In Vitro Antibody Formation by Human Tonsil Lymphocytes

Abstract

In vitro antibody formation by human lymphocytes was observed against hapten-protein conjugates by using human palatine tonsil cells in the presence of an optimum concentration of 2-mercaptoethanol. Relatively pure populations of B and T lymphocytes were prepared by the method of Ficoll-Hypaque gradient centrifugation to investigate cellular mechanism of antibody formation by human lymphocytes. Maximum response to hapten-protein conjugates was observed in vitro when T and B cells were mixed at an optimal ratio. Little response occurred when each cell alone was cultured with antigen. Depletion of glass-adherent cells also resulted in diminution of the anti-hapten response. These data indicated that three kinds of cells—T cells, B cells, and glass-adherent cells—are essentially necessary for in vitro primary antibody formation by human tonsil cells.

Isolation of Mononuclear Cells from Tonsillar Tissue

“…Total mononuclear cell yields will range from 5 × 10 8 to 5 × 10 9 cells per pair of tonsils. B cells comprise 60% to 70% of the cell population after Ficoll-Hypaque centrifugation, while 30% to 40% are T cells and 1% to 8% are monocytes (Watanabe et al, 1974). Dendritic cells comprise <1% of the cell population (Hart and McKenzie, 1988).…”

“…Investigators in the early 1970s first separated tonsillar lymphocytes from stroma by gentle teasing with small-gauge needles, and showed that these cells could be stimulated in vitro to produce immunoglobulin if the ratios of T and B cells were adjusted appropriately (Hoffmann et al, 1973;Sloyer et al, 1973). Preparation of single-cell suspensions was facilitated by the passage of cells through a fine-mesh sieve (Watanabe et al, 1974). Today, tonsils are most often used as a source of large numbers of human B cells, which are often further separated by size using countercurrent centrifugation (Muraguchi et al, 1983), or into fractions of differing density on Percoll gradients (Nakagawa et al, 1988).…”