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

Interleukin-2 (IL-2) is a cytokine with proven activity against metastatic renal cell carcinoma (RCC) and malignant melanoma (MM). The intravenous administration of high-dose IL-2 is limited by important cardiovascular side effects such as hypotension, fluid retention, arrhythmias, and myocardial ischemia, which often cause dose reduction and/or treatment withdrawal. The occurrence of these toxic events is not predicted by routine pretreatment examinations. The aim of the present study was to test the reliability of serial echocardiography in predicting subsequent cardiac adverse effects in patients undergoing IL-2 administration. In 19 patients (15 men, 4 women; median age: 51 years, range 27-71 years; 10 affected by metastatic RCC and 9 affected by MM) we performed two-dimensional and Doppler echocardiography before and immediately after 28 continuous intravenous infusions (CIVI) of IL-2 at the dose of 18 MIU/m2/day for 4 days. Left ventricular systolic function and the diastolic transmitral flow pattern were assessed before and after IL-2 administration. Significant changes of two indexes of left ventricular filling were noted: a decrease of the ratio of maximal flow velocity in early diastole to that in late diastole (E/A) (basal: 1.12 +/- 0.46, mean +/- SD; posttreatment: 0.83 +/- 0.27; p < 0.01) and an increase of the percentage of the atrial contribution to left ventricular filling (basal: 37.75 +/- 11.58%; posttreatment: 49.43 +/- 16.48%; p < 0.01). Eight major cardiovascular events causing IL-2 infusion withdrawal were observed (two ischemic electrocardiographic modifications, three grade III-IV hypotension, one atrial fibrillation, one pericardial effusion, one acute heart failure). These major cardiovascular events were observed more often when an abnormal basal E/A ratio < 1.0 (p < 0.05) was found. We conclude that Doppler transmitral flow pattern analysis before and subsequent to IL-2 infusion is a useful and easily available procedure for the monitoring of cardiac modifications during CIVI IL-2 administration. It might also predict a major cardiovascular event during IL-2 administration. Patients with basal E/A ratio < 1.0 should be more carefully monitored during treatment and/or should be treated with lower IL-2 doses to avoid cardiovascular toxicity.

Murine neuroblastoma, neuro-2a, was transduced with the retroviral vector MFG-granulocyte-macrophage colony-stimulating factor (GM-CSF), to examine immune stimulation conferred by localized GM-CSF production. Expression of murine GM-CSF by neuro-2a (N-2a/GM) significantly reduced its tumorigenicity. Moreover, immunization of mice with irradiated N-2a/GM cells resulted in a significant protective effect against live tumor challenge 14 days later. Approximately 41% of mice immunized with irradiated N-2a/GM versus 0% of those vaccinated with irradiated parental tumor survived. Surviving mice were rechallenged after 50 days with wild-type neuro-2a or with the Sa1 syngeneic sarcoma to discern whether the generated immunity was durable and tumor specific. All mice survived wild-type neuro-2a challenge, whereas none survived inoculation with Sa1. Because both CD4+ and CD8+ T cells were necessary during priming to this MHC class Ilo, II-tumor, these data indicate that major histocompatibility complex (MHC) class I+, II+ antigen-presenting cells (APCs) were required for the T-cell antitumor response. Co-expression of GM-CSF and IFN-gamma, both of which have immunostimulatory activities on antigen-presenting cells, abrogated the tumorigenic potential of this tumor and increased immunogenicity over N-2a/IFN but not N-2a/GM. Vaccination of mice with preexisting retroperitoneal tumors with irradiated N-2a/GM and irradiated N-2a/IFN/GM improved survival. There was a trend for nonirradiated transduced cells to be more immunogenic than their irradiated counterparts. Immunohistochemistry of tissues from the vaccination site revealed a pronounced macrophage infiltration associated with nonirradiated N-2a/GM and N-2a/IFN/GM. These data suggest that vaccination involving nonirradiated neuroblastoma cells transduced with genes that stimulate APCs may be a useful approach in stimulating antitumor T-cell responses.

Recently mouse models have shown that expression of costimulatory molecules such as B7-1 on tumor cells can induce tumor-specific immunity, suggesting that tumor cells modified to express costimulatory molecules can be a potential tumor vaccine. To investigate the importance of B7-1 co-stimulation in induction of autologous tumor immunity in humans, we established a renal carcinoma cell line, RCC-1, from a tumor resection and studied the patient's antitumor immune responses in vitro. The RCC-1 cell line constitutively expressed major histocompatibility complex (MHC) class I, intercellular adhesion molecule (ICAM)-1, and leukocyte function-associated antigen (LFA)-3 molecules, and MHC class II molecules were induced by interferon-gamma (IFN-gamma) treatment in vitro. However, neither RCC-1- nor IFN-gamma-treated RCC-1 cells expressed B7-1, and both failed to induce T-cell proliferative responses in mixed lymphocyte and tumor cell reaction (MLTR) assays, suggesting that the costimulatory signals provided by cell adhesion molecules such as ICAM-1 and LFA-3 were not sufficient to elicit an antitumor immune response. However, on transfection of the human B7-1 into RCC-1, these cells were able to induce a significant T-cell proliferation in MLTR assays. This T-cell response could be blocked by anti-B7 mAb treatment of the tumor cells. RCC-1B7 cells also induced the generation of tumor-specific cytolytic T lymphocytes to the parent RCC-1 cells in vitro, with little nonspecific cytolysis of an unrelated RCC line, A498, or autologous phytohemagglutinin (PHA) blasts. This specific cytotoxicity could be abrogated by anti-CD8 mAb and complement treatment. In summary, our study indicates that B7-1-CD28 interaction plays a critical role in induction of autologous tumor-specific cytotoxic T lymphocytes (CTLs) in humans, suggesting that the costimulatory molecule transfected tumor cells could be useful in expanding tumor-specific autologous CTL in vitro for adoptive tumor immunotherapy.

Hyperthermia sensitizes tumor cells to killing by tumor necrosis factor-alpha (TNF). Sensitization is greater in cells exposed to TNF before heating begins than with the reverse sequence, and heat-shock proteins (hsp) have been suggested to protect cells from TNF cytotoxicity. Here we examined the role of Hsp27 in TNF resistance. Murine L929 cells were stably transfected with the vector pRc/CMV constitutively to express an inserted human hsp27 complementary DNA (cDNA) sequence. Parental cells produced no detectable murine homolog to human hsp27. Hsp27-sense clones expressed hsp27 messenger RNA (mRNA) and protein at 37 degrees C. Cells transfected with the cDNA in the anti-sense orientation produced anti-sense mRNA but no protein, and cells transfected with the vector alone produced neither product. Expression of hsp27 conferred significant resistance to TNF cytotoxicity in both neutral red cytotoxicity and clonogenic survival assays. Vector along and hsp27 anti-sense transfectants had a TNF response similar to that of parental L929 cells. Kinetic studies in L929 cells showed that hsp27-expressing clones exhibited resistance relative to parental cells beginning 6 h after TNF exposure, and this differential response increased by 12 and 24 h. Addition of actinomycin D to the TNF cytotoxicity assays accelerated the cytotoxicity development in parental and transfected cells, but the hsp27-sense clones were still more resistant. Hsp27-sense clones of L929 cells were also resistant to oxidative stress induced by menadione and released less arachidonic acid in response to TNF induction. These results show that hsp27 can negatively regulate the TNF cytotoxic mechanism.

The humoral immune response of 85 metastatic breast, ovarian, and colorectal cancer patients was analyzed after immunization with THERATOPE STn-KLH (KLH, keyhole limpet hemocyanin) cancer vaccine emulsified in DETOX adjuvant. Enzyme-linked immunosorbent assay (ELISA) antibody titers against the synthetic sialyl-Tn (STn) epitope were estimated by using solid phase STn-HSA and compared with antibody titers generated to the more biologically relevant natural mucin STn epitopes by using ovine submaxillary mucin (OSM) as a solid phase. Anti-KLH antibody titers were compared with anti-STn antibody titers as a specificity control. All but two patients generated increased anti-OSM antibody titers after immunization with STn-KLH. Breast and colorectal cancer patients who had the highest anti-OSM antibody titers, determined 4 weeks after the fourth immunization with STn-KLH (post-4 ASI), survived longer than the patients who had lower post-4 active specific immunotherapy (ASI) anti-OSM antibody titers. In contrast, there was no correlation of anti-KLH antibody titers with survival, demonstrating the specificity of the association of anti-OSM antibodies with survival. Cox multivariate survival analysis models were used to attempt to determine whether the induction of high-titer antibodies after immunization is a prognostic indicator independent of age, level of various tumor markers, extent of disease, lactate dehydrogenase (LDH) level, and route of administration of low-dose cyclophosphamide before ASI. Increased pre-ASI CA-125 serum levels in the ovarian cancer patients were predictors of poor survival, independent of all of the other prognostic factors. The postimmunization increase in anti-OSM immunoglobulin M (IgM) titer was independently associated with longer survival of the colorectal cancer patients. Increased anti-OSM IgG titers were associated with a marked increased survival of the breast cancer patients, which was independent of all other prognostic factors except the size of measurable metastatic lesions at trial entry and the route of administration of cyclophosphamide. In a randomized trial design, breast cancer patients who received low-dose intravenous cyclophosphamide just before ASI showed longer survival and generated higher anti-OSM antibody titers than did patients who received low-dose oral cyclophosphamide before ASI.

A phase I trial of simultaneously administered recombinant interleukin-2 (rIL-2) and recombinant human IL-4 (rHuIL-4) was conducted to evaluate the toxicity and the clinical and immunologic effects of this cytokine combination. Thirty-nine eligible patients with refractory malignancy were treated at eight different dose levels (1A to 3B): 1-3 of rIL-2 [3.0, 12.0, and 48.0 x 10(6) IU/m(2) i.v. three times weekly (TIW)] and A-C of rHuIL-4 (40, 120, and 400 mu g/m(2) s.c. TIW). The toxicity of these two cytokines was moderate and was comparable with that seen with rIL-2 alone. The maximal tolerated dose (MTD) of the combination was not reached because of lack of sufficient rHuIL-4 but is at least 48.0 x 10(6) IU/m(2) of rIL-2 and 120 mu g/m(2) of rHuIL-4. Two patients with melanoma had partial responses. The immunologic effects included increases in absolute lymphocyte numbers, and the CD3- /CD56+/ CD2+, total CD56+, CD8+, and CD16c+ lymphocyte subsets with increasing rIL-2 dose levels, but not with rHuIL-4. This increase in natural killer (NK) cells in the peripheral blood was accompanied by an increase over baseline in NK lytic activity against K562 targets; however, concomitant increases in lymphokine-activated killer (LAK) activity (Daudi targets) were not seen. The CD3+, CD4+, and CD3+/CD25+/HLA-Dr+ T-cell subsets also increased, and these increases were related to both increasing rIL-2 and rRuIL-4 doses. Finally, in four of six patients, serial tumor biopsies demonstrated increases in major histocompatibility complex (MHC) class I or II antigen expression on tumor cells or increasing T-cell infiltrates during cytokine therapy or both. This trial demonstrated that rIL-2 and rHuIL-4 can be administered simultaneously with acceptable toxicity. The immunologic findings demonstrated the expected rIL-2-associated increases of CD56+ and CD16c+ lymphocytes and NK activity, and interestingly, no development of LAK activity. These findings suggest regulatory effects of rHuIL-4 on rIL-2-related effects in vivo.

The generation of a therapeutic immune response to malignancy is critically dependent on the inherent immunogenicity of the tumor. Our study demonstrates that secretion of both interleukin-2 (IL-2) and IL-4 by a seemingly nonimmunogenic tumor abrogates tumorigenicity, and mice that have rejected the genetically modified tumor are immune to challenges with the parental tumor. The induction of immunity by the IL-2/IL-4-secreting tumor was significantly better than that achieved with the admixture of tumor cells and the classic adjuvant, Corynebacterium parvum. To elicit a primary immune response, the majority of cells needed to secrete both cytokines. Ad-mixture of IL-2-secreting cells with IL-4-secreting cells did not result in tumor cell rejection. The IL-2/IL-4-secreting tumor cells were efficiently rejected in animals immunosuppressed by total body irradiation. Depletion of CD4+ or CD8+ T cells did not abrogate rejection of the tumor cells, but the animals depleted of CD4 cells failed to generate protective immunity. Our study demonstrates that secretion of the combination of IL-2 and IL-4 significantly enhances tumor immunogenicity. The requirement of cells secreting both cytokines suggests an intricate mechanism different from the mere presence of both cytokines at the tumor-inoculation site.

Patients with metastatic renal cell cancer and metastatic melanoma treated with high-dose interleukin-2-based immunotherapy were prospectively evaluated for the development of vitiligo. All patients seen in the Surgery Branch, NCI Immunotherapy Clinic, who had been followed for at least 1 year were evaluated. Of 104 patients with metastatic renal cancer none developed vitiligo, though vitiligo was seen in 11 of 74 (15%) patients with metastatic melanoma (p2 = 0.0001). No vitiligo was seen in 27 patients who did not respond to immunotherapy, although vitiligo was seen in 11 of 43 (26%) melanoma patients who had an objective response to IL-2-based immunotherapy (p2 = 0.0002). These findings provide further evidence that the presence of a growing melanoma can sensitize patients to melanocyte-differentiation antigens and that the immune response against these antigens is associated with cancer regression in patients undergoing immunotherapy.

The toxicity and clinical response to treatment with the combination of interferon-gamma (IFN-gamma) and interleukin-2 (IL-2) in patients with metastatic melanoma was evaluated. From May 1993 through February 1994, 20 patients were treated with 24 courses of IFN-gamma with or without IL-2. A 7-day course of subcutaneous IFN-gamma alone was administered to cohorts of two or three patients each at doses of 0.1, 0.2, or 0.3 mg/m2. Thirteen patients received escalating doses of IFN-gamma between 0.2 and 0.5 mg/m2 followed by the intravenous (i.v.) administration of IL-2 (720,000 IU/kg) given three times a day. A treatment course consisted of two cycles (maximum of 15 doses of IL-2 per cycle) separated by a 10-day interval. Five additional patients were treated with five courses of IFN-gamma, IL-2, and tumor-infiltrating lymphocytes (TILs). All patients treated had the diagnosis of metastatic melanoma. The maximal tolerated dose of subcutaneous IFN-gamma was established at 0.3 mg/m2 with dose-limiting hepatotoxicity. Immunohistochemistry analyses showed detectable upregulation of MHC class I alleles in one (8%) of 12 patients. Two of 20 patients who received the combination of IFN-gamma and IL-2 had responses, one partial and one complete response. The duration of response was 7 months for the partial response and 12 months for the complete response. IFN-gamma was tolerated with minimal side effects of nausea, vomiting, malaise, and decreased hematopoiesis. No increased toxicities were found with the combination treatment, as compared with IL-2 alone. One death occurred on the third day of treatment with IFN-gamma alone from hemorrhage into brain metastases. There were no responders in the five patients who received the combination treatment of TIL, IL-2, and IFN-gamma. From these findings, we conclude that further studies looking at this combination treatment are not warranted.