[Tolerogenic dendritic cells form microchimerism in vivo in collagen-induced arthritis rats]

Objective To find evidence of microchimerism formation following infusion of tolerogenic dendritic cells (tDCs) into collagen-induced arthritis (CIA) rats. Methods Bone marrow-derived DC precursor cells were induced into tDCs by granulocyte-macrophage colony- stimulating factor (GM-CSF), interleukin 4 (IL-4) and nuclear factor-κB oligonucleotide decoy (NF-κB ODN decoy) and then infused into CIA rats after labeling with 1, 1' -octadecyl-3, 3, 3', 3' -tetramethyltricarbocyanine iodide (DiR). At 4 hours, 24 hours, 5 days, 10 days and 15 days after cell infusion, the fluorescence intensity and distribution were observed by in vivo imaging system of small animals. Rats were sacrificed on the 15th days to detect the fluorescence signals of the main organs. Results tDCs had high expression of OX62 and low expression of CD80 and CD86. The fluorescence signal was mainly concentrated in the chest, abdomen and left posterior joint, with the strongest fluorescence signal in the chest and abdomen at 24 hours and the strongest fluorescence signal in the left posterior joint at 5 days. Fluorescence could still be detected on the 15th days after cell infusion, and the left posterior joint of the diseased foot always maintained a strong fluorescence signal. In isolated organs, the fluorescence signals in the lung, liver, spleen and mesenteric lymph nodes were strong, and the kidney fluorescence signals was weak, and the heart had little fluorescence. Conclusion tDCs forms microchimerism in the diseased foot joints, lungs, liver, spleen, and mesenteric lymph nodes.