L3T4⁺ T cells regulate Abelson virus-induced lymphomagenesis

To evaluate the role of T cells in regulation of lymphomagenesis, experiments were performed using Abelson murine leukemia virus (AMuLV). In vitro transformation of bone marrow target cells by this B lymphotropic retrovirus was inhibited by peripheral lymph node cells from naive mice. The inhibitory activity depended on Thy-1⁺ L3T4⁺ cells but did not require Lyt-2⁺ cells. In vivo depletion of L3T4⁺ T cells with mAb (GK1.5) altered the course of AMuLV-induced lymphoma. L3T4 depletion of naturally resistant C57BL/6 mice resulted in dramatic susceptibility to lymphoma induction. Lymphoma cells from anti-L3T4-treated C57BL/6 mice infected with AMuLV displayed the B lineage transformation marker P160(6C3). These studies reveal an important immunologic component of Abelson disease resistance involving L3T4⁺ T cells.