Abstract 2342: Experimental modeling of acute- and chronic-GvHD by xenotransplanting human donor PBMCs or cord blood CD34+ cells (HSC) into NSG mice

Abstract

Abstract Graft vs. host diseases (GvHD) accounts for 15-30% of deaths following allogenic hematopoietic stem cell transplantation (allo-HSCT) for treatment of malignant diseases. Acute GvHD (aGvHD) typically involves skin, gastrointestinal and hepatic inflammation, and occurs within 100 days of transplantation; Chronic GvHD (cGvHD) involves multiple organs and occurs beyond 100 days. aGvHD is largely due to the rapid activation of donor T cells (Th1, CD8+ biased), causing tissue damage and often leading to mortality; in contrast, cGvHD is Th2 biased, typically display autoimmune-like syndrome, involving both T- and B-cell. Currently, GvHD models are mostly allo-transplantations between mice, which are criticized for poor physiological relevance. Here, we present Xenotransplantation of human donor into NSG mice, which will address some of the limitation of current models. Human peripheral blood mononuclear cells (PBMC) derived from normal donors were transplanted into NSG or NSG-like strains for modeling aGvHD. Cord blood derived HSCs (hCD34+) NSG (Jackson) were transplanted for modeling cGvHD. Hosts were monitored twice weekly, including clinical observations (e.g. animal postures, activity, fur texture, and skin integrity), body weight changes, gross pathology and histopathology upon termination, along with human-immunological phenotyping of peripheral blood, spleen, lung, liver and skin by flow cytometry, histopathology and/or immunohistochemistry. In addition, GvHD novel biomarkers Elafin, IL-18, REG3α and ST2, measured by ELISA (MBL International) at baseline and post cells engraftment. NSG mice engrafted with human PBMC, or purified T-cells, from normal donors rapidly developed typical symptoms of aGvHD, as early as 4 weeks post transplantation, including severe body loss, reduced activity, hunched posture, loss of fur, severe ruffling and overall poor grooming. Significant engraftment of human CD45+ cells were detected up to 6 weeks post-engraftment dominated with CD3+ human T-cells of single positive CD4+ or CD8+ T-cells. The corresponding kinetics of clinical symptoms in parallel with the degree of engraftment of T cells suggests xenografting were responsible for aGvHD. As for the cGvHD, NSG-mice engrafted with CD34+ cells derived from cord blood with cGvHD high- risk HLA haplotypes C*0602 and C*0401. Manifestation of cGvHD was observed 18 weeks to 39 weeks post-engraftment; symptoms were similar to aGvHD, but also include facial/full body alopecia, and scaly skin. Interestingly, in correlation of this, human engraftment of CD45+, particularly T-cells including CD4+ and their CD30+ subsets, are kinetically increased in blood and spleen with similar timeline, suggesting their roles in the observed cGvHD. The xenograft murine model using adult human PBMC and cord blood derived CD34+ HSCs could be alternative experimental systems to model human aGvHD and cGvHD for investigating disease mechanisms and evaluating treatment strategy. Citation Format: Ann E. Lin, Annie X. An, Mingfa Zang, Derron Yu, Eunmi Hwang, Israel Romero, Linda Quirino, Marybeth George, Pirouz Daftarian, Wenqing Yang, Henry Li. Experimental modeling of acute- and chronic-GvHD by xenotransplanting human donor PBMCs or cord blood CD34+ cells (HSC) into NSG mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2342.