CLONAL PROLIFERATION AND LONG-TERM CULTURE OF MALIGNANT LYMPHOMA CELLS UNDER SERUM-FREE CULTURE CONDITIONS

We developed a serum-free culture system that promoted the growth of B cell colonies in peripheral blood, bone marrow, lymph nodes and cerebrospinal fluid (CSF) from 7 out of 8 patients with non-Hodgkin's lymphomas of B cell type. The culture cells were pretreated with or without galactose oxi-dase (GO) prior to plating. Colony growth was best supported with BCGF. A moderate increment was observed with rIL-3, as well as rIL-1β and even to a lesser degree, by rlL-2, while B cell stimulating factor-2 (rBCSF-2) and rlL-1β did not show significant activity. rGM-CSF and rG-CSF had little effect, while rM-CSF enhanced the formation of lymphoma colonies. The cells from different patients had different requirements for Staphylococcus aureus protein A and GO pretreatment. It reflected the differences in activation and differentiation status and surface properties of lymphoma cells from different patients. The cells from CSF of one patient were successfully maintained in serum-free culture medium supplemented with 10% BCGF or 5% PHA-LCM for more than 4 months. The long-term culture cells were EBV negative, phenotypically consistent with B cells and gene rearrangements for JH, Kappa and myc. This serum-free culture system allowed extensive analysis of the growth requirements for clonogenic precursors.

Establishment of a Human Malignant T Lymphoma Cell Line Carrying a Retrovirus-like Particles with RT Activity

We have established an IL-2 independent malignant lymphoma line (CM-1) from peripheral T lymphocytes donated by a femalc patient with nervous systcm disease, the binlogical characteristics of CM-1 cells was studied in this paper. Another T lymphocytes,such as peripheral T lymphocytes donated by a maIe patient with multiple sclerosis, could be transformed into a malignant lymphoma line by using filtered supernatant of the CM-1 cultured medium, thus the CM-2 cell line u'as estabIished. The CM-1 and CM-2 cells were transplanted by subcutaneous inoculation into nude mice, and could cause the occurrenceof typical maIignant lymphoma. The observation of eIectron micrographs suggested the existence of virions in the CM-1 and CM-2 cells, and these virions were similar toretrovirus in the ultra-structure characteristics. lt was found that this virus possesses reverse transcriptase activity. ResuIts obtained from serological assay, molecular hybridization and PCR excluded the existence of other human viruses, which were commonly usedin our laboratory. The unknown virus possesses strong transformation activity, and probably is a new retro virus. Meanwhile, the work on the clone and sequence analysis ofthis virus are being carried out.

EXPRESSION OF PROLIFERATING CELL NUCLEAR ANTIGEN IN CUTANEOUS MALIGNANT LYMPHOMAS AND LYMPHOID INFILTRATES

Paraffin-embedded tissue of skin biopsy specimens taken retrospectively from 24 patients with cutaneous malignant lymphomas (CML) and 8 patients with cutaneous lymphoid infiltrates (CLI) and other dennatoses were studied retrospectively with PCIO immunostaining. The results show a statistical significant difference among PCIO indices for cutaneous genuine histiocytic lymphoma (CGHL), cutaneous germinal center cell-derived lymphomas (CGCCL), cutaneous peripheral T-cell lymphomas (CPTL), non-mycosis fungoides (MF) and Sezary's syndrome (SS), and MF when compared with those for CLI. There is a linear relationship between PCIO index and square root of PCIO density, both of which seem to have a parallel relationship to the severity of malignancy in CML. The nuclear volume of the positive tumor cell or lymphocyte with PCIO immunostaining may be also useful in differentiating CML from CLI.