ALDH1A1 Activity in Tumor-Initiating Cells Remodels Myeloid-Derived Suppressor Cells to Promote Breast Cancer Progression.

Tumor-initiating cells (TIC) are associated with tumor initiation, growth, metastasis, and recurrence. Aldehyde dehydrogenase 1A1 (ALDH1A1) is a TIC marker in many cancers, including breast cancer. However, the molecular mechanisms underlying ALDH1A1 functions in solid tumors remain largely unknown. Here we demonstrate that ALDH1A1 enzymatic activity facilitates breast tumor growth. Mechanistically, ALDH1A1 decreased the intracellular pH in breast cancer cells to promote phosphorylation of TAK1, activate NFκB signaling, and increase the secretion of GM-CSF, which led to myeloid-derived suppressor cell expansion and immunosuppression. Furthermore, the ALDH1A1 inhibitor disulfiram and chemotherapeutic agent gemcitabine cooperatively inhibited breast tumor growth and tumorigenesis by purging ALDH+ TICs and activating T-cell immunity. These findings elucidate how active ALDH1A1 modulates the immune system to promote tumor development, highlighting new therapeutic strategies for malignant breast cancer. SIGNIFICANCE: ALDH1A1 enzyme activity induces MDSC expansion and triggers a procancer immune microenvironment to facilitate breast cancer progression, providing a novel therapeutic vulnerability in this disease.

Enhanced Protection by Recombinant Newcastle Disease Virus Expressing Infectious Bronchitis Virus Spike Ectodomain and Chicken Granulocyte-Macrophage Colony-Stimulating Factor.

We previously reported that recombinant Newcastle disease virus LaSota (rLS) expressing infectious bronchitis virus (IBV) Arkansas (Ark)-type trimeric spike (S) ectodomain (Se; rLS/ArkSe) provides suboptimal protection against IBV challenge. We have now developed rLS expressing chicken granulocyte-macrophage colony-stimulating factor (GMCSF) and IBV Ark Se in an attempt to enhance vaccine effectiveness. In the current study, we first compared protection conferred by vaccination with rLS/ArkSe and rLS/ArkSe.GMCSF. Vaccinated chickens were challenged with virulent Ark, and protection was determined by clinical signs, viral load, and tracheal histomorphometry. Results showed that coexpression of GMCSF and the Se from rLS significantly reduced tracheal viral load and tracheal lesions compared with chickens vaccinated with rLS/ArkSe. In a second experiment, we evaluated enhancement of cross-protection of a Massachusetts (Mass) attenuated vaccine by priming or boosting with rLS/ArkSe.GMCSF. Vaccinated chickens were challenged with Ark, and protection was evaluated. Results show that priming or boosting with the recombinant virus significantly increased cross-protection conferred by Mass against Ark virulent challenge. Greater reductions of viral loads in both trachea and lachrymal fluids were observed in chickens primed with rLS/ArkSe.GMCSF and boosted with Mass. Consistently, Ark Se antibody levels measured with recombinant Ark Se protein-coated ELISA plates 14 days after boost were significantly higher in these chickens. Unexpectedly, the inverse vaccination scheme, that is, priming with Mass and boosting with the recombinant vaccine, proved somewhat less effective. We concluded that a prime and boost strategy by using rLS/ArkSe.GMCSF and the worldwide ubiquitous Mass attenuated vaccine provides enhanced cross-protection. Thus, rLS/GMCSF coexpressing the Se of regionally relevant IBV serotypes could be used in combination with live Mass to protect against regionally circulating IBV variant strains.

Protección incrementada por el virus recombinante de la enfermedad de Newcastle que expresa el ectodominio de la espícula del virus de la bronquitis infecciosa y el factor estimulante de colonias de granulocitos y macrófagos del pollo. Anteriormente se reportó que la cepa LaSota recombinante del virus de la enfermedad de Newcastle (rLS) que expresa el ectodominio de la espícula trimérica (S) de tipo Arkansas (Ark) del virus de la bronquitis infecciosa (IBV) (Se; rLS/ArkSe) proporciona una protección subóptima contra la exposición al virus de la bronquitis infecciosa. Ahora se ha desarrollado hemos desarrollado una cepa LaSota recombinante (rLS) que expresa el factor estimulante de colonias de granulocitos y macrófagos de pollo (GMCSF) y la espícula del virus de bronquitis Arkansas en un intento para mejorar la efectividad de la vacuna. En el estudio actual, primero se comparó la protección conferida por la vacunación con los virus rLS/ArkSe y rLS/ArkSe.GMCSF. Los pollos vacunados se desafiaron con un virus Arkansas virulento y la protección se determinó mediante los signos clínicos, la carga viral y la histomorfometría de la tráquea. Los resultados mostraron que la coexpresión del factor estimulante de colonias de granulocitos y macrófagos de pollo y la espícula de la cepa recombinante LaSota redujo significativamente la carga viral traqueal y las lesiones traqueales en comparación con los pollos vacunados con el virus rLS/ArkSe. En un segundo experimento, se evaluó el incremento en la protección cruzada por una vacuna atenuada de Massachusetts (Mass) mediante la primovacunación o la vacunación de refuerzo con rLS/ArkSe.GMCSF. Los pollos vacunados fueron desafiados con el virus Arkansas y se evaluó la protección. Los resultados mostraron que la primovacunación o la vacunación de refuerzo con el virus recombinante aumentó significativamente la protección cruzada conferida por el virus Massachusetts contra el desafío virulento con el virus Arkansas. Se observaron mayores reducciones de las cargas virales en los fluidos traqueales y lagrimales en pollos primovacunadoss con rLS/ArkSe.GMCSF y con vacunación de refuerzo con Massachusetts. De manera consistente, los niveles de anticuerpos Ark Se medidos con placas de ELISA recubiertas con proteína Ark Se recombinante a los 14 días después del refuerzo fueron significativamente más altos en estos pollos. De manera inesperada, el esquema de vacunación inverso, es decir, la primovacunación con Massachusetts y el refuerzo con la vacuna recombinante, resultó menos efectivo. Se concluye que una estrategia de primovacunación y refuerzo mediante el uso de rLS/ArkSe.GMCSF y la vacuna atenuada con Massachusetts usada en todo el mundo proporciona una protección cruzada aumentada. Por tanto, el virus rLS/GMCSF que coexpresa la proteína de la espícula de los serotipos regionales relevantes de bronquitis infecciosa podría usarse en combinación con una vacuna viva Massachusetts para proteger contra cepas variantes del virus de la bronquitis infecciosa que circulan regionalmente.

Recombinant Newcastle Disease Virus Immunotherapy Drives Oncolytic Effects and Durable Systemic Antitumor Immunity.

A recombinant Newcastle Disease Virus (NDV), encoding either a human (NDVhuGM-CSF, MEDI5395) or murine (NDVmuGM-CSF) GM-CSF transgene, combined broad oncolytic activity with the ability to significantly modulate genes related to immune functionality in human tumor cells. Replication in murine tumor lines was significantly diminished relative to human tumor cells. Nonetheless, intratumoral injection of NDVmuGM-CSF conferred antitumor effects in three syngeneic models in vivo; with efficacy further augmented by concomitant treatment with anti-PD-1/PD-L1 or T-cell agonists. Ex vivo immune profiling, including T-cell receptor sequencing, revealed profound immune-contexture changes consistent with priming and potentiation of adaptive immunity and tumor microenvironment (TME) reprogramming toward an immune-permissive state. CRISPR modifications rendered CT26 tumors significantly more permissive to NDV replication, and in this setting, NDVmuGM-CSF confers immune-mediated effects in the noninjected tumor in vivo Taken together, the data support the thesis that MEDI5395 primes and augments cell-mediated antitumor immunity and has significant utility as a combination partner with other immunomodulatory cancer treatments.

Sargramostim and immune checkpoint inhibitors: combinatorial therapeutic studies in metastatic melanoma.

The use of immune checkpoint inhibitors in patients with metastatic melanoma generates clinical benefit, including improved survival. Yet disease resistance and immune-related adverse events persist as unmet needs. Sargramostim, a yeast-derived recombinant human GM-CSF, has shown clinical activity against diverse solid tumors, including metastatic melanoma. Here we review the use of sargramostim for treatment of advanced melanoma. Potential sargramostim applications in melanoma draw on the unique ability of GM-CSF to link innate and adaptive immune responses. We review preclinical and translational data describing the mechanism of action of sargramostim and synergy with immune checkpoint inhibitors to enhance efficacy and reduce treatment-related toxicity.

Lay abstract Immune checkpoint inhibitors are medications that help the immune system to fight cancer. Side effects with these medicines may occur because the immune system may attack healthy cells. Sargramostim is a medication that is similar to a protein in the body (GM-CSF). Studies have shown that sargramostim can fight cancer, including melanoma. When sargramostim is used with immune checkpoint inhibitors, the body's natural defense to fight cancer (the immune system) is boosted and some side effects are reduced. This article reviews how GM-CSF is thought to boost the immune system's response against cancer in the laboratory and in animal models. We also review the use of sargramostim alone and combined with ipilimumab in patients with advanced melanoma.

Formulation and In Vitro Characterization of PLGA/PLGA-PEG Nanoparticles Loaded with Murine Granulocyte-Macrophage Colony-Stimulating Factor.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) has demonstrated notable clinical activity in cancer immunotherapy, but it is limited by systemic toxicities, poor bioavailability, rapid clearance, and instability in vivo. Nanoparticles (NPs) may overcome these limitations and provide a mechanism for passive targeting of tumors. This study aimed to develop GM-CSF-loaded PLGA/PLGA-PEG NPs and evaluate them in vitro as a potential candidate for in vivo administration. NPs were created by a phase-separation technique that did not require toxic/protein-denaturing solvents or harsh agitation techniques and encapsulated GM-CSF in a more stable precipitated form. NP sizes were within 200 nm for enhanced permeability and retention (EPR) effect with negative zeta potentials, spherical morphology, and high entrapment efficiencies. The optimal formulation was identified by sustained release of approximately 70% of loaded GM-CSF over 24 h, alongside an average size of 143 ± 35 nm and entrapment efficiency of 84 ± 5%. These NPs were successfully freeze-dried in 5% (w/v) hydroxypropyl-ß-cyclodextrin for long-term storage and further characterized. Bioactivity of released GM-CSF was determined by observing GM-CSF receptor activation on murine monocytes and remained fully intact. NPs were not cytotoxic to murine bone marrow-derived macrophages (BMDMs) at concentrations up to 1 mg/mL as determined by MTT and trypan blue exclusion assays. Lastly, NP components generated no significant transcription of inflammation-regulating genes from BMDMs compared to IFNγ+LPS "M1" controls. This report lays the preliminary groundwork to validate in vivo studies with GM-CSF-loaded PLGA/PEG-PLGA NPs for tumor immunomodulation. Overall, these data suggest that in vivo delivery will be well tolerated.

Immunogenicity in humans of a transdermal multipeptide melanoma vaccine administered with or without a TLR7 agonist.

BACKGROUND: Experimental cancer vaccines are traditionally administered by injection in subcutaneous tissue or muscle, commonly with adjuvants that create chronic inflammatory depots. Injection of melanoma-derived peptides induces T cell responses; however, the depots that form following injection may inhibit optimization of the immune response. In skin, epidermal Langerhans cells (LC) are a dominant source of professional antigen presenting cells. We hypothesized that: (1) applying melanoma-derived peptides topically, in proximity to LC, could be immunogenic and safe, with low vaccine-site toxicity and (2) topical toll-like receptor 7 (TLR7) agonist would increase immunogenicity of the peptide vaccine. METHODS: Twelve melanoma peptides plus a tetanus helper peptide were combined with granulocyte macrophage colony stimulating factor (GM-CSF) and were administered topically on days 1, 8, and 15, to 28 patients randomized to one of four adjuvant preparations: (1) incomplete Freund's adjuvant (IFA); (2) IFA plus a TLR7 agonist (imiquimod) administered on days 0, 7, 14; (3) dimethyl sulfoxide (DMSO) or (4) DMSO+ imiquimod administered on day 0, 7, 14. Every 3 weeks thereafter (x 6), the peptides were combined with GM-CSF and were injected into the dermis and subcutis in an emulsion with IFA. Toxicities were recorded and immune responses assayed by ELIspot. RESULTS: CD8+ T cell responses to transdermal vaccination in DMSO occurred in 83% of participants in group 3 and 86% in group 4, and responses to vaccination in IFA were observed in 29% of participants in group 1 and 14% in group 2. Overall, 61% of participants had CD4+ T cell immune responses to the tetanus peptide, with large, durable responses in groups 3 and 4. Five of seven participants in group 4 had a severe rash, one that was dose limiting. Ten-year overall survival was 67% and disease-free survival was 44%. CONCLUSIONS: These data provide proof of principle for immunogenicity in humans of transdermal immunization using peptides in DMSO. Further study is warranted into the pharmacokinetics and immunobiology of TLR agonists as vaccine adjuvants during transcutaneous application. Overall survival is high, supporting further investigation of this immunization approach.

Safety, tolerability, and immune-biomarker profiling for year-long sargramostim treatment of Parkinson's disease.

BACKGROUND: Neuroinflammation plays a pathogenic role in Parkinson's disease (PD). Immunotherapies that restore brain homeostasis can mitigate neurodegeneration by transforming T cell phenotypes. Sargramostim has gained considerable attention as an immune transformer through laboratory bench to bedside clinical studies. However, its therapeutic use has been offset by dose-dependent adverse events. Therefore, we performed a reduced drug dose regimen to evaluate safety and to uncover novel disease-linked biomarkers during 5 days/week sargramostim treatments for one year. METHODS: Five PD subjects were enrolled in a Phase 1b, unblinded, open-label study to assess safety and tolerability of 3 µg/kg/day sargramostim. Complete blood counts and chemistry profiles, physical examinations, adverse events (AEs), immune profiling, Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) scores, T cell phenotypes/function, DNA methylation, and gene and protein patterns were evaluated. FINDINGS: Sargramostim administered at 3 µg/kg/day significantly reduced numbers and severity of AEs/subject/month compared to 6 µg/kg/day treatment. While MDS-UPDRS Part III score reductions were recorded, peripheral blood immunoregulatory phenotypes and function were elevated. Hypomethylation of upstream FOXP3 DNA elements was also increased. INTERPRETATION: Long-term sargramostim treatment at 3 µg/kg/day is well-tolerated and effective in restoring immune homeostasis. There were decreased numbers and severity of AEs and restored peripheral immune function coordinate with increased numbers and function of Treg. MDS-UPDRS Part III scores did not worsen. Larger patient numbers need be evaluated to assess conclusive drug efficacy (ClinicalTrials.gov NCT03790670). FUNDING: The research was supported by community funds to the University of Nebraska Foundation and federal research support from 5 R01NS034239-25.

Boosting immune response with GM-CSF optimizes primary cryotherapy outcomes in the treatment of prostate cancer: a prospective randomized clinical trial.

OBJECTIVE: We explored the association of prostate cryotherapy and immunomodulation with granulocyte-macrophage colony-stimulating factor (GMCSF) in the generation of detectable tumor-specific T- and B-cell responses in men with prostate cancer. MATERIALS AND METHODS: A randomized pilot study of patients assigned to either cryotherapy alone (Control group) or in combination with GMCSF (Treatment group). The impact of therapy on the development of T- and B-cell responses against tumor-related antigens was studied using enzyme-linked immune absorbent spot (ELISpot) and protein microarray panels (Sematrix) assays, respectively. Fold changes in response to treatment were calculated by normalization of post-treatment ELISpot values against the mean pre-cryoablation response. Student t tests between treatment and control groups at 4 weeks and 12 weeks across all the antigens were performed. RESULTS: A total of 20 patients were randomized to either control or treatment arm. At 4 weeks after cryotherapy, the treatment group demonstrated an average fold change in cancer antigen-related antibodies of 2.8% above their mean baseline values, whereas controls averaged an 18% change below mean baseline (p < 0.05). At 12 weeks, antibody response in treatment group increased to 25% above baseline, while the average of control group patients remained 9% below baseline (p < 0.05). Patients in treatment group displayed, on average, higher ELISPOT readings for the 4- and 12-week times points (527 vs 481 for PSA and 748 vs 562 for PAP). CONCLUSIONS: GMCSF appeared to broadly elevate antibodies against prostate-specific and nonspecific antigens. Prostate antigen-specific T-cell responses were more enhanced over non-prostate-specific responses, preferentially in the treatment group. Our findings suggest a possible therapeutic effect of adjuvant immunotherapy in association with cryotherapy for the treatment of prostate cancer.

Association of miltefosine with granulocyte and macrophage colony-stimulating factor (GM-CSF) in the treatment of cutaneous leishmaniasis in the Amazon region: A randomized and controlled trial.

OBJECTIVES: To compare topical granulocyte and macrophage colony-stimulating factor (GM-CSF) and miltefosine (G + M) versus placebo and miltefosine (P + M) or parenteral meglumine antimoniate (MA) in the treatment of 150 patients with cutaneous leishmaniasis (CL) caused by Leishmania guyanensis in the Amazon. DESIGN: A randomized and double-blinded clinical trial. RESULTS: At 90 days after the initiation of therapy, the cure rates were 66%, 58%, and 52% for the groups P + M, G + M, and MA, respectively (p > 0.05). Cure rates at 180 days did not differ. Healing time was similar in the 3 groups, but faster in the MA group as compared to the G + M group (p = 0.04). Mild and transitory systemic adverse events were frequent in all groups (above 85%). Nausea (85%) and vomiting (39%) predominated in the miltefosine groups and arthralgia (51%) and myalgia (48%) in the MA group. One patient (group MA) stopped treatment after presenting with fever, exanthema, and severe arthralgia. CONCLUSIONS: Miltefosine did not present a higher cure rate than MA, and the association of GM-CSF did not improve the therapeutic response. Nevertheless, because of its less toxicity, easier administration, and a similar cure rate when compared with MA, miltefosine should remain as one of the main drugs for treating CL due to L. guyanensis. (Clinicaltrials.gov Identifier NCT03023111).

Inhaled Molgramostim Therapy in Autoimmune Pulmonary Alveolar Proteinosis.

BACKGROUND: Autoimmune pulmonary alveolar proteinosis (aPAP) is a rare disease characterized by progressive surfactant accumulation and hypoxemia. It is caused by disruption of granulocyte-macrophage colony-stimulating factor (GM-CSF) signaling, which pulmonary alveolar macrophages require to clear surfactant. Recently, inhaled GM-CSF was shown to improve the partial pressure of arterial oxygen in patients with aPAP. METHODS: In a double-blind, placebo-controlled, three-group trial, we randomly assigned patients with aPAP to receive the recombinant GM-CSF molgramostim (300 µg once daily by inhalation), either continuously or intermittently (every other week), or matching placebo. The 24-week intervention period was followed by an open-label treatment-extension period. The primary end point was the change from baseline in the alveolar-arterial difference in oxygen concentration (A-aDo2) at week 24. RESULTS: In total, 138 patients underwent randomization; 46 were assigned to receive continuous molgramostim, 45 to receive intermittent molgramostim, and 47 to receive placebo. Invalid A-aDo2 data for 4 patients (1 in each molgramostim group and 2 in the placebo group) who received nasal oxygen therapy during arterial blood gas measurement were replaced by means of imputation. For the primary end point - the change from baseline in the A-aDo2 at week 24 - improvement was greater among patients receiving continuous molgramostim than among those receiving placebo (-12.8 mm Hg vs. -6.6 mm Hg; estimated treatment difference, -6.2 mm Hg; P = 0.03 by comparison of least-squares means). Patients receiving continuous molgramostim also had greater improvement than those receiving placebo for secondary end points, including the change from baseline in the St. George's Respiratory Questionnaire total score at week 24 (-12.4 points vs. -5.1 points; estimated treatment difference, -7.4 points; P = 0.01 by comparison of least-squares means). For multiple end points, improvement was greater with continuous molgramostim than with intermittent molgramostim. The percentages of patients with adverse events and serious adverse events were similar in the three groups, except for the percentage of patients with chest pain, which was higher in the continuous-molgramostim group. CONCLUSIONS: In patients with aPAP, daily administration of inhaled molgramostim resulted in greater improvements in pulmonary gas transfer and functional health status than placebo, with similar rates of adverse events. (Funded by Savara Pharmaceuticals; IMPALA ClinicalTrials.gov number, NCT02702180.).

Evaluation of the Ability of Miltefosine Associated with Topical GM-CSF in Modulating the Immune Response of Patients with Cutaneous Leishmaniasis.

Cutaneous leishmaniasis (CL) due to L. braziliensis is associated with an exaggerated inflammatory response and tissue damage. Miltefosine is more effective than pentavalent antimony (Sbv) in the treatment of CL, and here, we evaluate the ability of Sbv, miltefosine, and GM-CSF administered intravenously, orally, or topically, respectively, to modify the immune response. Patients were treated with miltefosine plus GM-CSF, miltefosine plus placebo, or Sbv. Mononuclear cells were stimulated with soluble Leishmania antigen (SLA) on day 0 and day 15 of therapy, and cytokine levels were determined in supernatants by ELISA. The lymphocyte proliferation and oxidative burst were evaluated by flow cytometry, and the degree of infection and Leishmania killing by optical microscopy. Proliferation of CD4+ T cells were enhanced in patients using miltefosine and in CD8+ T cells when GM-CSF was associated. Enhancement in the oxidative burst occurred in the miltefosine plus GM-CSF group on day 15 of therapy. Moreover, the number of L. braziliensis in infected monocytes on day 15 as well as the percentage of infected cells was lower after 48- and 72-hour culture in cells from patients treated with miltefosine plus GM-CSF. In addition to the ability of miltefosine to kill Leishmania, the changes in the immune response caused by miltefosine and GM-CSF may increase the cure rate of CL patients using these drugs.

Neuroprotective Activities of Long-Acting Granulocyte-Macrophage Colony-Stimulating Factor (mPDM608) in 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine-Intoxicated Mice.

Loss of dopaminergic neurons along the nigrostriatal axis, neuroinflammation, and peripheral immune dysfunction are the pathobiological hallmarks of Parkinson's disease (PD). Granulocyte-macrophage colony-stimulating factor (GM-CSF) has been successfully tested for PD treatment. GM-CSF is a known immune modulator that induces regulatory T cells (Tregs) and serves as a neuronal protectant in a broad range of neurodegenerative diseases. Due to its short half-life, limited biodistribution, and potential adverse effects, alternative long-acting treatment schemes are of immediate need. A long-acting mouse GM-CSF (mPDM608) was developed through Calibr, a Division of Scripps Research. Following mPDM608 treatment, complete hematologic and chemistry profiles and T-cell phenotypes and functions were determined. Neuroprotective and anti-inflammatory capacities of mPDM608 were assessed in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-intoxicated mice that included transcriptomic immune profiles. Treatment with a single dose of mPDM608 resulted in dose-dependent spleen and white blood cell increases with parallel enhancements in Treg numbers and immunosuppressive function. A shift in CD4+ T-cell gene expression towards an anti-inflammatory phenotype corresponded with decreased microgliosis and increased dopaminergic neuronal cell survival. mPDM608 elicited a neuroprotective peripheral immune transformation. The observed phenotypic shift and neuroprotective response was greater than observed with recombinant GM-CSF (rGM-CSF) suggesting human PDM608 as a candidate for PD treatment.

Pharmacotherapy options in pulmonary alveolar proteinosis.

INTRODUCTION: Pulmonary alveolar proteinosis (PAP) is a heterogeneous group of rare diseases characterized by the abnormal production and impaired degradation of pulmonary surfactant as a result of malfunctioning of alveolar macrophages. This is due to the downstream dysregulation of the GM-CSF pathway, which can be caused by specific autoantibodies (autoimmune, aPAP formerly known as idiopathic iPAP), direct injury to alveolar macrophages (e.g. by toxic inhaled agents.), or by genetic defects (hereditary or congenital PAP). Few pharmacotherapy options are currently available to treat this disease. AREA COVERED: The authors discuss the exogenous administration of GM-CSF, rituximab, and the potential role of cholesterol lowering medications in this review. The authors, furthermore, provide their opinion on the available pharmacotherapeutic options and give their future perspectives. EXPERT OPINION: Inhaled GM-CSF remains the most commonly used therapy in patients with iPAP but other inhaled therapies such as PPARγ activators should be considered, especially in patients who are partially responsive or unresponsive to traditional treatments.

Granulocyte-macrophage colony-stimulating factor enhances effect of temozolomide on high-grade glioma cells.

In the present study, to delve into the effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) combined with temozolomide (TMZ) on high-grade glioma cells and related mechanism, six cases of high-grade glioma cells from patient's tumor tissues were cultured. 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide (MTT) assay was performed to detect cell proliferation and toxicity. Flow cytometry was performed to ascertain cell cycle and apoptosis rate. To detect the expressions of O6-methylguanine-DNA methyltransferase (MGMT) methylation status and MGMT protein, respectively, specific PCR and immunofluorescence were performed. According to the results of MTT assay, compared with the results of control group, GM-CSF group exhibited enhanced cell viability in varying degrees. In three cases of cells (MGMT gene methylation), the combination group [(67.67 ± 1.16), (68.13 ± 1.06), (68.42 ± 1.73)] had noticeably lower cell viability than the corresponding TMZ group [(90.00 ± 1.73), (82.33 ± 1.53), (82.67 ± 2.11)] (P < 0.01). Nevertheless, the two groups showed no significant difference in another three cases (MGMT gene unmethylated) (P > 0.05). In combination group, the apoptosis rate of the MGMT methylation cells was higher than that in the corresponding TMZ group (P < 0.01), which is consistent with MTT assay results. In all six cases of primary glioma cells, the fraction of cells in G1 phase of GM-CSF-treated group was noticeably down-regulated and was up-regulated in S phase (P < 0.01). GM-CSF could induce high-grade glioma cells to rapidly enter the cell cycle, thereby enhancing the lethal effect of TMZ on glioma cells with MGMT gene promoter methylation. However, this effect is not ideal on glioma cells with MGMT unmethylation.

Combination immunotherapy induces distinct T-cell repertoire responses when administered to patients with different malignancies.

BACKGROUND: CTLA-4 blockade with ipilimumab is Food and Drug Administration-approved for melanoma as a monotherapy and has been shown to modulate the circulating T-cell repertoire. We have previously reported clinical trials combining CTLA-4 blockade with granulocyte-macrophage colony-stimulating factor (GM-CSF) in metastatic melanoma patients and in metastatic castration resistant prostate cancer (mCRPC) patients. Here, we investigate the effect that cancer type has on circulating T cells in metastatic melanoma and mCRPC patients, treated with ipilimumab and GM-CSF. METHODS: We used next-generation sequencing of T-cell receptors (TCR) to compare the circulating T cells of melanoma and mCRPC patients receiving the same treatment with ipilimumab and GM-CSF by Wilcoxon rank sum test. Flow cytometry was utilized to investigate specific T-cell populations. TCR sequencing results were correlated with each T-cell subpopulation by Spearman's rank correlation coefficient. Of note, 14 metastatic melanoma patients had samples available for TCR sequencing and 21 had samples available for flow cytometry analysis; 37 mCRPC patients had samples available for sequencing of whom 22 have TCR data available at both timepoints; 20 of these patients had samples available for flow cytometry analysis and 16 had data available at both timepoints. RESULTS: While melanoma and mCRPC patients had similar pretreatment circulating T-cell counts, treatment induces greater expansion of circulating T cells in melanoma patients. Metastatic melanoma patients have a higher proportion of clones that increased more than fourfold after the treatment compared with mCRPC patients (18.9% vs 11.0%, p=0.017). Additionally, melanoma patients compared with mCRPC patients had a higher ratio of convergent frequency (1.22 vs 0.60, p=0.012). Decreases in clonality induced by treatment are associated with baseline CD8+ T-cell counts in both patient groups, but are more pronounced in the melanoma patients (r=-0.81, p<0.001 vs r=-0.59, p=0.02). TRIAL REGISTRATION NUMBERS: NCT00064129; NCT01363206.

Medical treatment options for COVID-19.

Therapeutic options for coronavirus disease 2019 are desperately needed to respond to the ongoing severe acute respiratory syndrome coronavirus 2 pandemic. Both antiviral drugs and immunomodulators might have their place in the management of coronavirus disease 2019. Unfortunately, no drugs have been approved yet to treat infections with human coronaviruses. As it will take years to develop new therapies for severe acute respiratory syndrome coronavirus 2, the current focus is on the repurposing of drugs that have been approved or are in development for other conditions. Several clinical trials have already been conducted or are currently ongoing to evaluate the efficacy of such drugs. Here, we discuss the potential of these therapies for the treatment of coronavirus disease 2019.

Therapeutic role of granulocyte macrophage colony-stimulating factor (GM-CSF) in patients with persistent thin endometrium: A prospective and randomized study.

OBJECTIVE: To assess the effect of granulocyte macrophage colony-stimulating factor (GM-CSF) on unresponsive thin (<7 mm) endometrium in women undergoing frozen-thawed embryo transfer. METHODS: A single-center, randomized, prospective study enrolled 304 women with thin unresponsive endometrium from Shanghai Ninth People's Hospital between March 2017 and May 2018. Of them, 161 patients received an intrauterine infusion of GM-CSF and 143 patients served as controls. After hysteroscopy, a gel with or without GM-CSF was administered to fill the uterine cavity completely or up to 5 mL only. The primary outcome was confirmed pregnancy and secondary outcomes included endometrial thickness and implantation rate. RESULTS: Patients who were administered GM-CSF had a significantly higher chemical pregnancy rate (35.3% vs 20.0%; P=0.009) and clinical pregnancy rate (28.6% vs 13.3%; P=0.005) compared with patients in the control group. Patients treated with GM-CSF had significantly higher endometrial thickness compared with controls (7.83 ± 1.45 mm vs 7.37 ± 0.70 mm, P=0.003). CONCLUSION: GM-CSF therapy can effectively increase endometrial thickness and improve the clinical pregnancy rate in patients with persistent thin endometrium. The therapeutic role of GM-CSF for infertile women under in vitro fertilization and embryo transfer (IVF-ET) treatment can be further explored. CHINESE CLINICAL TRIAL REGISTER: ChiCTR-IPR-17011242.

Rationale and design of the granulocyte-macrophage colony stimulating factor in peripheral arterial disease (GPAD-3) study.

BACKGROUND: Lower extremity peripheral arterial disease (PAD) is a public health problem and many patients with PAD experience claudication despite adequate medical and/or surgical management. Mobilization of endogenous progenitor cells using Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF) is a novel therapeutic option that has shown promising results in experimental models and phase I/IIA clinical trials. The GPAD-3 trial will study the effect of two successive administrations of GM-CSF at 3-month interval for improving claudication among patients with lower extremity PAD. METHODS: We plan to recruit 176 patients in this ongoing randomized, double-blind, placebo-controlled Phase IIB trial. After screening for inclusion and exclusion criteria, eligible subjects undergo a 4-week screening phase where they perform subcutaneous placebo injections thrice weekly and walk at least three times a day until they develop claudication. After the screening phase, eligible subjects undergo baseline testing and are randomized 2:1 to receive 500 µg/day of GM-CSF subcutaneously thrice weekly for three weeks or placebo injections. After 3 months, follow-up endpoint testing is performed and subjects in the GM-CSF group receive the second administration of the drug for three weeks while subjects in placebo group receive matching placebo injections. All participants undergo endpoint testing at six-month and nine-month follow-up. The primary endpoint is change in 6-min walk distance between baseline and 6-month follow-up. CONCLUSION: GPAD-3 explores a novel approach to address the need for alternative therapies that can alleviate symptoms among patients with lower extremity PAD. If successful, this study will pave the way for a pivotal Phase III trial.

Lower respiratory tract delivery, airway clearance, and preclinical efficacy of inhaled GM-CSF in a postinfluenza pneumococcal pneumonia model.

Inhaled granulocyte/macrophage colony-stimulating factor (GM-CSF) shows promise as a therapeutic to treat viral and bacterial pneumonia, but no mouse model of inhaled GM-CSF has been described. We sought to 1) develop a mouse model of aerosolized recombinant mouse GM-CSF administration and 2) investigate the protection conferred by inhaled GM-CSF during influenza A virus (IAV) infection against secondary bacterial infection with pneumococcus. To assess lower respiratory tract delivery of aerosolized therapeutics, mice were exposed to aerosolized fluorescein (FITC)-labeled dextran noninvasively via an aerosolization tower or invasively using a rodent ventilator. The efficiency of delivery to the lower respiratory tracts of mice was 0.01% noninvasively compared with 0.3% invasively. The airway pharmacokinetics of inhaled GM-CSF fit a two-compartment model with a terminal phase half-life of 1.3 h. To test if lower respiratory tract levels were sufficient for biological effect, mice were infected intranasally with IAV, treated with aerosolized recombinant mouse GM-CSF, and then secondarily infected with Streptococcus pneumoniae. Inhaled GM-CSF conferred a significant survival benefit to mice against secondary challenge with S. pneumoniae (P < 0.05). Inhaled GM-CSF did not reduce airway or lung parenchymal bacterial growth but significantly reduced the incidence of S. pneumoniae bacteremia (P < 0.01). However, GM-CSF overexpression during influenza virus infection did not affect lung epithelial permeability to FITC-dextran ingress into the bloodstream. Therefore, the mechanism of protection conferred by inhaled GM-CSF appears to be locally mediated improved lung antibacterial resistance to systemic bacteremia during IAV infection.

A biomaterial-based vaccine eliciting durable tumour-specific responses against acute myeloid leukaemia.

Acute myeloid leukaemia (AML) is a malignancy of haematopoietic origin that has limited therapeutic options. The standard-of-care cytoreductive chemotherapy depletes AML cells to induce remission, but is infrequently curative. An immunosuppressive AML microenvironment in the bone marrow and the paucity of suitable immunotherapy targets limit the induction of effective immune responses. Here, in mouse models of AML, we show that a macroporous-biomaterial vaccine that delivers the cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF), the Toll-like-receptor-9 agonist cytosine-guanosine oligodeoxynucleotide and one or multiple leukaemia antigens (in the form of a defined peptide antigen, cell lysates or antigens sourced from AML cells recruited in vivo) induces local immune-cell infiltration and activated dendritic cells, evoking a potent anti-AML response. The biomaterial-based vaccine prevented the engraftment of AML cells when administered as a prophylactic and when combined with chemotherapy, and eradicated established AML even in the absence of a defined vaccine antigen. Biomaterial-based AML vaccination can induce potent immune responses, deplete AML cells and prevent disease relapse.