A new xenograft model for graft-versus-host disease by intravenous transfer of human peripheral blood mononuclear cells in RAG2-/- γc-/- double-mutant mice

Abstract

The safe application of new strategies for the treatment of graft-versus-host disease (GVHD) is hampered by the lack of a clinically relevant model for preclinical testing. Current models are based on intraperitoneal transfer of human peripheral blood mononuclear cells (huPBMCs) into NOD-SCID (nonobese diabetic-severe combined immunodeficient)/SCID mice. Intravenous transfer would be preferred but this has always been ineffective. We developed a new model for xenogeneic GVHD (X-GVHD) by intravenous transfer of huPBMCs into RAG2 ؊/؊ ␥c ؊/؊ mice. Our results show a high human T-cell chimerism of more than 20% (up to 98%) in more than 90% of mice, associated with a consistent development of X-GVHD within 14 to 28 days and a total mortality rate of 85% shorter than 2 months. After murine macrophage depletion, engraftment was earlier and equally high with lower doses of huPBMCs. Human macrophages were also absent in these mice. Purified huCD3 ؉ cells showed a similar X-GVH effect with contribution of both CD4 and CD8 phenotypes. Human immunoglobulins and cytokines were produced in diseased mice. One of 30 mice developed chronic X-GVHD with skin histology similar to human GVHD. In conclusion, we present a new model for X-GVHD by intravenous transfer of huPBMCs in RAG2 ؊/؊ ␥c ؊/؊ mice. Murine and human macrophages do not seem to be necessary for acute X-GVHD in this model.

IL-21 accelerates xenogeneic graft-versus-host disease correlated with increased B-cell proliferation

“…Because serum hIL-21 can sustain as long as 7 days, hu-PBMC-BRG mice were sacrifi ced on day 7. In agreement with previous studies (van Rijn et al, 2003), the majority of engrafted cells in BRG mice were CD3 + T cells and CD19 + B cells (>90%, Fig. 2A).…”

“…Previous report showed that NK cells were very low in all compartments during the process of xenogeneic GVHD (van Rijn et al, 2003). And in our xenogeneic GVHD model, CD56 + CD3 -NK cells were almost absent in spleen of IL-21-treated group and control group on day 7.…”

“…Neither CB17-scid nor NOD-scid immunodefi cent mice engrafted with human PBMCs provided a reproducible model of xenogeneic GVHD (Shultz et al, 2007). BALB/c-Rag2 −/− IL2Rγc −/− (BRG) mice, which have no B, T, or NK cells and no leakiness, showed improved human PBMCs engraftment compared with NOD-scid mice (van Rijn et al, 2003;Shultz et al, 2007;Ito et al, 2009;Shultz et al, 2011). Recently, BRG mice which transferred with hPBMCs (hu-PBMC BRG mice) were used as a suitable platform to explore the effect of novel GVHD therapy agents, such as immunoglobulin or regulatory T cells (Tregs) (Mutis et al, 2006;Gregoire-Gauthier et al, 2012).…”

Factors affecting human T cell engraftment, trafficking, and associated xenogeneic graft-vs-host disease in NOD/SCID β2mnull mice

“…pretransplant conditioning with sublethal irradiation [19,23,26,[32][33][34][35][36][37][38][39][40], (ii.) targeted reduction of murine natural killer (NK) cell activity with antibodies directed towards specific cell membrane markers (anti-asialo-GM1 [19,[33][34][35] or anti-CD122 [23,36,39]), (iii.)…”

“…targeted reduction of murine natural killer (NK) cell activity with antibodies directed towards specific cell membrane markers (anti-asialo-GM1 [19,[33][34][35] or anti-CD122 [23,36,39]), (iii.) targeted reduction of murine macrophages with clodronate-containing liposomes [37], (iv.) using newborn mice which lack a fully developed innate immune system [32], (v.) administration of interleukin-15 (IL-15) [38,40], and/or (vi.)…”