Enhanced green fluorescent protein lysozyme M knock in mice were obtained from the University of Missouri Mutant Mouse Regional Resource Center and were back crossed to BALBc for 10 generations. Mice were immunized intraperitoneally on days 0, 21, and 42 with human cartilage PG emulsified in the synthetic adjuvant dimethyl dioctadecyl ammonium bromide. The paws of mice, including the ankle and wrist joints, were inspected for signs of arthritis twice a week after the third immuniza tion. The degree of arthritis was scored visually on a scale of 0 to 4 for each paw. Severity was expressed as a sum of inflammation scores as described. Collec tion of human osteoarthritc cartilage from consenting patients who had undergone joint replacement surgery was approved by the Institutional Review Board of Rush University Medical Center.
Likewise, all experiments involving ani mals were reviewed and approved by the Institutional Animal Care and Use Committee of Rush University Medical Center. Cell separation, labeling, and transfer for imaging studies Cells were harvested under aseptic conditions from the spleens and JDLNs of BALBc mice with severe arthritis in at least two mTOR tumor paws. After hypotonic lysis of erythrocytes from the spleen cell preparations, spleen and JDLN cells were combined. T cell enrichment was done using Abs against non T cell populations, followed by immunomagnetic removal of the Ab tagged cells. The purity of enriched T cells, assessed by flow cytometry, was typically 95% or greater. Non T cells, which con sisted mostly of B cells.
were pre pared by immunomagnetic removal of T cells from the donor population, resulting in less than 5% T cell contamination. Donor T cells were labeled with a red fluorescent CellTracker dye. Non T cells either read what he said were left unlabeled or were labeled with the green fluorescent CellTracker dye CMFDA. Red fluorescent T cells were mixed with non T cells at 11 to 13 ratios and injected intravenously into SCID mice. Ag was also injected intraperitone ally at the time of cell transfer to ensure in vivo re sti mulation of donor cells. Migration of fluorescent cells to the ankle joint or to both the ankle and the ankle draining popliteal LN was monitored by in vivo TPM, using SCID mice that received labeled donor cells 2 to 4 hours or 1, 2, 3, 4, 7, 12, or 18 days before ima ging. To visualize the entry of freshly isolated and labeled T cells into already inflamed joints, some SCID mice were injected first with unlabeled donor cells. After the hindpaws became arthritic, these mice received a second transfer of Cell Tracker labeled donor cells, and the migration of fluor escent cells to the inflamed ankles and the popliteal LNs was monitored by TPM.