Gravity changes during animal development affect IgM heavy-chain transcription and probably lymphopoiesisHuin-Schohn, Cécile ; Gueguinou, Nathan ; Schenten, Véronique et alin FASEB Journal (2013), 27(1), 333-341 Our previous research demonstrated that spaceflight conditions affect antibody production in response to an antigenic stimulation in adult amphibians. Here, we investigated whether antibody synthesis is ... [more ▼] Our previous research demonstrated that spaceflight conditions affect antibody production in response to an antigenic stimulation in adult amphibians. Here, we investigated whether antibody synthesis is affected when animal development occurs onboard a space station. To answer this question, embryos of the Iberian ribbed newt, Pleurodeles waltl, were sent to the International Space Station (ISS) before the initiation of immunoglobulin heavy-chain expression. Thus, antibody synthesis began in space. On landing, we determined the effects of spaceflight on P. waltl development and IgM heavy-chain transcription. Results were compared with those obtained using embryos that developed on Earth. We find that IgM heavy-chain transcription is doubled at landing and that spaceflight does not affect P. waltl development and does not induce inflammation. We also recreated the environmental modifications encountered by the embryos during their development onboard the ISS. This strategy allowed us to demonstrate that gravity change is the factor responsible for antibody heavy-chain transcription modifications that are associated with NF-κB mRNA level variations. Taken together, and given that the larvae were not immunized, these data suggest a modification of lymphopoiesis when gravity changes occur during ontogeny.-Huin-Schohn, C., Guéguinou, N., Schenten, V., Bascove, M., Koch, G. G., Baatout, S., Tschirhart, E., Frippiat, J.-P. Gravity changes during animal development affect IgM heavy-chain transcription and probably lymphopoiesis. [less ▲] Detailed reference viewed: 253 (8 UL) Pharmacological countermeasures to spaceflight-induced alterations of the immune systemGueguinou, Nathan ; ; in Stress Challenges and Immunity in Space: From Mechanisms to Monitoring and Preventive Strategies (2012) Opportunities for microbes to establish infections are enhanced under spaceflight conditions because space travel stimulates their growth (Chap. 15) and has a negative impact on immune functions. Indeed ... [more ▼] Opportunities for microbes to establish infections are enhanced under spaceflight conditions because space travel stimulates their growth (Chap. 15) and has a negative impact on immune functions. Indeed, it has been shown that spaceflight affects lymphoid organs (Gridley et al. 2003; Baqai et al. 2009) and induces variations in peripheral blood leukocyte subsets (Chap. 9). Neutrophil, monocyte, and NK cell functions are affected by spaceflight (Chaps. 10-12). The activation of T lymphocytes is also severely depressed under low gravity conditions (Cogoli et al. 1984) because interleukin-2 (IL-2) and IL-2receptor gene expression are modified, the delivery of the costimulatory signal to activate the B7/CD28 pathway and the protein kinase A (PKA) signaling pathway, which is a key early regulator in T cell activation, are hindered. Furthermore, a TH2 cytokine shift is associated with spaceflight. If this TH2 shift persists during long missions, it could represent a significant clinical risk for TH2-related autoimmune diseases, allergies, hypersensitivities, and disease susceptibility related to diminished cell-mediated immunity. Studies on plasma antibody levels did not reveal significant changes after short spaceflights (Rykova et al. 2008), but contradictory results were reported after long missions. Indeed, several studies (Konstantinova et al. 1993; Bascove et al. 2008, 2009; Guéguinou et al. 2009, 2010) reported increased levels of immunoglobulin while Rykova et al. (2008) reported normal amounts of antibodies after prolonged space missions. Lastly, a differential sensitivity of cellular and humoral immunity to spaceflight conditions seems to exist because it was shown that the cellular, but not the humoral, systems are affected by short periods of flight. © 2012 Springer-Verlag Berlin Heidelberg. All rights are reserved. [less ▲] Detailed reference viewed: 170 (0 UL) Spaceflight-associated changes in immunoglobulin VH gene expression in the amphibian Pleurodeles waltl; Huin-Schohn, Cécile ; Gueguinou, Nathan et alin FASEB Journal (2009), 23(5), 1607-1615 Understanding why the immune system is depressed during spaceflight is of obvious importance for future human deep-space missions, such as the foreseen missions to Mars. However, little is known about the ... [more ▼] Understanding why the immune system is depressed during spaceflight is of obvious importance for future human deep-space missions, such as the foreseen missions to Mars. However, little is known about the effects of these flights on humoral immunity. We previously immunized adult Pleurodeles waltl (urodele amphibian) onboard the Mir space station and showed that heavy-chain variable (VH) domains of specific IgM antibodies are encoded by genes belonging to the VHII and VHVI families. We have now determined how these animals use their individual VHII and VHVI genes by screening IgM heavy-chain cDNA libraries and by quantifying IgM heavy-chain transcripts encoded by these genes. Results were compared with those obtained using control animals immunized on Earth under the same conditions as onboard Mir. Our experiments revealed an increase in the expression of IgM heavy-chain mRNAs encoded by the VHII and VHVI.C genes and a strong decrease in the expression of IgM heavy-chain mRNAs encoded by the VHVI.A and VHVI.B genes in spaceflight animals. Consequently, different heavy-chain mRNAs are expressed by spaceflight animals, demonstrating that this environment affects the humoral response. These observations may be due to a change in B-cell selection under spaceflight conditions. [less ▲] Detailed reference viewed: 246 (6 UL) Could spaceflight-associated immune system weakening preclude the expansion of human presence beyond Earth’s orbit?Gueguinou, Nathan ; Huin-Schohn, Cécile ; et alin Journal of Leukocyte Biology (2009), 86(5), 1027-1038 This year, we celebrate the 40th birthday of the first landing of humans on the moon. By 2020, astronauts should return to the lunar surface and establish an outpost there that will provide a technical ... [more ▼] This year, we celebrate the 40th birthday of the first landing of humans on the moon. By 2020, astronauts should return to the lunar surface and establish an outpost there that will provide a technical basis for future manned missions to Mars. This paper summarizes major constraints associated with a trip to Mars, presents immunological hazards associated with this type of mission, and shows that our current understanding of the immunosuppressive effects of spaceflight is limited. Weakening of the immune system associated with spaceflight is therefore an area that should be considered more thoroughly before we undertake prolonged space voyages. [less ▲] Detailed reference viewed: 235 (16 UL) |
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