Establishment and characterization of a human null-cell lymphoblastic lymphoma cell line (K-LL-3)

Abstract

A new cell line (K‐LL‐3) with exceptional characteristics was derived from a bone‐marrow aspirate from a patient with poorly differentiated lymphoblastic lymphoma. The cell line was established and the cells maintained on agar feeders for over 1 year. The morphology and cytochemical staining of the primary tumor and the cell line were remarkably similar. The growth characteristics, chromosome pattern, cell‐surface receptors and Epstein‐Barr virus studies clearly differentiated this cell line from non‐malignant lymphoblastoid cell lines. The assay technique used was able to correlate in vitro colony growth with the patient's clinical course. The cells grew on the agar as colonies rather than as a single‐cell suspension, and individual colonies could be aspirated and successfully passaged. The K‐LL‐3 cells lacked cell‐surface markers (cytoplasmic and surface immunoglobulins, Fc receptors, C₃ receptors, SRBC) except HL‐A and thus were classified as null cells. These cells were EBNA (Epstein‐Barr virus‐specific nuclear antigen) negative and had a pseudodiploid 46XY karyotype.