Spaceflight alters the body’s immune system. Bed-rest studies with head-down tilt show a pattern similar to the results observed when humans are exposed to space. Previous bed-rest studies have shown changes in the immune system, yet all studies to date have been carried out on men. Dr. Gerald Sonnenfeld is conducting a bed-rest study of women to determine if participants experience suppression of immune responses and an enhanced susceptibility to infection. Additionally, Studies will be carried out to determine if countermeasures (exercise and diet supplementation) designed to deal with the negative effects of spaceflight on muscle have a positive or negative effect on the function of the immune system.
Overview
Bed Rest and Immunity
Principal Investigator:
Gerald Sonnenfeld, Ph.D.
Organization:
Binghamton University - State University of New York
Technical Summary
The exposure of humans to spaceflight conditions results in changes in immune responses. The contribution of these changes to alterations in resistance to infection and tumors remains to be fully established. Chronic bedrest with a head-down tilt has been a human model of choice for the effects of spaceflight on physiological systems. This model allows for no load-bearing on the legs of the subjects as well as a fluid shift to the head. Results utilizing the head-down tilt bed-rest model to study the effects of spaceflight conditions on the immune system are limited, but show a pattern similar to the results observed when humans are exposed to space. The head-down tilt bed-rest model has been established as valid for studying the effects of spaceflight conditions on functional dynamic immune responses such as cytokine production, but all of the studies to date have been carried out on men. to determine effects of maintenance of female subjects in the head-down tilt bed-rest model on functional immune responses and; to determine effects of maintenance of female subjects in the head-down tilt bed-rest model on resistance to infection.
The study is designed to determine the effects of bedrest on immune responses of women. The overall hypothesis to be tested is that maintenance of female subjects in the head-down tilt bed-rest model will result in suppression of functional immune responses and enhance susceptibility to infection.
Specific Aims
By carrying out these studies, we will correlate the effects of bed rest on immune function and control of viral infections. The French bed-rest campaigns have been completed, and the results are under analysis at the present time.
Earth Applications
Many elderly individuals must remain in chronic bed rest and often develop decubiti (infected bed sores). The results of this study may aid in understanding mechanisms and in providing treatment for these patients. The analysis of the results of the study will provide new insight in this area as well as in the validity of the bed-rest model for determining the effects of spaceflight conditions and countermeasures on the immune responses of women.
This project's funding ended in 2007