,C+, HLA-DR+, S-100+), and the absence of T-cell lineage phenotype. These findings were corroborated by the enzymatic phenotype of these cells observed in plastic sections (membrane ATPase+, weak paranuclear acid phosphatase+, weak paranuclear alpha-napthylacetate esterase+). Although all paracortical dendritic cells were otherwise identical, only a subset of these cells were Leu-6+. The close phenotypic similarity between these Leu-6+ and Leu-6- paracortical dendritic cell subsets suggests a close ontogenetic relation. Furthermore, the greater abundance of the Leu-6+ subset in dermatopathic lymph nodes than in nodes exhibiting only reactive follicular hyperplasia, in conjunction with the presence of Leu-6+ dendritic cells within the sinuses of dermatopathic lymph nodes, suggests that at least some of the paracortical Leu-6+ cells are Leu-6+ Langerhans cells or indeterminate cells derived from the skin via the afferent lymphatics.
authors.forename: L M
authors.initials: LM
authors.lastname: Weiss
authors.forename: J H
authors.initials: JH
authors.lastname: Beckstead
authors.forename: R A
authors.initials: RA
authors.lastname: Warnke
authors.forename: G S
authors.initials: GS
authors.lastname: Wood
mesh_terms: D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000032:analysis / Q000276:immunology*; D006680:HLA Antigens / Q000032:analysis; D006651:Histocytochemistry; D006652:Histological Techniques; D006801:Humans; D007120:Immunochemistry; D008198:Lymph Nodes / Q000276:immunology* / Q000473:pathology; D008206:Lymphatic Diseases / Q000276:immunology / Q000473:pathology; D008221:Lymphoid Tissue / Q000166:cytology; D010641:Phenotype
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D006680:HLA Antigens