Enhanced human lymphokine-activated killer cell function after brief exposure to granulocyte-macrophage-colony stimulating factor.
BACKGROUND
Lymphokine-activated killer (LAK) cell function can be generated in peripheral blood mononuclear cells (PBMC) after brief exposure of high dose interleukin-2 (IL-2) over the course of 1 or 2 days' culture in plain culture medium (IL-2-pulsed PBMC). The aim of the present study was to investigate the ability of granulocyte-macrophage-colony stimulating factor (GM-CSF) to augment LAK induction in low dose IL-2-pulsed PBMC derived from patients with cancer undergoing immunotherapy with IL-2.


METHODS
Peripheral blood mononuclear cells were collected from patients with cancer receiving a 5-day cycle of local (intraperitoneal or intrapleural) infusions with IL-2. The cells were incubated with IL-2 in the presence or absence of GM-CSF for 1 hour and then tested as effectors against allogeneic tumor cells and LAK-sensitive cell lines.


RESULTS
Granulocyte-macrophage-colony stimulating factor at doses between 10 and 100 ng/ml was synergized with low dose IL-2 (100 IU/ml) in the generation of LAK activity in PBMC. Lymphokine-activated killer cell-mediated cytotoxicity derived from PBMC cultures incubated with IL-2 and GM-CSF was significantly higher (up to three-fold) compared with that generated with IL-2 alone. The GM-CSF-induced enhanced LAK activity was maintained when tested at day 5. GM-CSF increased the percentages of IL-2 receptor (R) positive (+) and CD8+ cells in the IL-2-pulsed PBMC. In contrast to CD56+ cells, highly purified CD8+ cells isolated from PBMC pulsed with IL-2 and GM-CSF responded with increased LAK activity, thus representing the cell-type that mediates the augmenting effect of GM-CSF. Major histocompatibility complex (MHC) molecules or the CD3 surface antigens were not involved in the GM-CSF-mediated enhancement of LAK induction because anti-MHC class I and class II monoclonal antibodies (MoAb) or MoAb against the CD3 molecules remained without any effect in this system. The GM-CSF-mediated LAK-enhancement was IL-2-dependent because MoAb against IL-2 receptor completely inhibited the generation of LAK activity.


CONCLUSIONS
The use of GM-CSF for the enhancement of IL-2-induced LAK activity in 1 hour cultures may improve clinical results in cancer immunotherapy. In addition, implementation of this procedure could eliminate the high cost of cell culture which usually accompanies IL-2/LAK cell therapy as well as eliminate the known toxic side effects associated with this kind of therapy.
Baxevanis
C N
CN
Department of Immunology, Hellenic Anticancer Institute, Athens, Greece.
Dedoussis
G V
GV
Papadopoulos
N G
NG
Missitzis
I
I
Beroukas
C
C
Stathopoulos
G P
GP
Papamichail
M
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D019002:CD56 Antigen / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D003602:Cytotoxicity, Immunologic; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D006801:Humans; D016219:Immunotherapy, Adoptive / Q000379:methods; D007376:Interleukin-2 / Q000494:pharmacology; D015979:Killer Cells, Lymphokine-Activated / Q000276:immunology*; D008297:Male; D015375:Receptors, Interleukin-2 / Q000378:metabolism
D019002:CD56 Antigen; D007376:Interleukin-2; D015375:Receptors, Interleukin-2; D016178:Granulocyte-Macrophage Colony-Stimulating Factor