Although THP-1 cells are of the same lineage, mutations can cause differences as the progeny proliferates. In general, THP-1 cells exhibit a large, round, single-cell morphology. The cells were derived from the peripheral blood of a 1-year-old human male with acute monocytic leukemia. Some of their characteristics are:
Expression of Fc receptor and C3b receptors while lacking surface and cytoplasmic immunoglobulins.
Increased CO2 production on phagocytosis and differentiation into macrophage-like cells
Polarization into the M1 phenotype by incubation with IFN-γ and LPS, or to the M2 phenotype by incubation with interleukin 4 and interleukin 13
Differentiation into immature dendritic cells, using recombinant human interleukin 4 and recombinant human granulocyte macrophage colony-stimulating factor, and mature dendritic cells using rhIL-4, rhGM-CSF, recombinant human tumour necrotic factor α and Ionomycin.
The HLA type for THP-1 is HLA-A*02:01; A*24:02; B*15:11; B*35:01; C*03:03; DRB1*01:01; DRB1*15:01; DQB1*05:01; DQB1*06:02; DPB1*02:01; DPB1*04:02. This HLA type can change depending on the reference biorepository, due to loss of heterozygosity in multiple chromosomal regions, as THP-1 from the American Type Culture Collection do not express the HLA-A*24:02 and B*35:01 alleles.
Growth Information
THP-1 can provide continuous culture when grown in suspension; RPMI 1640 + 10% FBS + 2mM L-Glutamine. The average doubling time is 19 to 50 hours. 1 mMsodium pyruvate, penicillin and streptomycin are also commonly added to inhibit bacterial contamination. Cultures should be maintained at cell densities in the range 2-9x105 cells/ml at 37 °C, 5% CO2. Cells are non-adherent.
Hazards
THP-1 cells are of human origin, and no evidence has been found for the presence of infectious viruses or toxic products. The ATCC Biosafety recommendation is level 1.
Research applications
THP-1 cells are used as in vitrocancer cell models, as well as a models to study the monocyte-macrophage differentiation process, and as a model to examine some macrophage-related physiological processes, for example the macrophage cholesterol efflux.
