Thank you, Sabine. I will try to collect both. Do you think the possible stimulation of thioglycollate to bone marrow will be gone after the differentiation to macrophages over 7 days?

Xianfeng:

How many peritoneal macrophages do you need? You can obtain an interesting number WITHOUT thioglycolate induction. We usually inject 5 ml of sterile PBS, give a gentle abdominal massage (approx. 5-10 min), and collect all the liquid we can after that. Of course the number of cells is much lower, but may be it is enought for you. Checking some old data, I have obtained at least 2-5x10(6) peritoneal cells per mouse. Take into account that approx. 50% of them are macrophages.

Good luck!

Thanks, Matias. That's good idea.

Xianfeng Wang, could you comment whether BMDMs were affected by thio or not? Would be great to see some kind of conclusion  :-)

This is an old thread, so maybe this information is not very useful, but I have on many occasions collected BMDM and thioglycollate-elicted macrophages from the same mice without problems. I looked for potential effects on BMDM, but saw no changes on a variety of parameters (compared to BMDM from unstimulated mice), including mean number of BMDM per mouse, activation markers (both surface markers, such as class II as analysed by FACS, and functional markers such as IL-12 p40, TNF-a or iNOS, analysed by qPCR), growth in GM-CSF suplemented medium or functional efficacy post-differentiation (killing assay using L. major, or antigen presentation using a crude protein lysate and primed T cells from infected mice).

My own impression is that with thioglycollate injection you are recruiting and then expanding mature, but non-activated macrophages from the circulation and MALT, but what you grow out of BM is primarily derived from undifferentiated macrophage precursors (there are relatively few macrophage-like cells in your starting BM).

Hi Timothy. Do you have published data about what you said? Thanks.

Unfortunately, no. The macrophage work itself was published together with Alan Sher and Bob Coffman in the late 90's in a series of articles (the Material and Methods have the protocols I used to assess markers), but the comparative work was all just part of the setup phase when I was working out my protocols. That kind of stuff tends not to get published.

Thank you , Timothy.  I think this is what you are talking about....

http://www.jimmunol.org/content/156/2/735.full.pdf

I found 2 papers which have a little different data with what you said.

http://www.ncbi.nlm.nih.gov/pubmed/8325351

http://www.sciencedirect.com/science/article/pii/S0531556504002189

I don't think that those two papers are different from our results: it's been known for a long time that differentiated macrophages from different tissues have quite different monokine and surface molecule expression patterns, and also that immune reactivity changes with age.

However, the original question was essentially asking if thioglycollate induction of peritoneal macrophages would have an activating effect on macrophages derived from bone marrow precursors and as far as we could find, it did not.

Thank you so much! Let me read more...