Table 2

A large panel of tumor cells suppresses CTL activity in short-term coculture assays1

Suppression of CTL lytic ability2
Tumor lines
Meth A3 +
CMS43 +
CMS53 +
UV-5117 +
UV-5125 -
10ME +
10CR +
63 +
A20 +
Normal cells
B cell -
PEC4 -
B/c-N -

1H-2d anti-H-2b CTLs were cocultured with the indicated tumor lines or normal cells for three hours, followed by selection of T cells with Thy1.2 antibody and the MACS cell sorting system. CTLs were immediately tested in a four hour 51Cr release assay against EL-4 target cells. 2Greater than 25% suppression of CTL lytic ability is indicated by a "+"; Less than 25% suppression is indicated by a "-". 3In further analyses, the CTL suppression induced by these tumor lines was observed to be reversible. Thus, CTLs which are allowed to recover overnight in the presence of IL-2 regain 95% of their lytic ability (see Fig. 9b). 4Peritoneal exudate cells.