Background Graft-versus-host disease (GVHD) is a severe complication of hematopoietic stem cell transplantation. Current therapies to prevent alloreactive T cell activation largely cause generalized immunosuppression and may result in adverse drug, antileukemia and antipathogen responses. Recently, several immunomodulatory therapeutics have been developed that show efficacy in maintaining antileukemia responses while inhibiting GVHD in murine models. To analyze efficacy and better understand immunological tolerance, escape mechanisms, and side effects of clinical reagents, testing of species cross-reactive human agents in large animal GVHD models is critical. Methods We have previously developed and refined a nonhuman primate (NHP) large animal GVHD model. However, this model is not readily amenable to semi-high throughput screening of candidate clinical reagents. Results Here, we report a novel, optimized NHP xenogeneic GVHD (xeno-GVHD) small animal model that recapitulates many aspects of NHP and human GVHD. This model was validated using a clinically available blocking, monovalent anti-CD28 antibody (FR104) whose effects in a human xeno-GVHD rodent model are known. Conclusions Because human-reactive reagents may not be fully cross-reactive or effective in vivo on NHP immune cells, this NHP xeno-GVHD model provides immunological insights and direct testing on NHP-induced GVHD before committing to the intensive NHP studies that are being increasingly used for detailed evaluation of new immune therapeutic strategies before human trials.
Bibliographical noteFunding Information:
This work was supported by the Yerkes National Primate Research Center Base grant, RR00165, as well as NIH 2U19 AI051731, NIH 1R01 HL095791 and by a Burroughs Wellcome Fund Career Award (L.S.K.). This work was also supported in part by NIH P30 CA77598 using the shared resource Flow Cytometry Core from the Masonic Cancer Center, University of Minnesota.