Monocyte phenotype and cytokine production profiles are dysregulated by short-duration spaceflight

B Crucian, R Stowe, H Quiriarte… - Aviation, space, and …, 2011 - ingentaconnect.com
B Crucian, R Stowe, H Quiriarte, D Pierson, C Sams
Aviation, space, and environmental medicine, 2011ingentaconnect.com
Crucian B, Stowe R, Quiriarte H, Pierson D, Sams C. Monocyte phenotype and cytokine
production profiles are dysregulated by short-duration spaceflight. Aviat Space Environ Med
2011; 82: 857–62. Introduction: Immune system dysregulation has been demonstrated to
occur during and immediately following spaceflight. As the initial bias and magnitude for an
immune response is heavily influenced by monocyte/macrophage secreted cytokines, this
study investigated monocyte phenotype and cytokine production patterns following short …
Crucian B, Stowe R, Quiriarte H, Pierson D, Sams C. Monocyte phenotype and cytokine production profiles are dysregulated by short-duration spaceflight. Aviat Space Environ Med 2011; 82:857–62.
Introduction
Immune system dysregulation has been demonstrated to occur during and immediately following spaceflight. As the initial bias and magnitude for an immune response is heavily influenced by monocyte/macrophage secreted cytokines, this study investigated monocyte phenotype and cytokine production patterns following short-duration spaceflight.
Methods
Secreted cytokine profiles were examined by cytometric bead array analysis of culture supernatants following whole blood culture activation with LPS or PMA+ionomycin. Nine short-duration Space Shuttle crewmembers participated in this study.
Results
Peripheral monocyte percentages were unaltered postflight. Constitutive monocyte expression of both CD62L and HLA-DR was reduced following spaceflight in a mission-specific fashion. Loss of either molecule indicates a functional disability of monocytes, either by inhibition of adhesion and tissue migration (CD62L) or by impaired antigen presentation (HLA-DR). Following LPS stimulation of monocytes, postflight expression of IL-6, TNFα, and IL-10 were significantly reduced (by 43%, 44%, and 41%, respectively) and expression of IL-1b was elevated (65%). IL-8 production was either elevated or reduced in a mission-specific fashion. Following PMA+ionomycin stimulation of all leukocyte populations, only expression of IL-6 was significantly reduced postflight.
Discussion
These data indicate that changes in monocyte constitutive phenotype and inflammatory cytokine production occur following short-duration spaceflight, which may impact overall crewmember immunocompetence. Also, monocyte/macrophage function may be highly sensitive to mission specific parameters.
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