Phenotyping of human tumor-infiltrating lymphocytes before and after exposure to different in vitro stimulation conditions.

Tumor-infiltrating lymphocytes (TiL) and autologous peripheral blood lymphocytes (PBL), mainly from breast and kidney tumor patients were cultivated with high- and low-dose rIL-2 under addition of autologous tumor cells or nonmalignant epithelial cells. Tumor cells added to TIL-cultures induced an additional proliferative response. Before cultivation, CD8+ and CD25+ lymphocytes were more frequent in TIL when compared to PBL, while CD16+, CD19+ and CD56+ cells were rare. After culture, lymphocytes of both origins showed an increase of CD2+, CD25+, CD56+ and HLA-DR+ cells and a relative decrease of CD3+ cells. The CD4+/CD8+ ratios and a number of CD56+ cells were rIL-2 dose dependent.