MedB-1, a human tumor cell line derived from a primary mediastinal large B-cell lymphoma

Primary mediastinal B-cell lymphoma is a locally highly aggressive but poor ly disseminating tumor composed of medium sized or large cells most probabl y of thymic medullary origin. it has a mature B-cell phenotype, typically l acks immunoglobulin expression and has variable defects in expression of HL A-molecules. We present here a cell line, MedB-1, derived from such a tumor . As is frequently found in mediastinal B-cell lymphomas in situ, MedB-1 is CD10(-), CD19(+), CD21(-). CD22(+), CD23(+) CD25(-), CD37(+), CD38(-), CD3 9(+), CD40(+), CD54(+), CD95(+), Like the parental tumor, MedB-1 lacks HLA- A,B,C alpha -chains and beta (2)microglobulin and expresses HLA-D molecules at decreased levels. Both parental tumor and MedB-1 cells are clonally rel ated as shown by immunoglobulin heavy chain gene rearrangement analysis, Un like the parental tumor tissue, the MedB-1 cell line cytoplasmically expres ses IgG/kappa in a very small subset of cells under standard culture condit ions. MedB-1 does not contain any Epstein-Barr virus DNA, In a tissue adhes ion assay MedB-1 cells showed an extensive binding to the medullary region of normal thymus, Altogether, MedB-1 is a suitable tool for functional and molecular analysis of this distinct lymphoma entity. (C) 2001 Wiley-Liss. I nc.