Evaluating the evidence for GM-CSF as a host-directed therapy in respiratory infections.

Novel therapeutic approaches are needed to treat respiratory infections due to the rising antimicrobial resistance and the lack of effective antiviral therapies. A promising avenue to overcome treatment failure is to develop strategies that target the host immune response rather than the pathogen itself. Granulocyte-macrophage colony-stimulating factor (GM-CSF) plays a critical role in controlling homeostasis in lungs, alveolar macrophages being the most sensitive cells to GM-CSF signaling. In this review, we discuss the importance of GM-CSF secretion for lung homeostasis and its alteration during respiratory infections. We also present the pre-clinical evidence and clinical investigations evaluating GM-CSF-based treatments (administration or inhibition) as a therapeutic strategy for treating respiratory infections, highlighting both supporting and contradictory findings.