Biology subjects

Fonseca, D. L. M.

Publications and source records attributed to Fonseca, D. L. M..

4 recordsLinked to original sources

bioRxiv2026

microRNA-721 is a host regulator of TNF-IRF1 axis in Leishmania infected macrophage

MicroRNAs (miRNAs) are small noncoding RNAs that play critical roles in regulating immune responses and have emerged as potential biomarkers and therapeutic targets in complex diseases. Leishmaniasis is a neglected disease that compromises host immunity and is associated with challenging treatments regimens. Leishmania amazonensis (L. amazonensis), an intracellular protozoan parasite, causes cutaneous leishmaniasis by replicating inside mammalian macrophages to establish infection. In this context, miRNAs have emerged as vital post-transcriptional factors that regulate the inflammatory landscape during infection. In this study, we aimed to analyze the function of miR-721 in macrophages during L. amazonensis infection by integrating in silico miR-721 target prediction with RNAseq data from macrophages of two distinct mouse genotypes, resistant C57BL/6 and susceptible BALB/c. We found that miR-721 is induced in macrophages infected with L. amazonensis, but is not in LPS-stimulated macrophages, suggesting a TLR4-independent activation. Integrating miR-721 target prediction with comparative transcriptomic analyses in resistant C57BL/6 and susceptible BALB/c models revealed the TNF-IRF1 axis as a primary miR-721-associated regulatory network. Specifically, miR-721 is predicted to target the 3UTRs of Tnf and Irf1 to suppress the inflammatory response. Functional inhibition of miR-721 successfully restored Tnf and Irf1 expression and reduced the amastigote burden over 24 hours. Furthermore, we showed that the miR-721/TNF-IRF1 axis regulates downstream genes associated with macrophage response, such as Serpine1, Csf1, Cd69 and Maf. Our work demonstrated that Leishmania induces miR-721, which negatively modulates the TNF-IRF1 axis, thereby suppressing the immune response and favoring parasite persistence. While C57BL/6 macrophages exhibit a robust activation of the TNF-IRF1 network, promoting inflammatory response, BALB/c macrophage showed a breakdown of this network. This was associated with post-transcriptional suppression of inflammatory responses, thereby favoring parasite persistence. These findings link miR-721 to the establishment of macrophage polarization, providing relevant insights into the mechanisms of parasite subversion of the host immune response.

immunology↗

bioRxiv2026

HTLV-1-Induced Neuroimmunome Correlates with Disease Progression and Severity

Human T-cell lymphotropic virus type 1 (HTLV-1) is a retrovirus that infects approximately 5-10 million people worldwide. While most individuals remain asymptomatic, a significant subset develops debilitating neuroinflammatory or malignant disorders, including adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). To unravel the systemic molecular mechanisms underlying HTLV-1 pathogenesis, we employed a multi-dimensional systems biology approach, integrating bulk transcriptomic data from total PBMCs (n = 200) with single-cell RNA sequencing (scRNA-seq) from 233,093 peripheral blood mononuclear cells (PBMCs). Our analysis revealed a consistent and clinically relevant neuroimmune signature within leukocytes, termed the neuroimmunome, comprising a set of differentially expressed genes shared across the nervous and immune systems. Through dimensionality reduction and machine learning techniques, such as PCA, gradient boosting, and MANOVA with bootstrapping, we identified potential biomarkers predictive of HTLV-1-driven leukemogenesis, which were subsequently validated across ATL, HAM/TSP, and asymptomatic cohorts via flow cytometry. Notably, expression levels of proteins such as ATF4 and SKIL were strongly correlated with proviral load, suggesting that sustained neuroimmune dysregulation may contribute to disease progression. These findings highlight a previously underappreciated neuroimmunological layer, redefining HTLV-1-associated disease as a condition deeply rooted in neuroimmune network disruption within leukocytes and offering potential novel targets.

molecular biology↗

bioRxiv2026

Single-cell RNA sequencing of CTLA-4 and PD-1 blockade in pulmonary paracoccidioidomycosis highlights a protective transcriptional program mediated by activated Th17 cells, neutrophils and macrophages

Pulmonary paracoccidioidomycosis (PCM) relies on a finely balanced lung-immune network in which Th17, Treg, neutrophils, and macrophages orchestrate fungal control and tissue integrity. Furthermore, within the context of single-cell sequencing, little is known about how immune checkpoint inhibition modulates this balance during systemic mycosis. In a previous study we verified that the blockade of checkpoint molecules (CTLA-4 and PD-1) restores protective immunity that reduces fungal loads, tissue pathology and mortality of infected mice. Here, we have further studied this model by single-cell RNA sequencing on lung leukocytes from mice infected with Paracoccidioides brasiliensis and treated with anti-CTLA-4 or anti-PD-1 antibodies to define the cellular and molecular consequences of checkpoint blockade in vivo. We generated a high-resolution atlas covering T cells, neutrophils, macrophages/monocytes, B cells, NK cells, and epithelial subsets. Checkpoint inhibition consistently remodeled the CD4 T cell compartment toward a Th17-enriched program, with reduced interleukin-10 expressing Treg frequencies and a prominent interleukin-17A (IL-17), C-C chemokine receptor type 2, CXC chemokine (CXC) receptor type 6, CD44 (Il17aCcr2Cxcr6Cd44) signature. This shift was accompanied by the expansion and activation of neutrophils and macrophages expressing tumor necrosis factor and chemokines (including CXC motif chemokine ligand (Cxcl1, Cxcl2 and Ccl4), microbicidal-associated genes (S100 calcium-binding protein A8 and A9), and regulatory mediators such as secretory leukocyte protease inhibitor and interleukin-15. Ligand-receptor and trajectory analyses revealed a reinforced Th17-myeloid communication axis, particularly under CTLA-4 blockade, converging on IL17-centered inflammatory circuits while attenuating canonical Treg checkpoints (cytotoxic T-lymphocyte-associated protein 4, programmed cell death protein 1, interleukin-10). Together, these data demonstrate that anti-CTLA-4 and anti-PD-1 immunotherapies profoundly rewire the lung-immune microenvironment during PCM, amplifying effector Th17-neutrophil-macrophage networks that benefits protective antifungal activity Our work provides a mechanistic framework for evaluating immune checkpoint inhibitors in chronic fungal infections.

immunology↗

bioRxiv2024

Integrative systems neuroimmunology reveals leukocyte-expressing PAX6 as a critical predictor of major depressive disorder

Major depressive disorder (MDD) is a complex psychiatric condition with a significant global impact. This study applied a genomic-driven integrative systems neuroimmunology approach to analyze transcriptomic data from 3,114 individuals (1,877 MDD patients and 1,237 controls). The analysis revealed neuroimmunological transcriptomic alterations, indicating cross-talk between the immune and nervous systems in peripheral blood mononuclear cells (PBMCs) and specific brain regions. Among 31 shared genes, NEGR1, PPP6C, SORCS3, and PAX6 emerged as significant predictors of MDD in patients PBMCs. Notably, PAX6 was also identified as a differentially expressed gene (DEG) in the amygdala, while NEGR1, PPP6C, and SORCS3 showed no significant differential expression in other central nervous system (CNS) regions. Validation by immunophenotyping in a mouse model of chronic stress demonstrated increased PAX6 expression in PBMCs, a gene previously associated with MDD in GWAS studies. Collectively, our findings suggest the existence of shared transcriptomic modules across the brain and immune system, highlighting PAX6 as a potential therapeutic target in MDD.

systems biology↗