Association of natural killer cell depletion with induction of mixed chimerism and allograft tolerance in non-human primates

• Published in: Transplantation Vol. 70; no. 2; p. 368
• Main Authors: Kawai, T, Wee, S L, Bazin, H, Latinne, D, Phelan, J, Boskovic, S, Ko, D S, Hong, H Z, Mauiyyedi, S, Nadazdin, O, Abrahamian, G, Preffer, F, Colvin, R B, Sachs, D H, Cosimi, A B
• Format: Journal Article
• Language: English
• Published: United States 27.07.2000
• Subjects: Animals; Cell Separation; Immune Tolerance; Kidney Transplantation - immunology; Killer Cells, Natural - cytology; Killer Cells, Natural - physiology; Macaca fascicularis - genetics; Male; Transplantation Chimera; Transplantation Conditioning
• ISSN: 0041-1337
• DOI: 10.1097/00007890-200007270-00023

Nonmyeloablative T cell depletion followed by donor bone marrow infusion has proved to be an effective approach to induction of mixed chimerism and tolerance of organ allografts in non-human primates. To help define the mechanisms involved we have compared T cell depletion with ATG versus anti-CD2 monoclonal antibody with respect to establishment of mixed chimerism and induction of tolerance. Both nonmyeloablative regimens included low dose total body irradiation (1.5 Gy x 2), thymic irradiation (7 Gy), splenectomy and kidney plus donor bone marrow transplantation, followed by a 4-week posttransplant course of cyclosporine. In addition, the ATG group (13 recipients) received antithymocyte globulin, although the LOCD2b group (10 recipients) were treated with an anti-CD2 monoclonal antibody (LOCD2b). In the ATG group, 11 of 13 monkeys developed multilineage chimerism and 9 survived for more than 100 days without kidney allograft rejection. In contrast, 0/10 monkeys in the LOCD2b group developed chimerism, 5 died of infection and 5 suffered progressive rejection; only 1 recipient survived beyond 100 days. Sequential monitoring of peripheral blood mononuclear cells revealed greater T cell (CD3+) depletion in the LOCD2b-treated animals compared to those receiving ATG. However, NK cells (CD16+CD8+) were significantly more depleted in the ATG group and NK function remained abrogated longer after ATG than LOCD2b treatment (3 weeks vs. <5 days). Despite excellent T cell depletion by LoCD2b, ATG was more effective in inducing chimerism and tolerance. This difference correlated with anti-NK activity of the two reagents. These data suggest that NK cells may also resist engraftment of allogeneic bone marrow cells in this model.