Antigen-induced murine B cell lymphomas. I. Induction and characterization of CH1 and CH2

Two unusual murine lymphomas, designated CH1 and CH2, were produced in the newly developed double congenic strain of mice, B 10 H-2(a)-H-4(b)p/Wts. Both tumors lack the T cell-specific antigen (thy-1), but express cell surface immunoglobulin and the H-2K, H-2D, and Ia specificities determined by the H-2(a) haplotype. Further studies have demonstrated that these tumors represent 'early' B cells in that they express surface IgM (μ heavy and λ light chains), but do not bear surface δ, γ, or α heavy chains. CH1 and CH2 lack surface C 3 receptors and results from assays for Fc receptors have proven variable. A competition radioimmunoassay directed against the gp71 group-specific antigen of Friend leukemia virus has shown that there is a murine leukemia virus associated with these tumors, however, we have been unable to establish a causal relationship between the virus and this malignancy. A comparison of the surface characteristics of the tumors with other mammalian B cell lymphomas is presented.