Ex vivo activated memory T-lymphocytes as adoptive cellular therapy of human soft-tissue sarcoma targets with potentiation by cis-diamminedichloroplatinum(II).

Autolymphocyte therapy (ALT) is tumor-specific, adoptive cellular therapy of neoplastic disease using nonspecific ex vivo activation of autologous peripheral blood lymphocytes (PBL), which are composed primarily of memory T-cells (ALT-cells) and are active in patients with metastatic renal cell carcinoma and melanoma. Ex vivo pretreatment of tumor target cells with certain chemotherapeutic agents can enhance susceptibility to lysis by antitumor lymphocytes. To determine if cis-diamminedichloroplatinum(II) (CDDP) enhances ex vivo antitumor cytotoxicity of ALT-cells and if this lysis is mediated by T- and/or NK-cells and is human leukocyte antigen (HLA)-restricted, human soft tissue sarcoma (STS) target cells were derived from primary and metastatic surgical specimens and were incubated with and without CDDP. ALT-cells were prepared from autologous PBL obtained prior to surgery. Primary (PSTS) and metastatic (MSTS) target cells from each group were labelled with chromium 51 (51Cr) and used as targets for ALT-cells, CD45-depleted ALT-cells, CD56 (NK)-depleted ALT-cells, and PBL in a standard (4-hour) and delayed (18-hour) 51Cr release assay. Interferon-gamma (IFN-gamma) release was measured as an indication of antitumor effect and recognition by the noncytolytic lymphocytes in ALT-cells. Primary tumor target cells incubated in CDDP showed enhanced lysis as measured by the 51Cr release assay compared to non-CDDP-treated controls. Metastatic tumor target cells showed less lysis than the primary targets, although this was enhanced by pretreating metastatic tumor targets with CDDP. Lysis of all tumor targets was significantly greater when ALT-cells were used as the effector cells rather than PBL. Depletion of memory T-cells abrogated ex vivo lysis. Depletion of NK cells (CD56+) affected ex vivo lysis of autologous targets during the 4-hour but not the 18-hour assay. Ex vivo ALT-cell lysis and IFN-gamma release against only the autologous tumor targets confirmed tumor-specificity in one patient. Restriction of ALT-cell lysis and IFN-gamma release against HLA-A2+ autologous and one allogeneic HLA-A2+ STS tumor target, but not other non-STS targets, was demonstrated in another patient. These data suggest that CDDP may help render STS susceptible to tumor-specific, immune-mediated attack and that the combination of ALT and CDDP may lead to effective tumor-specific chemoimmunotherapy in patients with metastatic STS.