The T-cell
enzyme markers, terminal deoxy-
nucleotidyltransferase (TDT) and
20 alpha hydroxysteroid dehydrogenase (20 alpha SDH), were used to classify
lymphomas induced by the Moloney leukemia virus (M-MuLV). Different subtypes of T cells were shown to be involved in different types of
lymphoma.
Thymomas were TdT-positive and grew as subcutaneous solid
tumors at the site of inoculation. Spleen cells from mice with generalized
lymphoma were of two types. In the majority of cases the
lymphomas consisted of 20 alpha SDH-positive cells that homed to spleen and lymph nodes upon
transplantation. In a few cases the cells of enlarged spleens were TdT-positive and, like the TdT-positive
thymomas, could be transplanted as subcutaneous
tumors. Thus, TdT-positive and 20 alpha SDH-positive
T-cell lymphomas can be distinguished by their homing properties. Preleukemic thymus cells from M-MuLV inoculated mice can, after transfer to 400 -R irradiated syngeneic hosts, induce new
lymphomas by virus release or grow in an autonomous fashion in the recipients. Whether of donor or recipient type, these
lymphomas are TdT-positive. In contrast, preleukemic bone marrow cells give
lymphomas of donor type which are as heterogeneous for T-cell
enzymes as are
lymphomas induced by neonatal inoculation of M-MuLV.