Phenotypic and functional analyses of tumour-infiltrating Leu 7 + natural killer-like cells in non-Hodgkin lymphomas.

Biopsy specimens of lymphoid tissues were analysed by two-colour flow cytometry to determine the proportions and phenotypes of natural killer-like cells present in the lesions. No significant difference was found between the proportions of Leu 7+ cells in reactive and malignant nodes. Low numbers of Leu 11+ cells were found in both benign and malignant nodes. The most common phenotype among the tumour-infiltrating Leu 7+ cells in the malignant nodes was Leu 7+OKT3+OKM1-. Only low numbers of Leu 7+ cells in malignant nodes coexpressed OKM1. Isolated Leu 7+ cells from four out of five malignant nodes were unable to lyse autologous B lymphoma cells in vitro. However, in one of five malignant nodes tested, autologous B lymphoma cells were lysed by isolated tumour-infiltrating Leu 7+ cells but not by Leu 7- cells. These observations indicate that tumour-infiltrating Leu 7+ cells are infrequently capable of lysing autologous lymphoma cells.