RTX supports C3b deposition in a primate model.

Alexa 594/633 RTX was infused, followed 10 to 20 minutes later by Alexa 488 mAb 3E7. Blood samples were anticoagulated with EDTA, washed and probed as indicated. Erythrocytes were lysed and the remaining cells analyzed by fluorescence microscopy (panels A-C) or flow cytometry (panel D). Original magnification × 250. (A) Monkey BL: 2 minutes after Alexa 594/633 RTX (0.5 mg/kg) infusion, washed cells were probed with Alexa 488 mAb 3E7. (B) Ten minutes after infusion of Alexa 594/633 RTX and 2 minutes after infusion of Alexa 488 mAb 3E7 (1 mg/kg), cells were washed and examined without further probing. (C) Monkey NA: Treated as described in the legend to panel B, except 1.0 mg/kg Alexa 594/633 RTX. MF: mixed function filter. (D) Dot plots present the results of flow cytometry analyses of blood samples taken at different times during the experiment with monkey BL. PerCp CD45 and side scattering were used to identify lymphocytes, and the PE CD21 probe was used to identify B cells.