Project Details
Projekt
Role of the materno-fetal IgG bone marrow macrophage axis for early B cell development
Applicant
Professor Dr. Falk Nimmerjahn
Subject Area
Cell Biology
Immunology
Immunology
Term
since 2025
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 533863915
Although frequently viewed as components of different arms of the immune system, the fate and function of B cells and macrophages are tightly linked. Thus, during central (bone marrow) and peripheral (spleen, lymph node) processes of B cell selection, macrophages remove large numbers of dying B cells expressing low affinity or self-reactive B cell receptors. During early life immunoglobulin G (IgG) transferred from mother to offspring via the placenta or milk protects the newborn from microbial infections via macrophage and neutrophil dependent clearance of opsonized pathogens via Fc-receptor mediated phagocytosis. A further crosstalk between macrophages and B cells occurs via the secretion of growth factors, cytokines, chemokines, and reactive oxygen species by macrophages, which can modulate B cell activation and differentiation. Reversely, cytokine secretion by B cells can modulate macrophage activation and/or polarization. Of note, more recent studies have established that in most peripheral tissues not only macrophages but also B cells are present, thus allowing a cross-talk between B cells and macrophages outside of secondary lymphoid organs during steady state. While the crosstalk of macrophages and B cells in peripheral organs has been studied in greater detail, there is much less knowledge about how macrophages or subsets thereof interact with B cells in the bone marrow. Thus, the central goals of the project are to understand bone marrow macrophage complexity and function in greater detail (I), to delineate how passively transferred maternal and endogenously produced IgG modulate bone marrow macrophage development and function during early life (II), and how bone marrow macrophages shape early B cell development and function (III).
DFG Programme
Research Units
