THP1 is a human monocytic cell line derived from an acute monocytic leukemia patient. It is used to test leukemia cell lines in immunocytochemical analysis of protein-protein interaction, and immunohistochemistry.

Cell Characteristics Growth Information
Note that although THP-1 cells are of the same lineage, mutations can cause differences as the progeny proliferates.

Characteristics
These cells show a large, round, single-cell morphology.
They are derived from the peripheral blood of a 1 year old human male with acute monocytic leukemia. Some of their characteristics are:
They have Fc receptor and C3b receptors and lack surface and cytoplasmic immunoglobulins.
They produce IL-1.
They stain positive for alpha-naphthyl butyrate esterase, produce lysozymes and are phagocytic (both for latex beads and sensitized erythrocytes).
They can restore the response of purified T lymphocytes to Con A.
They show increased CO2 production on phagocytosis and can be differentiated into macrophage-like cells using for example phorbol 12-myristate 13-acetate (commonly known as PMA or TPA).
The HLA type for THP-1 using molecular-based typing methods is HLA-A*02; B*15; C*03; DRB1*01, DRB1*15; DRB5*01/02;