Luis Sendra

FOXP3 is the master transcriptional regulator of regulatory T cells (Tregs) and is expressed in humans as two main alternatively spliced isoforms: full-length FOXP3 (FOXP3-FL) and the exon 2-deficient variant (FOXP3-Δ2). While the role of these isoforms has been mainly studied in CD4⁺ T cells, their distribution across peripheral blood leukocyte populations and their relationship with immune checkpoint expression remain incompletely defined. In this study, we used a multiparametric flow cytometry panel allowing isoform-specific detection of FOXP3-FL and FOXP3-Δ2, together with PD-1 and CTLA-4, to analyze peripheral blood samples from six healthy donors under basal conditions. Major leukocyte populations, including CD4⁺CD25⁺ and CD4⁺CD25⁻ T cells, CD8⁺ T cells, monocytes, and neutrophils, were evaluated. FOXP3-FL predominated in CD4⁺CD25⁺ T cells, whereas FOXP3-Δ2 was more frequently detected in CD8⁺ T cells, monocytes, and neutrophils. However, the absolute frequencies of these FOXP3-Δ2-positive populations were low, consistent with the overall low levels of FOXP3 expression observed in these cell types. In CD4⁺ T-cell subsets, PD-1 expression was generally higher than CTLA-4, regardless of FOXP3 isoform, and FOXP3-Δ2⁺ cells showed relatively higher PD-1 expression compared to FOXP3-FL⁺ cells. In contrast, checkpoint expression in non-CD4⁺ populations was limited. The observed FOXP3-FL⁺/FOXP3-Δ2⁺ ratios across immune cell populations were consistent with a predominant role of FOXP3-FL in maintaining immune tolerance under basal conditions; whether these patterns are preserved or altered in pathological settings warrants further investigation. These results provide a descriptive overview of FOXP3 isoform distribution and checkpoint expression across peripheral blood immune cell subsets in healthy individuals, which may serve as a reference for future studies in immune-mediated diseases.

Background/Objectives: Interleukin-10 (IL-10) is a potent anti-inflammatory cytokine that is critical for intestinal immune homeostasis. Despite its therapeutic potential, systemic delivery of IL-10 has failed in clinical trials for inflammatory bowel disease (IBD), largely due to its poor localization and short half-life. Methods: We present a proof-of-concept study demonstrating that hydrodynamic delivery of a naked plasmid bearing the human IL-10 gene to ex vivo human colonic segments from Crohn’s disease patients results in localized IL-10 expression and modulation of inflammatory mediators. Results: Compared to venous administration, arterial delivery yielded significantly higher IL-10 mRNA and protein levels, as well as decreased IL-6 and TNF-α expression. Furthermore, nanoparticle tracing confirmed efficient tissue penetration via the arterial route. Conclusions: These findings establish arterial hydrodynamic delivery as a feasible, non-viral strategy for targeted gene therapy in IBD.

El uso de la IA generativa es una realidad y está al alcance de los alumnos, quienes la utilizan habitualmente. De acuerdo con informes recientes de la Comisión Europea y CRUE, se debe integrar en la docencia superior y enseñar a los alumnos a utilizarla de forma ética y segura, dados los riesgos relativos a la calidad y veracidad del texto generado. Una de las maneras en las que se pueden evaluar sus capacidades es el método del caso. Éste es un modo de enseñanza eminentemente activo que ofrece a los estudiantes la oportunidad de relacionar los conocimientos teóricos y técnicos de la materia o curso en situaciones de aplicación práctica. En este modelo de aprendizaje, al solicitarle la resolución de cuestiones con un componente reflexivo y racional más complejo, se pueden observar los fallos y sesgos del modelo. Este proyecto pretende utilizar esta metodología para resolver casos prácticos en un contexto de tratamiento complejo. Los alumnos contrastarán los resultados de la resolución de casos utilizando bases de datos e información académica con los obtenidos mediante la IA generativa para identificar y corregir los errores encontrados y crear en ellos una conciencia más crítica acerca de estas herramientas.

Background/Objectives: The COVID-19 pandemic resulted in 675 million cases and 6.9 million deaths by 2022. Despite substantial declines in case fatalities following widespread vaccination campaigns, the threat of future coronavirus outbreaks remains a concern. Current treatments for COVID-19 have been repurposed from existing therapies for other infectious and non-infectious diseases. Emerging evidence suggests a role for genetic factors in both susceptibility to SARS-CoV-2 infection and response to treatment. However, comprehensive studies correlating clinical outcomes with genetic variants are lacking. The main aim of our study is the identification of host genetic biomarkers that predict the clinical outcome of COVID-19 pharmacological treatments. Methods: In this study, we present findings from GWAS and candidate gene and pathway enrichment analyses leveraging diverse patient samples from the Spanish Coalition to Unlock Research of Host Genetics on COVID-19 (SCOURGE), representing patients treated with immunomodulators (n = 849), corticoids (n = 2202), and the combined cohort of both treatments (n = 2487) who developed different outcomes. We assessed various phenotypes as indicators of treatment response, including survival at 90 days, admission to the intensive care unit (ICU), radiological affectation, and type of ventilation. Results: We identified significant polymorphisms in 16 genes from the GWAS and candidate gene studies (TLR1, TLR6, TLR10, CYP2C19, ACE2, UGT1A1, IL-1α, ZMAT3, TLR4, MIR924HG, IFNG-AS1, ABCG1, RBFOX1, ABCB11, TLR5, and ANK3) that may modulate the response to corticoid and immunomodulator therapies in COVID-19 patients. Enrichment analyses revealed overrepresentation of genes involved in the innate immune system, drug ADME, viral infection, and the programmed cell death pathways associated with the response phenotypes. Conclusions: Our study provides an initial framework for understanding the genetic determinants of treatment response in COVID-19 patients, offering insights that could inform precision medicine approaches for future epidemics.

Although calcineurin inhibitors are very effective as immunosuppressants in organ transplantation, complete graft acceptance remains as a challenge. Transfer of genes with immunosuppressant functions could contribute to improving the clinical evolution of transplantation. In this sense, hydrodynamic injection has proven very efficacious for liver gene transfer. In the present work, the hIL-10 gene was hydrofected ‘ex vivo’ to pig livers during the bench surgery stage, to circumvent the cardiovascular limitations of the procedure, in a model of porcine orthotopic transplantation with a 10-day follow-up. We used IL-10 because human and porcine proteins can be differentially quantified and for its immunomodulatory pleiotropic functions. Safety (biochemical parameters and histology), expression efficacy (RNA transcription and blood protein expression), and acute inflammatory response (cytokines panel) of the procedure were evaluated. The procedure proved safe as no change in biochemical parameters was observed in treated animals, and human IL-10 was efficaciously expressed, with stationary plasma protein levels over 20 pg/mL during the follow-up. Most studied cytokines showed increments (interferon-α, IFN-α; interleukin-1β, IL-1β; tumor necrosis factor α, TNFα; interleukin-6, IL-6; interleukin-8, IL-8; interleukin-4, IL-4; and transforming growth factor-β, TGF-β) in treated animals, without deleterious effects on tissue. Collectively, the results support the potential clinical interest in this gene therapy model that would require further longer-term dose–response studies to be confirmed.

Background: Pharmacogenetics is a personalized medicine tool that aims to optimize treatments by adapting them to each individual’s genetics, maximizing their efficacy while minimizing their toxicity. Infants with cancer are especially vulnerable, and their co-morbidities have vital repercussions. The study of their pharmacogenetics is new in this clinical field. Methods: A unicentric, ambispective study of a cohort of infants receiving chemotherapy (from January 2007 to August 2019). The genotypes of 64 patients under 18 months of age were correlated with severe drug toxicities and survival. A pharmacogenetics panel was configured based on PharmGKB, drug labels, and international experts’ consortiums. Results: Associations between SNPs and hematological toxicity were found. Most meaningful were: MTHFR rs1801131 GT increasing the anemia risk (OR 1.73); rs1517114 GC, XPC rs2228001 GT, increasing neutropenia risk (OR 1.50 and 4.63); ABCB1 rs1045642 AG, TNFRSF11B rs2073618 GG, CYP2B6 rs4802101 TC and SOD2 rs4880 GG increasing thrombocytopenia risk (OR 1.70, 1.77, 1.70, 1.73, respectively). Regarding survival, MTHFR rs1801133 GG, TNFRSF11B rs2073618 GG, XPC rs2228001 GT, CYP3A4 rs2740574 CT, CDA rs3215400 del.del, and SLC01B1 rs4149015 GA were associated with lower overall survival probabilities (HR 3.12, 1.84, 1.68, 2.92, 1.90, and 3.96, respectively). Lastly, for event-free survival, SLC19A1 rs1051266 TT and CDA rs3215400 del.del increased the relapse probability (HR 1.61 and 2.19, respectively). Conclusions: This pharmacogenetic study is a pioneer in dealing with infants under 18 months of age. Further studies are needed to confirm the utility of the findings in this work to be used as predictive genetic biomarkers of toxicity and therapeutic efficacy in the infant population. If confirmed, their use in therapeutic decisions could improve the quality of life and prognosis of these patients.

Therapeutic oligonucleotides have achieved great clinical interest since their approval as drug agents by regulatory agencies but their access and distribution in blood cells are not completely known. We evaluated by flow cytometry the ability of short fluorescent scramble oligonucleotides (ON*) to access human peripheral blood mononuclear cells (PBMC) after incubating with ON* during 1 h and 7 days of culture follow-up ‘in vitro’. Blood samples were treated with chemically modified oligonucleotides (phosphorothioate backbone and 2′ O-Me ends) to resist nuclease digestion under culture conditions. The ON* internalization was determined after discarding the membrane-associated fluorescence by trypan blue quenching. Whereas the oligonucleotide accessed neutrophils and monocytes rapidly, achieving their maximum in 1 h and 24 h, respectively, lymphocytes required 7 days to achieve the maximum (80% of cells) transfection. The ON*ability to access lymphocyte types (T, B, and NK) and T cell subtypes (CD4+, CD8+, and CD4-CD8-) were similar, with T cells being more accessible. Regulatory CD4+ and CD8+ T cells were classified in low and high Foxp3 expressers, whose expression proved not to alter the ON* internalization during the first hour, achieving 53% of CD4+Foxp3+ and 40% of CD8+Foxp3+ cells. Our results contribute to understanding and improving the management of therapeutic ONs.

Some gene polymorphisms have been previously associated individually with tacrolimus efficacy and toxicity, but no long-term study to determine the role of pharmacogene variants in the clinical evolution of liver-transplanted patients has been addressed so far. In the present work, we analyzed the relation between highly-evidenced genetic polymorphisms located in relevant pharmacogenes and the risk of suffering premature death and other comorbidities such as cancer, diabetes mellitus, arterial hypertension, graft rejection, infections and nephrotoxicities in a cohort of 87 patients (8 were excluded due to early loss of follow-up) transplanted at Hospital La Fe in Valencia (Spain) during a 12-year follow-up. Employing a logistic regression model with false discovery rate penalization and Kaplan–Meier analyses, we observed significant association between survival rates and metabolizer genes. In this sense, our results show an association between MTHFR gene variants in donor rs1801133 (HR: 7.90; p-value: 0.032) and recipient rs1801131 (HR: 7.34; p-value: 0.036) and the group of patients who died during the follow-up period, supporting the interest of confirming these results with larger patient cohorts. In addition, donor polymorphisms in UGT1A9 metabolizer gene rs6714486 (OR: 0.13; p-value: 0.032) were associated with a lower risk of suffering from de novo cancer. Genetic variants in CYP2B6 metabolizer gene rs2279343 demonstrated an association with a risk of infection. Other variants in different locations of SLCO1A2, ABCC2 and ABCB1 transporter genes were associated with a lower risk of suffering from type 2 diabetes mellitus, chronic and acute nephrotoxicities and arterial hypertension. Results suggest that pharmacogenetics-derived information may be an important support for personalized drug prescription, clinical follow-up and the evolution of liver-transplanted patients.

Pharmacogenetics is one of the cornerstones of Personalized Precision Medicine that needs to be implemented in the routine of our patients’ clinical management in order to tailor their therapies as much as possible, with the aim of maximizing efficacy and minimizing toxicity. This is of great importance, especially in pediatric cancer and even more in complex malignancies such as neuroblastoma, where the rates of therapeutic success are still below those of many other types of tumors. The studies are mainly focused on germline genetic variants and in the present review, state of the art is presented: which are the variants that have a level of evidence high enough to be implemented in the clinic, and how to distinguish them from the ones that still need validation to confirm their utility. Further aspects as relevant characteristics regarding ontogeny and future directions in the research will also be discussed.