The Influence of Interleukin-2, Feeder Cells, and Timing of Irradiation on the Radiosensitivity of Human T Lymphocytes Assessed by the Colony-Forming Assay

Abstract

The radiosensitivity of human lymphocytes was investigated by the method of colony formation in the absence of interleukin-2 (IL2) and feeder cells, both of which enhance growth of T-cell colonies. The shape of the survival curve and the radiosensitivity was shown to depend upon the ability of lymphocytes to produce IL2: the survival curve for lymphocytes that were the most competent producers of IL2 is the closest to linearity; the lymphocytes that were poor producers show biphasic survival curves. The radiosensitivity of the lymphocytes from the first group is less than that of the latter, when the comparison is based on the first part of the biphasic survival curve. This is more easily seen when cultures are irradiated 24 h after stimulation by phytohemagglutinin (the time of the peak IL2 production) than when cultures are irradiated 2 h before stimulation. This study demonstrates that growth conditions influence the response of lymphocytes to irradiation and that optimal growth conditions result in a linear survival curve.

Use of Low-dose Rate Irradiation to Measure the Intrinsic Radiosensitivity of Human T-lymphocytes

“…LDR sparing was seen in all the lymphocyte cultures examined in this study . Until the introduction of IL2 for lymphocyte clonogenic assays the majority of lymphocyte radiation survival curves were biphasic with radiosensitive and radioresistant subpopulations (Gerber et al 1989) . 1970) .…”

ACT Up TIL Now: The Evolution of Tumor-Infiltrating Lymphocytes in Adoptive Cell Therapy for the Treatment of Solid Tumors

“…The last key component of the REP is the allogenic feeder cells. It was shown in the 1980s that accessory cells in the T cell culture environment could profoundly accentuate lymphocyte growth [39,40]. While early experiments used feeder cells derived from various anatomical sites of animals, Riddle et al described a method to use peripheral blood-derived mononuclear cells as feeder cells to produce virus-specific T cells for murine adoptive cell transfer experiments [41].…”

Alteration of tumour response to radiation by interleukin-2 gene transfer

“…those present within the tumours and draining lymph nodes. Early studies (James et al, 1983;Gerber et al, 1989) demonstrated that IL-2 added to cultures of human Tcells made them more radioresistant. Similar effects have also been observed with natural killer cells (Hietanen et al, 1995).…”