The role of sargramostim (rhGM-CSF) as immunotherapy

Inflammation Regulation via an Agonist and Antagonists of α7 Nicotinic Acetylcholine Receptors in RAW264.7 Macrophages

The α7 nicotinic acetylcholine receptor (nAChR) is widely distributed in the central and peripheral nervous systems and is closely related to a variety of nervous system diseases and inflammatory responses. The α7 nAChR subtype plays a vital role in the cholinergic anti-inflammatory pathway. In vivo, ACh released from nerve endings stimulates α7 nAChR on macrophages to regulate the NF-κB and JAK2/STAT3 signaling pathways, thereby inhibiting the production and release of downstream proinflammatory cytokines and chemokines. Despite a considerable level of recent research on α7 nAChR-mediated immune responses, much is still unknown. In this study, we used an agonist (PNU282987) and antagonists (MLA and α-conotoxin [A10L]PnIA) of α7 nAChR as pharmacological tools to identify the molecular mechanism of the α7 nAChR-mediated cholinergic anti-inflammatory pathway in RAW264.7 mouse macrophages. The results of quantitative PCR, ELISAs, and transcriptome analysis were combined to clarify the function of α7 nAChR regulation in the inflammatory response. Our findings indicate that the agonist PNU282987 significantly reduced the expression of the IL-6 gene and protein in inflammatory macrophages to attenuate the inflammatory response, but the antagonists MLA and α-conotoxin [A10L]PnIA had the opposite effects. Neither the agonist nor antagonists of α7 nAChR changed the expression level of the α7 nAChR subunit gene; they only regulated receptor function. This study provides a reference and scientific basis for the discovery of novel α7 nAChR agonists and their anti-inflammatory applications in the future.

Case Report: Pathological Complete Response in a Lung Metastasis of Phyllodes Tumor Patient Following Treatment Containing Peptide Neoantigen Nano-Vaccine

Some of the mutant peptides produced by gene mutation transcription and translation have the ability to induce specific T cells, which are called new antigens. Neoantigen-based peptide, DNA, RNA, and dendritic cell vaccines have been used in the clinic. In this paper, we describe a lung metastasis of a phyllodes tumor patient demonstrating pathological complete response following treatment containing personalized multi-epitope peptide neoantigen nano-vaccine. Based on whole-exome sequencing (WES), RNA sequencing, and new antigen prediction, several mutated peptide fragments were predicted to bind to the patient’s human leukocyte antigen (HLA) allotypes, including ten peptides with high predicted binding affinity for six genes. The pulmonary metastases remained stable after the four cycles of anti-PD1 and anlotinib. After the addition of the multi-epitope peptide neoantigen nano-vaccine, the tumor began to collapse and contracture developed, accompanied by a decrease of tumor markers to normal, and complete pathological remission was achieved. With the use of the vaccination, recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) was used every time, and low-dose cyclophosphamide was injected every 3 weeks to improve efficacy. Peripheral blood immune monitoring demonstrated immune reactivity against a series of peptides, with the most robust post-vaccine T-cell response detected against the HLA-DRB1*0901-restricted SLC44A5 V54F peptide.

In Vitro Generated Dendritic Cells of Leukemic Origin Predict Response to Allogeneic Stem Cell Transplantation in Patients With AML and MDS

Allogeneic stem cell transplantation (alloSCT) is the treatment of choice for many patients with acute myeloid leukemia (AML) and myelodysplastic syndrome. The presentation of leukemic or allospecific antigens by malignant blasts is regarded as a crucial trigger for an effective allogeneic immune response. Conversely, insufficient stimulatory capacity by the leukemic blasts is thought to be a relevant escape mechanism from cellular immunotherapy (alloSCT). Our purpose was to test, whether the ability of malignant blasts to differentiate in vitro toward dendritic cells of leukemic origin (DCleu) is associated with clinical outcome. We isolated leukemic blasts from peripheral blood or bone marrow of AML and myelodysplastic syndrome patients before alloSCT (n=47) or at relapse after alloSCT (n=22). A panel of 6 different assays was used to generate DCleu in vitro. Results were correlated with clinical outcome. DCleu could be generated from all 69 samples. Significantly higher mean frequencies of DCleu were found in clinical long-term responders versus nonresponders to SCT (76.8% vs. 58.8%, P=0.006). Vice versa, the chance for response to SCT was significantly higher, if a DCleu+/dendritic cells (DC) ratio of >50% could be reached in vitro (P=0.004). Those patients were characterized by a longer time to relapse (P=0.04) and by a higher probability for leukemia-free survival (P=0.005). In vitro generation of DC and DCleu from leukemic blasts correlated with the clinical outcome. This observation may support a role of leukemic antigen presentation by "leukemia-derived DC" for the stimulation of an allogeneic immune response in AML.

Therapeutic and Prophylactic Use of Oral, Low-Dose IFNs in Species of Veterinary Interest: Back to the Future

Cytokines are important molecules that orchestrate the immune response. Given their role, cytokines have been explored as drugs in immunotherapy in the fight against different pathological conditions such as bacterial and viral infections, autoimmune diseases, transplantation and cancer. One of the problems related to their administration consists in the definition of the correct dose to avoid severe side effects. In the 70s and 80s different studies demonstrated the efficacy of cytokines in veterinary medicine, but soon the investigations were abandoned in favor of more profitable drugs such as antibiotics. Recently, the World Health Organization has deeply discouraged the use of antibiotics in order to reduce the spread of multi-drug resistant microorganisms. In this respect, the use of cytokines to prevent or ameliorate infectious diseases has been highlighted, and several studies show the potential of their use in therapy and prophylaxis also in the veterinary field. In this review we aim to review the principles of cytokine treatments, mainly IFNs, and to update the experiences encountered in animals.

Soluble Prokaryotic Overexpression and Purification of Human GM-CSF Using the Protein Disulfide Isomerase b'a' Domain

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a member of the colony-stimulating factor (CSF) family, which functions to enhance the proliferation and differentiation of hematopoietic stem cells and other hematopoietic lineages such as neutrophils, dendritic cells, or macrophages. These proteins have thus generated considerable interest in clinical therapy research. A current obstacle to the prokaryotic production of human GM-CSF (hGM-CSF) is its low solubility when overexpressed and subsequent complex refolding processes. In our present study, the solubility of hGM-CSF was examined when combined with three N-terminal fusion tags in five E. coli strains at three different expression temperatures. In the five E. coli strains BL21 (DE3), ClearColi BL21 (DE3), LOBSTR, SHuffle T7 and Origami2 (DE3), the hexahistidine-tagged hGM-CSF showed the best expression but was insoluble in all cases at each examined temperature. Tagging with the maltose-binding protein (MBP) and the b'a' domain of protein disulfide isomerase (PDIb'a') greatly improved the soluble overexpression of hGM-CSF at 30 °C and 18 °C. The solubility was not improved using the Origami2 (DE3) and SHuffle T7 strains that have been engineered for disulfide bond formation. Two conventional chromatographic steps were used to purify hGM-CSF from the overexpressed PDIb'a'-hGM-CSF produced in ClearColi BL21 (DE3). In the experiment, 0.65 mg of hGM-CSF was isolated from a 0.5 L flask culture of these E. coli and showed a 98% purity by SDS-PAGE analysis and silver staining. The bioactivity of this purified hGM-CSF was measured at an EC₅₀ of 16.4 ± 2 pM by a CCK8 assay in TF-1 human erythroleukemia cells.

GM-CSF enhanced the effect of CHOP and R-CHOP on inhibiting diffuse large B-cell lymphoma progression via influencing the macrophage polarization

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is a common type of the Non-Hodgkin lymphomas (NHLs) formed by the neoplastic transformation of mature B cells. As the first-line therapeutics, CHOP (cyclophosphamide/doxorubicin/vincristine/prednisone) chemotherapy and R-CHOP (Rituximab + CHOP), either using alone or in combination with GM-CSF, have achieved great efficacy in DLBCL patients. However, the underlying mechanisms are still largely unknown.

METHODS

In the present study, the combination use of CHOP and R-CHOP with GM-CSF was used to evaluate their effects on the tumor immune microenvironment of DLBCL. CHOP and R-CHOP administration was found to inhibit the growth and metastasis of DLBCL, with a higher efficacy in R-CHOP-challenged DLBCL mice. The anti-tumor effect of CHOP and R-CHOP was further amplified by GM-CSF.

RESULTS

CHOP and R-CHOP therapeutics potentiated the anti-tumor properties of macrophages, as evidenced by the increased M1 macrophage and the decreased M2 macrophage accumulation in DLBCL-bearing mice. In a co-culture system, macrophages primed with CHOP and R-CHOP therapeutics inhibited multiple malignant behaviors of DLCBL cells. Mechanistically, CHOP/R-CHOP suppressed the activation of AKT signaling. These anti-tumor effects of CHOP/R-CHOP were all augmented by GM-CSF.

CONCLUSIONS

Our work provided new insights into the immune-regulatory roles of CHOP and R-CHOP in the treatment of DLBCL, as well as the synergistic effects of GM-CSF in CHOP and R-CHOP therapeutics. Although our results suggest the synergistic effect of GM-CSF on DLBCL already sensitive to CHOP and R-CHOP, however, future studies are warranted to explore the role of GM-CSF on R-CHOP-resistant DLBCL. Trial registration Not applicable.

Efficacy of delayed administration of sargramostim up to 120 hours post exposure in a nonhuman primate total body radiation model

BACKGROUND

High dose ionizing radiation exposure is associated with myelo-depression leading to pancytopenia and the expected clinical manifestations of acute radiation syndrome (ARS). Herein, we evaluated the efficacy of sargramostim (Leukine®, yeast-derived rhu GM-CSF), with regimens delivered at 48, 72, 96, or 120 h after radiation exposure.

METHODS

A randomized and blinded nonhuman primate (NHP) study was conducted to assess the effects of sargramostim treatment on ARS. NHPs were exposed to total body radiation (LD83/60 or lethal dose 83% by Day 60) and were randomized to groups receiving daily subcutaneous dosing of sargramostim starting from either 48, 72, 96, or 120 h post-irradiation. Additionally, separate groups receiving sargramostim treatment at 48 h post-irradiation also received prophylactic treatment with azithromycin. Sargramostim treatment of each animal continued until the preliminary absolute neutrophil count (ANC) returned to ≥1000/μL post-nadir for three consecutive days or the preliminary ANC exceeded 10,000/μL, which amounted to be an average of 15.95 days for all treatment groups. Prophylactic administration of enrofloxacin was included in the supportive care given to all animals in all groups. All animals were monitored for 60 days post-irradiation for mortality, hematological parameters, and sepsis.

RESULTS

Delayed sargramostim treatment at 48 h post-irradiation significantly reduced mortality (p = .0032) and improved hematological parameters including neutrophil but also lymphocyte and platelet counts. Additional delays in sargramostim administration at 72, 96, and 120 h post-irradiation were also similarly effective at enhancing the recovery of lymphocyte, neutrophil, and platelet counts compared to control. Sargramostim treatment also improved the survival of the animals when administered at up to 96 h post-irradiation. While sargramostim treatment at 48 h significantly reduced mortality associated with sepsis (p ≤ .01), the additional prophylactic treatment with azithromycin did not have clinically significant effects.

CONCLUSION

In a NHP ARS model, sargramostim administered starting at 48 h post-radiation was effective to improve survival, while beneficial hematological effects were observed with sargramostim initiated up to 120 h post exposure.

Anti-VEGF therapy resistance in ovarian cancer is caused by GM-CSF-induced myeloid-derived suppressor cell recruitment

BACKGROUND

The mechanism of resistance development to anti-VEGF therapy in ovarian cancer is unclear. We focused on the changes in tumour immunity post anti-VEGF therapy.

METHODS

The frequencies of immune cell populations and hypoxic conditions in the resistant murine tumours and clinical samples were examined. The expression profiles of both the proteins and genes in the resistant tumours were analysed. The impact of granulocyte-monocyte colony-stimulating factor (GM-CSF) expression on myeloid-derived suppressor cell (MDSC) function in the resistant tumours was evaluated.

RESULTS

We found a marked increase and reduction in the number of Gr-1 + MDSCs and CD8 + lymphocytes in the resistant tumour, and the MDSCs preferentially infiltrated the hypoxic region. Protein array analysis showed upregulation of GM-CSF post anti-VEGF therapy. GM-CSF promoted migration and differentiation of MDSCs, which inhibited the CD8 + lymphocyte proliferation. Anti-GM-CSF therapy improved the anti-VEGF therapy efficacy, which reduced the infiltrating MDSCs and increased CD8 + lymphocytes. In immunohistochemical analysis of clinical samples, GM-CSF expression and MDSC infiltration was enhanced in the bevacizumab-resistant case.

CONCLUSIONS

The anti-VEGF therapy induces tumour hypoxia and GM-CSF expression, which recruits MDSCs and inhibits tumour immunity. Targeting the GM-CSF could help overcome the anti-VEGF therapy resistance in ovarian cancers.

Steamed Panax notoginseng Attenuates Anemia in Mice With Blood Deficiency Syndrome via Regulating Hematopoietic Factors and JAK-STAT Pathway

Panax notoginseng (Burk.) F. H. Chen is a medicinal herb used to treat blood disorders since ancient times, of which the steamed form exhibits the anti-anemia effect and acts with a “blood-tonifying” function according to traditional use. The present study aimed to investigate the anti-anemia effect and underlying mechanism of steamed P. notoginseng (SPN) on mice with blood deficiency syndrome induced by chemotherapy. Blood deficiency syndrome was induced in mice by cyclophosphamide and acetylphenylhydrazine. A number of peripheral blood cells and organs (liver, kidney, and spleen) coefficients were measured. The mRNA expression of hematopoietic function-related cytokines in the bone marrow of mice was detected by RT-qPCR. The janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway was screened based on our previous analysis by network pharmacology. The expression of related proteins and cell cycle factors predicted in the pathway was determined by Western blot and RT-qPCR. SPN could significantly increase the numbers of peripheral blood cells and reverse the enlargement of spleen in a dose-dependent manner. The quantities of related hematopoietic factors in bone marrow were also increased significantly after SPN administration. SPN was involved in the cell cycle reaction and activation of immune cells through the JAK-STAT pathway, which could promote the hematopoiesis.

Cloning, Optimization of Periplasmic Expression and Purification of Recombinant Granulocyte Macrophage-Stimulating Factor in Escherichia coli BL21 (DE3)

Background:

Molgramostim, a nonglycosylated version of recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF), can be produced in a high level by Escherichia coli. However, overexpression of GM-CSF in bacterial cells usually leads to formation of inclusion bodies and insoluble protein aggregates which are not biologically active. The aim of the present study was to improve the expression of soluble and biologically active GM-CSF in periplasmic space of E. coli BL21 (DE3).

Materials and Methods:

The codon-optimized GM-CSF gene was subcloned into pET-22b expression vector, in frame with the pelB secretion signal peptide for periplasmic secretion. Cultivation conditions including as isopropyl β-D-1-thiogalactopyranoside (IPTG) concentration, incubation temperature, and presence of sucrose were optimized to improve periplasmic expression of GM-CSF. The expressed protein was purified using Ni-NTA affinity column. Biological activity of GM-CSF on HL-60 cells was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.

Results:

The amount of soluble protein for periplasmic expression was more when compared with one of the cytoplasmic expressions. The optimum condition for periplasmic expression of GM-CSF was expression at 23°C, using 1 mM IPTG as inducer and in the presence of 0.4 M sucrose. The biological activity of purified GM-CSF on HL-60 cell line was assessed by MTT assay, and the specific activity of produced GM-CSF was determined as 1.2 × 10⁴ IU/μg.

Conclusion:

The present work suggests that periplasmic expression and optimization of cultivation conditions could improve soluble expression of recombinant proteins by E. coli.

Can we cure stage IV triple-negative breast carcinoma?: Another case report of long-term survival (7 years)

RATIONALE

Triple-negative breast cancer has a dismal prognosis, especially once it has spread to other organs, due to the lack of effective treatments available at this time. Finding an effective treatment for metastatic triple-negative breast cancer remains an unmet medical need.

PATIENT CONCERNS

A 60-year-old woman was diagnosed with stage IIIC triple-negative breast cancer after undergoing a mastectomy. Her mastectomy was followed by adjuvant chemotherapy and radiation therapy. Approximately 1 year later, the patient presented with enlarging lymph nodes in her neck. A biopsy of a left supraclavicular lymph node was positive for recurrent disease. Positron emission tomography and computed tomography scans performed after the biopsy showed metabolic activity in the T6 vertebral body and the right level IIB lymph nodes.

DIAGNOSES

The patient was diagnosed with recurrent metastatic triple-negative breast carcinoma with metastases to the bone and lymph nodes.

INTERVENTIONS

The patient was treated with weekly metronomic chemotherapy, sequential chemotherapy regimens, and immunotherapy.

OUTCOMES

The patient is now 68 years old and 7 years out from her diagnosis of metastatic disease. She achieved a complete response to her treatment and routine scans continue to show no evidence of recurrent disease.

LESSONS

Utilizing sequential weekly metronomic chemotherapy regimens in combination with immunotherapy looks to be a promising treatment option for patients with metastatic triple-negative breast carcinoma. This is a second case where we were able to achieve long-term remission by using the above treatment strategy. These exciting results warrant further investigation of this treatment methodology. We hope that the treatment strategy described in this article can provide an outline for researchers and give patients with this disease more treatment options.

[Immunotherapy - The New Era of Oncology]

In the field of immunotherapy, essential progress was achieved over the past years partially demonstrating long lasting therapeutic responses in different tumor entities. A better understanding of the interactions between the tumor and the immune system as well as the integration of immunotherapeutic approaches into clinical routine were the foundations for this development. The different approaches intervene on multiple levels of the immune response and directly or indirectly mount the patient‘s own immune defense against tumor cells. Immunotherapeutic approaches are represented by cytokine therapies, vaccinations, the use of oncolytic viruses and monoclonal antibody therapies as well as adoptive cell transfer strategies.

Herbal approach in the treatment of pancytopenia

Pancytopenia is a health condition in which there is a reduction in the amount of leucocytes, erythrocytes and thrombocytes. If more than one of the blood cells is low then the condition is called as bicytopenia. The pancytopenic condition is observed in treatment of diseased conditions like thalassemia and hepatitis C. Iatrogenically pancytopenia is caused by some antibiotics and anti-HCV drugs. Medical conditions like aplastic anaemia, lymphoma, copper deficiency, and so forth can also cause pancytopenia. Pancytopenia can in turn decrease the immunity of the person and thereby can be fatal. Current therapies for pancytopenia include bone marrow stimulant drugs, blood transfusion and bone marrow transplant. The current therapies are very excruciating and have long-term side-effects. Therefore, treating these condition using herbal drugs is very important. Herbs like wheatgrass, papaya leaves and garlic are effective in treating single lineage cytopenias. The present review is focused on the potential effects of natural herbs for the treatment of pancytopenia.

Systemic GM-CSF Recruits Effector T Cells into the Tumor Microenvironment in Localized Prostate Cancer

Granulocytic-macrophage colony-stimulating factor (GM-CSF) is used as an adjuvant in cancer vaccine trials and has the potential to enhance antitumor efficacy with immunotherapy; however, its immunologic effects are not fully understood. Here, we report results from a phase I study of neoadjuvant GM-CSF in patients with localized prostate cancer undergoing radical prostatectomy. Patients received subcutaneous injections of GM-CSF (250 μg/m²/day) daily for 2 weeks (cohort 1; n = 6), 3 weeks (cohort 2; n = 6), or 4 weeks (cohort 3; n = 6). Treatment was well tolerated with all grade 1 or 2 adverse events. Two patients had a decline in prostate-specific antigen (PSA) of more than 50%. GM-CSF treatment increased the numbers of circulating mature myeloid dendritic cells, proliferating conventional CD4 T cells, proliferating CD8 T cells, and to a lesser magnitude FoxP3⁺ regulatory CD4 T cells. Although GM-CSF treatment did not augment antigen-presenting cell localization to the prostate, treatment was associated with recruitment of CD8⁺ T cells to the tumor. These results suggest that systemic GM-CSF can modulate T-cell infiltration in the tumor microenvironment. Cancer Immunol Res; 4(11); 948-58. ©2016 AACR.

Restoration of MYC-repressed targets mediates the negative effects of GM-CSF on RUNX1-ETO leukemogenicity

GM-CSF signaling regulates hematopoiesis and immune responses. CSF2RA, the gene encoding the α subunit for GM-CSF, is significantly downregulated in t(8;21) (RUNX1-ETO or RE) leukemia patients, suggesting that it may serve as a tumor suppressor. We previously reported that GM-CSF signaling is inhibitory to RE leukemogenesis. Here we conducted gene expression profiling of primary RE hematopoietic stem/progenitor cells (HSPCs) treated with GM-CSF to elucidate the mechanisms mediating the negative effects of GM on RE leukemogenicity. We observed that GM treatment of RE HSPCs resulted in a unique gene expression profile that resembles primary human cells undergoing myelopoiesis, which was not observed in control HSPCs. Additionally we discovered that GM-CSF signaling attenuates MYC-associated gene signatures in RE HSPCs. In agreement with this, a functional screen of a subset of GM-CSF-responsive genes demonstrated that a MYC inhibitor, MXI1, reduced the leukemic potential of RE HSPCs and t(8;21) AML cells. Furthermore, MYC knockdown and treatment with the BET inhibitor JQ1 reduced the leukemic potential of t(8;21) cell lines. Altogether, we discovered a novel molecular mechanism mediating the GM-CSF-induced reduction in leukemic potential of RE cells, and our findings support MYC inhibition as an effective strategy for reducing the leukemogenicity of t(8;21) AML.

Overcoming HBV immune tolerance to eliminate HBsAg-positive hepatocytes via pre-administration of GM-CSF as a novel adjuvant for a hepatitis B vaccine in HBV transgenic mice

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is known to be a potential vaccine adjuvant despite contradictory results from animal and human studies. The discrepancies may be due to the different doses and regimens of GM-CSF that were used, given that either mature or immature dendritic cells (DCs) could be induced under different conditions. To test the hypothesis that GM-CSF can be used as a novel adjuvant for a hepatitis B virus (HBV) therapeutic vaccine, we administered GM-CSF once per day for three days prior to vaccination with recombinant HBV vaccine (rHBVvac) in mice. We observed greater DC maturation in these pre-treated animals at day 3 as compared to day 1 or day 2 of daily GM-CSF administration. This strategy was further investigated for its ability to break the immune tolerance established in hepatitis B surface antigen-transgenic (HBsAg-Tg) animals. We found that the levels of induced anti-HBsAg antibodies were significantly higher in animals following three days of GM-CSF pre-treatment before rHBV vaccination after the third immunization. In addition to the increase in anti-HBsAg antibody levels, cell-mediated anti-HBsAg responses, including delayed-type hypersensitivity, T-cell proliferation, interferon-γ production, and cytotoxic T lymphocytes, were dramatically enhanced in the three-day GM-CSF pre-treated group. After adoptive transfers of CD8⁺ T cells from immunized animals, antigen-specific CD8⁺ T cells were observed in the livers of recipient HBsAg-Tg animals. Moreover, the three-day pre-treatments with GM-CSF prior to rHBVvac vaccination could significantly eliminate HBsAg-positive hepatocytes, suggesting beneficial therapeutic effects. Therefore, this protocol utilizing GM-CSF as an adjuvant in combination with the rHBVvac vaccine has the potential to become a novel immunotherapy for chronic hepatitis B patients.

Th17 cytokine deficiency in patients with Aspergillus skull base osteomyelitis

BACKGROUND

Fungal skull base osteomyelitis (SBO) is a severe complication of otitis externa or sinonasal infection, and is mainly caused by Aspergillus species. Here we investigate innate and adaptive immune responses in patients with Aspergillus SBO to identify defects in the immune response that could explain the susceptibility to this devastating disease.

METHODS

Peripheral blood mononuclear cells isolated from six patients with Aspergillus SBO and healthy volunteers were stimulated with various microbial stimuli, among which also the fungal pathogens Candida albicans and Aspergillus fumigatus. The proinflammatory cytokines IL-6, TNFα and IL-1β, and the T-helper cell-derived cytokines IFNγ, IL-17 and IL-22 were measured in cell culture supernatants by ELISA.

RESULTS

Proinflammatory cytokine responses did not differ between SBO patients and healthy volunteers. The Candida- and Aspergillus-specific Th17 response (production of IL-17 and IL-22) was significantly decreased in the SBO patients compared to healthy individuals, while Th1 cytokine response (IFNγ production) did not differ between the two groups.

CONCLUSIONS

We show that patients with Aspergillus skull base osteomyelitis infection have specific defects in Th17 responses. Since IL-17 and IL-22 are important for stimulating antifungal host defense, we hypothesize that strategies that have the ability to improve IL-17 and IL-22 production may be useful as adjuvant immunotherapy in patients with Aspergillus SBO.

Multifarious immunotherapeutic approaches to cure HIV-1 infection

Immunotherapy in the context of treated HIV-1 infection aims to improve immune responses to achieve better control of the virus. To date, multifaceted immunotherapeutic approaches have been shown to reduce immune activation and increase CD4 T-lymphocyte counts, further to the effects of antiretroviral therapy alone, in addition to improving HIV-1-specific T-cell responses. While sterilizing cure of HIV-1 would involve elimination of all replication-competent virus, a functional cure in which the host has long-lasting control of viral replication may be more feasible. In this commentary, we discuss novel strategies aimed at targeting the latent viral reservoir with cure of HIV-1 infection being the ultimate goal, an achievement that would have considerable impact on worldwide HIV-1 infection.

Therapeutic immunisation plus cytokine and hormone therapy improves CD4 T-cell counts, restores anti-HIV-1 responses and reduces immune activation in treated chronic HIV-1 infection

BACKGROUND

This randomised, open label, phase I, immunotherapeutic study investigated the effects of interleukin (IL)-2, granulocyte-macrophage colony-stimulating factor (GM-CSF), recombinant human growth hormone (rhGH), and therapeutic immunisation (a Clade B DNA vaccine) on combination antiretroviral therapy (cART)-treated HIV-1-infected individuals, with the objective to reverse residual T-cell dysfunction.

METHODS

Twelve HIV-1(+) patients on suppressive cART with baseline CD4 T-cell counts >400 cells/mm(3) blood were randomised into one of three groups: (1) vaccine, IL-2, GM-CSF and rhGH (n=3); (2) vaccine alone (n=4); or (3) IL-2, GM-CSF and rhGH (n=5). Samples were collected at weeks 0, 1, 2, 4, 6, 8, 12, 16, 24 and 48. Interferon (IFN)-γ, IL-2, IL-4 and perforin ELISpot assays performed at each time point quantified functional responses to Gag p17/p24, Nef, Rev, and Tat peptides; and detailed T-cell immunophenotyping was undertaken by flow cytometry. Proviral DNA was also measured.

RESULTS

Median baseline CD4 T-cell count was 757 cells/mm(3) (interquartile range [IQR] 567-886 cells/mm(3)), median age 48 years (IQR 42-51 years), and plasma HIV-1-RNA <50 copies/ml for all subjects. Patients who received vaccine plus IL-2, GM-CSF and rhGH (group 1) showed the most marked changes. Assessing mean changes from baseline to week 48 revealed significantly elevated numbers of CD4 T cells (p=0.0083) and improved CD4/CD8 T-cell ratios (p=0.0033). This was accompanied by a significant reduction in expression of CD38 on CD4 T cells (p=0.0194), significantly increased IFN-γ and IL-2 production in response to Gag (p=0.0122) and elevated IFN-γ production in response to Tat (p=0.041) at week 48 compared to baseline. Subjects in all treatment groups showed significantly reduced PD-1 expression at week 48 compared to baseline, with some reductions in proviral DNA.

CONCLUSIONS

Multifarious immunotherapeutic approaches in the context of fully suppressive cART further reduce immune activation, and improve both CD4 T-lymphocyte counts and HIV-1-specific T-cell responses (NCT01130376).

Engineered fusokine GIFT4 licenses the ability of B cells to trigger a tumoricidal T-cell response

Engineered chimeric cytokines can generate gain-of-function activity in immune cells. Here, we report potent antitumor activity for a novel fusion cytokine generated by N-terminal coupling of GM-CSF to IL4, generating a fusokine termed GIFT4. B cells treated with GIFT4 clustered GM-CSF and IL4 receptors on the cell surface and displayed a pan-STAT hyperphosphorylation associated with acquisition of a distinct phenotype and function described to date. In C57BL/6J mice, administration of GIFT4 expanded endogenous B cells and suppressed the growth of B16F0 melanoma cells. Furthermore, B16F0 melanoma cells engineered to secrete GIFT4 were rejected immunologically in a B-cell-dependent manner. This effect was abolished when GIFT4-expressing B16F0 cells were implanted in B-cell-deficient mice, confirming a B-cell-dependent antitumor effect. Human GIFT4-licensed B cells primed cytotoxic T cells and specifically killed melanoma cells in vitro and in vivo. Taken together, our results demonstrated that GIFT4 could mediate expansion of B cells with potent antigen-specific effector function. GIFT4 may offer a novel immunotherapeutic tool and define a previously unrecognized potential for B cells in melanoma immunotherapy.

Monocyte/macrophage inflammatory response pathways to combat Francisella infection: possible therapeutic targets?

Francisella tularensis can bypass and suppress host immune responses, even to the point of manipulating immune cell phenotypes and intercellular inflammatory networks. Strengthening these responses such that immune cells more readily identify and destroy the bacteria is likely to become a viable (and perhaps necessary) strategy for combating infections with Francisella, especially given the likelihood of antibiotic resistance in the foreseeable future. Monocytes and macrophages offer a niche wherein Francisella can invade and replicate, resulting in substantially higher bacterial load that can overcome the host. As such, understanding their responses to Francisella may uncover potential avenues of therapy that could promote a lowering of bacterial burden and clearance of infection. These response pathways include Toll-like Receptor 2 (TLR2), the caspase-1 inflammasome, Interferons, NADPH oxidase, Phosphatidylinositide 3-kinase (PI3K), and the Ras pathway. In this review we summarize the literature pertaining to the roles of these pathways during Francisella infection, with an emphasis on monocyte/macrophage responses. The therapeutic targeting of one or more such pathways may ultimately become a valuable tool for the treatment of tularemia, and several possibilities are discussed.

Immunomodulatory approaches for prevention and treatment of infectious diseases

With increasing pathogen resistance to antibiotics, population ageing, and threat of pandemics there is a strong interest in the development of new approaches for the treatment of infectious diseases. Immunomodulatory therapies are defined as interventions that target the host rather than the pathogen, modulating the immune response with the aim of disease prevention or treatment. Our growing understanding of the immune system continues to offer novel drug targets and approaches for immunomodulatory interventions. In this review we will cover prominent examples of immunomodulatory therapies already in clinical use, as well as the recent advances in the development of new immunomodulators in ongoing clinical trials.

A randomized pilot phase I study of modified carcinoembryonic antigen (CEA) peptide (CAP1-6D)/montanide/GM-CSF-vaccine in patients with pancreatic adenocarcinoma

Background

CEA is expressed in >90% of pancreatic cancers (PC) and may be an appropriate immunotherapy target. CEA is poorly immunogenic due to immune tolerance; CAP1-6D, an altered peptide ligand can help bypass tolerance. We conducted a pilot randomized phase I trial in PC patients to determine the peptide dose required to induce an optimal CD8⁺ T cell response.

Methods

Patients with a PS 0-1, HLA-A2+ and CEA-expressing, previously-treated PC were randomized to receive 10 μg (arm A), 100 μg (arm B) or 1000 μg (arm C) of CEA peptide emulsified in Montanide and GM-CSF, given every 2 weeks until disease progression.

Results

Sixty-six patients were screened and 19 enrolled of whom 14 received at least 3 doses of the vaccine and thus evaluated for the primary immunologic endpoint. A median of 4 cycles (range 1-81) was delivered. Median and mean peak IFN-γ T cell response by ELISPOT (spots per 10⁴ CD8⁺ cells, Arm A/B/C) was 11/52/271 (A vs. C, p = 0.028) for medians and 37/148/248 (A vs. C, p = 0.032) for means. T cell responses developed or increased in 20%/60%/100% of pts in Arms A/B/C. Seven of the 19 patients remain alive at a minimum 32 months from trial initiation, including three with unresectable disease.

Conclusions

The T cell response in this randomized phase I trial was dose-dependent with the 1 mg CEA peptide dose eliciting the most robust T cell responses. A signal of clinical benefit was observed and no significant toxicity was noted. Further evaluation of 1 mg CEA peptide with stronger adjuvants, and/or combined with agents to overcome immune inhibitory pathways, may be warranted in PC pts.

Trial registration

ClinicalTrials.gov NCT00203892

New insights into the role of the immune microenvironment in breast carcinoma

Recently, immune edition has been recognized as a new hallmark of cancer. In this respect, some clinical trials in breast cancer have reported imppressive outcomes related to laboratory immune findings, especially in the neoadjuvant and metastatic setting. Infiltration by tumor infiltrating lymphocytes (TIL) and their subtypes, tumor-associated macrophages (TAM) and myeloid-derived suppressive cells (MDSC) seem bona fide prognostic and even predictive biomarkers, that will eventually be incorporated into diagnostic and therapeutic algorithms of breast cancer. In addition, the complex interaction of costimulatory and coinhibitory molecules on the immune synapse and the different signals that they may exert represent another exciting field to explore. In this review we try to summarize and elucidate these new concepts and knowledge from a translational perspective focusing on breast cancer, paying special attention to those aspects that might have more significance in clinical practice and could be useful to design successful therapeutic strategies in the future.

Bone sarcomas: from biology to targeted therapies

Primary malignant bone tumours, osteosarcomas, and Ewing sarcomas are rare diseases which occur mainly in adolescents and young adults. With the current therapies, some patients remain very difficult to treat, such as tumour with poor histological response to preoperative CT (or large initial tumour volume for Ewing sarcomas not operated), patients with multiple metastases at or those who relapsed. In order to develop new therapies against these rare tumours, we need to unveil the key driving factors and molecular abnormalities behind the malignant characteristics and to broaden our understanding of the phenomena sustaining the metastatic phenotype and treatment resistance in these tumours. In this paper, starting with the biology of these tumours, we will discuss potential therapeutic targets aimed at increasing local tumour control, limiting metastatic spread, and finally improving patient survival.

Adult recurrent respirator papillomatosis: a new therapeutic approach with pegylated interferon alpha 2a (Peg-IFNα-2a) and GM-CSF

OBJECTIVE

To determine a new therapeutic approach using granulocyte monocyte-colony-stimulating factor (GM-CSF) and pegylated interferon alpha 2a (Peg-IFNα-2a) as adjuvant therapy in patients with adult recurrent respiratory papillomatosis.

STUDY DESIGN

Descriptive observational clinical trial.

SETTING

Departments of Otolaryngology and Immunology.

METHODS

Fourteen patients with adult recurrent respiratory papillomatosis were examined regarding medical history and number of operations before and after treatment. Voice disorder and glottal stop were evaluated using the Voice-Related Quality-of-Life instrument. Papilloma staging was determined using the Coltera/Derkay diagram. The patients received Peg-IFNα-2a at 180 mcg weekly for 6 months. In the third month, the patients began GM-CSF treatment at 400 mcg weekly for 2 months. The patients were observed for 12 months after treatment ended.

RESULTS

Eleven patients met the study criteria; 3 patients had tracheotomies before treatment, and they were decannulated after treatment. Before treatment, the scale of voice quality ranged from 34 to 45 points (mean, 38.31). After treatment, the range was 12 to 35 points (mean, 21.09; P < .001). Prior to therapy, the glottal stop ranged from 50% to 90% (average, 62.27%). After therapy, the range decreased to 0% to 15% (mean, 4.63%; P < .001). The number of surgical interventions decreased. Two patients each had 1 surgical intervention after treatment began.

CONCLUSION

A new adjuvant treatment based on immunogenetic mechanisms against human laryngeal papilloma virus, with expectations of reducing disease aggressiveness and the number of operations, avoids the risks of surgery.

IMPLICATION FOR PRACTICE

Peg-IFNα-2a and GM-CSF is an adjuvant therapy for treating adult recurrent respiratory papillomatosis.

Regulation of dendritic cell development by GM-CSF: molecular control and implications for immune homeostasis and therapy

Dendritic cells (DCs) represent a small and heterogeneous fraction of the hematopoietic system, specialized in antigen capture, processing, and presentation. The different DC subsets act as sentinels throughout the body and perform a key role in the induction of immunogenic as well as tolerogenic immune responses. Because of their limited lifespan, continuous replenishment of DC is required. Whereas the importance of GM-CSF in regulating DC homeostasis has long been underestimated, this cytokine is currently considered a critical factor for DC development under both steady-state and inflammatory conditions. Regulation of cellular actions by GM-CSF depends on the activation of intracellular signaling modules, including JAK/STAT, MAPK, PI3K, and canonical NF-κB. By directing the activity of transcription factors and other cellular effector proteins, these pathways influence differentiation, survival and/or proliferation of uncommitted hematopoietic progenitors, and DC subset–specific precursors, thereby contributing to specific aspects of DC subset development. The specific intracellular events resulting from GM-CSF–induced signaling provide a molecular explanation for GM-CSF–dependent subset distribution as well as clues to the specific characteristics and functions of GM-CSF–differentiated DCs compared with DCs generated by fms-related tyrosine kinase 3 ligand. This knowledge can be used to identify therapeutic targets to improve GM-CSF–dependent DC-based strategies to regulate immunity.

Chapter six--Adenovirus-based immunotherapy of cancer: promises to keep

Progress in vector design and an increased knowledge of mechanisms underlying tumor-induced immune suppression have led to a new and promising generation of Adenovirus (Ad)-based immunotherapies, which are discussed in this review. As vaccine vehicles Ad vectors (AdVs) have been clinically evaluated and proven safe, but a major limitation of the commonly used Ad5 serotype is neutralization by preexistent or rapidly induced immune responses. Genetic modifications in the Ad capsid can reduce intrinsic immunogenicity and facilitate escape from antibody-mediated neutralization. Further modification of the Ad hexon and fiber allows for liver and scavenger detargeting and selective targeting of, for example, dendritic cells. These next-generation Ad vaccines with enhanced efficacy are now becoming available for testing as tumor vaccines. In addition, AdVs encoding immune-modulating products may be used to convert the tumor microenvironment from immune-suppressive and proinvasive to proinflammatory, thus facilitating cell-mediated effector functions that can keep tumor growth and invasion in check. Oncolytic AdVs, that selectively replicate in tumor cells and induce an immunogenic form of cell death, can also be armed with immune-activating transgenes to amplify primed antitumor immune responses. These novel immunotherapy strategies, employing highly efficacious AdVs in optimized configurations, show great promise and warrant clinical exploration.

Immune microenvironment in colorectal cancer: a new hallmark to change old paradigms

Impact of immune microenvironment in prognosis of solid tumors has been extensively studied in the last few years. Specifically in colorectal carcinoma, increased knowledge of the immune events around these tumors and their relation with clinical outcomes have led to consider immune microenvironment as one of the most important prognostic factors in this disease. In this review we will summarize and update the current knowledge with respect to this intriguing and complex new hallmark of cancer, paying special attention to infiltration by T-infiltrating lymphocytes and their subtypes in colorectal cancer, as well as its eventual clinical translation in terms of long-term prognosis. Finally, we suggest some possible investigational approaches based on combinatorial strategies to trigger and boost immune reaction against tumor cells.

Cancer immunotherapy

Cancer immunotherapy consists of approaches that modify the host immune system, and/or the utilization of components of the immune system, as cancer treatment. During the past 25 years, 17 immunologic products have received regulatory approval based on anticancer activity as single agents and/or in combination with chemotherapy. These include the nonspecific immune stimulants BCG and levamisole; the cytokines interferon-α and interleukin-2; the monoclonal antibodies rituximab, ofatumumab, alemtuzumab, trastuzumab, bevacizumab, cetuximab, and panitumumab; the radiolabeled antibodies Y-90 ibritumomab tiuxetan and I-131 tositumomab; the immunotoxins denileukin diftitox and gemtuzumab ozogamicin; nonmyeloablative allogeneic transplants with donor lymphocyte infusions; and the anti-prostate cancer cell-based therapy sipuleucel-T. All but two of these products are still regularly used to treat various B- and T-cell malignancies, and numerous solid tumors, including breast, lung, colorectal, prostate, melanoma, kidney, glioblastoma, bladder, and head and neck. Positive randomized trials have recently been reported for idiotype vaccines in lymphoma and a peptide vaccine in melanoma. The anti-CTLA-4 monoclonal antibody ipilumumab, which blocks regulatory T-cells, is expected to receive regulatory approval in the near future, based on a randomized trial in melanoma. As the fourth modality of cancer treatment, biotherapy/immunotherapy is an increasingly important component of the anticancer armamentarium.

Relapse after allogeneic stem cell transplantation

Since allogeneic stem cell transplantation (SCT) represents an intensive curative treatment for high-risk malignancies, its failure to prevent relapse leaves few options for successful salvage treatment. While many patients have a high early mortality from relapse, some respond and have sustained remissions, and a minority has a second chance of cure with appropriate therapy. The prognosis for relapsed hematological malignancies after SCT depends on four factors: the time elapsed from SCT to relapse (with relapses occurring within 6 months having the worst prognosis), the disease type (with chronic leukemias and some lymphomas having a second possibility of cure with further treatment), the disease burden and site of relapse (with better treatment success if disease is treated early), and the conditions of the first transplant (with superior outcome for patients where there is an opportunity to increase either the alloimmune effect, the specificity of the antileukemia effect with targeted agents or the intensity of the conditioning in a second transplant). These features direct treatments toward either modified second transplants, chemotherapy, targeted antileukemia therapy, immunotherapy or palliative care.

15 kDa Granulysin versus GM-CSF for monocytes differentiation: analogies and differences at the transcriptome level

Background

Granulysin is an antimicrobial and proinflammatory protein with several isoforms. While the 9 kDa isoform is a well described cytolytic molecule with pro-inflammatory activity, the functions of the 15 kDa isoform is less well understood. Recently it was shown that 15 kDa Granulysin can act as an alarmin that is able to activate monocytes and immature dendritic cells. Granulocyte Macrophage Colony Stimulating Factor (GM-CSF) is a growth factor widely used in immunotherapy both for in vivo and ex vivo applications, especially for its proliferative effects.

Methods

We analyzed gene expression profiles of monocytes cultured with 15 kDa Granulysin or GM-CSF for 4, 12, 24 and 48 hours to unravel both similarities and differences between the effects of these stimulators.

Results

The analysis revealed a common signature induced by both factors at each time point, but over time, a more specific signature for each factor became evident. At all time points, 15 kDa Granulysin induced immune response, chemotaxis and cell adhesion genes. In addition, only 15 kDa Granulsyin induced the activation of pathways related to fundamental dendritic cell functions, such as co-stimulation of T-cell activation and Th1 development. GM-CSF specifically down-regulated genes related to cell cycle arrest and the immune response. More specifically, cytokine production, lymphocyte mediated immunity and humoral immune response were down-regulated at late time points.

Conclusion

This study provides important insights on the effects of a novel agent, 15 kDa granulysin, that holds promise for therapeutic applications aimed at the activation of the immune response.

Telomerase-specific GV1001 peptide vaccination fails to induce objective tumor response in patients with cutaneous T cell lymphoma

BACKGROUND

There is currently no curative therapy for cutaneous T cell lymphoma (CTCL). New therapies are therefore needed. Telomerase, the enzyme that allows for unrestricted cell divisions of cancer cells, is a promising target for cancer therapy. The telomerase-specific peptide vaccination GV1001 has shown promising results in previous studies. Since telomerase is expressed in malignant cells of CTCL, GV1001 vaccination in CTCL is a promising new therapeutic approach.

OBJECTIVE

We sought to investigate the efficacy of GV1001 vaccination in CTCL patients and characterize the induced immune response.

METHODS

Six CTCL patients were vaccinated with the GV-peptide using granulocyte/macrophage colony-stimulating factor as adjuvant. Objective clinical response and the T cell response were assessed.

RESULTS

None of the patients demonstrated objective clinical response to the vaccination whereas one patient showed disease progression. 1/6 patients acquired a GV1001-specifc T cell response with a Th1 cytokine profile and expression of skin-homing receptors. This hTERT-specific T cell response was not associated with beneficial modulation of the tumor-infiltrating leukocytes. Furthermore, removal of regulatory T cells did not enhance responsiveness to GV1001 in vitro in any of the patients analyzed.

CONCLUSIONS

Our results suggest that the GV1001 vaccination is not effective in CTCL patients and disease progression in 1/6 patients raises concerns about its safety. By analyzing skin-homing properties of GV1001-specific T cells and the involvement of regulatory T cells we nevertheless provide insight into vaccine-induced immune responses which may help to improve vaccine strategies in CTCL.

The dermis as a portal for dendritic cell-targeted immunotherapy of cutaneous melanoma

Complete surgical excision at an early stage remains the only curative treatment for cutaneous melanoma with few available adjuvant therapy options. Nevertheless, melanoma is a relatively immunogenic tumor type and particularly amenable to immunotherapeutic approaches. A dense network of cutaneous dendritic cells (DC) may account for the reported efficacy of vaccination through the skin and provide an attractive target for the immunotherapy of melanoma. Several phenotypically distinct DC subsets are discernable in the skin, among others, epidermal Langerhans cells and dermal DC. Upon appropriate activation both subsets can efficiently migrate to melanoma-draining lymph nodes (LN) to prime T cell-mediated responses. Unfortunately, from an early stage, melanoma development is characterized by strong immune suppression, facilitating unchecked tumor growth and spread. Particularly the primary tumor site and the first-line tumor-draining LN, the so-called sentinel LN, bear the brunt of this melanoma-induced immune suppression-and these are exactly the sites where anti-melanoma effector T cell responses should be primed by DC in order to prevent early metastasis. Through local immunopotentiation or through DC-targeted vaccination, the dermis may be utilized as a portal to activate DC and kick-start or boost effective T cell-mediated anti-melanoma immunity, even in the face of this immune suppression.

Treatment of skin injury due to vinorelbine extravasation using bFGF and rhGM-CSF: an experimental study in a murine model

BACKGROUND AND OBJECTIVE

A murine model of skin injury from vinorelbine extravasation was established to evaluate the treatment efficacy of basic fibroblast growth factor (bFGF) and recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF).

MATERIALS AND METHOD

Experimental models were divided into bFGF, rhGM-CSF, and control (saline) groups, with 40 mice in each group. Edema and ulceration were measured on Days 1, 3, 5, 7, 10, 14, and 18 after the onset of extravasation; injuries were examined pathomorphologically in three mice/group/time point.

RESULTS

Edema reached maximum size on Day 3 in the bFGF and rhGM-CSF groups and Day 5 in the control group. The difference between the two experimental groups was not significant; differences between the control group and the experimental groups were statistically significant at all time points. Edema and ulceration began to improve on Day 10 in the bFGF and rhGM-CSF groups and Day 18 in the control group. Healing duration was 14-18 days in the experimental groups, with a (not significantly) shorter duration in the bFGF group. Healing was completed by Day 27.5 in the control group. Pathomorphological evaluation showed regular re-epithelization and newly formed granulation tissue in the bFGF and rhGM-CSF groups on Day 13. In the control group, wounds were partially healed, edema and shallow ulcers existed, and epithelization was fragile and disorganized on Day 18.

CONCLUSIONS

bFGF and rhGM-CSF are useful for the treatment of skin injury due to vinorelbine extravasation, but bFGF may be slightly more effective in decreasing time and improving quality of healing.

Tumor microenvironment and immune effects of antineoplastic therapy in lymphoproliferative syndromes

Lymphomas represent a wide group of heterogenic diseases with different biological and clinical behavior. The underlying microenvironment-specific composition seems to play an essential role in this scenario, harboring the ability to develop successful immune responses or, on the contrary, leading to immune evasion and even promotion of tumor growth. Depending on surrounding lymphoid infiltrates, lymphomas may have different prognosis. Moreover, recent evidences have emerged that confer a significant impact of main lymphoma's treatment over microenvironment, with clinical consequences. In this review, we summarize these concepts from a pathological and clinical perspective. Also, the state of the art of lymphoma's anti-idiotype vaccine development is revised, highlighting the situations where this strategy has proven to be successful and eventual clues to obtain better results in the future.

Role of Kupffer cells in the outgrowth of colorectal cancer liver metastases

Colorectal cancer is one of the commonest malignancies in the "developed" world. The liver constitutes the main host organ for its distant metastases which, when present, augur a bad prognosis for the disease. Kupffer cells (KCs) are macrophages that constantly reside within the liver and form an effective first line defence against multiple harmful agents which reach the hepatic sinusoids via the portal circulation. KCs remove chemical compounds and dead or damaged cells, eliminate bacteria and protect against invading tumour cells. They may play a crucial tumouricidal role, exerting cytotoxic and cytostatic functions through the release of multiple cytokines and chemokines. Subsequently, colorectal metastasising cells are destroyed either by KC-performed phagocytosis or via the stimulation of other immune cells which migrate into the sinusoids and act accordingly. On the contrary, KC products, including cytokines, growth factors and matrix-degrading enzymes may promote liver metastasis, supporting tumour cell extravasation, motility and invasion. Current research aims to exploit the antineoplastic properties of KCs in new therapeutic approaches of colorectal cancer liver metastasis. Numerous agents, such as the granulocyte macrophage-colony stimulating factor, interferon gamma, muramyl peptide analogues and various antibody based treatments, have been tested in experimental models with promising results. Future trials may investigate their use in everyday clinical practice and compare their therapeutic value with current treatment of the disease.

Induction of IL-4 release and upregulated expression of protease activated receptors by GM-CSF in P815 cells

GM-CSF has been showed to be able to induce up-regulated receptor and cytokine expression in mast cells in inflammatory conditions. However, little is known of its effects on protease activated receptor (PAR) expression and Th2 cytokine secretion from mast cells. In the present study, we examined potential influence of GM-CSF on mast cell PAR expression and IL-4 and IL-10 release by using flow cytometry analysis, quantitative real time PCR, ELISA and cellular activation of signaling ELISA (CASE) techniques. The results showed that GM-CSF induced up to 3.0-fold increase in IL-4 release from P815 cells, and FSLLRY-NH(2) and trans-cinnamoyl (tc)-YPGKF-NH(2) did not affect GM-CSF induced IL-4 release. GM-CSF reduced tryptase and trypsin induced IL-4 release by up to approximately 55.8% and 70.3%, respectively. GM-CSF elicited the upregulated expression of PAR-1, PAR-2, PAR-3 and PAR-4 mRNAs, but enhanced only PAR-4 protein expression in P815 cells. U0126, PD98059 and LY204002 almost completely abolished GM-CSF induced IL-4 release when they were preincubated with P815 cells for 30 min, indicating ERK and Akt cell signaling pathways may be involved in the event. In conclusion, GM-CSF can stimulate IL-4 release from mast cells through an ERK and Akt cell signaling pathway dependent, but PAR independent mechanism. GM-CSF may serve as a regulator for IL-4 production in mast cells and through which participates in the mast cell related inflammation.

Current status and challenges of cytokine pharmacology

The major concern of pharmacology about cytokines has originated from plentiful data showing association between gross changes in their production and pathophysiological processes. Despite the enigmatic role of cytokines in diseases, a number of them have become a subject of cytokine and anti-cytokine immunotherapies. Production of cytokines can be influenced by many endogenous and exogenous stimuli including drugs. Cells of the immune system, such as macrophages and lymphocytes, are richly endowed with receptors for the mediators of physiological functions, such as biogenic amines, adenosine, prostanoids, steroids, etc. Drugs, agonists or antagonists of these receptors can directly or indirectly up- and down-regulate secretion of cytokines and expression of cytokine receptors. Vice versa, cytokines interfere with drug pharmacokinetics and pharmacodynamics through the interactions with cytochrome P450 and multiple drug resistance proteins. The aim of the review is to encourage more intensive studies in these fields of cytokine pharmacology. It also outlines major areas of searching promising candidates for immunotherapeutic interventions.

Cancer and immune response: old and new evidence for future challenges

Cancer may occur as a result of abnormal host immune system tolerance. Recent studies have confirmed the occurrence of spontaneous and induced antitumor immune responses expressed as the presence of tumor-infiltrating T cells in the tumor microenvironment in some cancer models. This finding has been recognized as a good prognostic factor in several types of tumors. Some chemotherapy agents, such as anthracyclines and gemcitabine, are effective boosters of the immune response through tumor-specific antigen overexpression after apoptotic tumor cell destruction. Other strategies, such as GM-CSF or interleukin-2, are pursued to increase immune cell availability in the tumor vicinity, and thus improve both antigen presentation and T-cell activation and proliferation. In addition, cytotoxic T lymphocyte antigen 4-blocking monoclonal antibodies enhance immune activity by prolonging T-cell activation. Strategies to stimulate the dormant immune system against tumors are varied and warrant further investigation of their applications to cancer therapy in the future.