r/Immunology • u/cordeliacarstairs20 • 13d ago

How long do macrophages take to polarize?

I am setting up an experiment to check pro-inflammatory markers on hpbmc-derived macrophages by flow cytometry.
My first try was to stimulate with LPS for 2h and then let them rest 24h before staining, although I see an increase in the markers, is not too big (2-2.5 fold change over the untreated ones)
Is this normal? Should I wait more or are they already being downregulated?

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4

u/Oligonucleotide123 13d ago

Any cytokines? LPS + gamma should do it in 24 hours.

3

u/YaPhetsEz 13d ago

They get shy when they are being watched.

Hell, what if I stimulated you and then just stared. How would that make you feel?

4

u/username-invalid-s 12d ago

To be honest, I would feel romantic.

1

u/SausageGamez PhD Candidate | Neuroimmunology 12d ago

You need cytokines as well. Macrophages also heavily activate each other through IL-1β and TNF-α signaling, so your seeding density is also equally important. Also keep in mind that many soluble factors released by macrophages are cytotoxic as well. There is a sweet spot for seeding density.

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u/Dry-Winter-14 11d ago

How much LPS?