Tumor infiltrating lymphocytes: the effect of bacillus Calmette Guerin on helper/suppressor-T cell ratios of treated and untreated tumors.

Copenhagen X Fischer rats bearing single and bilateral Dunning R3327 AT-3 tumors were either treated or not treated at a single site with bacillus Calmette Guerin (BCG). One week later tumors were removed, tumor infiltrating lymphocytes (TIL's) isolated, and then characterized for total-T, helper-T and suppressor-T cell subsets utilizing monoclonal antibodies. The purpose was to determine the effect of BCG on TIL's in treated as well as untreated tumors. In summary: 1) BCG treatment significantly alters TIL distributions at both injected and noninjected sites; 2) a noninjected contralateral tumor compromises the effectiveness of BCG therapy at the suppressor T cell level; 3) contralateral tumors, whether inoculated or not, have similar TIL distributions.