Amelioration of splenic architecture and erythropoiesis in TNS9-treated chimeras.

(A) Upper left: spleens from the normal control mice showed distinct red and white pulp areas. Upper right: spleens from the Hbb^th3/+ control mice showed marked expansion of the red pulp. Lower left: spleens from mice that received transplants of control eGFP-transduced Hbb^th3/+ bone marrow showed marked expansion of the red pulp. Lower right: spleens of Hbb^th3/+ mice that received transplants of Hbb^th3/+ bone marrow treated with TNS9 showed less expansion of the red pulp and were morphologically intermediate between those of the normal and Hbb^th3/+ control mice. Table 1presents a complete analysis. Chimeras and control mice were age-matched. Original magnification × 22. (B) Upper left: red pulp from the normal control mice contained only a small number of nucleated erythroid cells. Upper right: red pulp of Hbb^th3/+ control mice was almost entirely composed of nucleated erythroid precursors packing the cords and compressing the sinuses. The latter contained anucleated cells, but in reduced proportions (here, about 10%-20% of the red pulp), along with a significant number of megakaryocytes and some myeloid precursors. Lower left: red pulp of mice that received transplants of control eGFP-transduced Hbb^th3/+ bone marrow showed a similar amount of EMH as the Hbb^th3/+ control mice. Lower right: the splenic red pulp of the Hbb^th3/+mice that received transplants of TNS9-treated Hbb^th3/+bone marrow contained significantly fewer nucleated erythrocytes (here, about 20% of the red pulp), indicating a decreased amount of EMH compared to both Hbb^th3/+ control mice and mice that received transplants of eGFP-transduced Hbb^th3/+ bone marrow. Original magnification × 132.