- Neutrophils: Rapidly respond to infections by phagocytosing bacteria and releasing enzymes. - Eosinophils: Combat parasitic infections and modulate allergic reactions. - Basophils: Release histamine and other mediators during allergic responses. - Monocytes/Macrophages: Engulf pathogens and dead cells, present antigens to T-cells, and release cytokines. - Dendritic Cells: Capture and present antigens, initiating adaptive immunity.