Prevention of graft-versus-host-disease with preserved graft-versus-leukemia-effect by ex vivo and in vivo modulation of CD4+ T-cells

Abstract

This is the first report showing that an epitope-specific ex vivo modulation of an allogeneic hematopoietic stem cell graft by the anti-human CD4 antibody MAX.16H5 IgG1 simultaneously facilitates the anti-tumor capacity of the graft (Graft-versus-leukemia effect, GvL) and the long-term suppression of the deleterious side effect Graft-versus-host-disease (GvHD). To distinguish and consolidate GvL from GvHD, the anti-human CD4 antibody MAX16.H5 IgG1 was tested in murine GvHD and tumor models. The survival rate was significantly increased in recipients receiving a MAX.16H5 IgG1 short-term (2 h) pre-incubated graft even when tumor cells were co-transplanted or when recipient mice were treated by MAX.16H5 IgG1 before transplantation. After engraftment, regulatory T-cells are generated only supporting the GvL effect. It was also possible to transfer the immune tolerance from GvHD-free recipient chimeras into third party recipient mice without the need of reapplication of MAX.16H5 IgG1 anti-human CD4 antibodies. These findings are also benefical for patients with leukemia when no matched related or unrelated donor is available and provides a safer allogeneic HSCT, which is more effective against leukemia. It also facilitates allogeneic (stem) cell transplantations for other indications (e.g., autoimmune-disorders).

Attenuation of graft‐versus‐host‐disease in NOD scid IL‐2Rγ−/− (NSG) mice by ex vivo modulation of human CD4+ T cells

“…It was previously shown in a murine model that the short-term pre-incubation of an allogeneic graft with MAX.16H5 IgG1 was able to prevent GvHD development while preserving the GvL effect to mast cell leukemia (P815 cells) (18). The induced tolerance (lack of GvHD) was transferable to other recipients without the need of reapplication of the MAX.16H5 IgG1 antibody (18).…”

“…All animals were handled in accordance with the guidelines of the Leipzig University Animal Care Committee and the Regional Board of Animal Care for Leipzig (18). Survival of the recipient animals and weight were assessed 5 days a week, a full blood cell count and reconstitution of immune cells (human CD3, CD4, CD8, CD14, CD19, CD45 and murine cd45) were measured on days 25, 7, 14, 25, 39, 46 and 53 (18).…”

“…The MAX.16H5 IgG1 antibody was used as described previously (18). The MAX.16H5 IgG4 antibody was expressed in a CHO cell line produced by Antitope (Babraham, Cambridge, UK) and was purified by ProteoGenix (Schiltigheim, France).…”

“…The MAX.16H5 IgG4 antibody was expressed in a CHO cell line produced by Antitope (Babraham, Cambridge, UK) and was purified by ProteoGenix (Schiltigheim, France). As isotype controls, the antibody from LEAF TM (Low Endotoxin, Azide-Free TM ) purified mouse IgG1 (j isotype control antibody, BioLegend, San Diego, CA) and Natural Human IgG4 kappa protein ab98893 (Abcam, Cambridge, UK) were used (18).…”

“…We investigated an alternative therapeutic approach using an anti-human CD4 antibody in a murine model that showed prevention of GvHD with simultaneous preservation of the GvL effect (2,18).…”