Abstracts (complete list) - Wissenschaft Online

Ariel H. Achtman, Sven Golfier, Martin Lipp
SPHINGOSINE-1-PHOSPHATE RECEPTOR-4 IS MAINLY
EXPRESSED BY LYMPHOID CELLS
Sphingosine-1-phosphate is a bioactive lipid involved in cell migration, survival and
differentiation. It binds to a panel of receptors, called S1P1 to S1P5 , which differ in their
expression patterns. At the mRNA level, it has been shown that S1P4 expression is
restricted to lymphocyte-containing tissues. However, determining protein expression
patterns for S1P4 has been hampered by the lack of sufficiently sensitive antibodies.
Therefore, a reporter gene mouse was generated, in which the S1P4 gene is replaced by
lacZ. The insertion and correct orientation of the gene were confirmed by Southern Blot
and PCR. Back crossing onto the C57BL/6 background was initiated. Expression levels of
the reporter protein β-galactosidase were low but detectable by luminometric analysis. β-
Galactosidase expression was detected in the spleen, bone marrow, lymph nodes,
thymus, peripheral blood and Peyer’s plaques. No expression was seen in the lung,
brain, liver or heart. Further analysis revealed that S1P4 is expressed on white blood
cells but not erythrocytes. In sorted cell populations, B cells and CD4 + and CD8 + T cells
were the main cell populations carrying the gene. More detailed analysis of changes in
S1P 4 expression during active immune responses is currently underway.