Integrative analysis of mononuclear phagocyte heterogeneity using high-dimensional cytometry and multiphoton imaging

• Grant number: 25/21148-3
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: December 01, 2025
• End date: November 30, 2026
• Field of knowledge: Biological Sciences - Immunology - Cellular Immunology
• Principal Investigator: Sergio Costa Oliveira
• Grantee: Ana Carolina Valente Santos Cruz de Araujo
• Supervisor: Alexandre Boissonnas
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: Université Paris-Est Créteil, France
• Associated to the scholarship: 23/09226-3 - Unraveling trained immune mechanisms mediated by BCG in macrophages and dendritic cells during infection by the intracellular bacterium Brucella abortus, BP.PD

Abstract

The mononuclear phagocyte system (MPS) plays a crucial role in maintaining lung homeostasis and orchestrating immune responses to environmental challenges. In the lung, MPS subsets, including alveolar and interstitial macrophages, as well as classical and non-classical monocytes, form specialized networks that regulate immune surveillance and determine the outcome of infectious insults. The Mycobacterium bovis bacillus Calmette-Guérin (BCG), the only licensed vaccine against tuberculosis, has been shown to induce trained immunity and confer heterologous protection against unrelated respiratory pathogens. Importantly, we have demonstrated that BCG vaccination protects against intranasal infection with Brucella abortus, the causative agent of brucellosis, a zoonotic disease with high impact on human and animal health. Understanding how MPS subsets in the lung undergo functional and metabolic reprogramming during trained immunity is, therefore, central to advancing host-directed strategies against respiratory infections.To address this, my research internship in the laboratory of Prof. Alexandre Boissonnas at Institut Mondor de Recherche Biomédicale (IMRB, Créteil, France) will employ high-dimensional spectral cytometry to define the heterogeneity and immunophenotypic remodeling of MPS subsets, with a particular focus on their metabolic state, a central driver of immune cell function and plasticity. In parallel, multiphoton intravital imaging will be used to track their localization and dynamic interactions with the lung vasculature, airways, and interstitial compartments. These approaches will be applied to investigate how acute exposure to cigarette smoke (CS), a relevant environmental insult that perturbs lung immunity, reshapes MPS behavior, metabolism,and dynamics. The CS model is currently used by the host professor to evaluate MPS heterogeneity. Together, these approaches will generate a detailed and integrated view of the lung MPS under acute environmental stress, linking metabolic remodeling to spatial and functional changes.The expertise acquired through this internship will represent a major gain for Brazilian science. By integrating advanced training in single-cell technologies, metabolism, and intravital imaging, the project will contribute to the study of monocytes, macrophages, and dendritic cells in the context of trained immunity in Brazil. Applying the methodologies developed during this internship to the lung microenvironment will enable us to dissect the mechanisms by which BCG-induced trained immunity reshapes the function, metabolism, and dynamics of MPS subsets both before and after B. abortus i.n. infection. This knowledge transfer will strengthen national research capacity, foster international collaboration, and support the development of innovative approaches with translational potential in immunology.