Lysosomal activity in immune cells

Lysosomes are membrane-bound organelles present in nearly all mammalian cells except red blood cells. In immune cells such as macrophages and dendritic cells, lysosomes play a central role in degrading pathogens (bacteria, viruses) that have been engulfed by the cell. This degradation is essential for both innate and adaptive immunity. After breaking down pathogens into small peptide fragments, these antigens are loaded onto major histocompatibility complex (MHC) molecules—primarily MHC class II—and presented on the cell surface to activate T-cells[2][3]. Lysosomes also participate in autophagy and regulate cellular metabolism by sensing nutrient availability through mTOR signaling[3]. They contain various hydrolytic enzymes that require an acidic environment maintained by proton pumps such as vacuolar ATPases[3]. In addition to their degradative functions, lysosomes influence antigen presentation processes critical for T-cell activation and can modulate the expression or degradation of co-stimulatory molecules and checkpoint proteins involved in cancer immunology[2]. Disruption of normal lysosomal activity can impair antigen presentation or phagocytic clearance, contributing to diseases like cancer or increased susceptibility to infections[2][3]. Note on target status: "Lysosomal activity in immune cells" refers broadly to a cellular process rather than a specific molecular target such as a receptor or enzyme. While individual components within this system (e.g., specific lysosomal enzymes or transporters) may be considered drug targets, "lysosomal activity" itself is not a canonical therapeutic target but rather describes an essential biological function/process within immunity. Therefore, this entry is marked as incorrect with respect to being a discrete druggable target suitable for structured databases focused on molecular entities.

Other names

Lysosome function in immune cellsImmune cell lysosomal activityLysosomal function in immunity