Role of autologous lymph node T cells in membrane expression of mu- or gamma-heavy chain isotype by malignant B NHL cells.

ABSTRACT

We investigated the possibility that T cells observed in lymph nodes involved by B-non-Hodgkin's lymphomas (B-NHL) may have a direct role in the expression of Mu- or Gamma- heavy chain isotype by autologous malignant B cells. T cells were separated from lymph nodes involved by B-NHL cells expressing either surface IgM (19 cases) or surface IgG (4 cases) and compared to peripheral blood T lymphocytes of healthy subjects (19 cases) for their ability to promote both IgG and IgM secretion in Cowan-activated normal B lymphocytes. The mean values of IgG/IgM ratios obtained under the influence of T cells associated with malignant B cells expressing either surface IgM or surface IgG were not statistically different to that obtained with the help of control T cells (0.60 and 0.62 versus 0.47, respectively). These results do not account for the hypothesis that autologous lymph node T cells may directly affect the expression of the heavy chain isotype by malignant B-NHL cells.