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EFFECTS OF A FIVE-MONTH STAY ON BOARD THE MIR SPACE STATION ON IMMUNOGLOBULIN PRODUCTION IN THE URODELE AMPHIBIAN PLEURODELES WALTL.  J.-P. Frippiat and C. Dournon.  Lab. of Experimental Biology and Immunology, Univ. Nancy 1, Bvd des Aiguillettes, B.P.239. F-54506 Vandoeuvre-lиs-Nancy FRANCE.

   During the Perseus mission, two adult P. waltl did stay 5 months on board the MIR space station. Ten days after their return on Earth, animals were sacrificed and their spleen dissected. Total RNA was extracted from these tissues and used to analyze, by Northern blotting, the expression of IgM and IgY heavy chains. Our results indicated that the levels of IgM heavy chain transcripts in the spleen of animals which stayed in MIR are similar to those found in animals reared on Earth.  However, the levels of IgY heavy chain transcripts were about three times higher than those found in ground control animals. We also analyzed the usage of the different VH families in the IgM heavy chain transcripts. Our experiments revealed important changes in the usage of the VH II and VH VI families. These families are used, respectively, in 28% and 60% of the IgM transcripts of ground control animals, and in 60% and 25% of the IgM transcripts of animals which stayed 5 months on board MIR.

   In conclusion, a prolonged stay on board a space station could affect the immunoglobulin production quantitatively and qualitatively. To confirm these first results, we will perform the same experiments on 30 P. waltl which stayed on board the International Space Station during the Andromede mission performed in October 2001.

(Supported by CNES: DAR4800000024 and 8626)

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