Lymphocytocidal lymphocyte trapping by human lymph node cells: a tissue culture-ultrastructural study.

An ultrastructural study was carried out on 25 lymphocyte-trapping cells selected from tissue cultures of human axillary lymph nodes. The trapping cells contained several hundred intravacuolar lymphocytes, most of which showed degenerative changes. The principal findings are: (a) a braod spectrum of lymphocyte degeneration; (b) a consistent pattern of lymphocyte degeneration beginning with perinuclear vacuoles and ending with breakdown of the nuclear envelope; (c) the viable lymphocytes tended to be located in a juxtanuclear region; (d) a lysosomal relationship was suggested for lymphocyte degeneration but not for lymphocyte trapping; and (e) degeneration of the trapping cell, or lymphocytes associated with other cells, was not observed. The sequence of degenerative changes differs from those reported for several classes of lymphocytocidal agents. There were no morphologic properties of the trapping cell which served to identify it more specifically. The findings, together with previous time-lapse film observations, warrant further investigation of the hypothesis that lymphocytocidal lymphocyte trapping may be involved in the control of lymphocyte populations.