title: Stimulation of germinal center B lymphocyte proliferation by an FDC-like cell line, HK.
abstract: To identify the signals given to the germinal center (GC) B cells by FDC, we have established an FDC-like cell line, HK. HK cells have the important functions of FDC, which are the preferential binding and stimulation of GC B cells. Cell-cell interaction between IgD- B cells and HK cells resulted in the rescue of these cells from apoptosis, whereas the majority of unbound B cells or B cells cultured in the absence of HK cells underwent apoptosis. We investigated the effects of HK cells on the subpopulations of tonsillar B lymphocytes that are at different stages of maturation and differentiation. The subpopulations of tonsillar B cells were purified by panning and/or MACS according to the surface expression of IgD, CD38, and CD44. Although HK cells alone did not stimulate B cell proliferation, HK cells in the presence of either anti-mu or anti-CD40 significantly enhanced the proliferation of B cells. The data show that HK cells preferentially bind, rescue, and stimulate GC B cells (IgD-CD38+) generating CD38-CD44+ memory B cells. The costimulation activity of HK cells is also provided in a form of soluble factor(s). Hence, the phenotypic and functional analysis of HK cells suggests that these cells may be derived from FDC.
authors.affiliation: Laboratory of Cellular Immunology, Alton Ochsner Medical Foundation, New Orleans, LA 70121, USA.
authors.forename: H S
authors.initials: HS
authors.lastname: Kim
authors.forename: X
authors.initials: X
authors.lastname: Zhang
authors.forename: E
authors.initials: E
authors.lastname: Klyushnenkova
authors.forename: Y S
authors.initials: YS
authors.lastname: Choi
mesh_terms: D036541:ADP-ribosyl Cyclase; D051997:ADP-ribosyl Cyclase 1; D000911:Antibodies, Monoclonal / Q000276:immunology; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000276:immunology; D017209:Apoptosis; D001402:B-Lymphocytes / Q000276:immunology*; D002352:Carrier Proteins / Q000276:immunology; D002454:Cell Differentiation; D002455:Cell Division; D002460:Cell Line; D002469:Cell Separation; D003713:Dendritic Cells / Q000276:immunology*; D006801:Humans; D018960:Hyaluronan Receptors; D007072:Immunoglobulin D / Q000276:immunology; D008562:Membrane Glycoproteins; D009699:N-Glycosyl Hydrolases / Q000276:immunology; D014066:Palatine Tonsil / Q000166:cytology; D011956:Receptors, Cell Surface / Q000276:immunology; D016201:Receptors, Lymphocyte Homing / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000943:Antigens, Differentiation; D002352:Carrier Proteins; D018960:Hyaluronan Receptors; D007072:Immunoglobulin D; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; D016201:Receptors, Lymphocyte Homing; D009699:N-Glycosyl Hydrolases; D036541:ADP-ribosyl Cyclase; C498154:CD38 protein, human; D051997:ADP-ribosyl Cyclase 1