title: Differential mechanism for differentiation into immunoglobulin-secreting cells in human resting B lymphocyte subsets isolated on the basis of cell density.
abstract: We have investigated differential mechanism for differentiation of human peripheral blood resting B cells to Ig-secreting cells. Purified resting B cells were further fractionated into subsets by discontinuous density gradients of Percoll, and proliferation and differentiation responses to Staphylococcus aureus Cowan I (SAC) and/or T cell-derived soluble factors were studied. High density resting B cells were stimulated to proliferate vigorously in response to SAC, but were poorly differentiated by SAC in presence of T cell factors. In contrast, low density resting B cells failed to proliferate in response to SAC and/or T cell factors; these cells could, however, be induced by stimulation with SAC plus T cell factors to become cells actively secreting Ig. These results indicate that there may exist heterogeneity in the human resting B cells: one subset of resting B cells (B cells with low density) can differentiate directly into Ig-secreting cells without the need for proliferation, and another subset (B cells with high density) can proliferate actively without subsequent differentiation into Ig-secreting cells. To address whether these resting B cell subsets belong to the same lineage, only high density B cells recovered from circulating resting B cells were first stimulated for 7 d with SAC, refractionated on Percoll gradients, and differentiation response of the refractionated B cells to SAC and T cell factors was examined. B cells shifting toward low density fraction were located in the resting status and could differentiate in response to SAC plus T cell factors. These results indicate that some of B cells with high density belong to the same cell lineage as those with low density and they must first proliferate before differentiation.
authors.affiliation: Department of Internal Medicine, Shimane Medical University, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Suzuki
authors.forename: Y
authors.initials: Y
authors.lastname: Ueda
authors.forename: T
authors.initials: T
authors.lastname: Sakane
mesh_terms: D000921:Antibody-Producing Cells / Q000166:cytology* / Q000276:immunology; D001402:B-Lymphocytes / Q000145:classification* / Q000166:cytology / Q000276:immunology; D002454:Cell Differentiation; D002469:Cell Separation; D002499:Centrifugation, Density Gradient; D006462:Hemolytic Plaque Technique; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D008213:Lymphocyte Activation; D009000:Monocytes / Q000502:physiology; D011205:Povidone; D012822:Silicon Dioxide; D013211:Staphylococcus aureus / Q000276:immunology
chemical_list: D007376:Interleukin-2; C016039:Percoll; D012822:Silicon Dioxide; D011205:Povidone