EFFECTS OF MENTAL STRESSORS ON MITOGEN-INDUCED LYMPHOCYTE-RESPONSES IN THE LABORATORY

There is considerable evidence from naturalistic studies that psychoso cial stressors affect human immune function. To achieve control over f actors that could bias naturalistic studies, laboratory stressors deve loped by cardiovascular researchers were tested to determine if they a ffected immune function. Thirty volunteer students were exposed to 20 minutes of mental tasks. Psychophysiological indices (heart rate, bloo d pressure, skin conductance) and subjective responses were monitored prior to, during, and 1-hour after the tasks, blood, samples for immun ological analyses were also drawn at these times. Thirteen subjects wh o were not exposed to the tasks served as controls. Subjects exposed t o the tasks showed increased levels of subjective distress and increas ed psychophysiologic responses (except diastolic blood pressure) durin g the tasks. Relative to controls, stressed subjects had reduced lymph ocyte proliferative responses to classic T cell mitogens both immediat eiy after and 1-hour after the tasks were found in whole blood culture s, although responses of isolated lymphocytes were not significantly a ffected. There were only marginal differences in whole blood mitogen r esponses for stressed subjects with low versus high autonomic reaction s to the stressor. These results support an emerging view that the imm une system is sensitive to brief stressors and that laboratory models may be useful for exploring stress-induced changes in immune function.