Fig. 4: The CLL-like disease populating the spleen of Eµ-MTCP1 mice is amenable to adoptive transfer.

A Schematic review of Eµ-MTCP1 adoptive transfer leukemia model. 1 × 10⁶ splenocytes isolated from an Eµ-MTCP1 mouse (from founder line Z36) having reached predefined euthanasia criteria due to progressive leukemic expansion were engrafted via tail vein injection into immunocompetent C57/BL6NTac (wildtype) mice. B Immunocompetent recipient mice described in (A) were monitored weekly for expansion of CD5⁺/CD19⁺ and CD19⁺/B220^dim circulating CD45⁺ cells by flow cytometry. A representative flow analysis is shown describing the progressive accumulation of CD45⁺/CD5⁺/CD19⁺ cells. C Nine of ten recipient mice displayed significant peripheral disease (CD45⁺/CD5⁺/CD19⁺ cells) between 3 and 10 weeks post-adoptive transfer of splenic cells from Eµ-MTCP1 mice. In mice surviving at least 12 weeks post-engraftment, the engrafted tumor population nearly composes the entire peripheral blood compartment (>75%). Box elements reflect 2nd - 3rd quartile, center line reflects the median value, and whiskers reflect the distance from the upper and lower limit to the box elements. D Kaplan–Meier estimation of median survival in recipient adoptive transfer mice. Without intervention, adoptive transfer of splenic CLL-like cells from Eµ-MTCP1 mice results in a lethal disease with a median time to disease at 11.4 weeks. All successfully engrafted mice eventually succumbed to disease. E Representative post-mortem histopathology analysis of lymph node (2x, 60x), bone marrow (60x), spleen (20x), thymus (10x), and liver (40x) from a mouse in the Eµ-MTCP1 adoptive transfer model reaching ERC due to progressive disease. Hematoxylin & eosin staining shows histologic changes consistent with a systemically disseminated round cell neoplasm of small to intermediate lymphocytes that was homogenous between engrafted animals. Images representative of n = 3 mice. Scale bars as indicated.