Voltage-sensitive ion channels in human B lymphocytes.

Human tonsillar B cells were found to contain type n K+ channels, and have K+ channel densities somewhere between those of murine B cells and those of human T cells. Unlike human T lymphocytes, some human B lymphocytes were able to increase K+ channel density in response to mitogenic activation, but the increases were smaller than those observed in murine B lymphocytes. Some mitogen-stimulated human B cells increased in size, but, unlike murine B cells, cell size was not related to K+ channel density. There may be a down-regulation of K+ channel density in human B cells treated with SAC for 6 days, while no such effect occurs in murine B cells. A fraction of human B cells possess inward current channels (probably Na+ channels) that are similar to channels sometimes seen in human T cells, but not seen in murine B cells.