Journal of immunotherapy with emphasis on tumor immunology : official journal of the Society for Biological Therapy最新文献

We immunohistochemically evaluated lymphoid cell infiltration and HLA-DR antigen expression in gastric tumor tissue obtained from advanced gastric cancer patients 1 day after the completion of the treatment with mitomycin C (MMC) 12 mg/m2 i.v. on day 1 and recombinant interleukin-2 (IL-2) i.v. every 12 h from day 4 through day 8. Then the results were compared with those in 11 patients pretreated with MMC alone, 5 treated with IL-2 alone, and 24 untreated patients. Widespread lymphoid infiltration was observed in 17% of untreated tumors, 27% of MMC-pretreated tumors, and 40% of tumors treated with IL-2 alone. However, 71% of carcinomas pretreated with MMC plus IL-2 exhibited widespread infiltration. The frequency of cases with high-grade infiltration of CD4+ cells was significantly higher in either group of patients treated with MMC alone or MMC plus IL-2. Because the CD8+ cell infiltration was not significantly altered, the ratio of CD4+ to CD8+ cells estimated as being > 1 was more frequently noted in patients given MMC alone or MMC plus IL-2, as compared with untreated control. Furthermore, 86% of tumors pretreated with MMC plus IL-2 exhibited positive HLA-DR antigen expression, whereas 29% of untreated carcinomas did so. MMC or IL-2 alone did not significantly increase HLA-DR expression. These results indicate that the combination of low-dose of IL-2 with MMC enhances the intensity of lymphoid cell infiltration in tumors, with the predominance of CD4+ cells, and HLA-DR antigen expression on tumor cells in patients with advanced gastric carcinoma.

We previously reported that DT-5461 exhibits potent antitumor effects on various murine syngeneic tumors, probably via activation of host immune systems. Of the various systemic administration routes, intravenous (i.v.) administration gave the best antitumor effects. When the total dose was fixed, multiple and intermittent applications resulted in greater therapeutic efficacy than single and daily applications, respectively. The therapeutically effective applications of DT-5461 induced endogenous tumor necrosis factor (TNF) activity in serum and tumor tissue. The TNF activity peaked at 1-2 h after the administration. Although TNF activity in the serum declined to an undetectable level by 4 h, intratumoral TNF activity persisted even at 16 h. TNF-alpha messenger RNA (mRNA) was clearly expressed in the tumor tissues as early as 0.5 h after the DT-5461 administration. DT-5461 also caused increases in interferon activity in tumor-bearing mice. In vivo treatment with anti-interferon-alpha/beta serum or anti-interferon-gamma serum, as well as with anti-TNF-alpha serum, significantly reduced the antitumor effect of DT-5461. DT-5461-induced endogenous TNF production was also inhibited by treatment with either of these anti-interferon antisera alone. These results suggest that intermittent i.v. administration is optimal for cancer treatment with DT-5461, and that the optimal application of DT-5461 causes a long-lasting production of intratumoral TNF-alpha that may play a crucial role in the antitumor mechanisms of this compound. Furthermore, endogenous interferons induced by DT-5461 are involved in the antitumor mechanisms of this compound, probably by regulating the intratumoral TNF induction.

Preclinical studies have shown that anti-CD3 antibodies can enhance the in vitro activation of human T lymphocytes in combination with low-dose interleukin-2 (IL-2) and induce the in vivo rejection of murine tumors. A Phase IA/IB trial combining a murine monoclonal antibody, anti-CD3 antibody (OKT3), with low-dose continuous-infusion IL-2 was conducted in cancer patients to define the toxicity and immunologic effects of this combination. OKT3 administered weekly as a 15-min infusion at dose levels of 10, 100, 200, 400, and 600 micrograms/m2 was followed 18 h later by a 100-h infusion of IL-2 at 3 MIU/m2/day for 3 consecutive weeks. When feasible, patients also received the IL-2 course without OKT3 to assess the effects of OKT3 on the IL-2 regimen within the same patient. Thirty patients were enrolled onto the study, with 24 completing the OKT3/IL-2 course and 18 completing both OKT3/IL-2 and IL-2 alone courses. OKT3 administration was associated with acute hypotension with fevers of > 40 degrees C and in two patients cerebral vascular infarcts. At 600 micrograms/m2 OKT3, these toxicities were dose limiting. In a dose-dependent manner, OKT3 induced the transient release of tumor necrosis factor (TNF) and IL-6 into the serum and a profound lymphopenia. OKT3 did not significantly enhance the toxicity of this schedule of IL-2 administration. All solid tumor patients treated at 100-600 micrograms/m2 OKT3 showed induction of a human anti-murine antibody response prior to the third week of treatment. A patient with renal cell cancer treated at the 600-micrograms/m2 OKT3 dose level experienced a 4-month partial remission, and two mixed responses were observed in a sarcoma and a melanoma patient treated at 100- and 400-micrograms/m2 OKT3 dose levels, respectively. Most importantly, we were unable to demonstrate that the addition of OKT3 enhanced immune activation within peripheral blood based upon the magnitude of rebound lymphocytosis, increase in CD56+ or CD3+, CD25+ lymphocytes, induction of natural killer, lymphokine activated killer, or cytolytic T lymphocyte cytotoxicity, or release of serum cytokines (TNF, IL-6) or soluble CD25 (as assayed 24 h following IL-2 infusion). Therefore, this approach was ineffective at enhancing the immunologic effects of a low-dose continuous-infusion IL-2 regimen and will not be pursued further in clinical trials.

The purposes of this study were to determine the maximally tolerated dose (MTD) of IL-2 when sequentially administered following TNF (at its MTD), to identify any unique toxicities, and determine the immunomodulatory effects of this combination. Patients with metastatic cancer were treated with 160 micrograms/ml rTNF by rapid i.v. infusion for 5 days, followed by rIL-2 therapy daily at doses up to 18 x 10(6) IU/m2/day for 5 days and 6 x 10(6) IU/m2/day for 7 days. Cycles were repeated at 3- or 4-week intervals until progressive disease or unacceptable toxicity developed. Fifteen patients received 46 cycles of therapy (range 1-8, median 3). Major toxicities included hypotension, weight loss, and decreased performance status comparable to that reported with rIL-2 alone. No novel toxicities were identified. Two of 14 patients who received two cycles of therapy had objective responses (1 complete, 1 partial). Both occurred in patients with malignant melanoma, lasted 30 and 75 weeks, respectively, and included a complete response in liver metastasis. Dosage reductions of IL-2 were necessary for 3 patients over 11 treatment cycles (23%), and rTNF in 1 patient for 1 cycle (2%). The MTD of 5-day infusional rIL-2 was determined at 18 x 10(6) IU/m2/day. rTNF did not augment natural killer/lymphokine-activated killer activities beyond that commonly seen with IL-2 infusions. We conclude that full doses of rTNF can be combined with escalating rIL-2 infusions in an outpatient setting without additive toxicity and with clinical activity in patients with malignant melanoma.

FC-2.15 is a new murine IgM monoclonal antibody (MAb) that recognizes previously undescribed antigens present in proliferating breast cancer cells and normal peripheral granulocytes. A phase I clinical trial was performed in 11 patients with advanced cancer (breast, 5; colon, 2; melanoma, 1; lung, 1; medullary thyroid, 1; skin squamous carcinoma, 1). FC-2.15 was administered by i.v. infusion every other day; eight patients received four infusions, two patients three infusions and one patient received two infusions. One patient received two cycles of treatment. Total doses of MAb ranged between 2.5 and 5 mg/kg. Maximal FC-2.15 serum concentrations for different patients ranged between 1.3 and 7.5 micrograms/ml, and the serum half-life (t1/2-alpha) was approximately 7-9 h. All patients developed human anti-murine antibody. The most consistent toxicity (10 of 11 patients) was a profound and selective neutropenia that occurred within 1 h after the start of each infusion and reversed within 1 h after its discontinuation. Other frequent side effects included fever and chills that were easily manageable. Only two patients needed dose reduction or treatment interruption. The patient who received two treatment cycles did not develop allergic reactions. An objective partial response, consisting of a sustained (4 months) > 50% reduction of breast carcinoma liver metastases, was observed.

We have previously shown that administration of cyclosporine A (CsA) plus interferon-gamma (IFN) after chemotherapy to mice bearing B16 melanoma results in the generation of cells with major histocompatibility complex (MHC)-unrestricted cytotoxicity in vitro and in vivo; the antitumor effect of these cells could be attenuated by normal spleen cells. This study shows that antitumor effect after treatment with CsA plus IFN after chemotherapy was mediated by T and natural killer (NK) cells, both in vitro and in vivo. Infusion of purified T or NK cells into secondary recipients after chemotherapy resulted in a significant control in the dissemination of tumor as compared to chemotherapy alone. The antitumor potential of NK cells was at least 10 times greater than that of T cells. The effector cells could inhibit the proliferation of tumor cells in vitro without a contact between the effector and tumor cells, suggesting that antitumor effect in this system was partly related to the secretion of cytotoxic factors by the effector cells. Infusion of normal spleen cells inhibited the antitumor effect of adoptively transferred effector cells. This study defines the nature of effector cells involved in mediating the antitumor effect in this model; the optimal efficacy of these cells in the recipient is possibly related to the abolition of a suppressor system by chemotherapy.

A phase IIb trial using liposome-encapsulated muramyl tripeptide phosphatidylethanolamine (L-MTP-PE) in combination with ifosfamide (IFX) for patients with relapsed osteosarcoma was undertaken to determine (a) the tolerability of the combination therapy, (b) if L-MTP-PE increased the toxicity of IFX, and (c) whether IFX altered or suppressed the in vivo immune response to L-MTP-PE. Patients had histologically proven osteosarcoma and pulmonary metastases that either developed during adjuvant chemotherapy or were present at diagnosis, persisted despite chemotherapy, and recurred following surgical excision. Stratum A patients were rendered clinically free of disease within 4 weeks of study entry prior to receiving combination therapy. IFX was administered at 1.8 g/m2 for 5 days every 21 days for up to eight cycles. L-MTP-PE was administered twice weekly for 12 weeks, then once weekly for 12 weeks. Once cycle of combination therapy was defined as 5 days of IFX and 3 weeks of L-MTP-PE therapy. Stratum B patients had measurable disease at study entry that was judged to be amenable to surgical resection. Stratum B patients received three cycles of combination therapy prior to surgery to judge clinical and histologic response. Postoperatively, patients received an additional five cycles. A total of nine patients were entered into the protocol: six on stratum A and three on stratum B. Serial blood samples were collected and assayed for cytokine levels (tumor necrosis factor-alpha [TNF alpha], interleukin-6 [IL-6], IL-8, neopterin, C-reactive protein). In addition, peripheral blood monocyte tumoricidal activity was evaluated pre- and post-combination therapy. Complete blood counts with differential and platelet counts were followed weekly. No increase in the toxic side effects of IFX was demonstrated when administered with L-MTP-PE nor were delays in IFX administration due to neutropenia experienced. The toxic side effects of L-MTP-PE were also not increased. Elevations of serum C-reactive protein, plasma neopterin, IL-6, IL-8, and TNF alpha following combination therapy were similar to those observed in patients treated with L-MTP-PE alone. Monocyte-mediated tumoricidal activity was elevated 24 and 72 h following L-MTP-PE and IFX therapy, similar to what has been reported following L-MTP-PE alone. Tumor specimens obtained from stratum B patients showed the histologic characteristics consistent with a "chemotherapy effect," i.e., dead, amorphous, acellular osteoid with cell drop-out.(ABSTRACT TRUNCATED AT 400 WORDS)

Active immunization with autologous idiotypic immunoglobulin, obtained by somatic fusion techniques, has been shown to be a useful alternative treatment in patients with B-cell lymphoma. Nevertheless, the requirement for biopsy specimens to obtain lymphoma cells could be a limitation to this therapeutic strategy. We address the question of whether peripheral blood samples containing small amounts of tumor cells can be used as appropriate fusion partners to rescue tumor-derived idiotypic proteins. In this report, we show that hybrid cells can be obtained from somatic fusions of K6H6/B5 heterohybridoma with lymphoma cells obtained from both lymph node (LN) and peripheral blood mononuclear cells (PBMC) containing only minor amounts of tumor cells. Some hybrid cells obtained from LN or PBMC fusions present an immunoglobulin (Ig) heavy-chain gene rearrangement identical with that of the original tumor and secrete identical Ig protein containing the expected H and L chains.

Guanine ribonucleosides with single substitutions at the C8 position (monosubstituted) or with dual substitutions at the C8 and N7 positions (disubstituted) up-regulate a spectrum of immunologic responses, including cytolytic responses to tumor cells. The current studies were undertaken to determine the effects of dual substitution on a number of nucleoside-inducible immunological parameters. To do so, two monosubstituted analogues, 8-bromoguanosine and 8-mercaptoguanosine, were directly compared with two disubstituted analogues, 7-methyl-8-oxoguanosine and 7-allyl-8-oxoguanosine (loxoribine). All of the compounds enhance natural killer (NK) activity, lymphocyte proliferation, and antibody production in dose-dependent fashion. However, the potency and maximal activity of the disubstituted analogues are considerably greater than those of the monosubstituted analogues. Spleen cells stimulated for 48 h with the disubstituted compounds produce immunoreactive interleukin (IL) 1 alpha, IL-6, tumor necrosis factor-alpha (TNF alpha), and interferon-gamma (IFN gamma). Monosubstituted analogues induce lower quantities of IL-6, TNF alpha, and IFN gamma and fail to induce detectable levels of IL-1 alpha. Total IFN activity, assessed by viral inhibition assay, is also lower for the monosubstituted analogues. Augmentation of antibody secretion by B cells is diminished for neither mono- nor disubstituted compounds upon incubation with anti-cytokine antibodies. In contrast, anti-IFN alpha beta markedly reduces the effects of monosubstituted analogues on NK activity but has less marked effects on NK induction by the disubstituted compounds. A similar pattern of differences is seen for lymphocyte proliferation. Thus, although the analogues induce synthesis of several cytokines, to date only IFN alpha beta appears directly involved in enhancement of NK activity and lymphocyte proliferation. The present data do not, however, exclude the existence of an autocrine stimulatory mechanism not susceptible to inhibition by anti-cytokine antibodies.