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CONTAMINATION OF SPACECRAFT ENVIRONMENT: IMMUNOLOGICAL CONSEQUENCES.  William T. Shearer.  Departments of Pediatrics and Immunology, Baylor College of Medicine and Texas Children’s Hospital, Houston TX.

        Space flight immunology is the study of human and animal immune responses under the conditions of space travel (stress, isolation, microgravity, containment, microbial contamination, radiation) or in suitable ground models.  A large body of circumstantial evidence is suggesting that immune responses are altered by space travel itself or in ground models, possibly to the point of creating immune deficiency.  Contamination of the spacecraft environment by microbial organisms made more virulent by space travel could be predicted to possibly tip the balance between opportunistic or latent infections and the host defense system.  The detection system must include assessment of the 4 components of the immune system: 1) antibodies, 2) T-cells, 3) phagocytes, and 4) complement.  Simple and accurate in-flight screening tests must be devised to test these components of immunity in functional assays such as: 1) specific antibody production, 2) T-cell responses to neo- and recall antigens, 3) neutrophil superoxide production, and bactericidal capacity of complement.  By devising this system of surrogate markers to detect an immune imbalance during space travel, it would be possible to create a countermeasures program with agents of immunoreconstitution that would prevent the collapse of immune responses and restore normal immune function.  Such agents include drugs, immunoglobulins, and stem cell autotransplants, all of which are currently being used in immunosuppressed patients on Earth.  Exploration of alterations of immune responses in space is an essential component of interplanetary space travel.

(Supported by a grant from the National Space Biomedical Research Institute.)