Human monocytic leukemia THP-1 cells

The THP-1 cell line is a pro-monocytic leukaemia cell line first isolated from a 1 year old boy suffering from acute monocytic leukemia. Today THP-1 cells are widely used in cell culture across the world.

Some of the characteristics of THP-1 cells include the presence of the Fc and C3b receptors and absence of any surface and cytoplasmic immunoglobulins. They have the ability to secrete mediators such as tumor necrosis factor-alpha (TNF-alpha), interleukin-1 alpha (IL-1 alpha) and interleukin-1 beta (IL-1 beta) into the media. A major characteristic of THP-1 cells is the ability to undergo differentiation by phorbol esters such as 12-myristate 13-acetate (PMA).

Physiologically it behaves like monocytes and has the ability to differentiate under with phorbol esters. This ability has been widely used to convert these human cells into macrophage-like cells and even foam cells and used to investigate pathogenesis of atherosclerosis.


They can be grown in RPMI 1640 with 10% fetal calf serum supplemented with 2mM L-Glutamine. The cells are incubated in a 37 degree incubator with 5% C02 and 95% air. In addition, (100 units per ml) penicillin and (100 µg per ml) streptomycin are used to prevent bacterial growth. However this is often omitted when transfecting THP-1 cells with DNA. THP-1 cells are often grown at a density about 500,000 cells per ml and handled in a level 2 biosafety cabinet.

Other similar cells:

Other human myeloid leukemia cells that have the ability to undergo differentiation by PMA include; HL-60 and U937 cells.


Auwerx J. 1991. The human leukemia cell line, THP-1: a multifacetted model for the study of monocyte-macrophage differentiation. Experientia. 47(1): 22-31

Abe T, Ohno M, Sato T, Murakami M, Kajiki M, Kodaira R. 1991. "Differentiation induction" culture of human leukemic myeloid cells stimulates high production of macrophage differentiation inducing factor. Cytotechnology. 2: S75-93

Hass R. 1992. Retrodifferentiation-an alternative biological pathway in human leukemia cells. Eur J Cell Biol. 58 (1): 1-11