title: Morphologic, flow cytometric, functional, and molecular analyses of S100B positive lymphocytes, unique cytotoxic lymphocytes containing S100B protein.
abstract: Little is known about the S100B⁺ lymphocytes, which are unique human peripheral blood lymphocytes (PBL) containing the S100B protein. It has recently been shown that S100B is released from various types of S100B⁺ cells and exhibits varied cytokine-like activities. In this study, we precisely characterized the S100B⁺ lymphocytes of healthy adults with respect to the proportion in the whole PBL, immunophenotypes, function, and their S100B mRNA expression and also evaluated their S100B-releasing activity upon stimulation. S100B⁺ lymphocytes were detected in all individuals examined, and the proportion of S100B⁺ lymphocytes in the whole PBL ranged from 0.42% to 16.15% (mean, 4.21%). In addition, two subtypes of S100B ⁺ lymphocytes, a CTL subtype (CD3⁺ CD8⁺ CD16⁻) and a NK subtype (CD3⁻ CD3⁻ CD16⁺), were detected. The majority of the CTL subtype of S100B⁺ lymphocytes expressed the αβ-T-cell receptor. Surprisingly, S100B mRNA was detected not only in S100B⁺ lymphocytes, but also in every S100B⁺ lymphocytes, although the expression levels of S100B mRNA in S100B⁻ lymphocytes were much lower than those of S100B⁺ lymphocytes. The CTL subtype of S100B⁺ lymphocytes exhibited blastic morphological changes, proliferated and released S100B upon stimulation with phytohemagglutinin. The NK subtype of S100B⁺ lymphocytes exhibited morphological NK activity when cocultivated with NK-sensitive target, K-562 cells. Thus, the CTL subtype of S100B⁺ lymphocytes exhibit the biological characteristics of T cells, while the NK subtype of S100B⁺ lymphocytes exhibit the characteristics of NK cells. These results suggest that S100B⁺ lymphocytes are a particular subtype of cytotoxic lymphocytes that play a unique role in antitumor immunity.
authors.affiliation: Department of Medical Technology, Graduate School of Health Sciences, Okayama University, Okayama, Japan.
authors.forename: Yukari
authors.initials: Y
authors.lastname: Miki
authors.forename: Yuka
authors.initials: Y
authors.lastname: Gion
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Mukae
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hayashi
authors.forename: Hiaki
authors.initials: H
authors.lastname: Sato
authors.forename: Tadashi
authors.initials: T
authors.lastname: Yoshino
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Takahashi
mesh_terms: D000328:Adult; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000187:drug effects / Q000276:immunology*; D006801:Humans; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D009414:Nerve Growth Factors / Q000096:biosynthesis / Q000276:immunology*; D010835:Phytohemagglutinins / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000276:immunology; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology / Q000378:metabolism; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000096:biosynthesis / Q000276:immunology*
chemical_list: D009414:Nerve Growth Factors; D010835:Phytohemagglutinins; D012333:RNA, Messenger; D016693:Receptors, Antigen, T-Cell, alpha-beta; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; C579160:S100B protein, human