In vitro activation of low-grade non-Hodgkin's lymphoma by murine fibroblasts, IL-4, anti-CD40 antibodies and the soluble CD40 ligand.
The in vitro analysis of growth regulation in low-grade B non-Hodgkin's lymphoma (B-NHL) is hampered by the rapid apoptotic death of the malignant B cells ex vivo. A complex culture system, using murine CDw32 transfected fibroblasts (LTK-cells), IL-4 and anti-CD40 mAb, has been established for the propagation of normal mature B cells in vitro. We investigated the influence of the different components of this coculture system on cell survival and apoptosis of B-NHL cells. Nine samples from patients with follicular lymphoma and from eight patients with immunocytoma were analyzed. No cell proliferation of B-NHL cells could be induced in the culture system. However, CDw32-transfected murine fibroblasts most efficiently supported cell viability of B-NHL cells with an increase in cell survival by 114% compared to the control (P = 0.047). IL-4 alone also had a stimulatory effect on cell survival of B-NHL cells after 6 days. In contrast, the soluble recombinant CD40 ligand gp39 and the anti-CD40 mAbs mAb89 and EA-5 did not prolong cell survival. CDw32 transfectants blocked apoptosis of B-NHL cells efficiently from 67% in the control to 16% (P = 0.001). Reduction in apoptosis was accompanied by an elevated bcl-2 protein expression. IL-4 or mAb89 did not further reduce apoptotic cell death in CDw32 transfectant-dependent cocultures. Our data underline the pivotal role of LTK- cells for cell survival of B-NHL cells in vitro. The efficient blockage of apoptosis associated with increased bcl-2 protein expression causes prolonged cell viability of the B-NHL cells.
Buske
C
C
Department of Hematology/Oncology, University of Göttingen, Germany.
Twiling
A
A
Gogowski
G
G
Schreiber
K
K
Feuring-Buske
M
M
Wulf
G G
GG
Hiddemann
W
W
Wörmann
B
B
D000368:Aged; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D017209:Apoptosis; D019013:CD40 Antigens / Q000276:immunology; D023201:CD40 Ligand; D002470:Cell Survival / Q000187:drug effects*; D005347:Fibroblasts / Q000187:drug effects / Q000502:physiology*; D005434:Flow Cytometry; D019254:Genes, bcl-2 / Q000235:genetics; D006801:Humans; D015847:Interleukin-4 / Q000494:pharmacology*; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000473:pathology* / Q000503:physiopathology; D008224:Lymphoma, Follicular / Q000473:pathology* / Q000503:physiopathology; D008562:Membrane Glycoproteins / Q000494:pharmacology; D051379:Mice; D008875:Middle Aged; D014162:Transfection
D000911:Antibodies, Monoclonal; D019013:CD40 Antigens; D008562:Membrane Glycoproteins; D023201:CD40 Ligand; D015847:Interleukin-4