Yuko Nagayama-Hasegawa1, Shin-Ichiro Honda1,2, Akira Shibuya1,2, Kazuko Shibuya1. 1. Department of Immunology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan. 2. Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Ibaraki, Japan.
Abstract
BACKGROUND: Although DNAM-1 is an activating receptor constitutively expressed on the majority of NK cells, CD8+ T cells, CD4+ T cells, monocytes, and platelets in human, several evidences demonstrated that a small population in B-lineage cells also expressed DNAM-1. However, the expression profile of DNAM-1 on B-lineage cells and its function remain obscure. Previous reports revealed that a considerable number of leukocytes including B cells in the peripheral blood conjugated to platelet. Thus, the proportion of DNAM-1+ B-lineage cells determined by flow cytometry analysis in the previous reports might be overestimated. METHODS: We examined whether platelets conjugate B cells and then analyzed the expression of DNAM-1 on the subpopulations of B-lineage cells according to their maturation stages after exclusion of platelet-conjugated B cells. We also assessed the involvement of DNAM-1 in IL-10 and antibody production from cultured B-lineage cells stimulated with CpG-ODN. RESULTS: Approximately 10% of human DNAM-1+ CD19+ B cells in the peripheral blood conjugated to platelets, resulting in the overestimation of the proportion of DNAM-1+ B cells. After exclusion of platelet-conjugating B cells, we show that DNAM-1 expression was detected on subpopulations of memory B cells, plasmablasts, and plasma cells and upregulated by stimulation with CpG-ODN. Moreover, DNAM-1 was involved in IL-10 and antibody productions by B cells after CpG-ODN stimulation. CONCLUSIONS: DNAM-1 may be involved in B-lineage cell-mediated immune responses.
BACKGROUND: Although DNAM-1 is an activating receptor constitutively expressed on the majority of NK cells, CD8+ T cells, CD4+ T cells, monocytes, and platelets in human, several evidences demonstrated that a small population in B-lineage cells also expressed DNAM-1. However, the expression profile of DNAM-1 on B-lineage cells and its function remain obscure. Previous reports revealed that a considerable number of leukocytes including B cells in the peripheral blood conjugated to platelet. Thus, the proportion of DNAM-1+ B-lineage cells determined by flow cytometry analysis in the previous reports might be overestimated. METHODS: We examined whether platelets conjugate B cells and then analyzed the expression of DNAM-1 on the subpopulations of B-lineage cells according to their maturation stages after exclusion of platelet-conjugated B cells. We also assessed the involvement of DNAM-1 in IL-10 and antibody production from cultured B-lineage cells stimulated with CpG-ODN. RESULTS: Approximately 10% of humanDNAM-1+ CD19+ B cells in the peripheral blood conjugated to platelets, resulting in the overestimation of the proportion of DNAM-1+ B cells. After exclusion of platelet-conjugating B cells, we show that DNAM-1 expression was detected on subpopulations of memory B cells, plasmablasts, and plasma cells and upregulated by stimulation with CpG-ODN. Moreover, DNAM-1 was involved in IL-10 and antibody productions by B cells after CpG-ODN stimulation. CONCLUSIONS:DNAM-1 may be involved in B-lineage cell-mediated immune responses.
Authors: Anna Chashchina; Melanie Märklin; Clemens Hinterleitner; Helmut R Salih; Jonas S Heitmann; Boris Klimovich Journal: Sci Rep Date: 2021-09-09 Impact factor: 4.379