Characterization of interleukin 2 (IL-2)-dependent cytotoxic T-cell clones. V. Transfer of resistance to allografts and tumor grafts requires exogenous IL-2

Effects of interleukin-2 (IL-2) on human plasma lipid, lipoprotein, and C-reactive protein

Six patients with confirmed malignant disease received four consecutive weekly cycles of human recombinant interleukin-2 (IL-2) 4 days/week, continuous iv. infusion, 3 X 10(6) U/m2/day. Plasma cholesterol decreased a mean of 7% within 24 hours after IL-2 infusion and decreased by 33% within 4 days. Plasma cholesterol was significantly lower than baseline concentration by day 21 (-21%), and day 25 (-41%) was significantly lower than day 21. Decreased plasma cholesterol was the result of decreased HDL and LDL cholesterol concentrations. Plasma triglyceride demonstrated a mean increase of 46% after 4 days of therapy and remained greater than baseline concentrations at all time points analyzed. Apolipoprotein AI and AII decreased concomitantly with HDL-cholesterol concentrations, whereas apolipoprotein B after an initial mean decrease of 17% during the first cycle was not significantly different from baseline during the fourth cycle. Apolipoprotein E and Lp(a) were not significantly affected by IL-2 treatment. Plasma C-reactive protein (CRP) increased by 79% within 24 hours of therapy, increased by 254% on day 4, then decreased to baseline concentrations by day 21 after 3 days off of IL-2. Day 25 CRP was elevated compared to both baseline and day 21 concentrations. IL-2 induced plasma lipoprotein changes may be due in part to the induction of interferon gamma.

Murine intracerebral interleukin-2 injection: pathological and immunological effects

The authors have investigated whether specific pathological changes and antibodies against interleukin-2 (IL-2) are induced after intracerebral administration of recombinant IL-2 (rIL-2). In addition, IL-2 receptor (IL-2R) expression was checked on the cell surface of normal brain tissues before and after the intracerebral infusion. Reconstituted rIL-2 (specific activity 1.2 x 10(7) U/mg protein) was injected into the right cerebral hemisphere of normal adult C57BL/6 mice in three different dose groups, each receiving single or multiple infusions of 8, 32, or 80 U. In sham control experiments, mouse albumin purified by gel filtration and ion exchange chromatography and adjusted to the same concentration of protein as rIL-2 was injected into mice at various doses. Anti-IL-2 antibodies were measured by an enzyme-linked immunosorbent assay concurrently with assessment of IL-2 activity in serum. The IL-2R expression was determined by using immunofluorescence techniques with monoclonal antibodies against mouse IL-2R. Since histological alteration after rIL-2 injection did not differ from that in the sham control preparations, it seems that there is no direct toxic action of rIL-2 on normal brain tissues. Interleukin-2 antibodies were produced at low levels only in mice injected repeatedly at the maximum dose, and levels were insignificant in other groups. Serum levels of IL-2 activity remained low. The IL-2R expression within the brain was not enhanced within 8 weeks following the intracerebral administration of rIL-2, suggesting that direct intracerebral infusion of rIL-2 may be safely used in the immunotherapy of brain tumors.

Effects of lymphokine-activated killer cells and interleukin-2 on the ascites formation and the survival time of nude mice bearing human ovarian cancer cells

The effect of intraperitoneal instillations of interleukin-2 (IL-2) and/or lymphokine-activated killer (LAK) cells on the ascites formation and the survival time was examined using nude mice as a model, with malignant ascites produced by intraperitoneal inoculation of human ovarian cancer cells derived from ascites of a patient with serous cystadenocarcinoma of the ovary. Twenty-eight days after tumor inoculation, all nude mice in the untreated group and in the group treated with spleen cells alone formed ascites. Two of ten nude mice treated with IL-2 alone after tumor inoculation survived without forming ascites during the experimental period. On the other hand, all nude mice treated with LAK cells alone had formed ascites 14 days after tumor inoculation. When LAK cells and IL-2 were combined, five of ten mice survived without forming ascites during the experimental period. The survival time of the group treated with IL-2 alone was significantly prolonged compared to the groups that received medium alone, spleen cells alone and LAK cells alone. When administration of LAK cells was followed by IL-2, the survival time was further prolonged.

Transfer of murine host protection by using interleukin-2-dependent T-lymphocyte lines

We have demonstrated in this study that long-term, interleukin-2 (IL-2)-dependent, salmonella antigen-specific T-lymphocyte lines, as well as peritoneal exudate-enriched T cells, could be developed from both the antigen-sensitized inguinal and periaortic lymph nodes. Only those lines (salmonella-specific lymph node cells or peritoneal exudate T cells) were capable of adoptively transferring significant host protection (P less than 0.01) compared with the immune reactions of lethally challenged naive controls or of mice that had ovalbumin-specific T-cell lines transferred. Of particular interest was the finding that IL-2-dependent T-cell lines derived from the lymph nodes could only confer host protection to naive mice when both the transfer and challenge dose were administered via the intravenous route. Likewise, those T-cell lines derived from the peritoneal exudate were only capable of adoptively transferring significant protection when the cells and challenge dose of salmonellae were administered intraperitoneally. These studies indicate that systemic host protection can be transferred to naive mice, but depending on the source, the IL-2-dependent T-cell lines (lymph node or peritoneally isolated) functioned differentially upon challenge. Also, the results of this study indicate that the administration of greater numbers of IL-2-specific T cells may result in decreased, rather than enhanced, host protection. This may be due to the fact that the IL-2-dependent T-cell population consisted of 20 to 25% Lyt-2,3+ cells, indicating that cells of the suppressor/cytotoxic phenotype were present. Thus, increasing the number of cells transferred may result in an abrogation of protection.

Potential uses of interleukin 2 in cancer therapy

Interleukin 2 (IL 2) has several potential uses in cancer therapy including: the augmentation of specific T cell mediated anti-tumor immunity and the activation of non-specific cytolytic effector cells, termed lymphokine-activated killer (LAK) cells. The current review will present data from our laboratory demonstrating in animal models the feasibility of both potential approaches. Studies to be reviewed show that: IL 2 can induce the proliferation and expansion in number of tumor-reactive T cells in vitro; T cells grown in culture in IL 2 can be effective reagents in vivo for specific tumor therapy; the administration of exogenous IL 2 can induce the growth and augment the function of cultured T cells in vivo; however, as a corollary, T cells cultured long-term in vivo with IL 2 are functionally limited in vivo without the administration of exogenous IL 2 in vivo; by contrast, T cells grown in vitro with specific antigen, as opposed to IL 2, as the major stimulus for proliferation are able to proliferate rapidly in vivo, distribute widely in host lymphoid organs, and mediate therapy of disseminated murine leukemia; importantly, such antigen-driven long-term cultured T cells can survive long-term in vivo and provide specific immunologic memory, and, the administration of low-dose IL 2 in vivo can induce the growth of antigen-driven long-term cultured T cells in vivo and thereby increase the number of functional memory T cells; the culture of lymphoid cells in high concentrations of IL 2 can induce LAK cells in vitro capable of lysing leukemia in vitro; LAK cells generated in vitro can mediate a small but detectable anti-tumor effect in vivo against disseminated leukemia as an adjunct to chemotherapy; and, high-dose IL 2 administered in vivo can activate LAK cells in vivo and cure disseminated murine leukemia. Therefore, it is highly likely that IL 2 can become an effective reagent for the therapy of human cancer.

Antigen-driven long term-cultured T cells proliferate in vivo, distribute widely, mediate specific tumor therapy, and persist long-term as functional memory T cells

Mice bearing disseminated syngeneic FBL-3 leukemia were treated with cyclophosphamide plus long term-cultured T cells immune to FBL-3. The cultured T cells for therapy had been induced to grow in vitro for 62 d by intermittent stimulation with irradiated FBL-3. At the time of therapy, such antigen-driven long term-cultured T cells were greatly expanded in number, proliferated in vitro in response to FBL-3, and were specifically cytotoxic. Following adoptive transfer, donor T cells persisting in the host were identified and counted using donor and host mice congenic for the T cell marker Thy-1. The results show that antigen-driven long term-cultured T cells proliferated rapidly in vivo, distributed widely in host lymphoid organs, and were effective in tumor therapy. Moreover, the already rapid in vivo growth rate of donor T cells could be augmented by administration of exogenous IL-2. When cured mice were examined 120 d after therapy, donor L3T4+ T cells and donor Lyt-2+ T cells could be found in large numbers in host ascites, spleen, and mesenteric and axillary lymph nodes. The persisting donor T cells proliferated in vitro, and became specifically cytotoxic in response to FBL-3, demonstrating that antigen-driven long term-cultured T cells can persist long term in vivo and provide immunologic memory.

Adoptive immunotherapy of cancer with immune and activated lymphocytes: experimental and clinical studies

Recent studies of passive adoptive immunotherapy of experimental tumors indicate that histologically different neoplasms can be cured by this procedure in mice, rats and guinea pigs. In this paper two main approaches of adoptive immunotherapy with lymphocytes are considered. One which makes use of specific tumor-immune cells and is applicable to immunogenic tumors, and the other which uses activated (allostimulated and/or IL-2-activated) lymphocytes and is applicable to immunogenic and non-immunogenic neoplasms. Experimental models of both approaches and results provided by them are reviewed. These studies indicate that transfer of tumor-reactive lymphocytes with or without the combined administration of IL-2 into syngeneic tumor-bearing animals can lead to the eradication of a disseminated neoplasia when certain conditions are met. In particular, it was found that high tumor burdens, delay of treatment and low number of transferred lymphocytes can adversely affect the results. It has also been shown that the therapeutic effect of treatment with anti-cancer drugs or irradiation may be significantly improved by the addition of adoptive immunotherapy. The successful treatment of immunogenic tumors often requires the inhibition of suppressor lymphocytes by Cy or irradiation. Non-immunogenic tumors can be successfully treated only by providing activated lymphocytes and high doses of IL-2. Recent findings of few available human studies of adoptive immunotherapy are also reviewed, and the problems of toxicity and possible therapeutic effects of infusion of autologous, activated lymphocytes and IL-2 are discussed.