Changes in membrane receptors of B and T human lymphocytes exposed to ⁶⁰Co gamma rays

The presented report describes the effect of 50 to 2500 rad of ⁶⁰Co gamma rays on the membrane receptors of B and T lymphocytes. Surface membrane immunoglobulins and Fc receptors were used as markers for B cells, while the formation of rosettes with sheep red blood cells was used as a marker for T cells. The effect of radiation is expressed as the percentage of viable cells that bear membrane receptors. The radiation effects were studied after 2, 24, and 36 hr of culture. For B lymphocytes no reduction in SmIg and Fc receptors was seen 2 hr after radiation, whereas a dose related reduction was observed after 24 and 36 hr. A dose related inhibition of the 'capping' of SmIg was observed. For T lymphocytes a reduction of E rosette formation was seen starting 2 hr after irradiation. Electron microscopy of separated B and T cells showed a higher sensitivity of T cells as well as a different structural arrangement of the chromatin as a consequence of radiation damage. These data suggest differential behavior of B and T lymphocyte membrane receptors after exposure to radiation.