Spleens in FX1-treating mice are macroscopically indistinguishable from vehicle controls. Total B cell abundance measured by flow cytometry is unaffected by FX1. GC B cells (GL7+FAS+B220+) are significantly depleted by exposure to FX1. Splenic architecture is examined by IHC. Staining with B220 antibody reveals normal B cell follicular structures, whereas staining for the GC B cell-specific marker peanut agglutinin shows profound loss of GCs. The half-life is estimated to be approximately 12 hours. Finally, whether FX1 can induce toxic effects in mice is assessed. No signs of toxicity, inflammation, or infection are evident from H&E-stained sections of lung, gastrointestinal tract, heart, kidney, liver, spleen, and bone marrow of the fixed organs from mice treated with FX1 compare with vehicle[1].
