CHAPTER 5
Effects of Low-Dose Radiation
on the Immune Response
Robert E. Anderson, University of New Mexico, School of Medicine,
Albuquerque, New Mexico
The extreme radiosensitivity of the small lymphocyte has been known for
some time.1-10 More recently, it has been recognized that under highly spe
cific experimental conditions, ionizing radiation may also exert an
immunostimulatory effect. The purpose of this chapter is to summarize our
current understanding of this phenomenon with particular reference to
- radiation dose
- the involved cell type(s)
- the temporal relationships between exposure to radiation, introduction of
antigen, or related immunostimulatory agent, and the resultant immune
response
Prior to reviewing the experimental data, however, a few introductory com
ments with respect to the normal function of the immune system are in
order (for a more detailed description, see Anderson et al.11).
IMMUNE SYSTEM
The raison d'etre of the immune system is to protect the host against
infectious agents and their products. In order to discharge this function, the
various involved cells and cell types are in a constant state of flux as the host
responds to a continuous series of both new and familiar stimuli, while
simultaneously experiencing the slow decay of responses to more remote
stimuli. Thus, at any one time, a myriad of reactions are commencing while
others are reaching their maximum and still others are waning.
The immediate response of the host to an unfamiliar immunologic stimu
lus involves a complex series of events encompassing several different types
of cells located in a variety of anatomic locations. These events are regu
lated by a complex communications network, involving not only several
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