Genetic models in applied physiology: selected contribution: effects of spaceflight on immunity in the C57BL/6 mouse. I. Immune population distributions.
There are several aspects of the spaceflight environment that may lead to changes in immunity: mission-related psychological stress, radiation, and changes in gravity. On December 5, 2001, the space shuttle Endeavor launched for a 12-day mission to examine these effects on C57BL/6 mice for the first time. On their return, assays were performed on the spleen, blood, and bone marrow. In response to flight, there were no significant differences in the general circulating leukocyte proportions. In contrast, there was an increase in splenic lymphocyte percentages, with a corresponding decrease in granulocytes. There was an overall shift in splenic lymphocytes away from T cells toward B cells, and a decrease in the CD4-to-CD8 ratios due to a decrease in T helpers. In contrast, there were proportional increases in bone marrow T cells, with decreases in B cells. Although the blast percentage and count were decreased in flight mice, the CD34(+) population was increased. The data were more consistent with a shift in bone marrow populations rather than a response to changes in the periphery. Many of the results are similar to those using other models. Clearly, spaceflight can influence immune parameters ranging from hematopoiesis to mature leukocyte mechanisms.
Pecaut
Michael J
MJ
Department of Radiation Medicine, Radiobiology Program, Division of Microbiology and Molecular Genetics, Loma Linda University and Medical Center, Loma Linda, California 92354, USA. mpecaut@dominion.llumc.edu
Nelson
Gregory A
GA
Peters
Luanne L
LL
Kostenuik
Paul J
PJ
Bateman
Ted A
TA
Morony
Sean
S
Stodieck
Louis S
LS
Lacey
David L
DL
Simske
Steven J
SJ
Gridley
Daila S
DS
D000818:Animals; D001853:Bone Marrow / Q000276:immunology / Q000502:physiology; D005260:Female; D005434:Flow Cytometry; D006098:Granulocytes / Q000276:immunology; D007109:Immunity / Q000502:physiology*; D007111:Immunity, Cellular / Q000276:immunology / Q000502:physiology; D007958:Leukocyte Count; D008208:Lymphatic System / Q000276:immunology / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D013026:Space Flight; D013154:Spleen / Q000166:cytology / Q000276:immunology; D013234:Stem Cells / Q000502:physiology