Figure 2

Effector leukocytes and antibody-promoted ADCC in EL4 and EL4-v10 bearing mice. (A) Recovery of NK and Mf by immunohistochemistry (cryosections of EL4 and EL4-v10 TB spleen): hematoxilin (blue) staining of nuclei, antibodies recognizing NK cells or Mf (red); scale bar: 100 μm. (B) ADCC in 3 wk EL4 and EL4-v10 TB SC after 2d in RPMI1640/100 U/ml IL2 and 10 μg/ml IM7 or K926 corresponding to in vivo treatment; mean±SD (triplicates); significant differences (p <0.05) by antibody treatment: *. (C) Recovery of HSC and progenitors in 2 wk TB and at autopsy (flow cytometry); mean±SD (3 mice/group); (D) serum IgG recovery (ELISA) in 2 wk TB, OD405 at 1:20 serum dilution (mean±SD, 3 mice/group); (C,D) significant differences (p <0.05) between EL4 and EL4-v10 TB: s; and by IM7 or K926 treatment: *. (E,F) BALB/c SCID mice (5/group) received 2×106 HSC or HSC plus 1×106 EL4 or EL4-v10 (i.v.) and 100 μg/mouse IM7 or K926 (i.v.) 24 h after HSC application. Antibody application was repeated in 5d intervals. BM, thymus, spleen and LN were excised after 3 wk for recovery of the indicated cell populations by flow cytometry. (E) Mean percent±SD/organ (5 mice/group) and (F) representative examples; significant differences (p <0.05) between tumor-free and EL4 or EL4-v10 TB: s and by IM7 or K926 treatment: *. NK and Mf are enriched in splenic tumors in IM7- or K926-treated mice, which corresponds to increased ADCC. Significantly fewer HSC are recovered in EL4 than EL4-v10 TB, HSC being further decreased in IM7-treated EL4 TB. There is a slight increase in Gr1+ cells in the BM and a decrease in serum IgG in K926-treated EL4-v10 TB. Upon transfer of HSC into SCID mice, maturation/differentiation into lymphocytes is severely impaired in EL4 TB and is most strongly reduced by concomitant IM7 application. K926 slightly affected B cell recovery.