title: Phenotypic characterization of human B-lymphocyte subpopulations, particularly human CD5+ B-lymphocyte subpopulation within the mantle zones of secondary follicles.
abstract: We have investigated the precise distribution of human B-lymphocyte subpopulations (CD5+ B lymphocyte, Leu-8+ lymphocyte, immunoglobulin D (IgD)+ lymphocyte, alkaline phosphatase (ALPase)+ B lymphocyte and bcl-2 protein+ B lymphocyte) within the mantle zones (MZs) and phenotypic characterization of human CD5+ B lymphocytes using immunohistochemical techniques and flow cytometric analysis. IgD+ lymphocytes and ALPase B lymphocytes were confined to the inner layer and outer layer of the MZs of secondary follicles, respectively. CD5+ B lymphocytes and Leu-8+ B lymphocytes were mostly located in the inner layer of the MZs. Bcl-2 protein+ B lymphocytes were seen throughout the MZs. The precise distribution pattern of human B-lymphocyte subpopulations may help further understanding of the histogenesis and features of B-cell lymphomas, particularly mantle cell-derived lymphomas as well as the B-cell differentiation pathway. A minor population of CD5+ B lymphocytes expressed IgD. Almost all the CD5+ lymphocytes did not express ALPase. The data support the fact that CD5+ B lymphocytes are located more in the inner layer than in the outer layer of the MZs. Leu-8 and bcl-2 protein were detected in a large population of CD5+ B lymphocytes. In addition, Ki-67 antigen was not expressed on the CD5+ B lymphocytes. The data suggest that human CD5+ B lymphocytes may be long-living and resting (G0 and G1a stage) cells possessing the capability of continuously recirculating between blood and lymph nodes to participate in some immune responses. Moreover, Leu-8 and CD44 were detected in the majority of CD5+ B lymphocytes but intercellular adhesion molecule-1 (ICAM-1) and very late antigen-4 (VLA-4) were detected in the minority. The data may account for a high percentage of Leu-8 and CD44 expression and a low percentage of ICAM-1 and VLA-4 expression on B-chronic lymphocytic leukemia (B-CLL), which is considered to be a neoplastic counterpart of normal CD5+ B lymphocyte.
authors.affiliation: First Department of Pathology, Fukushima Medical College, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Abe
authors.forename: K
authors.initials: K
authors.lastname: Tominaga
authors.forename: H
authors.initials: H
authors.lastname: Wakasa
mesh_terms: D015703:Antigens, CD / Q000032:analysis; D016175:B-Lymphocyte Subsets / Q000166:cytology* / Q000276:immunology*; D001402:B-Lymphocytes / Q000737:chemistry / Q000502:physiology; D018956:CD5 Antigens; D006801:Humans; D007150:Immunohistochemistry; D008198:Lymph Nodes / Q000166:cytology* / Q000473:pathology; D008199:Lymphadenitis / Q000473:pathology; D014066:Palatine Tonsil / Q000166:cytology* / Q000473:pathology; D010641:Phenotype; D014069:Tonsillitis / Q000473:pathology
chemical_list: D015703:Antigens, CD; D018956:CD5 Antigens