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

Development of an effective immunotherapeutic approach for treatment of CNS tumors must take into account the unique anatomic and immunologic features of the brain. We explored the antitumor immune response in the brain elicited by nonreplicating melanoma cells genetically engineered to produce either granulocyte-macrophage colony-stimulating factor (GM-CSF) or interleukin-2 (IL-2) in a paracrine fashion. Using a new model of intracranial melanoma in C57BL/6 mice, the cytokine-producing cells were given either as a subcutaneous vaccine to induce systemic antitumor immunity or as a direct injection into the brain as local immunotherapy. We found that GM-CSF-transduced cells, as a subcutaneous vaccine but not as an intracranial injection, afforded some protection from intracranial challenge with the wild-type tumor. In contrast, direct intracranial injection of tumor cells secreting IL-2 was protective whereas flank vaccination with IL-2 transductants was not. Combination therapy with both the subcutaneous GM-CSF-transductants as a vaccine and local administration of IL-2-transductants in the brain achieved a synergistic response. These findings provide a basis for the application of paracrine cytokine delivery to brain cancer therapy both as a systemic vaccine and via local administration. The demonstration of synergy between paracrine cytokine therapies holds promise as a novel therapy for brain tumors.

The objective of this study was to study the antitumor, host toxicity, and immunomodulatory effects of recombinant interferon-alpha 2b (IFN) in patients with recurrent or metastatic squamous cell carcinoma of the head and neck (SCCHN). Seventy-one patients with recurrent or metastatic SCCHN were entered into a phase II noncomparative randomized trial of IFN at two dosage schedules. Eligible patients with histologically proven SCCHN were randomized to receive low-dose IFN, 6 x 10(6) U/m2 daily x 3 every 4 weeks or high-dose IFN, 12 x 10(6) U/m2, 3 x/week. Pretreatment levels of natural killer (NK) activity, CD3, CD4, CD5, CD8, CD16, CD19, CD56, DR, and the CD4/CD8 ratio were evaluated for any relationship with survival. The toxicity encountered in patients receiving low-dose IFN was for the most part mild to moderate. With high-dose IFN, toxicity was greater with significantly more episodes of grade 3 and 4 toxicity encountered. Dosage reduction was required in the majority of patients receiving high-dose IFN. Of the four lethal complications, only one was thought to be possibly associated with therapy. Of the 32 evaluable patients receiving low-dose IFN, there were 1 complete response, 1 stable disease, 24 patients with progressive disease, and 6 unevaluable. Of the 29 evaluable patients taking high-dose IFN, there were 2 complete responses, 7 with stable disease, 16 with progressive disease, and 4 patients were unevaluable. Median survival in the two arms was similar (6.2 months). Because it was postulated that a more prolonged exposure to IFN might be needed for it to be effective, patients receiving > or = 6 weeks of therapy were evaluated. Median survival in that subset was 10 and 12 months for patients receiving low- and high-dose IFN, respectively. None of the immune parameters tested was a significant predictor of survival when evaluated in all cases entered into study regardless of therapy duration. No difference in baseline NK activity was noted between patients who received < 6 or > or = 6 weeks of IFN (p = 0.90). However, among the 35 patients who received > or = 6 weeks of therapy, a high baseline NK activity was a significant predictor of the duration of survival (p = 0.04). IFN was well tolerated in patients with recurrent or metastatic SCCHN. The higher incidence of toxicity encountered in the high-dose arm could be ameliorated by reducing the dose 50%. In patients receiving 6 or more weeks of therapy, elevated baseline NK activity was associated with increases in survival, suggesting that IFN may play an immunomodulatory role. Although the overall response rates were low, disease stabilization was noted, suggesting an antiproliferative, noncytotoxic role of IFN in this group of heavily pretreated patients.

We determined in the peritoneal cavity (p.c.) of epithelial ovarian carcinoma patients during a 4-day treatment cycle of low-dose recombinant human interleukin-2 (rIL-2): (a) pharmacokinetics of IL-2, (b) endogenous cytokine production, and (c) numbers and percentages of peritoneal exudate lymphocytes. We administered 6 x 10(5) IU/m2 of rIL-2 (0.03 mg/m2 Proleukin rIL-2) intraperitoneally (i.p.) over 30 min on each of 4 days. One and one-half liters of D5 0.25 NS was injected i.p. before each rIL-2 infusion. Multiple peritoneal fluid samples were obtained from each of four patients on day 1 and day 4 for detection of IL-2, endogenous cytokines, and soluble IL-2 receptor (IL-2R-alpha). IL-2 concentrations in the peritoneal fluid were determined by bioassay and interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, IL-10, transforming growth factor (TGF)-beta 2, and sIL-2R-alpha by enzyme-linked immunosorbent assay. Numbers of cells per microliter and lymphocyte subpopulation percentages after staining with a panel of monoclonal antibodies were determined on day 1, day 4, and subsequent off-treatment days. IL-2 disappearance in the p.c. was well described by a pharmacokinetic model having constant-rate infusion and biexponential disposition. About 90% of the IL-2 disappearance occurred during the beta-phase, during which IL-2 concentrations were sustained at approximately 10-30 ng/ml (day 1 and day 4) and the median t1/2 beta was 21.5 and 9.2 h on days 1 and 4, respectively. In four of four patients, p.c. production of IL-10 was observed on day 1 and day 4 (maximum 387 pg/ml). Maximum levels of IFN-gamma and sIL-2R-alpha were observed on day 4. (IFN-gamma 217 pg/ml; sIL2-R-alpha: 3486 U/ml). No increases in TNF-alpha or TGF-beta 2 were observed. Large increases in p.c. CD3+, CD4+, CD8+, CD16+, and CD56+ cells were observed. We conclude that biologically active levels of IL-2 are generated in p.c. fluids after i.p. administration of rIL-2 at 0.03 mg/m2.

For prostate cancer, a correlation exists between overexpression of the epidermal growth factor receptor (EGFR) and poor clinical prognosis. In addition, late-stage metastatic disease is characterized by a change from a paracrine to an autocrine mode of expression for TGF-alpha, the ligand for the EGFR. These observations suggest that activation of the EGFR may be important for the growth of prostatic carcinoma in situ, and blockade of the receptor-ligand interaction may offer a means of therapeutic intervention for this disease. We describe the biologic effects of a chimeric anti-EGFR monoclonal antibody, C225, on several human prostate tumor cell lines in culture and the tumor inhibitory properties of the antibody for the treatment of human prostate carcinoma xenografts in nude mice. In vitro analysis of the EGFR from androgen-responsive and independent prostatic carcinoma cell lines revealed that C225 blocked EGF-induced receptor activation and induced internalization of the receptor. In vivo, a treatment regimen of C225 alone or antibody plus doxorubicin significantly inhibited tumor progression of well-established DU145 and PC-3 xenografts in nude mice. These results suggest that C225 may have utility for the treatment of human prostate carcinoma in a clinical setting.

Constitutive expression of major histocompatibility complex (MHC) class II molecules is normally restricted to professional antigen-presenting cells (APCs) of the immune system, although it also occurs frequently in melanoma. Clinical evidence suggesting that MHC class II expression by melanoma is associated with tumor progression led us to postulate a role for MHC class II-mediated antigen presentation in this disease. First, we investigated whether melanoma cells derived from metastases can process antigen and/or present peptide vi MHC class II molecules to a peptide-specific CD4+ T-cell clone. In all cell lines tested, melanoma cells were able to process antigen and present peptide efficiently to CD4+ T cells, resulting in T-cell proliferation increased 5-26-fold over controls. Next, we found that CD28-mediated costimulation was not required, because blocking with CTLA-4Ig had no effect on the T-cell response to either melanoma or B cells as APCs. In contrast, blocking CD54 (ICAM-1) resulted in a decrease in proliferation in response to peptide presentation by melanoma but not B cells. These data demonstrate that MHC class II molecules on melanoma cells are functional and that antigen-processing pathways are intact. In addition, CD54 seems to play a significant role in peptide presentation by melanoma.

Mice bearing palpable tumors expressing a mutant p53 gene were treated with intravenous injection of mutant p53-specific peptide-pulsed dendritic cells (DCs). Control groups were treated with control peptide-pulsed DCs. All mice received three injections of 10(5) DCs on days 0, 5, and 10 after the start of the therapy. Half of the animals in each group were also treated with intraperitoneal injections of interleukin (IL)-12 (300 ng per mouse every other day, from day 0 to day 20). Mice treated with control peptide-pulsed DCs showed fast tumor progression. This growth was not substantially affected by treatment with IL-12 alone. Tumor growth in mice treated with mutant p53 peptide-pulsed DCs was significantly slowed during therapy, but resumed after cessation of therapy. In contrast, tumor growth in mice receiving both specific peptide-pulsed DCs and IL-12 remained very slow even 4 weeks after termination of the immunotherapy. To investigate the immunological basis for these effects, mutant p53 specific cytotoxic T lymphocyte (CTL) response was tested in mice 2 weeks after the last injection of DCs. Significant levels of CTLs were registered only in mice treated with IL-12 in addition to specific immunization. Thus, IL-12 dramatically improved the effect of the mutant p53-specific immunotherapy of palpable, preexisting tumors, supporting the use of IL-12 as an immunoadjuvant in clinical trials of tumor-specific peptide-pulsed DC.

Erythropoietin production by renal cell carcinoma (RCC) is reported to be a potential marker for interleukin-2/interferon-alpha-responding tumor. We have investigated whether erythropoietin of RCC cells is involved in the immune recognition by lymphokine-activated killer (LAK) cells. Cells from primary culture of RCC cells expressing erythropoietin-mRNA or producing erythropoietin were more susceptible to lysis by LAK cells than those not expressing or producing it, respectively. RCC cells transfected with erythropoietin-cDNA became more susceptible to lysis by LAK cells than their erythropoietin-negative parental cells. These results indicate higher susceptibility of erythropoietin-producing RCC cells to lysis by LAK cells, suggesting that erythropoietin of RCC cells is involved in the immune recognition by LAK cells.

In this study, we analyzed the frequencies of human leukocyte antigen (HLA) class I alleles in 110 Japanese patients with melanoma using serological methods, and compared such frequencies with clinical parameters. As expected, frequencies of HLA allele distribution in patients with melanoma reflected the frequencies observed in the normal Japanese population. Because these are different from populations belonging to other races (e.g., white), it followed that the HLA allele distribution in melanoma patients varies among different races. This differences may have significant implications for T-cell-mediated, HLA-restricted therapeutic modalities. No significant associations between HLA and clinical parameters were noted in this study. This report may help design future clinical trials involving therapeutic approaches based on HLA-restricted mechanisms.