Restoration of the immunocompetence by IL-2 activation and TCR-CD3 engagement of the in vivo anergized tumor-specific CTL from lung cancer patients

Immune killer cells treatment for previously treated stage IV NSCLC patients

The 5-year survival is poor for stage IV non-small cell lung cancer (NSCLC). Recently, cell immunotherapy has emerged as a new treatment strategy. This study aimed to evaluate the efficacy and safety of Immune killer cells (IKC) in patients with stage IV NSCLC after the failure of prior chemotherapy. This study enrolled 26 patients with stage IV NSCLC who failed at least two lines of chemotherapy with or without targeted therapy. The IKC was given alone weekly for 24 weeks. The primary endpoint was progression-free survival (PFS). Secondary outcomes included overall survival (OS), pain intensity, quality of life (QOL), and safety. The median PFS for the intent-to-treat (ITT) population (i.e., all enrolled patients) was 3.8 month. In the per-protocol (PP) population (i.e., patients receiving > 12 IKC infusions), the median PFS was 5.6 months. Moreover, the ITT population showed a 1-year survival rate of 60.0%, while that for the PP population was 85.7%. Only 7 out of 200 AEs (3.5%) were related to the IKC infusion, and they were all rated as grade 1 in severity. The IKC infusion was well tolerated. This novel immunotherapy prolonged the PFS and improved the survival compared with historical data. It might be a potential treatment strategy for stage IV NSCLC patient who failed prior chemotherapy.ClinicalTrials.gov identifier: NCT03499834.

Comprehensive analysis of cutaneous and uveal melanoma liver metastases

BACKGROUND

The profound disparity in response to immune checkpoint blockade (ICB) by cutaneous melanoma (CM) and uveal melanoma (UM) patients is not well understood. Therefore, we characterized metastases of CM and UM from the same metastatic site (liver), in order to dissect the potential underlying mechanism in differential response on ICB.

METHODS

Tumor liver samples from CM (n=38) and UM (n=28) patients were analyzed at the genomic (whole exome sequencing), transcriptional (RNA sequencing) and protein (immunohistochemistry and GeoMx Digital Spatial Profiling) level.

RESULTS

Comparison of CM and UM metastases from the same metastatic site revealed that, although originating from the same melanocyte lineage, CM and UM differed in somatic mutation profile, copy number profile, tumor mutational burden (TMB) and consequently predicted neoantigens. A higher melanin content and higher expression of the melanoma differentiation antigen MelanA was observed in liver metastases of UM patients. No difference in B2M and human leukocyte antigen-DR (HLA-DR) expression was observed. A higher expression of programmed cell death ligand 1 (PD-L1) was found in CM compared with UM liver metastases, although the majority of CM and UM liver metastases lacked PD-L1 expression. There was no difference in the extent of immune infiltration observed between CM and UM metastases, with the exception of a higher expression of CD163 (p<0.0001) in CM liver samples. While the extent of immune infiltration was similar for CM and UM metastases, the ratio of exhausted CD8 T cells to cytotoxic T cells, to total CD8 T cells and to Th1 cells, was significantly higher in UM metastases.

CONCLUSIONS

While TMB was different between CM and UM metastases, tumor immune infiltration was similar. The greater dependency on PD-L1 as an immune checkpoint in CM and the identification of higher exhaustion ratios in UM may both serve as explanations for the difference in response to ICB. Consequently, in order to improve current treatment for metastatic UM, reversal of T cell exhaustion beyond programmed cell death 1 blockade should be considered.

Study on the Mechanism of Ginseng in the Treatment of Lung Adenocarcinoma Based on Network Pharmacology

Background

Ginseng, a traditional Chinese medicine, was used to prevent and treat many diseases such as diabetes, inflammation, and cancer. In recent years, there are some reports about the treatment of lung adenocarcinoma with ginseng monomer compounds, but there is no systematic study on the related core targets and mechanism of ginseng in the treatment of lung adenocarcinoma up to now. Therefore, this study systematically and comprehensively studied the molecular mechanism of ginseng in the treatment of lung adenocarcinoma based on network pharmacology and further proved the potential targets by A549 cell experiments for the first time.

Methods

The targets of disease and drug were obtained from Gene database. Subsequently, the compound-target network was constructed, and the core potential targets were screened out by plug-in into Cytoscape. Furthermore, the core targets and mechanism of ginseng in the treatment of lung adenocarcinoma were verified by MTT test, cell scratch test, immunohistochemistry, and qRT-PCR.

Results

1791 disease targets and 144 drug targets were obtained by searching the Gene database. Meanwhile, 15 core targets were screened out: JUN, MAPK8, PTGS2, CASP3, VEGFA, MMP9, AKT1, TNF, FN1, FOS, MMP782, IL-1β, IL-2, ICAM1, and HMOX1. The results of cell experiments indicate that ginseng could treat lung adenocarcinoma by cell proliferation, migration, and apoptosis. In addition, according to the results of the 15 core targets by qRT-PCR, JUN, IL-1β, IL-2, ICAM1, HMOX1, MMP9, and MMP2 are upregulated core targets, while PTGS2 and TNF are downregulated core targets.

Conclusion

This study systematically and comprehensively studied 15 core targets by network pharmacology for the first time. Subsequently, it is verified that 9 core targets for ginseng treatment of lung adenocarcinoma, namely, JUN, IL-1β, IL-2, ICAM1, HMOX1, MMP9, MMP2, PTGS2, and TNF, are closely related to the proliferation, migration, and apoptosis of lung adenocarcinoma cells. This study has reference value for the clinical application of ginseng in the treatment of lung adenocarcinoma.

Recombinant human thrombopoietin combined with interleukin-2 improves the effects of chemosensitivity and thrombocytopenia on a basic gemcitabine and carboplatin combination therapy for non-small cell lung cancer in a nude mouse model

Background

To investigate the effects of recombinant human thrombopoietin (rhTPO) and interleukin-2 (IL-2) on a basic gemcitabine (GEM) plus carboplatin (GC) treatment regimen in a murine lung carcinoma model.

Methods

Fifty nude mice with subcutaneous tumors derived from human lung cancer cells were divided into 5 groups, each comprised of 10 mice: A blank group (intraperitoneal injection of saline), a control group (GC) (intraperitoneal injections of GC), a rhTPO group (same as the control group plus subcutaneous injection of rhTPO), an IL-2 group (same as the control group plus subcutaneous injection of IL-2) and a rhTPO + IL-2 group (same as the rhTPO group plus subcutaneous injection of IL-2). Tumor development and histology as well as CD4+, phosphorylated-adenosine monophosphate-activated protein kinase (p-AMPK), phosphorylated-protein kinase B (p-AKT), phosphorylated-extracellular signal-regulated kinase (p-ERK), phosphorylated-phosphoinositide 3-kinase (p-pI3K) and GTPase RAS1 expression in tumor tissues were measured and blood analyses performed.

Results

Tumor sizes from all treated mice were significant smaller than the controls, as were the tumors of IL-2 plus GC treated mice compared to other treated groups. CD4+ expressing cells were increased in tumors after IL-2 and rhTPO treatment and the application of rhTPO significantly restored the blood platelet count. The expression of p-AMPK, p-AKT, p-ERK, p-pI3K and RAS1 in tumor cells were all significantly diminished after the addition of rhTPO and IL-2 to the GC regimen.

Conclusions

The supplementation of rhTPO and IL-2 to a GC regime effectively reduced tumor sizes and restored the platelet count in a human lung cancer mouse model.

Induced Pluripotent Stem Cell-conditioned Medium Suppressed Melanoma Tumorigenicity Through the Enhancement of Natural-Killer Cellular Immunity

Induced pluripotent stem cells (iPSCs) can secrete cytokines that are involved in T-cell development and affect cytotoxic activity. To assess the effect of iPSC-conditioned medium on tumorigenicity, we retrieved splenocytes from B6 mice and cocultured them with or without irradiated B16 melanoma cells, mouse interleukin-2 (mIL-2), or iPSC-conditioned medium. Splenocyte cytotoxicity assays against B16 melanoma cells [as cytotoxic T lymphocyte (CTL) activity] and P815 cells [as natural killer (NK) activity] were performed. IL-10 and interferon-γ concentrations were measured. An in vivo subcutaneous B16 melanoma growth model was performed in B6 mice and treated with iPSC-conditioned medium. The lymphocyte subpopulation depletion test was performed to determine effectors against B16 melanoma cells. We found that unstimulated splenocytes had little cytotoxic activity. Without tumor cells, mIL-2 could augment iPSC-conditioned medium-treated CTL and NK activities (P<0.01). With irradiated tumor cells, mIL-2 treatment of splenocytes could not enhance CTL or NK activity, but iPSC-conditioned medium could enhance CTL and NK activity (P<0.001). Irradiated tumor cells induced mice splenocytes to secrete more IL-10, similar to mIL-2 treatment, but not iPSC-conditioned medium treatment. mIL-2 had better efficacy than conditioned medium in inducing splenocyte interferon-γ production. The CTL and NK cell depletion test showed that the immunostimulating effect of iPSC-conditioned medium on splenocytes was through the enhancement of NK cellular activity (P<0.05). The subcutaneous melanoma growth model showed that B16-bearing mice treated with an iPSC-conditioned medium intraperitoneal injection had a decreased tumor growth rate (P<0.01). Our study suggests that iPSC-conditioned medium had a protective effect against tumor-induced immunosuppression through the enhancement of host NK cellular activity.

Role of IL-2 in cancer immunotherapy

Interleukin-2 (IL-2) is one of the key cytokines with pleiotropic effects on immune system. It has been approved for the treatment of metastatic renal cell carcinoma and metastatic melanoma. Recent progress has been made in our understanding of IL-2 in regulating lymphocytes that has led to exciting new directions for cancer immunotherapy. While improved IL-2 formulations might be used as monotherapies, their combination with other anticancer immunotherapies, such as adoptive cell transfer regimens, antigen-specific vaccination, and blockade of immune checkpoint inhibitory molecules, for example cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) and programmed death 1 (PD-1) mono-antibodies, would held the promise of treating metastatic cancer. Despite the comprehensive studies of IL-2 on immune system have established the application of IL-2 for cancer immunotherapy, a number of poignant obstacles remain for future research. In the present review, we will focus on the key biological features of IL-2, current applications, limitations, and future directions of IL-2 in cancer immunotherapy.

Gefitinib plus interleukin-2 in advanced non-small cell lung cancer patients previously treated with chemotherapy

The activation of lymphocytes by gefitinib treatment has been described. In this phase II pilot trial, we explored the possible synergism between IL-2 and gefitinib for non-small cell lung cancer (NSCLC) treatment. From September, 2003, to November, 2006, 70 consecutive patients with advanced, progressive NSCLC, previously treated with chemotherapy, received oral gefitinib 250 mg daily. The first 39 patients received gefitinib alone (G group). The other 31 also received subcutaneous IL-2 (GIL-2 group): 1 MIU/m² (Million International Unit/m²)twice a day on Days 1 and 2, once a day on Days 3, 4, 5 every week for four consecutive weeks with a four-week rest period. Median follow-up was 25.2 months. Grade 3–4 toxicity of gefitinib was represented by skin rash (7%), asthenia/anorexia (6%) and diarrhea (7%); patients treated with IL-2 showed grade 2–3 fever (46%), fatigue (21%) and arthralgia (13%). In the GIL-2 group and G-group, we respectively observed: an overall response rate of 16.1% (6.4% complete response) and 5.1% (only partial response); a disease control rate of 41.9% and 41%; a median time to progression of 3.5 (CI 95% = 3.2–3.8) and 4.1 (CI 95% = 2.6–5.7) months; a median overall survival of 20.1 (CI 95% = 5.1–35.1) and 6.9 (CI 95% = 4.9–8.9) months (p = 0.002); and an actuarial one-year survival rate of 54% and 30%. Skin toxicity (p < 0.001; HR = 0.29; CI 95% = 0.16–0.54) and use of IL-2 (p < 0.001; HR = 0.33; CI 95% = 0.18–0.60) were independently associated with improvement of survival. In this consecutive, non-randomized, series of advanced NSCLC patients, the use of IL-2 increased the efficacy of gefitinib.

Tumor-induced CD8+ T-cell dysfunction in lung cancer patients

Lung cancer is the leading cause of cancer deaths worldwide and one of the most common types of cancers. The limited success of chemotherapy and radiotherapy regimes have highlighted the need to develop new therapies like antitumor immunotherapy. CD8+ T-cells represent a major arm of the cell-mediated anti-tumor response and a promising target for developing T-cell-based immunotherapies against lung cancer. Lung tumors, however, have been considered to possess poor immunogenicity; even so, lung tumor-specific CD8+ T-cell clones can be established that possess cytotoxicity against autologous tumor cells. This paper will focus on the alterations induced in CD8+ T-cells by lung cancer. Although memory CD8+ T-cells infiltrate lung tumors, in both tumor-infiltrating lymphocytes (TILs) and malignant pleural effusions, these cells are dysfunctional and the effector subset is reduced. We propose that chronic presence of lung tumors induces dysfunctions in CD8+ T-cells and sensitizes them to activation-induced cell death, which may be associated with the poor clinical responses observed in immunotherapeutic trials. Getting a deeper knowledge of the evasion mechanisms lung cancer induce in CD8+ T-cells should lead to further understanding of lung cancer biology, overcome tumor evasion mechanisms, and design improved immunotherapeutic treatments for lung cancer.

Immune suppression in tumors as a surmountable obstacle to clinical efficacy of cancer vaccines

Human tumors are usually not spontaneously eliminated by the immune system and therapeutic vaccination of cancer patients with defined antigens is followed by tumor regressions only in a small minority of the patients. The poor vaccination effectiveness could be explained by an immunosuppressive tumor microenvironment. Because T cells that infiltrate tumor metastases have an impaired ability to lyse target cells or to secrete cytokine, many researchers are trying to decipher the underlying immunosuppressive mechanisms. We will review these here, in particular those considered as potential therapeutic targets. A special attention will be given to galectins, a family of carbohydrate binding proteins. These lectins have often been implicated in inflammation and cancer and may be useful targets for the development of new anti-cancer therapies.

IL-8 induces exocytosis of arginase 1 by neutrophil polymorphonuclears in nonsmall cell lung cancer

Arginase 1 (ARG1) inhibits T-cell proliferation by degrading extracellular arginine, which results in decreased responsiveness of T cells to CD3/TCR stimulation. In humans, ARG1 is stored in inactive form within granules of polymorphonuclear neutrophils (PMNs) and gets activated on release. We studied the role of PMNs-related ARG1 activity in nonsmall cell lung cancer (NSLC), in which tumor-infiltrating lymphocytes showed reduced proliferation in response to CD3/TCR triggering. Patients with NSCLC had increased ARG1 plasma levels as compared to healthy controls. Furthermore, immunohistochemistry showed that tumor-infiltrating PMNs display reduced intracellular ARG1, in comparison to intravascular or peritumoral PMNs, suggesting a role of tumor microenvironment in ARG1 release. Indeed, supernatants of NSCLC cell lines induced exocytosis of ARG1 from PMNs. All (4/4) NSCLC cell lines and all (7/7) CD14- cell samples from NSCLC expressed interleukin (IL)-8 mRNA, whereas TNFalpha mRNA was expressed by 1 cell line and by 2 tumor specimens. Furthermore, all NSCLC cell lines secreted immunoreactive IL-8, albeit at different levels. IL-8 was as effective as TNFalpha in triggering ARG1 release and the 2 cytokines acted synergistically. Secreted ARG1 was biologically active and catabolized extracellular arginine. The supernatant of IL-8 gene-silenced NSCLC cells did not mediate ARG1 release by PMNs. Altogether these findings demonstrate a role of IL-8 in ARG1 exocytosis by PMNs and indicate that, due at least in part to IL-8 secreted by NSCLC cells, PMNs infiltrating NSCLC release ARG1. This phenomenon could contribute to local immune suppression.

Arginase 2 is expressed by human lung cancer, but it neither induces immune suppression, nor affects disease progression

In human prostate cancer, Arginase 2 (ARG2) and nitric oxide synthase (NOS) are concomitantly expressed by tumor cells, and induce tumor immune escape via peroxynitrite-dependent Tyrosine nitrosylation. Since there were no data regarding this immune suppressive mechanism in other tumor types, and an evaluation of its clinical relevance in human tumors had still to be provided, we have investigated presence and clinical relevance of ARG2 and NOS expression in lung cancer. No evidence of NOS expression was found, no significant NOS enzymatic activity was detected. Instead, ARG2 protein was expressed by tumor cells. In a cohort of 120 patients, the amount of ARG2-positive tumor cells was significantly higher in small cell lung cancers (SCLC) than in non-small cell lung cancers (NSCLC). Large cell undifferentiated carcinomas had twice ARG2 than the other NSCLC subtypes. ARG2 expression was increased in Grade 3 tumors, as compared to Grades 1 and 2. However, no relationship was found with tumor size and stage, and with patient survival. Indeed, the enzyme was active, since the Arginine catabolite Ornithine was produced, but Arginine depletion was not attained. In addition, nitrotyrosine was not found in tumor tissue. Accordingly, when tumor cells isolated from lung cancer were incubated with activated autologous T cells, no inhibition of proliferation was detected. Our results indicate that ARG2 is expressed in lung cancer, but it does not induce tumor immune escape and does not affect disease progression, most probably due to the lack of concomitant NOS expression.

Analysis of host versus tumor interaction in cancer patients: opposing role of transforming growth factor-β1 and interleukin-6 in the development of in situ tumor immunity

A different degree of immunodeficiency is often found at tumor sites in cancer patients. At the late stage many patients develop malignant effusion that contains large numbers of tumor cells and host immune cells that constantly interact with each other. These sites may provide an ideal model to examine in situ anti-tumor immunity. The T cells in effusion were found to be immunodeficient, which suggested a defective anti-tumor cytotoxic T lymphocytes response. To pursue the mechanism for the T cell deficiency, we determined the production of immunomodulating cytokines in the effusion and detected the presence of transforming growth factor-beta1 (TGFbeta), prostaglandin E2, IL-6, IL-10, and IFNgamma. There was no detectable IL-2, IL-4, IL-12, or TNFalpha. The most prominent feature was the presence of TGFbeta and IL-6 at a very high level. Thus, the possible role of these two cytokines on T cell competence was further determined. TGFbeta was found to induce T cell anergy and reduced the production of perforin in T killer cells and their lytic activity. These events lead to the induction of peripheral T cell tolerance with profound T cell deficiency. IL-6 did not affect perforin production or cytolytic activity of the T killer cells. But the CD4+ CD25+ regulatory T cells (TR) that were often employed by TGFbeta to suppress T cell response were reduced in the malignant effusion, consistent with the fact that IL-6 down-regulates TR and this may represent the host's vigorous response to the tumor's subversion. These results show that TGFbeta and IL-6 might play pivotal but opposing roles in the host tumor interaction that, together with other immunomodulating components, determines the outcome for the development of local tumor immunity.

Effector, memory and naïve CD8+ T cells in peripheral blood and pleural effusion from lung adenocarcinoma patients

The proportions of naïve, memory and effector CD8+ T cells in peripheral blood and pleural effusion from lung adenocarcinoma patients were studied. CD8+ T subsets were identified by using a combination of the following antibodies: anti-CD45RA, anti-CD45RO, anti-CD27 and anti-CD28, as well as antibodies to other markers. Fas-positive cells were determined in each CD8+ T subset. Also, the intracellular cytokine patterns of CD4+ and CD8+ lymphocytes from pleural effusion were analysed. In naïve, memory and effector CD8+ T subsets no significant differences were observed in peripheral blood between healthy donors and cancer patients. In contrast, a high proportion of cells with memory phenotype (CD45RA-CD45RO+CD27+CD28+) and a low proportion of cells with effector phenotype (CD45RA+CD45RO-CD27-CD28-) were found in pleural effusion with respect to peripheral blood (P<0.001). The altered proportions of CD8+ T subsets in pleural effusion were not mediated by type 2 cytokines produced by CD4+ or CD8+ lymphocytes. In the effector CD8+ T subset, from peripheral blood as well as from pleural effusion, a low percentage of perforin-expressing cells was observed compared to granzyme A-expressing cells. Additionally, a high percentage of naïve CD8+ T cells expressing Fas was found. Our data suggest that: (i) terminal-differentiation process of CD8+ T cells is blocked, and (ii) early Fas-expression in CD8+ T cells, which was reflected even in peripheral blood, may lead to apoptosis of naïve cells when they reach the effector stage. All these processes may contribute to the inadequate antitumour immune response found in lung carcinoma patients.

Restoration of tumor-specific HLA class I restricted cytotoxicity in tumor infiltrating lymphocytes of advanced breast cancer patients by in vitro stimulation with tumor antigen-pulsed autologous dendritic cells

Breast tumor infiltrating lymphocytes (TIL) are enriched in tumor-specific cytotoxic T lymphocytes (CTL), and may represent a superior source of CTL compare to peripheral blood lymphocytes (PBL), for adoptive T cell immunotherapy of breast cancer. However, the immunocompetence of TIL and the possibility to consistently restore their tumor-specific lytic activity in vitro remains an open issue. In this study we evaluated the potential of tumor antigen-pulsed fully mature dendritic cell (DC) stimulation in restoring tumor-specific cytotoxicity in anergic TIL populations from advanced breast cancer patients. In addition we have compared tumor-specific T cell responses induced by tumor antigen-loaded DC stimulation of TIL to responses induced from PBL. Although TIL were consistently non-cytotoxic after isolation or culture in the presence of interleukin-2 (IL-2), in matched experiments from three consecutive patients, tumor-lysate-pulsed DC-stimulated CD8+ T cell derived from TIL were found to be significantly more cytotoxic than PBL (p < 0.05). In addition, cytotoxicity against autologous tumor cells was more significantly inhibited by an anti-HLA class I (W6/32) MAb in TIL compared to PBL (p < 0.05). CTL populations derived from TIL and PBL did not lyse autologous EBV-transformed lymphoblastoid cell lines, and showed negligible cytotoxicity against the NK-sensitive cell line K562. Furthermore, in both CD8+ T cell populations the majority of the tumor-specific CTL exhibited a Th1 cytokine bias (IFN-gamma(high)/IL-4(low)). Taken together, these data show that tumor lysate-pulsed mature DC can consistently restore tumor-specific lytic activity in non-cytotoxic breast cancer TIL. These results may have important implications for the treatment of chemotherapy resistant breast cancer with active or adoptive immunotherapy.

Restoration of tumor specific human leukocyte antigens class I-restricted cytotoxicity by dendritic cell stimulation of tumor infiltrating lymphocytes in patients with advanced ovarian cancer

Despite the large number of potentially cytotoxic tumor-infiltrating (TIL) and tumor-associated (TAL) lymphocytes accumulated in the peritoneal cavity ascitic fluid and tumor tissue, advanced ovarian cancer is a progressive disease, suggesting that TIL and TAL populations eventually become functionally suppressed in vivo. Dendritic cells (DC) are the most powerful professional antigen presenting cells known in humans and recently, ovarian tumor antigen pulsed DC have been shown to elicit tumor specific human leukocyte antigens (HLA)-class I-restricted cytotoxicity from the peripheral blood of advanced ovarian cancer patients. In this study, we have evaluated the potential of tumor antigen-pulsed fully mature DC stimulation in restoring tumor-specific cytotoxicity in anergic TIL populations from advanced ovarian cancer patients. In addition, we have compared tumor-specific T-cell responses induced by tumor antigen-loaded DC in TIL to those induced in TAL and peripheral blood lymphocytes (PBL). DC stimulation induced powerful cytotoxicity against autologous tumor target cells in TIL-derived CD8+ T-cells from all patients tested, while autologous Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCL) were not lysed. Killing of autologous tumor cells was higher by CD8+ T-cells from TIL compared to PBL and TAL (P < 0.01) and was more strongly inhibited by anti-HLA class I MAb (P < 0.05 compared to PBL and TAL). Phenotypically, all cytotoxic T lymphocyte (CTL) populations were CD3+/CD8+, with variable levels of CD56 expression. Finally, although a marked Type 1 cytokine bias [ie, interferon-gamma/interleukin-4 (IFN-gammahigh/IL-4low)] was observable in all DC-stimulated CD8+ T-cell populations, TIL derived CD8+ T-cells showed a higher percentage of IFN-gamma positive cells compared to TAL and PBL. Taken together, these data show that tumor lysate-pulsed DC can consistently restore strong CD8+ CTL responses from TIL against autologous ovarian cancer cells. DC-stimulated TIL may represent a superior source of tumor-specific CTL for adoptive T-cell immunotherapy for advanced ovarian cancer.

Synergistic effect of a granulocyte-macrophage colony-stimulating factor-transduced tumor vaccine and systemic interleukin-2 in the treatment of murine colorectal cancer hepatic metastases

BACKGROUND

Granulocyte-macrophage colony-stimulating factor-transduced tumor cell vaccines are less effective against cancer as the interval between metastasis and the initial vaccination increases.

METHODS

Hepatic metastases were generated in BALB/c mice by using a syngeneic colorectal cancer line (CT26) with a splenic injection model. Irradiated CT26 cells transduced to secrete granulocyte-macrophage colony-stimulating factor were used as vaccine. Treatment groups received vaccine, systemic interleukin (IL-2), or both. Livers were examined for gross metastases 21 days after tumor challenge. Splenocytes were analyzed for in vitro activity against CT26 by using an enzyme-linked immunospot assay and a cytotoxic T lymphocyte assay.

RESULTS

Eighty-eight percent of mice treated with vaccines and IL-2 were tumor free on day 21 (P </=.001 vs. control). Treatment with vaccines or IL-2 alone did not result in a significant treatment effect. Splenocytes from mice treated with both vaccines and IL-2 showed greater CT26 lysis than splenocytes from mice treated with vaccines alone at effector:target ratios of 100, 30, and 10 (P <.05 for all). More splenocytes from these mice released interferon-gamma in response to stimulation with the CT26 tumor antigen AH1 compared with mice treated with vaccines alone (P =.05).

CONCLUSIONS

Systemic IL-2 augments tumor vaccine efficacy in the treatment of microscopic murine colorectal hepatic metastases.

Immunotherapy of cancer by active vaccination: does allogeneic bone marrow transplantation after non-myeloablative conditioning provide a new option?

The critical role of antigen-specific T cells in cancer immunotherapy has been amply demonstrated in many model systems. Though success of clinical trials still remains far behind expectation, the continuous improvement in our understanding of the biology of the immune response will provide the basis of optimized cancer vaccines and allow for new modalities of cancer treatment. This review focuses on the current status of active therapeutic vaccination and future prospects. The latter will mainly be concerned with allogeneic bone marrow cell transplantation after non-myeloablative conditioning, because it is my belief that this approach could provide a major breakthrough in cancer immunotherapy. Concerning active vaccination protocols the following aspects will be addressed: i) the targets of immunotherapeutic approaches; ii) the response elements needed for raising a therapeutically successful immune reaction; iii) ways to achieve an optimal confrontation of the immune system with the tumor and iv) supportive regimen of immunomodulation. Hazards which one is most frequently confronted with in trials to attack tumors with the inherent weapon of immune defense will only be briefly mentioned. Many question remain to be answered in the field of allogeneic bone marrow transplantation after non-myeloablative conditioning to optimize the therapeutic setting for this likely very powerful tool of cancer therapy. Current considerations to improve engraftment and to reduce graft versus host disease while strengthening graft versus tumor reactivity will be briefly reviewed. Finally, I will discuss whether tumor-reactive T cells can be "naturally" maintained during the process of T cell maturation in the allogeneic host. Provided this hypothesis can be substantiated, a T cell vaccine will meet a pool of virgin T cells in the allogeneically reconstituted host, which are tolerant towards the host, but not anergised towards tumor antigens presented by MHC molecules of the host.

Epidermal growth factor receptors and cyclooxygenase-2 in the pathogenesis of non-small cell lung cancer: potential targets for chemoprevention and systemic therapy

The epidermal growth factor receptor (EGFR) is part of a family of plasma membrane receptor tyrosine kinases that control many important cellular functions, from growth and proliferation to cell death. Cyclooxygenase (COX)-2 is an enzyme which catalyses the conversion of arachidonic acid to prostagladins and thromboxane. It is induced by various inflammatory stimuli, including the pro-inflammatory cytokines, Interleukin (IL)-1beta, Tumour Necrosis Factor (TNF)-alpha and IL-2. Both EGFR and COX-2 are over-expressed in non-small cell lung cancer (NSCLC) and have been implicated in the early stages of tumourigenesis. This paper considers their roles in the development and progression of lung cancer, their potential interactions, and reviews the recent progress in cancer therapies that are directed toward these targets. An increasing body of evidence suggests that selective inhibitors of both EGFR and COX-2 are potential therapeutic agents for the treatment of NSCLC, in the adjuvant, metastatic and chemopreventative settings.

Double signal stimulation was required for full recovery of the autologous tumor-killing effect of effusion-associated lymphocytes

STUDY OBJECTIVES

To determine the different effects of interleukin (IL)-2, IL-4, IL-7, IL-10, IL-12, and/or T-cell receptor (TCR)-CD3 engagement in recovering the functions of cytotoxic T lymphocytes (CTL) from malignant effusion.

SETTING

National teaching hospital.

MATERIALS AND METHODS

Effusion-associated lymphocytes (EAL) were isolated from 35 malignant pleural effusions. Interferon (IFN)-gamma production, proliferative response, and cytolytic activity of the cultured EAL against autologous tumors and K-562 cells were measured.

RESULTS

It was found that EAL had a significantly depressed function. Stimulation with two signals, including IL-2 plus IL-7, IL-2 plus IL-12, or IL-2 plus TCR-CD3 engagement, could fully restore the functions of EAL, including IFN-gamma production, proliferative response, and a specific increase in cytolytic activity against autologous tumor cells. IL-4 and IL-10, whether or not in combination with IL-2, did not augment the function of EAL, and even depressed it in some cases. The lymphocyte-depletion test showed that most of the recovered functions were from CD8(+) CTL.

CONCLUSION

The depressed cellular function of EAL could be reversed with double signal stimulation, including IL-2 plus IL-7, IL-2 plus IL-12, or IL-2 plus TCR-CD3 engagement. These recovered cellular functions were mainly from CD8(+) CTL.

A large quantity of CD3-/CD19-/CD16- lymphocytes in malignant pleural effusion from a patient with recurrent cholangio cell carcinoma

Tumor infiltrating lymphocytes (TILs) are candidates for adoptive cellular immunotherapy. Here we report on a patient whose TILs presented unusual lymphocyte antigens. Pleural effusions were collected from a 47-year-old man with recurrent cholangio cell carcinoma and malignant effusion. Effusion-associated lymphocytes (EALs) were separated by Ficoll-Hypaque gradient, and the EAL phenotype was determined by flow cytometry. The percentage of positive cells was determined for each lymphocyte-related differentiation antigen. The percentages of CD3+, CD19+, and CD16+ lymphocyte subpopulations among EALs were 20%, 7%, and 3%, respectively. Nearly 70% of EALs were CD3-/CD19-/CD56-/CD16- cells. The phenotypes of peripheral blood lymphocytes (PBLs) collected simultaneously from the patient's peripheral blood were CD3+ (52%), CD19+ (20%), and CD16+ (20%). When EALs were cultured in medium without pleural effusion, T cell-related antigens, but not B cell- or natural killer (NK) cell-related antigens, were newly expressed on EALs, and this expression reached a plateau after 48 h in culture. The proportions of CD3+, CD19+, and CD16+ cells were 69%, 7%, and 3%, respectively. However, when EALs were cultured in medium with pleural effusion, increased expression of T cell-related antigens was not observed; the proportions of CD3+, CD19+, and CD16+ cells were 16%, 6%, and 1%, respectively. Neither total cell numbers nor cellular viability of EALs changed significantly after in-vitro culture, suggesting that significant proliferation or death of EALs did not occur during the culture period. Co-culture of the patient's PBLs with autologous pleural effusion for 96 h did not alter the expression of lymphocyte-related antigens on the PBLs. These results indicate that expression of T cell-related antigens, but not B cell- or NK cell-related antigens, on EALs was blocked temporarily by the malignant pleural effusion. This is the first report concerning the existence of a large quantity of unclassified lymphocytes in which the T cell-related antigens were reversibly masked in the malignant pleural effusion.

Specific immunotherapy of cancer in elderly patients

The concept of immunotherapy of cancer is more than a century old, but only recently have molecularly defined therapeutic approaches been developed. In this review, we focus on the most promising approach, active therapeutic vaccination. The identification of tumour antigens can now be accelerated by methods allowing the amplification of gene products selectively or preferentially transcribed in the tumour. However, determining the potential immunogenicity of such gene products remains a demanding task, since major histocompatibility complex (MHC) restriction of T cells implies that for any newly defined antigen, immunogenicity will have to be defined for any individual MHC haplotype. Tumour-derived peptides eluted from MHC molecules of tumour tissue are also a promising source of antigen. Tumour antigens are mostly of weak immunogenicity, because the vast majority are tumour-associated differentiation antigens already 'seen' by the patient's immune system. Effective therapeutic vaccination will thus require adjuvant support, possibly by new approaches to immunomodulation such as bispecific antibodies or antibody-cytokine fusion proteins. Tumour-specific antigens, which could be a more potent target for immunotherapy, mostly arise by point mutations and have the disadvantage of being not only tumour-specific, but also individual-specific. Therapeutic vaccination will probably focus on defined antigens offered as protein, peptide or nucleic acid. Irrespective of the form in which the antigen is applied, emphasis will be given to the activation of dendritic cells as professional antigen presenters. Dendritic cells may be loaded in vitro with antigen, or, alternatively, initiation of an immune response may be approached in vivo by vaccination with RNA or DNA, given as such or packed into attenuated bacteria. The importance of activation of T helper cells has only recently been taken into account in cancer vaccination. Activation of cytotoxic T cells is facilitated by the provision of T helper cell-derived cytokines. T helper cell-dependent recruitment of elements of non-adaptive defence, such as leucocytes, natural killer cells and monocytes, is of particular importance when the tumour has lost MHC class I expression. Barriers to successful therapeutic vaccination include: (i) the escape mechanisms developed by tumour cells in response to immune attack; (ii) tolerance or anergy of the evoked immune response; (iii) the theoretical possibility of provoking an autoimmune reaction by vaccination against tumour-associated antigens; and (iv) the advanced age of many patients, implying reduced responsiveness of the senescent immune system.

Unexpected induction of unresponsiveness by vaccination with transformed Salmonella typhimurium

Rats vaccinated with attenuated Salmonella typhimurium transformed with a vector containing the v2 exon of CD44 (SL-v2) were not protected and developed thymic metastases at a high rate. This was surprising because there was evidence for concomitant induction of a CD44v2-specific helper and cytotoxic T-cell response. The inefficacy of vaccination was partly caused by tumor escape and tumor-induced immunosuppression. More important were the facts that (i) BSpl2v2 cells migrated from the intraperitoneal implantation site to the thymus and (ii) after vaccination with transformed attenuated Salmonella typhimurium, a small number of dendritic cells, which had transcribed the cDNA insert, were detected in the thymus. In the thymic environment, these v2 presenting dendritic cells, as well as the BSp12v2 tumor cells, supported tolerance induction. Thus, vaccination with tumor-associated differentiation antigens, which in many instances have induced antitumor response, may deteriorate survival time and rate if vaccination is accompanied by presentation of the antigen during intrathymic T-cell selection.

Chronic immune activation and inflammation in the pathogenesis of AIDS and cancer

Infection with the human immunodeficiency virus (HIV) invariably leads to the development of acquired immunodeficiency syndrome (AIDS) in most infected humans, yet does so rarely, if at all, in HIV-infected chimpanzees. The differences between the two species are not due to differences in cellular receptors or an inability of the chimpanzee to be infected, but rather to the lack of pan-immune activation in the infected primate. This results in reduced apoptotic death in CD4+ T-helper lymphocytes and a lower viral load. In humans the degree of chronic immune activation correlates with virus load and clinical outcome with high immune activation leading to high viral loads and the more rapid progression to AIDS and death. The type of immune perturbation seen in HIV-associated AIDS is similar to that of chronic graft-versus-host disease (GVHD) where reduced cell-mediated immune (CMI) responses occur early in the course of the disease and where humoral responses (HI) predominate. A reduced CMI response occurs in a number of chronic infectious diseases, including tuberculosis and leishmaniasis. More recently, it has become increasingly apparent that the CMI response is suppressed in virtually all malignant diseases, including melanoma and colorectal and prostate cancer. This raises the possibility that, as the malignant process develops, the cancer cells evolve to subvert the CMI response. Moreover, the reduced CMI response seen in colorectal cancer (CRC) patients is completely reversed following curative surgery strongly supporting the hypothesis that CRC can suppress the systemic immune response. Wound healing, ovulation, embryo implantation, and fetal growth are all associated with suppressed CMI and neovascularization (the formation of new blood vessels) or angiogenesis (the formation of new blood vessels from an existing vasculature). If unresolved, wound healing results in chronic inflammation, which can give rise to the phenomenon of "scar cancers." Indeed all the chronic inflammatory conditions known to be associated with the subsequent development of malignant disease, including chronic obstructive airway disease (COPD), ulcerative colitis (UC), and asbestosis, give rise to similar proangiogenic, suppressed CMI, and HI-predominant environments. In keeping with this CMI-associated cytokines such as interleukin (IL)-2 and interferon (IFN)-gamma tend to be antiangiogenic, whereas HI cytokines such as IL-6 tend to be proangiogenic. Furthermore, chronic immune activation leads to the synthesis and release of factors such as macrophage inflammatory protein (MIP)-1 that inhibit apoptosis through suppression of p53 activity. The "Golden Triangle" of suppressed CMI, angiogenesis, and reduced apoptosis would provide the ideal environment for the serial mutations to occur that are required for the development of malignant disease. If the observed association is relevant to carcinogenesis, then treatments aimed at reducing the components of these inflammatory conditions may be useful both in the setting of chemoprevention and the therapeutic management of established disease.

Interleukin-7 and interleukin-12 have different effects in rescue of depressed cellular immunity: comparison of malignant and tuberculous pleural effusions

The present study attempts to determine the role of interleukin-7 (IL-7) and IL-12 in recovering the functions of the lymphocytes of malignant effusion, in terms of cytokine production, proliferation, and cytolytic activity, compared with lymphocytes from tuberculous pleural effusion. Effusion-associated lymphocytes (EAL) were isolated from tuberculous (tEAL) and malignant (mEAL) pleural effusions. The EAL proliferate response was measured after 3 days in culture. Interferon-gamma (IFN-gamma) production and cytotoxicity against K-562 cells or autologous tumor cells were assessed after 6 days in culture. It was found that the mEAL had depressed proliferation, IFN-gamma production, and cytolytic activity, as compared with tEAL. Stimulation with IL-12 plus IL-2, but not with IL-7 plus IL-2, fully restored the IFN-gamma production of mEAL to that of tEAL levels. In contrast, the proliferate response of mEAL was enhanced significantly more with IL-7 plus IL-2 than with IL-12 plus IL-2. Both the IL-7 plus IL-2 and IL-12 plus IL-2 stimulation of mEAL showed a significant increase in cytolytic activity against autologous tumor cells, although the cytolytic activity against K-562 cells did not increase. These results suggest that tEAL had a higher cellular activity than mEAL. This depressed cellular function of mEAL could be reversed with cytokines. However, different cytokines had different effects on mEAL; for example, IL-7 had a better effect in the stimulation of lymphocyte proliferation compared with IL-12, which had a better effect in driving the lymphocytes to the T helper 1 (TH1) pathway and a higher IFN-gamma production. Both IL-7 and IL-12, in the presence of IL-2, can restore the immunosuppressed cytolytic activity of the lymphocytes of malignant pleural effusion against autologous tumor.

Restoration of cytotoxic T lymphocyte function in malignant pleural effusion: interleukin-15 vs. interleukin-2

The present study attempts to define the role of interleukin-15 (IL-15), as compared with IL-2, in generating cytotoxic T lymphocytes (CTL) from the malignant effusions of cancer patients. Effusion-associated lymphocytes (EAL) from malignant effusion were incubated with IL-15 or IL-2 with or without alphaCD3. Proliferation and cytotoxicity assays were performed. IL-15 was found to have at least an equivalent, if not higher, activity to IL-2 in terms of lymphocyte proliferation and generation of CTL from EAL. The proliferative response of EAL, cocultured with IL-15, with or without alphaCD3, was partly inhibited by pretreatment with an anti-IL2 receptor beta chain monoclonal antibody (mAb). The proliferative response of EAL, cocultured with alphaCD3, IL-2, or both, was partly inhibited by pretreatment with an anti-IL-2 receptor alpha chain mAb. Overnight [5lCr] release assays against K562, Daudi, and the patients' autologous tumor cells were done to evaluate EAL's cytolytic activity. MHC class I Ab blocked the stimulated cytolytic activity of EAL against autologous tumors. An mAb depletion assay showed that the phenotype of the restored EAL was CD16-CD4-CD8+; thus, the restored activity of EAL was CTL activity. The results suggest that both IL-15 and IL-2 can restore CTL activity from EAL in the presence of T cell receptor (TCR)-CD3 engagement, but the effect of IL-15 was superior.

The relationship between angiogenesis and the immune response in carcinogenesis and the progression of malignant disease

Recent studies have demonstrated that angiogenesis and suppressed cell-mediated immunity (CMI) play a central role in the pathogenesis of malignant disease facilitating tumour growth, invasion and metastasis. In the majority of tumours, the malignant process is preceded by a pathological condition or exposure to an irritant which itself is associated with the induction of angiogenesis and/or suppressed CMI. These include: cigarette smoking, chronic bronchitis and lung cancer; chronic oesophagitis and oesophageal cancer; chronic viral infections such as human papilloma virus and ano-genital cancers, chronic hepatitis B and C and hepatocellular carcinoma, and Epstein-Barr virus (EBV) and lymphomas; chronic inflammatory conditions such as Crohn's disease and ulcerative colitis and colorectal cancer; asbestos exposure and mesothelioma and excessive sunlight exposure/sunburn and malignant melanoma. Chronic exposure to growth factors (insulin-like growth factor-I in acromegaly), mutations in tumour suppressor genes (TP53 in Li Fraumeni syndrome) and long-term exposure to immunosuppressive agents (cyclosporin A) may also give rise to similar environments and are associated with the development of a range of solid tumours. The increased blood supply would facilitate the development and proliferation of an abnormal clone or clones of cells arising as the result of: (a) an inherited genetic abnormality; and/or (b) acquired somatic mutations, the latter due to local production and/or enhanced delivery of carcinogens and mutagenic growth factors. With progressive detrimental mutations and growth-induced tumour hypoxia, the transformed cell, to a lesser or greater extent, may amplify the angiogenic process and CMI suppression, thereby facilitating further tumour growth and metastasis. There is accumulating evidence that long-term treatment with cyclo-oxygenase inhibitors (aspirin and indomethacin), cytokines such as interferon-alpha, anti-oestrogens (tamoxifen and raloxifene) and captopril significantly reduces the incidence of solid tumours such as breast and colorectal cancer. These agents are anti-angiogenic and, in the case of aspirin, indomethacin and interferon-alpha have proven immunomodulatory effects. Collectively these observations indicate that angiogenesis and suppressed CMI play a central role in the development and progression of malignant disease.

Cancer therapy: new concepts on active immunization

There is increasing evidence that tumors express putative target molecules for a therapeutic immune reaction. Yet, tumor cells lack the prerequisites for appropriate antigen presentation and--hence--the immune system does not respond. This difficulty can probably be circumvented when tumor antigens are processed by conventional antigen presenting cells. Thus, the identification of immunogenic tumor-associated antigens may allow new modes of vaccination with the hope of adding a fourth and hopefully powerful weapon to surgery, radiation and chemotherapy in the fight against cancer.

Role of bronchoscopy in lung cancer research

The use of bronchoscopy for research into lung cancer is mostly limited by the imagination of the investigator. This technique allows the scientist direct access to tissue in a minimally invasive manner. We have discussed some of the applications of this technique in better understanding lung cancer. As we move onward in the areas of diagnosis and treatment of lung cancer, the bronchoscope will remain an important research tool.