Enhancement of the lytic activity of cloned human CD8 tumour-infiltrating lymphocytes by bispecific monoclonal antibodies

Abstract

SUMMARYWe have isolated tumour-infiltrating lymphocytes (TIL) clones from a patient wilh renal cell cancer. The cloning frequency and the effector function were measured. No difference in cloning frequency (H = 0-97, frequency = 1: i3) was observed between TIL expanded with ailogeneic rt'r^w.s autologous feeder cells. Sixty-four clones expanded with aulologous feeder eells and 37 clones expanded with allogeneic feeder cells were assayed for cytolytie activiiy on an autologous primary renai cell carcinoma (RCC) culture, an allogeneic RCC line, and on the K562 and Daudi cell lines. Most of these elones were also phenolyped. Although TIL clones expressing cytotoxie activity for RCC lines could be generated with both feeder cell preparations, none of the clones tested showed specificity for ceils from autologous primary RCC cultures. However, in the presence of relevant bispecific MoAbs (aOC/TR) all CDX' TIL clones tested could be induced to Iyse aulologous RCC cultures. Furthermore, the cytolytie activity of all CD8' clones tested against allogeneic RCC lines could be induced or furlher enhanced by aOC/TR or CD3/G250 bispeeific MoAbs. In contrast, none of the CD4' clones tested showed lytic activity. Quantitatively the eyloloxic response in the presence of «OC/TR or CD3/G250 of CD8^ TIL clones against G25O^ and MOvlS* cell lines appears to be associated with ihe level of antigen expression on [he target cells. Our results suggest thai; (i) expansion of TIL wilh allogeneic or aulologous feeder cells does not elTeet the lytic prolilc of the clones; (ii) the use of bispecific MoAbs may overcome a lack of specificity of eytotoxic T lymphocytes.

Tumour-infiltrating lymphocytes in primary melanoma: functional consequences of differential IL-2 receptor expression

“…In this study we demonstrate the heterogeneity of TILs obtained from early primary melanoma (Clark level III) by phenotypic and functional characterization. The yield of TILs from primary melanoma was lower than that reported for metastatic tumours [4][5][6] and themajor problem was contamination with residential skin bacteria and fungi. TIL were expanded in vitro using cultures conditions with low concentrations of IL-2 (50 U/ml).…”

“…and therefore contains lymphocytes with the potential to induce tumour regression, has led to the use of tumourinfiltrating lymphocytes (TIL) in clinical trials . In Ihis procedure lymphocytes are grown (' .Yi-iV/; directly fVom tumours in the presence of the lymphokine IL-2 [5]. Although 6O' M. of metastatic melanoma patients who had not previously received any immunotherapy showed objective responses in the largest clinical TIL trial to date [6], the characteristics of the tumour environment that produces TILs in vivo remains unclear.…”