THP1 Cell lines
Cell line description
Is the interferon (IFN) response in THP1 cells general or for specific subclasses of IFN?
What ligands do THP1 cells respond to?
Below is a non-exhaustive list of THP1 ligand responses :
• TLR2: Good response through the NFκB pathway
• TLR3: Very low response through the NFκB pathway and a higher response (via TRIF) through the ISG pathway
• TLR4: Good response through the NFκB pathway
• TLR5: Good response through the NFκB pathway
• TLR7: No response
• TLR8: Good response through the NFκB pathway
• TLR9: No response
InvivoGen’s THP-1 cells also respond to NOD1, RIG-I, MDA-5 and STING/cGAS agonists.
(Please see the validation data sheet on the THP1-Dual™ cells webpage for more information).
What are the advantages/disadvantages of the THP1-Blue™ NFκB cells compared to the THP1-Lucia™ NFκB cells?
These two cell lines have exactly the same sensitivity. The only difference is the reporting system.
Therefore, your choice will depend on if you prefer to monitor NFκB activation by determining the activity of SEAP, using a spectrophotometer, or Lucia™ luciferase using a luminometer.
What is the advantage of THP1-Null cells vs. other wildtype THP1 cells?
THP1-Null cells were derived from the same parental clone of THP1 cells used to engineer all of InvivoGen’s THP1 reporter cells.
Additionally, they have been transfected with a mock plasmid, and are a proper control in terms of response and functionality.
Cell line culture
What is the recommended cell concentration for the propagation of THP1 cells?
The recommended concentration is between 3 – 7 x 105 cells/ml depending on the cell line.
Generally, a concentration of 5 x 105 cells/ml is used.
I’m having trouble growing THP1 cells, do you have any tips for my initial culture?
Below are a few tips we recommend to help get your THP1 cells growing:
• These cells need to be passaged between 3 x 105 and 7 x 105 cells/ml (we recommend 5 x 105 cells/ml). Below this your cells will take a long time to grow and above 2 x 106 cells/ml you may have toxicity.
• For the first 2 - 3 passages, grow cells in media containing 20% FBS and no antibiotics.
• Between each passage, do not centrifuge the cells. THP1 cells grow better in conditioned media, therefore when passaging cells, leave 1 – 2 ml of the old media and add fresh media on top. Do not leave more than 50% of conditioned media as the cells will not have enough nutrients to properly grow.
• The cells should not be grown in 20% FBS for too long. Use media with 10% FBS after 2 - 3 passages.
• When making frozen stocks, continue growing additional cultures in case there is a problem with the frozen stock.
My THP1 cells have a doubling time of about a week. Is that expected?
It isn’t normal for your cells to divide only once a week. Depending on the clone, they usually have a doubling time of 24 – 72 hours.
THP1 cells must be cultured at quite a high concentration (~ 5 x 105 cells/ml).
Please note that our R&D teams have noticed that THP1 cells often die when they are too dilute.
Also, it may help to not add Normocin™ while waiting for improvement to their growth.
What do I do if THP1 cells are clumping but are not dead?
It is not a problem if the cells are clumping, as long as they are growing fine and have normal morphology.
You may want to centrifuge the cells to get rid of the dead cells as sometimes this is the reason for clumping.
Please note that we recommend homogenizing the cells before performing your assays.
Is there a protocol for the differentiation of THP1 cells?
Treatment with phorbol myristate acetate (PMA, catalog #tlrl-pma) induces differentiation of THP1 cells into adherent macrophage-like cells.
1- Add 180 µl of THP1 cell suspension per well of a 96-well plate (~ 100 000 cells/well).
2- Treat THP1 cells with 20 µl of PMA (final concentration 20 - 50 ng/ml) for 3 hours at 37°C in 5% CO2.
3- Wash cells gently with pre-warmed PBS and add 200 µl supplemented RPMI.
4- After 4-6 days (depending on the differentiation state of the cells) wash the cells with pre-warmed PBS and add 180 μl of supplemented RPMI.
5- Perform the reporter assay as per the TDS
How long after PMA treatment can I perform the reporter assay with the cells?
We highly recommend waiting at least 72 hours before testing samples on the PMA-treated cells.
PMA is a specific activator of Protein Kinase C (PKC) and NFκB.
Therefore, it activates the production of SEAP which will result in a high background when using QUANTI-Blue™ for approximately 4 days following PMA treatment.
Can I increase the production of IL-1β after PMA treatment?
The production of pro-IL-1β can be further increased by priming PMA-activated THP1 cells with LPS.
Frozen stock preparations
What should be the density of cells before making a frozen stock preparation?
THP1 cells should be at a density of approximately 7 x 106 cells/ml before aliquoting into cryogenic vials.
What freezing media should be used for THP1 cells?
For THP1 cells we recommend fetal bovine serum (FBS) and 10% DMSO.