Mitogenic stimulation of human tumor-infiltrating lymphocytes by secreted factor(s) from human tumor cell lines.

Abstract

Tumor-infiltrating lymphocytes (TILs) have shown in vivo antitumor efficacy in both animal and human studies. Functions thought necessary for antitumor activity include cytolysis, homing, and proliferation at tumor sites. TILs, which are T lymphocytes grown ex vivo directly from tumors, bear interleukin 2 (IL-2) receptors capable of transducing the IL-2 mitogenic signal. However, IL-2 is not normally synthesized by solid tumor cells. This study was aimed at exploring the possible presence of T-cell mitogens of tumor origin. To this end four TIL lines derived from four melanoma patients were studied for their ability to use the environments of cultured tumor cell lines as mitogenic sources. The presence of four irradiated cultured human tumor cell lines, three of which were derived from the same melanoma patients as the TILs, were found to stimulate proliferation of human TILs in the absence of IL-2. Further investigation showed that the observed proliferative stimulation by the fourth tumor line was due to secreted factor(s) as mitogenic activity was present in the serum-free tumor cell supernatant. Both immunologic analyses of this medium and proliferative assays in which TILs were stimulated with recombinant lymphokine standards suggest the presence of a yet uncharacterized T-cell mitogen.The idea that the tumor environment is intrinsically immunogenic and, therefore, contains lymphocytes with the potential to induce tumor regression has led to the use of tumor-infiltrating lymphocytes (TILs) in clinical trials (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). In this procedure lymphocytes are grown ex vivo directly from tumors in the presence of the lymphokine interleukin 2 (IL-2); patients are reinfused with their TILs after the latter have been expanded in culture for several weeks. Although 60% of metastatic melanoma patients who had not previously received any immunotherapy showed objective responses in the largest clinical TIL trial to date (15), the characteristics of the tumor environment that produces TILs in vivo remain unclear.Two classes of stimuli-one derived from cell-cell contact between tumor cells and immunocytes and the other from soluble factors-may influence T-cell homing and proliferation. IL-2 is a potent mitogen for T cells, the cell type of TILs used (Table 1); however, its biosynthesis appears to be confined to immunocytes (16). This fact is consistent with the current belief that immunologically competent cells such as lymphocytes and monocytes represent the major sources of secreted mitogenic stimulation for lymphocytes. In this study the subject of soluble factors secreted by tumor cell lines as sources of stimuli for lymphocyte proliferation was addressed.As a starting point for this work, the issue of whether a tumor cell line established from a melanoma tumor could stimulate the growth of TILs derived from melanoma masses was examined. After confirming the amplification potential of three melanoma cell lines, a nonmelanoma line was tested for the same bioactivity and found...

Human tumour-associated NK cells secrete increased amounts of interferon-γ and interleukin-4

“…It is, therefore, possible that this and/or other cytokines secreted by the neoplastic cell population may play a part in the stimulation of NK cell secretory activity at the tumour site. They may also play a part in the mitogenic stimulation of lymphocytes by tumour cell lines recently reported by Packard (1990).…”

Combined Ultrafiltration-Transduction in a Hollow-Fiber Bioreactor Facilitates Retrovirus-Mediated Gene Transfer into Peripheral Blood Lymphocytes from Patients with Mucopolysaccharidosis Type II

“…In the past, hollow -fiber bioreacto rs have been used for productio n of industrial and clinical-g rade reagents such as monoclonal antibodies (Knight, 1989;Roggenbuck et al, 1995;Inoue et al, 1996), expansion of infusible cells (Knazek et al, 1990;Packard, 1990;Freedm an et al, 1994), and other biologics destined for pharm acologica l applicati ons (Bano et al, 1985;Liu et al, 1987;Liu et al, 1991). An ACS available commercially (Cellco Division, Spectrum Laboratorie s, Lagura Hills, CA) would provide the potential advantage s of introducing a fixed pericellul ar environm ent and accomm odating a relatively large quantity of cells at high cell density; in fact, tum or-infiltr ating lym phocytes have been grow n in this system (Knazek et al, 1990).…”

Improved gene transfer and normalized enzyme levels in primitive hematopoietic progenitors from patients with mucopolysaccharidosis type I using a bioreactor

“…The application of a hollow‐fiber bioreactor system (HBS) may provide a solution for many of the difficulties associated with hematopoietic stem cell gene transfer. In the past, such systems have been used for production of industrial and clinical‐grade reagents such as monoclonal antibodies 24, cell lines 25, 26, and other biologics destined for pharmacological applications 27, 28. In our previous work 29, we have demonstrated that an HBS could be used to culture and transduce human primary peripheral blood lymphocytes (PBL) in clinically useful quantities (up to 10 10 primary PBL).…”