Hello,
I am working on the immune response in the respiratory tract 30 minutes after a stimulation, and I'm also analyzing the bone marrow. I observed a rise in the number of Lin-, MPP and CMP, but I'm wondering if 30 minutes of stimulation is enough to influence the BM . Does anyone know, how long it take for progenitors to "sense" the inflammation, to differenciate and to migrate ?
Thank you very much !
Hi Mahana,
Thanks for your question. I think it would depend on the type of "stimulation" if you have an antigen which will then move on to elicit an adaptive immune response then this would need to undergo maturation to express the correct ligands and receptors, then travel to a nearby lymph node.
This would be in conjunction with immune cell proliferation at the site of stimulation and the nearby upregulation of decoy receptors to prevent a constant chain of inflammation from the site of stimulation throughout the entire body.
Article Cytokine decoy and scavenger receptors as key regulators of ...
I would expect if there is a continued response at the site and the adaptive response is being generated then it will probably take around 1-2 days for proliferation in the BM to recruit and proliferate B-Cells. see:
https://ashpublications.org/blood/article/105/9/3633/21249/B-cell-kinetics-in-humans-rapid-turnover-of
This is also dependent on which cells exactly you want to proliferate. As with anything in the immune system there are so many topics and avenues to go down it makes for a good discussion.
I hope this helps but it quite interesting.
Thank you very much for your answer.
I stimulate with CNO 30min, and I observe a drop in the number of innate and adaptiv immune cells in the lung, and a rise in the number of the cells I mentionned above in the BM. I did'nt look at the lymphatic organs, so I can't assess if the cells migrate there, but do you think, 30min could be enough time ?
Hi Mahana,
Possibly, obviously the pathways are very complex but if you have mature APCs they would initially move to the nearest lymph and generate a specific humoral response which usually takes about 96 hours after stimulation and more than likely depends on the stimulus still being available. If the stimuli is there for ca 30 mins in the lead up to a more adaptive response and of course any sort of plasma cell or b cell proliferation then it may be too short as innate cells (such as macrophages) in the area in the lack of stimuli will apoptose leading to an increase in IL-10 and down regulating the immune response in the area and secondarily in the lymphatic system.
I think it may be enough to start plasma cell and B cell proliferation but may not be enough to continue the process and yield cells to fight the "infection".
It might be a different story if you repeatedly stimulated for 30 mins (e.g. every 24-48 hours) the times are just a random suggestion but I think repeated exposure within that 96 hour window may elicite more of a response as the antigen will still be present and presented on MHC receptors for example.
If it does stimulate a response in the bone marrow, I would be interested to know how they mature. If they fully differenciate and mature, I would expect with a short exposure that it may start but the stimuli may be too short if it starts at all.