CD3-immunotoxin mediated depletion of T cells in lymphoid tissues of rhesus macaques

Selective T-cell depletion prior to cell or organ transplantation is considered a preconditioning regimen induce tolerance and immunosuppression. An immunotoxin consisting of recombinant anti-CD3 antibody conjugated with diphtheria toxin was used eliminate T-cells. It showed significant activity in the peripheral blood lymph nodes animal models previous studies. To date, comprehensive evaluation CD3 proliferation for all lymphoid tissues has not been conducted. Here, two rhesus macaques were administered A-dmDT390-SCFBdb (CD3-IT) intravenously at 25 μg/kg twice daily four days. Samples collected one day days post administration. Flow cytometry immunofluorescence staining evaluate treatment efficiency accurately. Our preliminary results suggest that CD3-IT may higher CD4 T-cells spleen, but ineffective colon thymus. The data better elimination tendency B-cell zone relative germinal center nodes. Further, lead reduction T follicular helper cells compared healthy controls. number proliferating indicated repopulation different occur treatment. provide insights into differential efficacy tissues. Overall, shows potential depleting periphery, nodes, making it viable transplantation. pilot study provides critical descriptive statistics can contribute design larger future