According to this article Jim Boonyaratanakornkit, a medical student from The University of California San Francisco found a gravity-dependent immune deficiency. The article mentions that space crews have an increased susceptibility to infection…
I wonder how do bacteria and viruses respond to zero gravity?
The goal of Jim’s project was to analyze the changes in gene expression in immune cells upon gravity reduction to find gravity-dependent signaling pathways. Microarray gene expression analysis was performed in cultured human T lymphocytes. The low gravity conditions were simulated by Ficoll-Hypaque density gradient centrifugation. The lymphocytes used in the experiments were either activated (by Con A or anti-CD28 antibody) or not activated (used as a control). Around 99 genes were found to be up-regulated in the activated lymphocytes in a normal gravity environment. Among them is the gene for interleukin 2 (IL2), which stimulates T and B cell activation and proliferation and leads to mounting of an immune response. Il-2 and other effector genes of the activated T cells are under the transcriptional control of the upstream genes that are in turn regulated by protein kinases PKC, PKA, PI-3K. Jim and his research team discovered that a simulated low gravity condition resulted in a down-regulation of the genes comprising PKA, but not PKC or PI-3K pathways. Even though there exists an overlap in the expression of some downstream target genes in all three pathways, a gravity-dependent deficiency in one of them might now explain an increased susceptibility to infection in space crews.
Read via Synapse The UCSF Student Newspaper here.