TABLE 5
Lymphopenia by CYM-5442 administration is S1P1-dependent
Mice (three per group) were first injected with a 20 mg/kg i.p. W146 in a 300-μl volume. W146 vehicle control mice received equal volume of 10 mM sodium carbonate/2% β-cyclodextrin (v/v). Thirty minutes later, animals were injected with either 2 mg/kg CYM-5442 or vehicle (sterile water). Five hours after CYM-5442 treatment, animals were euthanized and blood was collected into tubes containing EDTA. The number of B220-positive cells (B220+, a marker for B cells) and single-positive CD4 (CD4+) and CD8 (CD8+) T cells was determined by FACS analysis and expressed as a percentage change relative to values obtained in animals receiving both drug vehicles. A sample aliquot of the blood was used to measure the serum drug concentration levels by LC-tandem mass spectrometry. Drug concentrations are included in parentheses as mean ± S.D.).