The effects of ionizing radiation on the B lymphocyte immune system

Much of the experimental work concerning the effects of ionizing radiation on the immune system was performed prior to the current developments in immunology. Most of the experiments must be repeated in order to study the radiation effects on defined populations of cells or cooperative immune mechanisms. Nevertheless, it is possible at the present time to conclude that: I) The humoral responses are generally more radiosensitive than the cellular immune responses; II) correspondingly, B lymphocytes are quite radiosensitive and probably are subject to interphase as well as mitotic death following irradiation; III) Conversely, activated B cells such as B lymphoblasts or plasmablasts are radioresistant while non-dividing antibody-synthesizing cells are highly radioresistant. The consequences of the ionizing radiation exposure to the humoral immune system are clearly important. The nature of the alterations or damages caused to the infection related immunity can be measured at two levels: 1) a decrease of specific antibody synthesis and as a consequence, 2) a diminution of all antibody dependent cytotoxicity which can include, directly or indirectly, macrophages, eosinophils, basophils, polymorphonuclear leukocytes, etc. Further studies on all presently evoked aspects are clearly required. (orig./MG)