Human tumor cells grown in fetal calf serum and human serum: Influences on the tests for lymphocyte cytotoxicity, serum blocking and serum arming effects

Abstract

Peripheral blood lymphoid cells (PBL) from cancer patients and normal donors were tested against three melanoma cell lines grown in either 10% fetal calf serum (FCS) or 2.5-5% human AB serum in order to determine if the heterologous membrane (HM) antigen or other FCS antigens acquired from the bovine serum supplement could influence lymphoid cell-mediated cytotoxicity in vitro. FCS-grown melanoma cells were more susceptible than the AB serum-grown subline to lymphocyte cytotoxic effects. Arming effects by autologous sera on normal donor lymphocytes and to a lesser extent on lymphocytes of cancer patients were more pronounced on the FCS-grown M12 melanoma cells. This effect was abrogated when the cells were grown in human AB serum for at least 8 weeks. The non-HM tumor-associated antigen remained at the same original low level. Blocking effects were more evident on the AB-grown M14 melanoma line. These data suggest that the FCS antigens on the cell surface may have been responsible for the augmented PBL cytotoxicity. The anti-FCS antibody present in normal and cancer patients' blood induced an antibody-dependent cellular cytotoxicity (ADCC). Elimination of arming activity against HM or other FCS antigens from AB-grown cells may have made the serum blocking factors more apparent. However, cytotoxicity against tumor cells by PBL from normal donors was still apparent even on the human serum-grown cells, suggesting that a different antigen-antibody system was also responsible for this "non-specific" activity.

Identification of a subpopulation of lymphocytes in human peripheral blood cytotoxic to autologous fibroblasts.

“…Naturally occurring human cells, spontaneously cytotoxic for long-term lymphoblast and solid tumor tissue culture lines, have been described (9,10) and may, in some cases, be due to acquired heterologous serum antigens (16). Experiments with short-term allogeneic or autologous fibroblast cultures have shown no cytotoxicity and have been used as control for tumor-specific cytotoxicity (17).…”

MDA-MB-435 and M14 Cell Lines: Identical but not M14 Melanoma?

“…The M14 human melanoma cell line, also called UCLA-SO-M14, was derived at the University of California Los Angeles (19). Chee and colleagues noted that ''the original culture was derived from an amelanotic lesion metastatic to the buttock of a 33-year-old patient'' (20).…”

Cell mediated cytotoxicity to human melanoma cell lines: Nonspecific active in vitro augmentation

“…Our findings in the present study support the latter view, in that T cells recovered from E-rosettes retained "natural" CMC, while the E-rosette depleted population was inactive (Table 4). "Natural" CMC is stronger against long-term melanoma cell lines than short-term lines (de Vries et al, 1974), especially if the lines are maintained in media containing fetal calf serum (Sulit et al, 1976), and may co-exist with a degree of tumor-specific CMC (der Vries and Rfimke, 1976;Steele et al, 1976). It was not our purpose in the present study to analyze this "natural" CMC; rather, we sought to augment CMC by in vitro stimulation of PBL, using in each case the "natural" CMC of unstimulated PBL as a control value.…”