Want to deplete skin-resident macrophages with either clodronate in normal mice or diphtheria toxin in CD11b-DTR or LysM-DTR mice and then repopulate the skin compartment by adoptively transferring macrophages directly to the skin or I.V. with monocytes, assuming the latter would migrate and differentiate in a predictable manner. Any input on this would be appreciated.
I assume that you are talking about local depletion, not the entire skin.
1) Clodronate-lip: titrate the dose very carefully, otherwise if you inject too much the newly recruited blood monocytes will eat up excess of it and die. This applies to adoptive transfer - if you have residual clo-lip in the tissues - your transferred macs will die as well.
2) DTR system: Make sure there is no systemic effect of DT. CD11b-DTR mice are quite sensitive to DT, even after local injections. I'd try local application of DT (bandage soaked in DT or somethign like that) or graft the skin from DTR (45.2) mouse to CD45.1 mouse (this will allow you to discriminate host/donor macs and your recruited monocytes/macrophages will be resistant to DT).
3) Tissue resident macrophages and bone-marrow/monocyte derived macrophages are quite different beasts. Keep this in mind in your restoration studies.
Good luck and let me know if you have more specific questions.
@ Alexandar
Is it possible to reconstitute macrophages by adoptive transfer of monocytes after 48-72hrs of injury?
Going to deplete macrophages in mice liver by clodronate liposomes (0.1mL/10gm) to check an effect;
1) 48hrs and 72hrs after an injury and then
2) Repopulating the macrophages by adoptive transfer of monocytes
Is it possible that transferred monocytes may differentiate into macrophages at indicated time points? How long intrahepatic clod.liposomes persists once injected. Any opinion regarding this would be appreciated