Vacunas basadas en neoantígenos y control del cáncer: perspectivas / Neoantigen vaccines and cancer control: perspectives

Resumen La supervivencia global y la calidad de vida son objetivos primarios del tratamiento del cáncer. El desarrollo de terapias blanco promovió el concepto de tratamientos personalizados, los que se han evaluado principalmente mediante desenlaces centrados en el tumor y han tenido foco en tumores de baja frecuencia y estados avanzados. La inmunoterapia rompe esta tendencia y genera expectativa por su efecto en la supervivencia global y su potencial uso en una gama amplia de tumores. Dentro de esta, las vacunas basadas en neoantígenos han mostrado alta eficacia y seguridad debido a su afinidad con células T y su elevada especificidad. Basado en sus principios biológicos se revisa su posible impacto en la carga de enfermedad según la relación entre potencial inmunogénico y prevalencia por tipo de tumor, el posible efecto en la práctica clínica por su combinación con otras modalidades de tratamiento, y el efecto en el acceso al tratamiento dado su proceso de desarrollo y producción y la disponibilidad de información propia.

Abstract Overall survival and quality of life are primary goals of cancer treatment. The recent development of targeted therapies has fostered the concept of personalized treatments, which have been evaluated mainly through tumor-centered outcomes and have focused on low-prevalence tumors and advanced stages. Immunotherapy halts this trend and generates expectation regarding its impact on overall survival and its potential use in a wide range of tumors. As part of immunotherapy, neoantigen vaccines have shown high efficacy and safety due to their affinity with T cells and their high specificity. Based on biological principles, we reviewed their potential impact on the burden of disease given the immunogenicity and prevalence by tumor type, the possible effect on clinical practice due to their combination with other treatment modalities, and the effect on access to treatment, given the process of development and production and the availability of local data.

High infiltration of B cells in tertiary lymphoid structures, TCR oligoclonality, and neoantigens are part of esophageal squamous cell carcinoma microenvironment.

Esophageal squamous cell carcinoma (ESCA) exhibits high intratumoral molecular heterogeneity posing a challenge to cancer therapy. Immune checkpoint blockade therapy has been approved for this disease, but with modest results. RNA-Seq data from paired tumor and surrounding nonmalignant tissue from 14 patients diagnosed with ESCA without previous treatment and from The Cancer Genome Atlas-ESCA cohort were analyzed. Herein, we investigated ESCA immune landscape including mutation-derived neoantigens and immune cell subpopulations. Tumor-associated antigen expression was determined by in silico analyses and confirmed by immunohistochemistry showing that PRAME, CEACAM4, and MAGEA11 proteins are expressed on tumors. Immune checkpoint molecules gene expression was higher in the tumor compared with surrounding nonmalignant tissue, but its expression varies greatly among patients. TCR repertoire and BCR transcripts analysis evidenced low clonal diversity with one TCR clone predicted to be specific for a MAGEA11-derived peptide. A high number of B-cell clones infiltrating the tumors and the abundance of these cells in tertiary lymphoid structures observed in ESCA tumors support B cells as a potential immune modulator in this tumor.

Increased carcinoembryonic antigen expression on the surface of lung cancer cells using gold nanoparticles during radiotherapy.

PURPOSE: Tumor-associated antigens are a promising target of immunotherapy approaches for cancer treatments but rely on sufficient expression of the target antigen. This study investigates the expression of the carcinoembryonic antigen (CEA) on the surface of irradiated lung cancer cells in vitro using gold nanoparticles as radio-enhancer. METHODS: Human lung carcinoma cells A549 were irradiated and expression of CEA on the cell surface measured by flow cytometry 3 h, 24 h, and 72 h after irradiation to doses of 2 Gy, 6 Gy, 10 Gy, and 20 Gy in the presence or absence of 0.1 mg/ml or 0.5 mg/ml gold nanoparticles. CEA expression was measured as median fluorescent intensity and percentage of CEA-positive cells. RESULTS: An increase in CEA expression was observed with both increasing radiation dose and time. There was doubling in median fluorescent intensity 24 h after 20 Gy irradiation and 72 h after 6 Gy irradiation. Use of gold nanoparticles resulted in additional significant increase in CEA expression. Change in cell morphology included swelling of cells and increased internal complexity in accordance with change in CEA expression. CONCLUSIONS: This study showed an increase in CEA expression on human lung carcinoma cells following irradiation. Increase in expression was observed with increasing radiation dose and in a time dependent manner up to 72 h post irradiation. The results further showed that gold nanoparticles can significantly increase CEA expression following radiotherapy.

Evaluation of T-Cell Responses Against Shared Melanoma Associated Antigens and Predicted Neoantigens in Cutaneous Melanoma Patients Treated With the CSF-470 Allogeneic Cell Vaccine Plus BCG and GM-CSF.

The CSF-470 vaccine consists of lethally-irradiated allogeneic cells derived from four cutaneous melanoma cell lines administered plus BCG and GM-CSF as adjuvants. In an adjuvant phase II study vs. IFN-α2b, the vaccine significantly prolonged the distant metastasis-free survival (DMFS) of stages IIB-IIC-III melanoma patients with evidence of the induction of immune responses against vaccine cells. Purpose: The aim of this study was to analyze the antigens against which the immune response was induced, as well as the T-helper profile and lytic ability of immune cells after CSF-470 treatment. Methods: HLA-restricted peptides from tumor-associated antigens (TAAs) were selected from TANTIGEN database for 13 evaluable vaccinated patients. In addition, for patient #006 (pt#006), tumor somatic variants were identified by NGS and candidate neoAgs were selected by predicted HLA binding affinity and similarity between wild type (wt) and mutant peptides. The patient's PBMC reactivity against selected peptides was detected by IFNγ-ELISPOT. T-helper transcriptional profile was determined by quantifying GATA-3, T-bet, and FOXP3 mRNA by RT-PCR, and intracellular cytokines were analyzed by flow cytometry. Autologous tumor cell lysis by PBMC was assessed in an in vitro calcein release assay. Results: Vaccinated patient's PBMC reactivity against selected TAAs derived peptides showed a progressive increase in the number of IFNγ-producing cells throughout the 2-yr vaccination protocol. ELISPOT response correlated with delayed type hypersensitivity (DTH) reaction to CSF-470 vaccine cells. Early upregulation of GATA-3 and Foxp3 mRNA, as well as an increase in CD4+IL4+cells, was associated with a low DMFS. Also, IFNγ response against 9/73 predicted neoAgs was evidenced in the case of pt#006; 7/9 emerged after vaccination. We verified in pt# 006 that post-vaccination PBMC boosted in vitro with the vaccine lysate were able to lyse autologous tumor cells. Conclusions: A progressive increase in the immune response against TAAs expressed in the vaccine and in the patient's tumor was induced by CSF-470 vaccination. In pt#006, we demonstrated immune recognition of patient's specific neoAgs, which emerged after vaccination. These results suggest that an initial response against shared TAAs could further stimulate an immune response against autologous tumor neoAgs.

neoANT-HILL: an integrated tool for identification of potential neoantigens.

BACKGROUND: Cancer neoantigens have attracted great interest in immunotherapy due to their capacity to elicit antitumoral responses. These molecules arise from somatic mutations in cancer cells, resulting in alterations on the original protein. Neoantigens identification remains a challenging task due largely to a high rate of false-positives. RESULTS: We have developed an efficient and automated pipeline for the identification of potential neoantigens. neoANT-HILL integrates several immunogenomic analyses to improve neoantigen detection from Next Generation Sequence (NGS) data. The pipeline has been compiled in a pre-built Docker image such that minimal computational background is required for download and setup. NeoANT-HILL was applied in The Cancer Genome Atlas (TCGA) melanoma dataset and found several putative neoantigens including ones derived from the recurrent RAC1:P29S and SERPINB3:E250K mutations. neoANT-HILL was also used to identify potential neoantigens in RNA-Seq data with a high sensitivity and specificity. CONCLUSION: neoANT-HILL is a user-friendly tool with a graphical interface that performs neoantigens prediction efficiently. neoANT-HILL is able to process multiple samples, provides several binding predictors, enables quantification of tumor-infiltrating immune cells and considers RNA-Seq data for identifying potential neoantigens. The software is available through github at https://github.com/neoanthill/neoANT-HILL.

T-Cell-Driven Inflammation as a Mediator of the Gut-Brain Axis Involved in Parkinson's Disease.

Parkinson's disease (PD) is a neurodegenerative disorder affecting mainly the dopaminergic neurons of the nigrostriatal pathway, a neuronal circuit involved in the control of movements, thereby the main manifestations correspond to motor impairments. The major molecular hallmark of this disease corresponds to the presence of pathological protein inclusions called Lewy bodies in the midbrain of patients, which have been extensively associated with neurotoxic effects. Importantly, different research groups have demonstrated that CD4+ T-cells infiltrate into the substantia nigra of PD patients and animal models. Moreover, several studies have consistently demonstrated that T-cell deficiency results in a strong attenuation of dopaminergic neurodegeneration in animal models of PD, thus indicating a key role of adaptive immunity in the neurodegenerative process. Recent evidence has shown that CD4+ T-cell response involved in PD patients is directed to oxidised forms of α-synuclein, one of the main constituents of Lewy bodies. On the other hand, most PD patients present a number of non-motor manifestations. Among non-motor manifestations, gastrointestinal dysfunctions result especially important as potential early biomarkers of PD, since they are ubiquitously found among confirmed patients and occur much earlier than motor symptoms. These gastrointestinal dysfunctions include constipation and inflammation of the gut mucosa and the most distinctive pathologic features associated are the loss of neurons of the enteric nervous system and the generation of Lewy bodies in the gut. Moreover, emerging evidence has recently shown a pivotal role of gut microbiota in triggering the development of PD in genetically predisposed individuals. Of note, PD has been positively correlated with inflammatory bowel diseases, a group of disorders involving a T-cell driven inflammation of gut mucosa, which is strongly dependent in the composition of gut microbiota. Here we raised the hypothesis that T-cell driven inflammation, which mediates dopaminergic neurodegeneration in PD, is triggered in the gut mucosa. Accordingly, we discuss how structural components of commensal bacteria or how different mediators produced by gut-microbiota, including short-chain fatty acids and dopamine, may affect the behaviour of T-cells, triggering the development of T-cell responses against Lewy bodies, initially confined to the gut mucosa but later extended to the brain.

Neuroimmune regulation of microglial activity involved in neuroinflammation and neurodegenerative diseases.

Neuroinflammation constitutes a fundamental process involved in the progression of several neurodegenerative disorders, such as Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis and multiple sclerosis. Microglial cells play a central role in neuroinflammation, promoting neuroprotective or neurotoxic microenvironments, thus controlling neuronal fate. Acquisition of different microglial functions is regulated by intercellular interactions with neurons, astrocytes, the blood-brain barrier, and T-cells infiltrating the central nervous system. In this study, an overview of the regulation of microglial function mediated by different intercellular communications is summarised and discussed. Afterward, we focus in T-cell-mediated regulation of neuroinflammation involved in neurodegenerative disorders.