Overexpression of v-abl uniquely cooperates with c-myc dysregulation in induction of plasma cell tumors,bypassing the need for T-lymphocytic help and overcoming T-lymphocytic interference

We have investigated the effects of T lymphocytes on induction of mouse plasma cell tumors. We show that ABL-MYC, a plasmacytomagenic retrovirus that constitutively expresses v-abl and c-myc, is able to induce plasmacytomas in 100% of athymic BALB/c mice, with or without intraperitoneal pristane pretreatment. Other induction regimens are ineffective under these conditions, indicating that the combination of v-abl and c-myc oncogenes is uniquely able to transform plasma cells in mice that are deficient in T lymphocytes. Furthermore, in the absence of pristane, ABL-MYC-infected athymic congenics developed plasmacytomas in half the time required for euthymic BALB/c mice, suggesting that T lymphocytes can have a negative effect and can retard, but not totally inhibit, the outgrowth of plasmacytomas. This phenomenon could not be appreciated in other regimens of plasmacytoma induction, because only ABL-MYC is sufficient to induce plasmacytomas in athymic mice or in euthymic mice in the absence of pristane pretreatment. © 1996 Wiley-Liss, Inc.