Toledo Cells

The Toledo cell line is a diffuse large B-cell lymphoma (DLBCL) cell line that was originally established from the peripheral blood of a patient with DLBCL who later developed a secondary lymphoma in the brain following high-dose chemotherapy and bone marrow transplantation. This cell line exhibits a complex karyotype with multiple chromosomal aberrations but does not possess the typical translocations associated with Burkitt’s lymphoma.

One of the unique characteristics of the Toledo cell line is its lack of immunoglobulin (Ig) polypeptide chain expression, and it also lacks detectable constant (C) region gene segments. Despite this, Toledo retains the ability to undergo somatic hypermutation in its variable (V) gene segments, a phenomenon typically observed in germinal center B cells. Intriguingly, Toledo accumulates intraclonal mutations at a higher frequency than other lymphoma cell lines such as Daudi and Raji, despite the absence of significant clonal mutations. This suggests that the mutation process may have continued in vitro after transformation, potentially offering a valuable model for studying the molecular mechanisms of somatic hypermutation.