title: Loss of T cell precursors after spaceflight and exposure to vector-averaged gravity.
abstract: Using fetal thymus organ culture (FTOC), we examined the effects of spaceflight and vector-averaged gravity on T cell development. Under both conditions, the development of T cells was significantly attenuated. Exposure to spaceflight for 16 days resulted in a loss of precursors for CD4+, CD8+, and CD4+CD8+ T cells in a rat/mouse xenogeneic co-culture. A significant decrease in the same precursor cells, as well as a decrease in CD4-CD8- T cell precursors, was also observed in a murine C57BL/6 FTOC after rotation in a clinostat to produce a vector-averaged microgravity-like environment. The block in T cell development appeared to occur between the pre-T cell and CD4+CD8+ T cell stage. These data indicate that gravity plays a decisive role in the development of T cells.
authors.affiliation: Department of Microbiology and Immunology, University of Arizona, Tucson, Arizona 85724, USA.
authors.forename: Chris C
authors.initials: CC
authors.lastname: Woods
authors.forename: Krista E
authors.initials: KE
authors.lastname: Banks
authors.forename: Raphael
authors.initials: R
authors.lastname: Gruener
authors.forename: Dominick
authors.initials: D
authors.lastname: DeLuca
mesh_terms: D000818:Animals; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D007700:Kinetics; D008954:Models, Biological; D009924:Organ Culture Techniques; D051381:Rats; D013026:Space Flight; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology / Q000196:embryology; D014893:Weightlessness / Q000009:adverse effects*; D018474:Weightlessness Simulation / Q000009:adverse effects*