Heat shock 70 kDa protein 1A (HSPA1A) (HSP70)

Heat shock 70 kDa protein 1A (HSP70) is a highly conserved molecular chaperone typically found in the cytosol, but it is uniquely translocated to the plasma membrane of cancer cells. In its ADP-bound state, HSP70 exhibits a high affinity for peptide antigens, forming a stable complex that is presented on the cell surface. This membrane-bound form (mHSP70) serves as a tumor-specific marker and a potent recognition structure for natural killer (NK) cells. Unlike its intracellular counterpart, which protects cells from apoptosis and aids in protein folding, cell surface HSP70 acts as a signaling molecule that triggers immune responses. Therapeutic strategies targeting this specific state include monoclonal antibodies like cmHsp70.1 and synthetic peptides that mimic the HSP70 sequence to enhance the cytolytic activity of immune cells against malignant tissues. Because mHSP70 is frequently expressed on a wide variety of human tumors but not on healthy resting cells, it represents a promising target for highly selective cancer immunotherapy and diagnostic imaging.

Other names

Membrane-bound heat shock protein 70mHSP70HSP72HSPA1Heat shock 70 kDa protein 1Antigen-loaded HSP70

Monoclonal antibodies target the extracellular domain of membrane-bound HSP70 to induce antibody-dependent cellular cytotoxicity (ADCC), while specific peptides like TKD mimic the C-terminal domain to activate natural killer (NK) cells against mHSP70-positive tumor cells.