Isolation and characterization of lymphocytes and macrophages from solid, malignant human tumours

In mechanically prepared cell suspensions from 17 solid, malignant human tumours, 0.5-5.0% (mean 2.0%) lymphocytes and 1.0-28.0% (mean 7.4+) macrophages were found. Mononuclear cells (MC) were isolated using the Böyum technique. From each biopsy weghing 1-4 g, on average, 1.3 x 10(6) lymphocytes and 0.8 x 10(6) macrophages were recovered. The tumour-infiltrating lymphocytes (TIL) were characterized with regard to T and B markers. The proportion of TIL-forming rosettes with SRBC (T cells) was 43%, which was significantly less than for peripheral blood lymphocytes (PBL) from cancer patients (58%), or normal controls (80%), On average, 15% of the TIL were B cells, whereas 42% had no T- or B-cell markers. Macrophages (TIM) were identified by non-specific esterase staining and phagocytosis. In four cases the tumour cells were also stained with alpha-naphthyl butyrate. Corresponding findings were made on esterase-stained cryostat sections from four tumours. Macrophages were found within and around the tumour tissues, occasionally localized to necrotic areas, but in most cases with no sign of necrosis of the surrounding cells. In some tumour cell suspensions typical clusters of lymphocytes and macrophages were seen. Total lymphocytes and T-cell were markedly reduced inthe peripheral blood of cancer patients, whereas total monocyte counts were within the normal range.