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:[1]
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[2]
Differentiation into immature dendritic cells, using recombinant human interleukin 4 (rhIL-4) and recombinant human granulocyte macrophage colony-stimulating factor (rhGM-CSF), and mature dendritic cells using rhIL-4, rhGM-CSF, recombinant human tumour necrotic factor α (rhTNF-α) and Ionomycin.[3]
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 (in the German Collection of Microorganisms and Cell Cultures (DSMZ) cell bank). 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 (ATCC) do not express the HLA-A*24:02 and B*35:01 alleles.[4]
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 mM sodium pyruvate, penicillin (100 units/ml) and streptomycin (100 μg/ml) 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.[5]
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.[5]
THP-1 cells are used as a models to study the monocyte-macrophage differentiation process,[6] and as a model to examine some macrophage-related physiological processes, for example the macrophage cholesterol efflux.[7]
^ abTsuchiya S, Yamabe M, Yamaguchi Y, Kobayashi Y, Konno T, Tada K (August 1980). "Establishment and characterization of a human acute monocytic leukemia cell line (THP-1)". International Journal of Cancer. 26 (2): 171–6. doi:10.1002/ijc.2910260208. PMID6970727. S2CID43603660.
^Berges C, Naujokat C, Tinapp S, Wieczorek H, Höh A, Sadeghi M, Opelz G, Daniel V (August 2005). "A cell line model for the differentiation of human dendritic cells". Biochemical and Biophysical Research Communications. 333 (3): 896–907. doi:10.1016/j.bbrc.2005.05.171. PMID15963458.
^Auwerx J (January 1991). "The human leukemia cell line, THP-1: a multifacetted model for the study of monocyte-macrophage differentiation". Experientia. 47 (1): 22–31. doi:10.1007/BF02041244. PMID1999239. S2CID24727878.
