THP-1 cell line - Passage number affect phagocytosis (Jul/19/2006 )

Hi,
We are working on the THP-1 cell line for drug delivery in the reference of M.tb infection could you tell
me whether passage no of cells influence pagocytosis ability of differentiated cells with PMA.

i dont know abt ur specific cell type but in general cells of higher passage numbers of cells change during the time.

Hi Scolix,
Thanks a lot for reply , but iam searching about passage no

awadh
Its a hard question to answer. Lety me put it in this way: more than likely you would see a gradual decline in cell activities if you keep on passing them. However, such aging effect is highly cell type dependent. There is no formular to estimate such assumption, unless by any chance that some member here actually has the first hand expeience with this cell line. The best way is to demonstrate it by experiment. Do you have cells still under Liq N2? Go do a side-by side experiment using labeled microbes to see it they are taken up or not by old THP and what is the difference with the fresh one.

Genehunter,
I am agree with your statement , but i thinks some body reporated after certain passage its phagocytosis activity decreases very much . In our cases when our cells not get proper differentiated
at thats time we agains thaw new cells stock and starting work on them.
thanks a lot for your reply.
awadh

Awadh

Its difficult to give a particular number of passages. Each times it could vary depending on how the cells have been cultured since they were thawed. For eg. my cells behaved different after 17 passages and the next time after 15 passages and once after 20 passages. So its not always the same.

Are you having difficulties of getting microbies uptaken by these cells? Serum-coated bacteria will speed up this process.

Hi Genehunter,
I not facing such types of problems but realy i dont know about thats but some peoples told me after 8 passage THP-1 not use . Thats why iam want to know because in my cases after 30 passage cells showing unusual behaviour then i discarded then and revives cells from new stock.
Still i try to geting some refernceses on the web site but still not geting about THP-1 cells.
Thanks a lot for your help
awadh

The "Rule of Thumb" is generally that the cell line/Primary you are using is only a RESEARCH TOOL. That tool should be regularly checked for your specific area of interest i.e phagocytosis. We have a cell line that we use to induce iNOS enzyme. It can be passaged 250 times and still give the same amount of iNOS from P1-P250.
In your hands the THP-1 will be affected by things like SERUM. Do you Fyrite your CO2 Incubators to ensure a stable CO2 concentration ? Is the incubator humidified at all times ? All these variables will affect your cultures.
Ensure you have a low passage master stock to go back to if your phagocytosis rates change.

Hi Rhombus,
thanks a lot i thinks your suggestion help me in my experiment i always seen thats i never seen change in the trand of expression of a specific markers in our cell line upto 30-40 passage after thats we discarded its and thaw new stock.